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QUINOA SEED QUALITY AND SENSORY EVALUATION
By
GEYANG WU
A dissertation submitted in partial fulfillment of the requirements for the degree of
DOCTOR OF PHILOSOPHY
WASHINGTON STATE UNIVERSITY School of Food Science
MAY 2016
copy Copyright by GEYANG WU 2016 All Rights Reserved
copy Copyright by GEYANG WU 2016 All Rights Reserved
ii
To the Faculty of Washington State University
The members of the Committee appointed to examine the dissertation of GEYANG WU find it satisfactory and recommend that it be accepted
_________________________________ Carolyn F Ross PhD Co-Chair
_________________________________
Craig F Morris PhD Co-Chair
_________________________________ Barbara Rasco PhD
_________________________________
Kevin M Murphy PhD
iii
ACKNOWLEDGMENT
This dissertation is accomplished with a lot of collaborations of Food Science USDA-
ARS Western Wheat Quality Lab and Crop Science I gained significant advice and help from
my co-chairs and co-advisors Dr Craig Morris and Dr Carolyn Ross as well as my committee
members Dr Barbara Rasco and Dr Kevin Murphy Working with them on research proposals
experiments data processing and editing manuscripts I learned so much from scientific
philosophy critical thinking and efficient argument to scientific writing skills This dissertation
could never have been accomplished without their professional patient and persistent work
Additionally I owe thanks to many lab members who provided important help with the
experiments From the USDA-ARS Western Wheat Quality Lab Bozena Paszczynska who is no
longer with us trained me on most of the flour testing equipment Patrick Fuerst Alecia
Kiszonas Douglas Engle and Eric Wegner helped with experimental methods manuscript
preparation milling and equipment maintenance From the WSU Sensory Evaluation Lab Beata
Vixie Karen Weller Charles Diako and Ben Bernhard provided help in sensory study
preparation and serving From the WSU Sustainable Seed System Lab Max Wood Janet
Matanguihan Hannah Walters Adam Peterson Raymond Kinney Cedric Habiyaremye
Leonardo Hinojosa and Kristofor Ludvigson helped with quinoa field work (planting weeding
harvesting) post-harvest cleaning and greenhouse management I feel grateful to have met so
many brilliant and kind people and it is a pleasant journey to work with them and develop
friendships with them
Finally thanks to my family and friends Their understanding and support helped me
sincerely enjoy life and work during the past four years
iv
QUINOA SEED QUALITY AND SENSORY EVALUATION
Abstract
by Geyang Wu PhD Washington State University
May 2016
Co-Chairs Carolyn F Ross Craig F Morris
Quinoa is a grain that has garnered increasing interest in recent years from global
markets as well as in academic research The studies in this dissertation focused on quinoa seed
quality and sensory evaluation among diverse quinoa varieties with potential adaptation to
growing conditions in Washington State The objectives in the dissertation were to study quinoa
seed quality as well as the sensory attributes of cooked quinoa as defined by both trained and
consumer panelists Regarding quinoa seed quality we investigated seed characteristics
(diameter weight density hardness seed coat proportion) seed composition (protein and ash
content) flour viscosity and thermal properties quinoa cooking quality and texture of cooked
quinoa Additionally the functional characteristics of quinoa were studied including the
determination of amylose content starch swelling power and water solubility texture of starch
gel and starch thermal properties Results indicated texture of cooked quinoa was significantly
influenced by protein content flour viscosity quinoa cooking quality amylose content and
starch enthalpy In addition the influences of soil salinity and fertility on quinoa seed quality
were evaluated The variety lsquoQQ065rsquo exhibited increased protein content and maintained similar
levels of hardness and density under salinity stress and is considered to be the best adapted
v
variety among four varieties Finally sensory evaluation studies on cooked quinoa were
conducted A lexicon of cooked quinoa was developed including the sensory attributes of aroma
tasteflavor texture and color Results from the trained and consumer panel indicated that
consumer liking of quinoa was positively influenced by grassy aroma and firm and crunchy
texture These results represent valuable information to quinoa breeders in the determination of
seed quality of diverse quinoa varieties In the food industry the results of seed quality and
sensory studies (lexicon and consumer-liking) can be utilized to evaluate quinoa ingredients from
multiple locations or years determine the efficiency of post-harvest processing and develop
appropriate products according to the properties of the specific quinoa variety Overall this
dissertation contributed to the growing body of research describing the chemical physical and
sensory properties of quinoa
vi
TABLE OF CONTENTS
Page
ACKNOWLEDGMENTS iii
ABSTRACT iv-v
LIST OF TABLES ix-xi
LIST OF FIGURES xii-xiii
CHAPTERS
1 Introduction 1
References 6
2 Literature review 9
References 26
Tables 41
Figures44
3 Evaluation of texture differences among varieties of cooked quinoa 46
Abstract 46
Introduction 48
Materials and Methods 51
Results 54
Discussion 60
vii
Conclusion 63
References 65
Tables 71
Figures78
4 Quinoa starch characteristics and their correlation with
texture of cooked quinoa 80
Abstract 80
Introduction 81
Materials and Methods 82
Results 87
Discussion 95
Conclusion 102
References 103
Tables 109
5 Quinoa seed quality response to sodium chloride and
Sodium sulfate salinity 118
Abstract 118
Introduction 120
Materials and Methods 122
Results 125
Discussion 123
viii
Conclusion 132
References 134
Tables 139
Figure 145
6 Lexicon development and sensory attributes of cooked quinoa 146
Abstract 146
Introduction 148
Materials and Methods 150
Results and Discussion 155
Conclusion 165
References 167
Tables 172
Figures183
7 Conclusions 189
ix
LIST OF TABLES
Page
CHAPTER 2
Table 1 Essential amino acid of quinoa protein and FAOWHO suggested requirement (mgg
protein) 41
Table 2 Quinoa vitamin content (mg100g) 42
Table 3 Quinoa mineral content (mgmg ) 43
CHAPTER 3
Table 1 Varieties of quinoa used in the experimenthelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip71
Table 2 Seed characteristics and composition 72
Table 3 Texture profile analysis (TPA) of cooked quinoa 73
Table 4 Cooking quality of quinoa 74
Table 5 Pasting properties of quinoa flour by RVA 75
Table 6 Thermal properties of quinoa flour by Differential Scanning Calorimetry (DSC) 76
Table 7 Correlation coefficients between quinoa seed characteristics composition and
processing parameters and TPA texture of cooked quinoa 77
CHAPTER 4
Table 1 Quinoa varieties tested 109
Table 2 Starch content and composition 110
Table 3 Starch properties and α-amylase activity 111
Table 4 Texture of starch gel 112
Table 5 Thermal properties of starch 113
x
Table 6 Pasting properties of starch 114
Table 7 Correlation coefficients between starch properties and texture of cooked quinoa 115
Table 8 Correlations between starch properties and seed DSC RVA characteristics 116
CHAPTER 5
Table 1 Analysis of variance with F-values for protein content hardness and density of quinoa
seed 139
Table 2 Salinity variety and fertilization effects on quinoa seed protein content () 140
Table 3 Salinity variety and fertilization effects on quinoa seed hardness (kg) 141
Table 4 Salinity variety and fertilization effects on quinoa seed density (g cm3) 142
Table 5 Correlation coefficients of protein hardness and density of quinoa seed 143
Table 6 Correlation coefficients of quinoa seed quality and agronomic performance and seed
mineral content144
CHAPTER 6
Table 1 Quinoa samples 172
Table 2 Lexicon of cooked quinoa as developed by the trained panelists (n = 9) 173
Table 3 Significance and F-value of the effects of panelist replicate and quinoa variety on
aroma flavor and texture of cooked quinoa as determined using a trained panel (n = 9) 176
Table 4 Mean separation of significant tasteflavor attributes of cooked quinoa determined by
the trained panel Different letters within a column indicate attribute intensities were different
among quinoa samples at P lt 005 as determined using Fisherrsquos LSD 178
Table 5 Mean separation of consumer preference Different letters within a column indicate
consumer evaluation scores were different among quinoa samples at P lt 005 179
xi
Table 6 Hardness adhesiveness cohesiveness springiness gumminess and chewiness of the
cooked quinoa samples as determined using Texture Profile Analysis (TPA) Different letters
within a column indicate attribute intensities were different among quinoa samples at P lt 005
180
Table 7 Correlation of trained panel texture evaluation data and instrumental TPA over the 21
quinoa varieties 181
Table 1S Mean separation of significant aroma attributes of cooked quinoa determined by the
trained panel (n = 9) Different letters within a column indicate attribute intensities were different
among quinoa samples at P lt 005 as determined using Fisherrsquos LSD 186
Table 2S Mean separation of significant texture attributes of cooked quinoa determined by the
trained panel Different letters within a column indicate attribute intensities were different among
quinoa samples at P lt 005 as determined using Fisherrsquos LSD 187
xii
LIST OF FIGURES
Page
CHAPTER 2
Figure 1 Quinoa seed section and two-layered pericarp under perianth (Wu et al 2014) 44
Figure 2 Figure 2-Quinoa seed structure (Prego et al 1998) 45
CHAPTER 3
Figure 1 Rapid Visco Analyzer (RVA) graph of lsquoCherry Vanillarsquo and lsquoRed Commercialrsquo quinoa
flours 78
Figure 2 Seed coat image by SEM 79
CHAPTER 5
Figure 1 Protein content () of quinoa in response to combined fertility and
salinity treatments 145
CHAPTER 6
Figure 1 Principal component Analysis (PCA) biplot of aroma evaluations by the trained
sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 182
Figure 2 Principal component Analysis (PCA) biplot of tasteflavor evaluations by the trained
sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 183
xiii
Figure 3 Principal component Analysis (PCA) biplot of texturemouthfeel evaluations by the
trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 184
Figure 4 Partial Least Squares (PLS) biplot correlating aroma color appearance tasteflavor
texture and overall attributes evaluated by the trained panel (n = 9) to the consumer panel (n =
102) for 6 quinoa samples (Consumer acceptances are in bold italics) 185
Figure-1S Demographic influence on preference of variety lsquoBlackrsquo 188
xiv
Dedication
This dissertation is dedicated to those who are interested in quinoa
the beautiful small grain providing nutrition and fun
1
Chapter 1 Introduction
Quinoa is growing rapidly in the global market largely due to its high nutritional value
and potential application in a wide range of products Bolivia and Peru are the major producers
and exporters of quinoa In Peru production increased from 31824 MT (Metric Ton) in 2007 to
108000 MT in 2015 (USDA 2015) In 2013 organic quinoa from Bolivia and Peru were sold at
averages of $8000MT and $7000MT respectively (Nuntildeez de Acro 2015) Of all countries the
US and Canada import the most quinoa and comprise 53 and 15 of the global imports
respectively (Carimentrand et al 2015) Quinoa yield is on average 600 kgha with yield
varying greatly and among varieties and environments (Garcia et al 2004) The total production
cost is $720ha in the southern Altiplano region of Bolivia and the farm-gate price reached
$60kg in 2013 (Nuntildeez de Acro 2015) With 2600 kg annual quinoa yield in a small 3 ha farm
the revenue would be $15390 which could potentially raise a family out of poverty (Nuntildeez de
Acro 2015)
Quinoa possesses many sensory properties Food texture refers to those qualities of a
food that can be felt with the fingers tongue palate or teeth (Sahin and Sumnu 2006) Texture is
one of most significant properties of food products Quinoa has unique texture ndash creamy smooth
and a little crunchy (James 2009) The texture of cooked quinoa is not only influenced by seed
structure but also determined by compounds such as starch and protein However publications
describing the texture of cooked quinoa are limited
Seed characteristics and structure are important factors influencing the textual properties
of cooked quinoa seed Quinoa is a dicotyledonous plant species very different from
2
monocotyledonous cereal grains The majority of the seed is the middle perisperm of which cells
have very thin walls and angular-shaped starch grains (Prego et al 1998) The two-layer
endosperm of the quinoa seed consists of living thick-walled cells rich in proteins and lipids but
without starch The protein bodies found in the embryo and endosperm lack crystalloids and
contain one or more globoids of phytin (Prego 1998) Given the structure of quinoa the seed
properties such as seed size hardness and seed coat proportion may influence the texture of the
cooked quinoa Nevertheless correlations between seed characteristics seed structure and
texture of cooked quinoa have not been performed
Beside the physical properties of seed the seed composition will influence the texture as
well Protein and starch are the major components in quinoa while their correlation to texture
has not been studied Starch characteristics and structures significantly influence the texture of
the end product Starch granules of quinoa is very small (1-2μm) compared to that of rice and
barley (Tari et al 2003) Quinoa starch is lower in amylose content (11 of starch) (Ahamed
1996) which may yield the hard texture Chain length of amylopectin also influences hardness of
food product (Ong and Blanshard 1995) In sum the influence of quinoa seed composition and
characteristics on cooked product should be studied
In addition to seed quality and characteristics the sensory attributes of quinoa are also
significant as they influence consumer acceptance and the application of the quinoa variety
However there is a lack of lexicon to describe the sensory attributes of cooked quinoa Rice is
considered as a model when studying quinoa sensory attributes because they are cooked in
similar ways The lexicon of cooked rice were developed and defined in the study of Champagne
3
et al (2004) Sewer floral starchygrain hay-likemusty popcorn green beans sweet taste
sour and astringent were among those attributes
Consumer acceptance is of great interested to breeders farmers and the food industry
Acceptability of quinoa bread was studied by Rosell et al (2009) and Chlopicka et al (2012)
Gluten free quinoa spaghetti (Chillo et al 2008) and dark chocolate with 20 quinoa
(Schumacher et al 2010) were evaluated using a sensory panel However cooked quinoa the
most common way of consuming quinoa has not been studied for its sensory properties and
consumer preference Additionally consumer acceptance of quinoa may be influenced by the
panelistsrsquo demographic such as origin food culture familiarity with less common grains and
quinoa and opinion of a healthy diet Furthermore compared to instrumental tests sensory
evaluation tests are generally more expensive and time consuming hence correlations of sensory
panel and instrumental data are of interest If correlations exist instrumental analyses can be
used to substitute or complement sensory panel evaluation
Based on the above discussion this dissertation focused on the study of seed
characteristics quality and texture of cooked quinoa and starch characteristics among various
quinoa varieties Seed quality under saline soil conditions was also investigated To develop the
sensory profiles of cooked quinoa a trained panel developed and validated a lexicon for cooked
quinoa while a consumer panel evaluated their acceptance of different quinoa varieties From
these data the drivers of consumer liking were determined
The dissertation is divided into 7 chapters Chapter 1 is an introduction of the topic and
overall objectives of the studies Chapter 2 provides a literature review of recent progress in
4
quinoa studies including quinoa seed structure and compositions physical properties flour
properties health benefits and quinoa products Chapter 3 was published in Journal of Food
Science under the title of lsquoEvaluation of texture differences among varieties of cooked quinoarsquo
The objectives of Chapter 3 were to study the texture difference among varieties of cooked
quinoa and evaluate the correlation between the texture and the seed characters and
composition cooking process flour pasting properties and thermal properties
Chapter 4 includes the manuscript entitled lsquoQuinoa starch characteristics and their
correlation with texture of cooked quinoarsquo The objectives of Chapter 4 were to determine starch
characteristics of quinoa among different varieties and investigate the correlations between the
starch characteristics and cooking quality of quinoa
Chapter 5 has been submitted to Frontier in Plant Science under the title lsquoQuinoa seed
quality response to sodium chloride and sodium sulfate salinityrsquo In Chapter 5 quinoa seed
quality grown under salinity stress was assessed Four quinoa varieties were grown under six
salinity treatments and two levels of fertilization and then quinoa seed quality characteristics
such as protein content seed hardness and seed density were evaluated
Chapter 6 is the manuscript entitled lsquoLexicon development and sensory attributes of
cooked quinoarsquo In Chapter 6 a lexicon of cooked quinoa was developed using a trained panel
The lexicon provided descriptions of the sensory attributes of aroma tasteflavor texture and
color with references developed for each attribute The trained panel then applied this lexicon to
the evaluation of 16 field trial quinoa varieties from WSU and 5 commercial quinoa samples
from Bolivia and Peru A consumer panel also evaluated their acceptance of 6 selected quinoa
5
samples Using data from the trained panel and the consumer panel the key sensory attributes
driving consumer liking were determined Finally Chapter 7 presents the conclusions and
recommendations for future studies
6
References
Nuntildeez de Acro Chapter 12 Quinoarsquos calling In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 211 ndash 25
Ahamed NT Singhal RS Kulkarni PR Pal M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 31 99-103
Ando H Chen Y Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food Components in
Fractions of Quinoa Seed Food Sci Technol Res 8(1) 80-4
Carimentrand A Baudoin A Lacroix P Bazile D Chia E 2015 Chapter 41 International
quinoa trade In D Bazile D Bertero and C Nieto editors State of the Art Report of
Quinoa in the World in 2013 Rome FAO amp CIRAD p 316 ndash 29
Champagne ET Bett-Garber KL McClung AM Bergman C 2004 Sensory characteristics of
diverse rice cultivars as influenced by genetic and environmental factors Cereal Chem 81
237-43
Chillo S Civica V Iannetti M Mastromatteo M Suriano N Del Nobile M 2010 Influence of
repeated extrusions on some properties of non-conventional spaghetti J Food Eng 100 329-
35
Chlopicka J Pasko P Gorinstein S Jedryas A Zagrodzki P 2012 Total phenolic and total
flavonoid content antioxidant activity and sensory evaluation of pseudocereal breads LWT-
Food Sci Technol 46 548-55
7
Garcia M Raes D Allen R Herbas C 2004 Dynamics of reference evapotranspiration in the
Bolivian highlands (Altiplano) Agr Forest Meteorol 125(1) 67-82
James LEA 2009 Quinoa (Chenopodium quinoa Willd) composition chemistry nutritional
and functional properties Adv Food Nutr Res 58 1-31
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine structure of amylopectin J Cereal Sci 21 251-60
Perdon AA Siebenmorgen TJ Buescher RW Gbur EE 1999 Starch retrogradation and texture
of cooked milled rice during storage J Food Sci 64 828-32
Prego I Maldonado S Otegui M 1998 Seed structure and localization of reserves in
Chenopodium quinoa Ann Bot 82(4) 481-8
Ramesh M Ali SZ Bhattacharya KR1999 Structure of rice starch and its relation to cooked-
rice texture Carbohydr Polym 38 337-47
Rosell CM Cortez G Repo-Carrasco R 2009 Bread making use of Andean crops quinoa
kantildeiwa kiwicha and tarwi Cereal Chem 86 386-92
Sahin S Sumnu SG 2006 Physical properties of foods Springer Science amp Business Media
P39 ndash 109
Schumacher AB Brandelli A Macedo FC Pieta L Klug TV de Jong EV 2010 Chemical and
sensory evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J
Food Sci Technol 47 202-6
8
Tari TA Annapure US Singhal RS Kulkarni PR 2003 Starch-based spherical aggregates
screening of small granule sized starches for entrapment of a model flavouring compound
vanillin Carbohydr Polym 53 45-51
USDA US Department of Agriculture 2015a Peru Quinoa outlook Access from
httpwwwfasusdagovdataperu-quinoa-outlook
9
Chapter 2 Literature Review
Introduction
Quinoa (Chenopodium quinoa Willd) is a dicotyledonous pseudocereal from the Andean
region of South America The plant belongs to a complex of allotetraploid taxa (2n = 4x = 36)
which includes Chenopodium berlandieri subsp berlandieri Chenopodium berlandieri subsp
nuttalliae Chenopodium hircinum and Chenopodium quinoa (Gomez-Pando 2015 Matanguihan
et al 2015) Closely related species include the weed lambsquarter (Chenopodium album)
amaranth (Amaranth palmeri) sugar beet (Beta vulgaris L) and spinach (Spinacea oleracea L)
(Maughan et al 2004) Quinoa plant is C3 specie with 90 self-pollenating (Gonzalez et al
2011) Quinoa was domesticated approximately 5000 ndash 7000 years ago in the Lake Titicaca area
in Bolivia and Peru (Gonzalez et al 2015) Quinoa produces small oval-shaped seeds with a
diameter of 2 mm and a weight of 2 g ndash 46 g 1000-seed (Wu et al 2014) The seed color varies
and can be white yellow orange red purple brown or gray White and red quinoas are the most
common commercially available varietals in the US marketplace (Data from online resources
and local stores in Pullman WA) With such small seeds quinoa provides excellent nutritional
value such as high protein content balanced essential amino acids high proportion of
unsaturated fatty acids rich vitamin B complex vitamin E and minerals antioxidants such as
phenolics and betalains and rich dietary fibers (Wu 2015) For these reasons quinoa is
recognized as a ldquocompleterdquo food (Taverna et al 2012)
10
This chapter reviewed publications in quinoa varieties global development seed
structure and constituents quinoa health benefits physical properties and thermal properties
quinoa flour characteristics processing and quinoa products
Quinoa varieties
There are 16422 quinoa accessions or genetypes conserved worldwide 14502 of which
are conserved in genebanks from the Andean region (Rojas et al 2013) Bolivia and Peru
manage 13023 quinoa accessions (80 of world total accessions) in 140 genebanks (Rojas and
Pinto 2015)
Based on genetic diversity adaptation and morphological characteristics five ecotypes
of quinoa have been identified in the Andean region including valley quinoa Altiplano quinoa
salar quinoa sea level quinoa and subtropical quinoa (Tapia et al 1980) The sea-level ecotype
or Chilean lowland ecotype is the best adapted to temperate climate and high summer
temperature (Peterson and Murphy 2015a)
Adaptation
Quinoa has shown excellent adaptation to marginal or extreme environments and such
adaptation was summarized by Gonzalez et al (2015) Quinoa growing areas range from sea
level to 4200 masl (meters above sea level) with growing temperature rangeing from -4 to 38 ordmC
The plant has adapted to drought-stressed environments but can also grow in areas with
humidity ranging from 40 to 88 Quinoa can grow in marginal soil conditions such as dry
(Garcia et al 2003) infertile (Sanchez et al 2003) and with wide pH range from acidic to basic
(Jacobsen and Stolen 1993) Quinoa has also adapted to high salinity soil (equal to sea salt level
11
or 40 dSm) (Koyro and Eisa 2008 Hariadi et al 2011 Peterson and Murphy 2015b)
Furthermore quinoa has shown tolerance to frost at -8 to -4 ordmC (Jacobsen et al 2005)
Even though quinoa varieties are remarkably diverse and able to adapt to extreme
conditions time and resources are required to breed the high-yielding varieties that are adapted
to regional environments in North America Challenges to achieving strong performance include
yield waterlogging pre-harvest sprouting weed control and tolerance to disease insect pests
and animal stress (Peterson and Murphy 2015a) The breeding work not only needs the effort
from breeders and researchers but also demands the participation and collaboration of local
farmers
In addition to being widely grown in South America quinoa has also recently been
grown in North America Europe Australia Africa and Asia In US quinoa cultivation and
breeding started in the 1980s by the efforts from seed companies private individuals and
Colorado State University (Peterson and Murphy 2015a) Since 2010 Washington State
University has been breeding quinoa in the Pacific Northwest to suit the diverse environmental
conditions including rainfall and temperature Peterson and Murphy (2015a) found the major
challenges in North America included heat susceptibility downy mildew (Plasmopara viticola)
saponin removal weed stress and insect stress (such as aphids and Lygus sp)
With high nutritional value quinoa is recognized as significant in food security and
treating malnutrition issue in developing countries (Rojas 2011) Maliro and Guwela (2015)
reviewed quinoa breeding in Africa Initial experiments showed quinoa can grow well in Malawi
and Kenya in both warm and cool areas The quinoa grain yields in Malawi and Kenya are 3-4
12
tonha which are comparable to the yields in South America However the challenge remains to
adopt quinoa into the local diet and cultivate a quinoa consuming market
Physical Properties of Quinoa
Physical properties of seed refer to seed morphology size gravimetric properties
(weight density and porosity) aerodynamic properties and hardness which are critical to
technology and equipment designed for post-harvest process such as seed cleaning
classification aeration drying and storage (Vilche et al 2003)
The quinoa seed is oval-shaped with a diameter of approximately 18 to 22 mm (Bertero
et al 2004 Wu et al 2014) Mean 1000-seed weight of quinoa is around 27 g (Bhargava et al
2006) and a range of 15 g to 45 g has been observed among varieties (Wu et al 2014)
Commercial quinoa from Bolivia tends to have higher 1000-seed weight of 38 g to 45 g
Additionally bulk density ranges from 066 gmL to 075 gmL in most varieties (Wu et al
2014) Porosity refers to the fraction of space in bulk seed which is not occupied by the seed
(Thompson and Isaac 1976) The porosity of quinoa is 23 (Vilche et al 2003) while that of
rice is 50 to 60 (Kunze et al 2004)
Terminal velocity is the air velocity at which seeds remain in suspension This parameter
is important in cleaning quinoa to remove impurities such as dockage hollow and immature
kernels and mixed weed seeds Vilche et al (2003) reported the terminal velocity of 081 ms-1
while the value of rice was 6 ms-1 to 77 ms-1 (Razavi and Farahmandfar 2008)
Seed hardness or crushing strength is used as a rough estimation of moisture content in
rice (Kunze et al 2004) The hardness of quinoa seed can be tested using a texture analyzer (Wu
13
et al 2014) A stainless cylinder (10 mm in diameter) compressed one quinoa seed to 90 strain
at the rate of 5 mms Because of hardness variation among individual seeds at least six
measurements were required Among the thirteen quinoa samples that were tested hardness
ranged from 58 kg to 110 kg (Wu et al 2014)
Quinoa Seed Structure
Grain structure of quinoa was described in detail by Taylor and Parker (2002) On the
outside of grain is a perianth which can be easily removed during cleaning or rubbing
Sometimes betalain pigments concentrate on this perianth layer and the seed shows bright purple
or golden colors However this color will disappear with the removal of the perianth Inside the
perianth is two-layered pericarp with papillose surface (Figure 1) Beneath the pericarp a seed
coat or episperm is located The seed coat can be white yellow orange red brown or black
Red and white quinoa share the largest market share with consumers exhibiting increasing
interest in brownblack mixed products such as lsquoCalifornia Tricolorrsquo(data from Google
Shopping Amazon and local stores in Pullman WA)
The main seed is enveloped in outside layers and the structure was depicted by Prego et
al (1998) (Figure 2) The embryo (two cotyledons and radicle) coils around a center pericarp
which occupies ~40 of seed volume (Fleming and Galwey 1998) Protein and lipid bodies are
primarily present in the embryo whereas starch granules provide storage in the thin-walled
perisperm Minerals of phosphorus potassium and magnesium are concentrated in phytin
globoids located in the embryo and calcium is located in the pericarp (Konishi et al 2004)
Quinoa Seed Constituents
14
Quinoa is known as a lsquocomplete foodrsquo (James 2009) The seed composition was recently
reviewed by Wu (2015) and Maradini Filho et al (2015) In sum the high nutritional value of
quinoa arises from its high protein content complete and balanced essential amino acids high
proportion of unsaturated fatty acids high concentrations of vitamin B complex vitamin E and
minerals and high phenolic and betalain content
A protein range of 12 to 17 in quinoa has been reported by most studies (Rojas et al
2015) This protein content is higher than wheat (8 to 14 ww) (Halverson and Zeleny 1988)
and rice (4 - 105 ww) (Champagne et al 2004) Additionally quinoa contains all essential
amino acids at concentrations exceeding the suggested requirements from FAOWHO (Table 1)
Quinoa is also gluten-free because it is lacking in prolamins Prolamins are a group of
storage proteins that are rich in proline Prolamins can interact with water and form the gluten
structure which cannot be tolerated by those with celiac disease (Fasano et al 2003) Quinoa and
rice both contain low prolamins (72 and 89 of total protein respectively) and are
considered gluten-free crops Prolamins in wheat (called gliadin) comprise 285 of its total
protein and in maize this concentration of prolamin is 245 (Koziol 1992)
The protein quality of quinoa protein was reported by Ruales and Nair (1992) In raw
quinoa the net protein utilization (NPU) was 757 biological value (BV) was 826 and
digestibility (TD) was 917 all of which were slightly lower than those of casein The
digestibility of quinoa protein is comparable to that of other high quality food proteins such as
soy beans and skim milk (Taylor and Parker 2002) The Protein Efficiency Ratio (PER) in
quinoa ranges from 195 to 31 and is similar to that of casein (Gross et al 1989 Guzmaacuten-
15
Maldonado and Paredes-Lopez 2002) Regarding functional properties of quinoa protein isolates
Eugenia et al (2015) found Bolivian quinoa exhibited the highest thermal stability oil binding
capacity and water binding capacity at acidic pH The Peruvian samples showed the highest
water binding capacity at basic pH and the best foaming capacity at pH 5
Quinoa starch content ranges from 58 to 64 of the dry seed weight (Vega‐Gaacutelvez et
al 2010) Quinoa possesses a small granule size of 06 to 2 μm similar to that of amaranth (1 to
2 μm) and much smaller than those of other grains such as rice wheat oat barley and
buckwheat (2 to 36 μm) (Lindeboom et al 2004) The amylose content in quinoa starch tends to
be lower than found in common grains A range of 3 to 20 was reported by Lindeboom et al
(2005) whereas amylose content is around 25 in cereals As in most cereals quinoa starch is
type A in X-ray diffraction pattern (Ando et al 2002) Li et al (2016) found significant variation
among 26 commercial quinoa samples in the physicochemical properties of starch such as gel
texture thermal and pasting parameters which were strongly affected by apparent amylose
content
Quinoa lipids comprise 55 to 71 of dry seed weight in most reports (Maradini Filho
et al 2015) Ando et al (2002) found quinoa (cultivar Real TKW from Bolivia) perisperm and
embryo contained 50 and 102 total fatty acids respectively Among these fatty acids
unsaturated fatty acids such as oleic linoleic and linolenic comprised 875 Ogungbenle
(2003) reported the properties of quinoa lipids The values of acid iodine peroxide and
saponification were 05 54 24 and 192 respectively
16
Quinoa micronutrients of vitamins and minerals and the relative lsquoreference daily intakersquo
are summarized in Table 2 and 3 respectively Compared to Daily Intake References quinoa
provides a good source of Vitamin B1 B2 and B9 and Vitamin E as well as minerals such as
magnesium phosphorous iron and copper
Quinoa is one of the crops representing diversity in color including white vanilla
yellow orange red brown gray and dark Besides the anthocyannins in dark quinoa (Paśko et
al 2009) the major pigment in quinoa is betalain primarily presenting in seed coat and the
compounds can be subdivided into red-violet betacyannins and yellow-orange betaxanthins
(Tang et al 2015) Betalain is a water-soluble pigment which is permitted quantum satis as a
natural food colorant and applied in fruit yogurt ice cream jams chewing gum sauces and
soups (Esatbeyoglu et al 2015) Additionally betalain potentially offers health benefits such as
antioxidant activity anti-inflammation activity preventing low-density lipoprotein (LDL)
oxidation and DNA damage (Benavente-Garcia and Castillo 2008 Esatbeyoglu et al 2015)
Saponins
Saponins are compounds on the seed coat of quinoa that confer a bitter taste The
compounds are considered to be a defense system against herbivores and pathogens Regarding
chemical structure saponins are a group of glycosides consisting of a hydrophilic carbohydrate
chain (such as arabinose glucose galactose xylose and rhamnose) and a hydrophobic aglycone
(Kuljanabhagavad and Wink 2009) Chemical structures of aglycones were summarized by
Kuljanabhagavad and Wink (2009)
17
Saponins have been considered as anti-nutrient because of haemolytic activity which
refers to the breakdown of red blood cells (Khalil and El-Adawy 1994) However saponins
exhibited health benefit functions such as anti-inflammation (Yao et al 2009) antibacterial
antimicrobial activity (Killeen et al 1998) anti-tumor activity (Shao et al 1996) and
antioxidant activity (Guumllccedilin et al 2006) Furthermore saponins have medicinal use Sun et al
(2009) reported saponins can activate immune system and were used as vaccine adjuvants
Saponins also exhibited anti-cancer activity (Man et al 2010)
Even though saponins have potential health benefits their bitter taste is not pleasant to
consumers To address the bitterness found in bitter quinoa varieties (gt 011 saponin content)
sweet quinoa varieties were bred through conventional genetic selection to contain a lower
saponin content (lt 011 saponin content) For instance lsquoSajamarsquo lsquoKurmirsquo lsquoAynoqarsquo
lsquoKosunarsquo and lsquoBlanquitarsquo in Bolivia lsquoBlanca de Juninrsquo in Peru and lsquoTunkahuanrsquo in Ecuador are
considered sweet quinoa varieties (Quiroga et al 2015) Unfortunately varieties from Bolivia
Peru and Ecuador do not adapt to temperate climates such as those found in the Pacific
Northwest in US and Europe A sweet variety called lsquoJessiersquo exhibits acceptable yield in Pacific
Northwest and has a great market potential Further development of sweet quinoa varieties
adapted to local climate will happen in near future
To remove saponins both dry and wet processing methods have been developed The wet
method or moist method refers to washing quinoa while rubbing the grain with hands or by a
stone Repo-Carrasco et al (2003) suggested the best washing conditions of 20 min soaking 20
min stirring with a water temperature of 70 degC The wet method becomes costly due to the
required drying process Additionally quinoa grain may begin to germinate during wet cleaning
18
The dry method or abrasive dehulling uses mechanical abrasion to polish the grain and
remove the saponins A dehulling process was reported by Reichert et al (1986) using Tanential
Abrasive Dehulling Device (TADD) and removal of 6 - 15 of kernel was required to reduce
the saponins content to lower than 011 Additionally a TM-05 Taka-Yama testing mill was
used in the quinoa pearling process (to 20 - 30 pearling degree) (Goacutemez-Caravaca et al
2014) The dry method is relatively cheaper than wet method and does not generate saponin
waste water The saponin removal efficiency of the dry and washing methods were reported to be
87 and 72 respectively (Reichert et al 1986 Gee et al 1993) A combination of dry and wet
methods was recommended to obtain the efficient cleaning (Repo-Carrasco et al 2003)
Since quinoa is such an expensive crop a 25 to 30 weight lost during the cleaning
process represents a substantial loss on an industrial scale In addition mineral phenolic and
fiber content may dramatically decrease during processing resulting in a loss of nutritional
value Hence cleaning process should be further optimized to reach lower grain weight loss
while maintain an efficient saponins elimination
Removed saponins can be utilized as side products Since saponins also have excellent
foaming property they can be applied in cosmetics and foods as foam-stabilizing and
emulsifying agents (Yang et al 2010) detergents (Chen et al 2010) and preservatives
(Taormina et al 2006)
Saponin content is important to analyze since it highly influences the taste of quinoa
Traditionally the afrosimetric method or foam method was used to estimate saponins content In
this method saponon content is calculated from foam height after shaking quinoa and water
19
mixture for a specific time (Koziol 1991) This afrosimetric method is fast and affordable and
can be used by farmers as a quick estimation of saponin content however the method is not very
accurate The foam stability varies among samples A more accurate method was developed
using Gas Chromatography (GC) (Ridout et al 1991) Using this method quinoa flour was first
defatted using a Soxhlet extraction and then hydrolyzed in reflux for 3 h with a methanol
solution of HCl (2 N) The hydrolysis product sapogenins were extracted with ethyl acetate and
derivatized with bis-(trimethylsilyl) trifluoroacetamide (BSTFA) and dry pyridine and then
tested using GC Generally GC method is a more solid and accurate method compared to foam
method however GC also requires high capital investment as well as long and complex sample
preparation For quinoa farmers and food manufactures fast and affordable methods to test
saponins content in quinoa need to be developed
Saponins have been an important topic in quinoa research Future studies in this area can
include 1) breeding and commercialization of saponin-free or sweet quinoa varieties with high
yield and high agronomy performance (resistance to biotic and abiotic stresses) 2) development
of quick and low cost detection method of saponin content and 3) application of saponin in
medicine foods and cosmetics can be further explored
Health benefits
Simnadis et al (2015) performed a meta-analysis of 18 studies which used animal models
to assess the physiological effects associated with quinoa consumption From these studies
purported physiological effects of quinoa consumption included decreased weight gain
improved lipid profile (decrease LDL and cholesterol) and improved capacity to respond to
20
oxidative stress Simnadis et al (2015) pointed out that the presence of saponins protein and
20-hydroxyecdysone (affects energy homeostasis and intestinal fat absorption) contributed to
those benefit effects
Furthermore Ruales et al (2002) found increased plasma levels of IGF-1 (insulin-like
growth factor) in 50-65 month-old boys after consuming a quinoa infant food for 15 days This
result implicated the potential of quinoa to reduce childhood malnutrition In another study of 22
students (aged 18 to 45) the daily consumption of a quinoa cereal bar for 30 days significantly
decreased triglycerides cholesterol and LDL compared to those parameters prior to quinoa
consumption These results suggest that quinoa intake may reduce the risk of developing
cardiovascular disease (Farinazzi-Machado et al 2012) De Carvalho et al (2014) studied the
influence of quinoa on over-weight postmenopausal women Consumption of quinoa flakes (25
gd for 4 weeks) was found to reduce serum triglycerides and TBARS (thiobarbituric acid
reactive substances) and increase GSH (glutathione) and urinary excretion of enterolignans
compared to those indexes before consuming quinoa flakes
Quinoa flour properties
Functional properties of quinoa flour were determined by Ogungbenle (2003) Quinoa
flour has high water absorption capacity (147) and low foaming capacity (9) and stability
(2) Water absorption capacity was determined by the volume of water retained per gram of
quinoa flour during 30-min mixing at 24 ordmC (Beuchat 1977) The water absorption of quinoa was
higher than that of fluted pumpkin seed (85) soy flour (130) and pigeon pea flour (138)
which implies the potential use of quinoa flour in viscous foods such as soups doughs and
21
baked products Additionally foaming capacity was determined by the foam volumes before and
after whipping of 8 protein solution at pH 70 (Coffmann and Garciaj 1977) Then foam
samples were inverted and dripped though 2 mm wire screen in to beakers The foam stability
was determined by the weight of liquid released from foam after a specific time and the original
weight of foam (Coffmann and Garciaj 1977) Furthermore minimum protein solubility was
observed at pH 60 similar to that of pearl millet and higher than pigeon pea (pH 50) and fluted
pumpkin seed (pH 40) Relatively high solubility of quinoa protein in acidic condition implies
the potential application of quinoa protein in acidic food and carbonated beverages
Wu et al (2014) studied flour viscosity among 13 quinoa samples with large variations
reported among samples The ranges of peak viscosity final viscosity and setback were 59
RVU ndash 197 RVU 56 RVU ndash 203 RVU and -62 RVU ndash 73 RVU respectively which were
comparable to those of rice flour (Zhou et al 2003) Flour viscosity significantly influence
texture of quinoa and rice (Champagne et al 1998 Wu et al 2014)
Ruales et al (1993) studied processing influence on the physico-chemical characteristics
of quinoa flour The process included cooking and autoclaving of the seeds drum drying of
flour and extrusion of the grits Autoclaved quinoa samples exhibited the lowest degree of starch
gelatinization (325) whereas precookeddrum dried quinoa samples were 974 Higher
polymer degradation was found in the cooked samples compared to the autoclaved samples
Water solubility in cooked samples (54 to 156) and autoclaved samples (70 to 96) increased
with the processing time (30 to 60 min cooking and 10 to 30 min autoclaving)
Thermal Properties of quinoa
22
Thermal properties of quinoa flour (both starch and protein) have been determined using
Differential Scanning Calorimetry (DSC) (Abugoch et al 2009) A quinoa flour suspension was
prepared in 20 (ww) concentration The testing temperature was raised from 27 to 120 degC at a
rate of 10 degCmin Two peaks in the DSC graph referenced the starch gelatinization temperature
at 657 degC and protein denaturalization at 989 degC Enthalpy refers to the energy required to
complete starch gelatinization or protein denaturazition In the study of Abugoch et al (2009)
the enthalpy was 59 Jg for starch and 22 Jg for proteins in quinoa
Product development with quinoa
Quinoa has been used in different products such as spaghetti bread and cookies to
enhance nutritional value including a higher protein content and more balanced amino acid
profile Chillo et al (2008) evaluated the quality of spaghetti from amaranth and quinoa flour
Compared to durum semolina spaghetti the spaghetti with amaranth and quinoa flour exhibited
equal breakage susceptibility higher cooking loss and lower instrumental stickiness The
sensory acceptance scores were not different from the control The solid loss weight increase
volume increase adhesiveness and moisture of a corn and quinoa mixed spaghetti were 162thinspg
kgminus1 23 times 26 times 20907thinspg and 384thinspg kgminus1 respectively (Caperuto et al 2001)
Schoenlechner et al (2010) found the optimal combination of 60 buckwheat 20 amaranth
and 20 quinoa yielded an improved dough matrix compared to other flour combinations With
the addition of 6 egg white powder and 12 emulsifier (distilled monoglycerides) this gluten-
free pasta exhibited acceptable firmness and cooking quality compared to wheat pasta
23
Stikic et al (2012) added 20 quinoa seeds in bread formulations which resulted in the
similar dough development time and stability compared to those of wheat dough even though
the bread specific volume was lower (63 mLg) compared to wheat bread (67 mLg) The
protein content of bread increased by 2 (ww) and sensory characteristics were lsquoexcellentrsquo as
evaluated by five trained expert panelists Iglesias-Puig et al (2015) found 25g100 g quinoa
flour substitution in wheat bread showed small depreciation in bread quality in terms of loaf
volume crumb firmness and acceptability whereas the nutritional value increased in dietary
fiber minerals protein and healthy fats Rizzello et al (2016) selected strains (lactic acid
bacteria) to develop a quinoa sourdough A wheat bread with 20 (ww) quinoa sourdough
exhibited improved nutritional (such as protein digestibility and quality) textural and sensory
features Quinoa leaves were also applied to bread making (Świeca et al 2014) With the
replacement of wheat flour by 1 to 5 (ww) quinoa leaves the bread crumb exhibited increased
firmness cohesiveness and gumminess Antioxidant activity and phenolic contents both
significantly increased compared to wheat bread
Pagamunici et al (2014) developed three gluten-free cookies with rice and quinoa flour
with 15 26 and 36 (ww) quinoa flour proportions respectively The formulation with
36 quinoa flour had the highest alpha-linolenic acid and mineral content and the cookie
displayed excellent sensory characteristics as evaluated by 80 non-trained consumer panelists
Another study optimized a gluten-free quinoa formulation with 30 quinoa flour 25 quinoa
flakes and 45 corn starch (Brito et al 2015) The cookie was characterized as a product rich in
essential amino acids linolenic acid minerals and dietary fiber This cookie was among those
24
products using the highest quinoa flour content (55 ww) while still received acceptable
sensory scores
Repo-Carrasco-Valencia and Serna (2011) introduced an extrusion process in Peru
Quinoa flour was tempered to 12 moisture for extrusion During extrusion total and insoluble
dietary fiber decreased by 5 to 17 and 13 to 29 respectively whereas the soluble dietary
fiber significantly increased by 38 to 71 Additionally the radical scavenging activity was
also increased in extruded quinoa compared to raw quinoa
Schumacher et al (2010) developed a dark chocolate with addition of 20 quinoa An
improved nutritional value was observed in 9 (ww) increase in vitamin E 70 - 104
increases in amino acids of cysteine tyrosine and methionine This quinoa dark chocolate
received over 70 acceptance index from sensory panel
Gluten-free beer is of increasing interest in the market (Dezelak et al 2014) Ogungbenle
(2003) found quinoa has high D-xylose and maltose and low glucose and fructose content
suggesting its potential use in malted drink de Meo et al (2011) applied alkaline steeping to
pseudocereal and found its positive effects on pseudocereals malt production by increasing total
soluble nitrogen and free amino nitrogen Kamelgard (2012) patented a method to create a
quinoa-based beverage fermented by a yeast Saccharomyces cerevisiae The beverage can be
distilled and aged to form gluten-free liquor Dezelak et al (2014) processed a quinoa beer-like
beverage (fermented with Saccharomyces pastorianus TUM 3470) resulting in a product with a
nutty aroma low alcohol content and rich in minerals and amino acids However further
development of the brewing procedure was necessary since the beverage showed a less attractive
25
appearance (near to black color and greyish foam) and astringent mouthfeel Compared to barley
brewing attributes of quinoa exhibited lower malt extracts longer saccharification times higher
values in total protein fermentable amino nitrogen content and iodine test
Processing quinoa grain to dried edible product and sweet quinoa product were developed
by Scanlin and Burnett (2010) The edible quinoa product was processed through pre-
conditioning (abrasion and washing) moist heating (steam cooking and pressure cooking) dry
heating (baking toasting and dehydrating) and post-production treatment As for sweet quinoa
product germination and malting processing were applied Caceres et al (2014) patented a
process to extract peptides and maltodextrins from quinoa flour and the extracts were applied in
a gel-format food as a supplement during and after physical activity
26
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2013-20
Abugoch LE Romero N Tapia CA Silva J Rivera M 2008 Study of some physicochemical
and functional properties of quinoa (Chenopodium quinoa Willd) protein isolates J Agric
Food Chem 56(12) 4745-50
Ando H Chen Y Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food Components in
Fractions of Quinoa Seed Food Sci Technol Res 8(1) 80-4
Benavente-Garcia O Castillo J 2008 Update on uses and properties of citrus flavonoids new
findings in anticancer cardiovascular and anti-inflammatory activity J Agric Food Chem
56(15) 6185-205
Bertero HD de la Vega AJ Correa G Jacobsen SE Mujica A 2004 Genotype and genotype-
by-environment interaction effects for grain yield and grain size of quinoa (Chenopodium
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Crops Res 89(2ndash3) 299-318
Beuchat LR 1977 Functional and electrophoretic characteristics of succinylated peanut flour
protein J Agric Food Chem 25(2) 258-61
Bhargava A Shukla S Rajan S Ohri D 2006 Genetic diversity for morphological and quality
traits in quinoa (Chenopodium quinoa Willd) Germplasm Genet Resour Crop Evol 54(1)
167-73
27
Brito IL de Souza EL Felex SSS Madruga MS Yamashita F Magnani M 2015 Nutritional
and sensory characteristics of gluten-free quinoa (Chenopodium quinoa Willd)-based
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73
Caceres JIE Calderon PD Lira FO 2014 Method for the formulation of a gel-format foodstuff
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quinoa flour Google Patents
Caperuto LC Amaya-Farfan J Camargo CRO 2001 Performance of quinoa (Chenopodium
quinoa Willd) flour in the manufacture of gluten-free spaghetti J Sci Food Agric 81(1) 95-
101
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5) 764-71
Champagne ET Wood DF Juliano BO Bechtel D 2004 Chapter 4 The rice grain and its gross
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Paul MN American Association of Cereal Chemists Inc p 88 ndash 9
Chen YF Yang CH Chang MS Ciou YP Huang YC 2010 Foam properties and detergent
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28
Chillo S Laverse J Falcone PM Del Nobile MA 2008 Quality of spaghetti in base amaranthus
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101-7
Coffmann CW Garciaj VV 1977 Functional properties and amino acid content of a protein
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De Carvalho FG Oviacutedio PP Padovan GJ Jordao Junior AA Marchini JS Navarro AM 2014
Metabolic parameters of postmenopausal women after quinoa or corn flakes intakendasha
prospective and double-blind study Int J Food Sci Nutr 65(3) 380-5
Deželak M Zarnkow M Becker T Košir IJ 2014 Processing of bottom-fermented gluten-free
beer-like beverages based on buckwheat and quinoa malt with chemical and sensory
characterization J Inst Brew 120(4) 360-70
Farinazzi-Machado FMV Barbalho SM Oshiiwa M Goulart R Pessan Junior O 2012 Use of
cereal bars with quinoa (Chenopodium quinoa W) to reduce risk factors related to
cardiovascular diseases Food Sci Technol(Campinas) 32(2) 239-44
Fasano A Berti I Gerarduzzi T Not T Colletti RB Drago S Hill ID 2003 Prevalence of celiac
disease in at-risk and not-at-risk groups in the United States a large multicenter study Arch
Intern Med 163(3) 286-92
Fleming JE Galwey NW 1998 Quinoa (Chenopodium quinoa Willd) nutritional quality and
technological aspects as human food In Belton PS Taylor JRN editors Increasing the
29
utilisation of sorghum buckwheat grain amaranth and quinoa for improved nutrition
Norwich UK Institute of Food Research p 49-64
Friedman M Brandon DL 2001 Nutritional and health benefits of soy proteins J Agric Food
Chem 49(3)1069-86
Garcia M Raes D Jacobsen SE 2003 Evapotranspiration analysis and irrigation requirements
of quinoa (Chenopodium quinoa) in the Bolivian highlands Agr Water Manage 60(2) 119-
34
Gee JM Price KR Ridout CL Wortley GM Hurrell RF Johnson IT 1993 Saponins of quinoa
(Chenopodium quinoa) effects of processing on their abundance in quinoa products and their
biological effects on intestinal mucosal tissue J Sci Food Agric 63(2) 201-9
Goacutemez-Caravaca AM Iafelice G Verardo V Marconi E Caboni MF 2014 Influence of
pearling process on phenolic and saponin content in quinoa (Chenopodium quinoa Willd)
Food Chem 157 174-8
Gomez-Pando L 2015 Chapter 6 Quinoa breeding In Murphy KM Matanguihan J editors
Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p
87 ndash 97
Gonzaacutelez JA Bruno M Valoy M Prado FE 2011 Genotypic variation of gas exchange
parameters and leaf stable carbon and nitrogen isotopes in ten quinoa cultivars grown under
drought J Agron Crop Sci 197(2) 81-93
30
Gonzaacutelez JA Eisa SSS Hussin SAES and Prado FE 2015 Chapter 1 Quinoa An Incan Crop
to Face Global Changes in Agriculture In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 182-6
Graf BL Rojas-Silva P Rojo LE Delatorre-Herrera J Baldeoacuten ME Raskin I 2015 Innovations
in health value and functional food development of quinoa (Chenopodium quinoa Willd)
Comp Rev Food Sci Food Safety 14(4) 431-45
Gross R Koch F Malaga I de Miranda A Schoeneberger H Trugo L 1989 Chemical
composition and protein quality of some local Andean food sources Food Chem 34(1) 25-
34
Guumllccedilin İ Mshvildadze V Gepdiremen A Elias R 2006 The antioxidant activity of a
triterpenoid glycoside isolated from the berries of Hedera colchica 3-O-(β-d-
glucopyranosyl)-hederagenin Phytother Res 20(2) 130-4
Guzmaacuten-Maldonado S Paredes-Lopez O 2002 Functional products of plants indigenous to
Latin America amaranth quinoa common beans and botanicals In Shi J Mazza G
Maguer ML editors Functional foods Biochemical and processing aspects CRC Press p
293-328
Halverson J Zeleny L 1988 Chapter 2 Criteria of wheat quality In Pomeranz Y editor
Wheat Chemistry and Technology 3rd edition St Paul MN American Association of
Cereal Chemists Inc p 25 ndash 6
31
Hariadi Y Marandon K Tian Y Jacobsen SE Shabala S 2011 Ionic and osmotic relations in
quinoa (Chenopodium quinoa Willd) plants grown at various salinity levels J Exp Bot
62(1) 185-93
Iglesias-Puig E Monedero V Haros M 2015 Bread with whole quinoa flour and bifidobacterial
phytases increases dietary mineral intake and bioavailability LWT-Food Sci Technol 60(1)
71-7
Jacobsen SE Monteros C Christiansen J Bravo L Corcuera L Mujica A 2005 Plant responses
of quinoa (Chenopodium quinoa Willd) to frost at various phenological stages Eur J Agron
22(2) 131-9
Jacobsen SE Stoslashlen O 1993 Quinoa-morphology phenology and prospects for its production as
a new crop in Europe Eur J Agron 2(1) 19-29
James LEA 2009 Quinoa (Chenopodium quinoa Willd) composition chemistry nutritional
and functional properties Adv Food Nutr Res 58 1-31
Kamelgard JI 2012 Quinoa-based beverages and method of creating quinoa-based beverages
Google Patents
Khalil A El-Adawy T 1994 Isolation identification and toxicity of saponin from different
legumes Food Chem 50(2) 197-201
Killeen GF Madigan CA Connolly CR Walsh GA Clark C Hynes MJ Power RF 1998
Antimicrobial saponins of Yucca schidigera and the implications of their in vitro properties
for their in vivo impact J Agric Food Chem 46(8) 3178-86
32
Konishi Y Hirano S Tsuboi H Wada M 2004 Distribution of minerals in quinoa
(Chenopodium quinoa Willd) seeds Biotechnol Appl Biochem 68(1) 231-4
Koyro HW Eisa SS 2008 Effect of salinity on composition viability and germination of seeds
of Chenopodium quinoa Willd Plant Soil 302(1-2) 79-90
Kozioł M1992 Chemical composition and nutritional evaluation of quinoa (Chenopodium
quinoa Willd) J Food Compost Anal 5(1) 35-68
Kuljanabhagavad T Wink M 2009 Biological activities and chemistry of saponins from
Chenopodium quinoa Willd Phytochem Rev 8(2) 473-90
Kunze OR Lan Y and Wratten FT 2004 Chapter 8 Physical and mechanical properties of rice
In Champagne ET editor Rice Chemistry and Technology 3rd edition St Paul MN
American Association of Cereal Chemists Inc p 193 ndash 211
Li G Wang S Zhu F 2016 Physicochemical properties of quinoa starch Carbohydr Polym 137
328-38
Lindeboom N Chang PR Falk KC Tyler RT 2005 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2) 216-22
Lindeboom N Chang PR Tyler RT 2004 Analytical biochemical and physicochemical aspects
of starch granule size with emphasis on small granule starches a review Starch-Staumlrke 56(3-
4) 89-99
Man S Gao W Zhang Y Huang L Liu C 2010 Chemical study and medical application of
saponins as anti-cancer agents Fitoterapia 81(7) 703-14
33
Maradini Filho AM Pirozi MR Da Silva Borges JT Pinheiro SantAna HM Paes Chaves JB
Dos Reis Coimbra JS 2015 Quinoa nutritional functional and antinutritional aspects Crit
Rev Food Sci Nutr (just-accepted)
Matanguihan JB Jellen EN and Kolano A 2015 Chapter 7 Quinoa cytogenetics molecular
genetics and diversity In Murphy KM Matanguihan J editors Quinoa Improvement and
Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 109-24
Maughan PJ Bonifacio A Jellen EN Stevens MR Coleman CE Ricks M Mason SL Jarvis
DE Gardunia BW Fairbanks DJ 2004 A genetic linkage map of quinoa (Chenopodium
quinoa) based on AFLP RAPD and SSR markers Theor Appl Genet 109(6) 1188-95
de Meo B Freeman G Marconi O Booer C Perretti G Fantozzi P 2011 Behaviour of Malted
Cereals and Pseudo-Cereals for Gluten-Free Beer Production J Inst Brew 117(4) 541-6
Ogungbenle H 2003 Nutritional evaluation and functional properties of quinoa (Chenopodium
quinoa) flour Int J Food Sci Nutr 54(2) 153-8
Ogungbenle HN 2003 Nutritional evaluation and functional properties of quinoa (Chenopodium
quinoa) flour Int J Food Sci Nutr 54(2) 153-8
Quiroga C Escalera R Aroni G Bonifacio A Gonzaacutelez JA Villca M Saravia R Ruiz A 2015
Chapter 31 Traditional processes and Technological Innovations in Quinoa Harvesting
Processing and Industrialization In D Bazile D Bertero and C Nieto editors State of the
Art Report of Quinoa in the World in 2013 Rome FAO amp CIRAD p 213 - 4
34
Pagamunici LM Gohara AK Souza AHP Bittencourt PRS Torquato AS Batiston WP
Matsushita M 2014 Using chemometric techniques to characterize gluten-free cookies
containing the whole flour of a new quinoa cultivar J Brazil Chem Soc 25 219-28
Paśko P Bartoń H Zagrodzki P Gorinstein S Fołta M Zachwieja Z 2009 Anthocyanins total
polyphenols and antioxidant activity in amaranth and quinoa seeds and sprouts during their
growth Food Chem 115(3) 994-8
Peterson AJ Murphy KM 2015a Chapter 10 Quinoa Cultivation for Temperate North America
Considerations and Areas for Investigation In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 182-6
Peterson A Murphy K 2015b Tolerance of lowland quinoa cultivars to sodium chloride and
sodium sulfate salinity Crop Sci 55(1) 331-8
Prego I Maldonado S Otegui M 1998 Seed structure and localization of reserves in
Chenopodium quinoa Ann Bot 82(4) 481-8
Ranhotra GS Gelroth JA Glaser BK Lorenz KJ Johnson DL 1993 Composition and protein
nutritional quality of quinoa Cereal Chem 70(3)303-5
Razavi SMA Farahmandfar R 2008 Effect of hulling and milling on the physical properties of
rice grains Int Agrophys 22(4) 353-9
Reichert R Tatarynovich J Tyler R 1986 Abrasive dehulling of quinoa (Chenopodium quinoa)
effect on saponin content as determined by an adapted hemolytic assay Cereal Chem 63(6)
471-5
35
Repo-Carrasco-Valencia RAM Serna LA 2011 Quinoa (Chenopodium quinoa Willd) as a
source of dietary fiber and other functional components Food Sci Technol (Campinas) 31
225-30
Repo-Carrasco R Espinoza C Jacobsen SE 2003 Nutritional value and use of the Andean crops
quinoa (Chenopodium quinoa) and kantildeiwa (Chenopodium pallidicaule) Food Rev Int 19(1-
2) 179-89
Ridout CL Price KR Dupont MS Parker ML Fenwick GR 1991 Quinoa saponinsmdashanalysis
and preliminary investigations into the effects of reduction by processing J Sci Food Agric
54(2) 165-76
Rizzello CG Lorusso A Montemurro M Gobbetti M 2016 Use of sourdough made with
quinoa (Chenopodium quinoa) flour and autochthonous selected lactic acid bacteria for
enhancing the nutritional textural and sensory features of white bread Food Microbiol 56 1-
13
Rojas W 2011 Quinoa an ancient crop to contribute to world food security Santiago Chile
FAO Oficina Regional para America Latina y el Caribe
Rojas W Pinto M Alanoca C Goacutemez-Pando L Leoacuten-Lobos P Alercia A Diulgheroff S
Padulosi S Bazile D 2013 Estado de la conservacioacuten ex situ de los recursos geneacuteticos de
quinua In Didier B Daniel BH Carlos N editors Estado del arte de la quinua en el mundo
en Libro de resuacutemenes Santiago FAO p 20-21
36
Rojas W Pinto M 2015 Chapter 8 Ex situ conservation of quinoa the bolivian experience In
Murphy KM Matanguihan J editors Quinoa Improvement and Sustainable Production
Hoboken NJ John Wiley amp Sons Inc p 128-30
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile D
Bertero D Nieto C editors State of the Art Report of Quinoa in the World in 2013 Rome
FAO amp CIRAD p 67
Ruales J Nair BM 1992 Nutritional quality of the protein in quinoa (Chenopodium quinoa
Willd) seeds Plant Foods Hum Nutr 42(1) 1-11
Ruales J Nair BM 1993 Saponins phytic acid tannins and protease inhibitors in quinoa
(Chenopodium quinoa Willd) seeds Food Chem 48(2)137-43
Ruales J Valencia S Nair B 1993 Effect of processing on the physico-chemical characteristics
of quinoa flour (Chenopodium quinoa Willd) Starch - Staumlrke 45(1)13-9
Ruales J Grijalva YD Lopez-Jaramillo P Nair BM 2002 The nutritional quality of an infant
food from quinoa and its effect on the plasma level of insulin-like growth factor-1 (IGF-1) in
undernourished children Int J Food Sci Nutr 53(2) 143-54
Sanchez HB Lemeur R Damme PV Jacobsen SE 2003 Ecophysiological analysis of drought
and salinity stress of quinoa (Chenopodium quinoa Willd) Food Rev Int 19(1-2) 111-9
Scanlin LA Burnett C (2010) Quinoa grain processing and products Google Patents
37
Schoenlechner R Drausinger J Ottenschlaeger V Jurackova K Berghofer E 2010 Functional
Properties of Gluten-Free Pasta Produced from Amaranth Quinoa and Buckwheat Plant
Foods Hum Nutr 65(4) 339-49
Schumacher AB Brandelli A Macedo FC Pieta L Klug TV de Jong EV 2010 Chemical and
sensory evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J
Food Sci Technol 47(2) 202-6
Shao Y Chin CK Ho CT Ma W Garrison SA Huang MT 1996 Anti-tumor activity of the
crude saponins obtained from asparagus Cancer Lett 104(1) 31-6
Simnadis TG Tapsell LC Beck EJ 2015 Physiological Effects Associated with Quinoa
Consumption and Implications for Research Involving Humans a Review Plant Foods Hum
Nutr 70(3) 238-49
Steffolani ME Villacorta P Morales-Soriano E Repo-Carrasco R Leoacuten AE Perez GT 2015
Physico-chemical and functional characterization of protein isolated from different quinoa
varieties (Chenopodium quinoa Willd) Cereal Chem (Accepted for publication)
Stevens MR Coleman CE Parkinson SE Maughan PJ Zhang HB Balzotti MR Kooyman DL
Arumuganathan K Bonifacio A Fairbanks DJ Jellen EN Stevens JJ 2006 Construction of
a quinoa (Chenopodium quinoa Willd) BAC library and its use in identifying genes
encoding seed storage proteins Theor Appl Genet 112(8) 1593-600
Stikic R Glamoclija D Demin M Vucelic-Radovic B Jovanovic Z Milojkovic-Opsenica D
Jacobsen SE Milovanovic M 2012 Agronomical and nutritional evaluation of quinoa seeds
38
(Chenopodium quinoa Willd) as an ingredient in bread formulations J Cereal Sci 55(2)
132-8
Sun HX Xie Y Ye YP 2009 Advances in saponin-based adjuvants Vaccine 27(12) 1787-96
Świeca M Sęczyk Ł Gawlik-Dziki U Dziki D 2014 Bread enriched with quinoa leaves - The
influence of protein-phenolics interactions on the nutritional and antioxidant quality Food
Chem 162 54-62
Tang Y Li X Zhang B Chen PX Liu R Tsao R 2015 Characterisation of phenolics betanins
and antioxidant activities in seeds of three Chenopodium quinoa Willd genotypes Food
Chem 166 380-8
Taormina PJ Simpson PG Bertera EA Komitopoulou E 2006 Beverage preservatives Google
Patents
Tapia M Mujica A Canahua A 1980 Origen y distribucion geografica y sistemas de
produccion de la quinua (Chenopodium quinoa Wild) Publicacion Universidad Nacional
Tecnica del Altiplano
Taverna LG Leonel M Mischan MM 2012 Changes in physical properties of extruded sour
cassava starch and quinoa flour blend snacks Food Sci Technol (Campinas) 32 826-34
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Taylor JRN Parker ML editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science amp Business Media p 96-9
39
Thompson R Isaacs G 1967 Porosity determinations of grains and seeds with an air-
comparison pycnometer T ASAE 10(5) 693-6
Vega-Gaacutelvez A Miranda M Vergara J Uribe E Puente L Martiacutenez EA 2010 Nutrition facts
and functional potential of quinoa (Chenopodium quinoa willd) an ancient Andean grain a
review J Sci Food Agric 90(15) 2541-7
USDA US Department of Agriculture Agricultrual Research Service 2015 USDA national
nutrient database for standard reference Release 18 Nutrient Data Laboratory Home Page
Available from httpwwwarsusdagovServicesdocshtmdocid=8964
Vilche C Gely M Santalla E 2003 Physical Properties of Quinoa Seeds Biosyst Eng 86(1) 59-
65
Wu G Morris CF Murphy KM 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79(11) 2337-45
Wu G Chapter 11 Nutritional properties of quinoa In Murphy KM Matanguihan J editors
Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc
p193 ndash 205
Yang CH Huang YC Chen YF Chang MH 2010 Foam properties detergent abilities and long-
term preservative efficacy of the saponins from J Food Drug Anal 18(3) 4417-25
Yao Y Yang X Shi Z Ren G 2014 Anti-inflammatory activity of saponins from quinoa
(Chenopodium quinoa Willd) Seeds in lipopolysaccharide-stimulated raw 2647
Macrophages Cells J Food Sci 79(5) 1018-23
40
Zhou Z Robards K Helliwell S Blanchard C 2003 Effect of rice storage on pasting properties
of rice flour Food Res Int 36(6) 625-34
41
Table 1-Essential amino acid of quinoa protein and FAOWHO suggested requirement (mgg protein)
Essential amino acid Quinoa protein a FAOWHO suggested requirement b
Histidine 258 18
Isoleucine 433 25
Leucine 736 55
Lysine 525 51
Methionine amp Cysteine 273 25
Phenylalanine amp Tyrosine 803 47
Threonine 439 27
Tryptophan 385 7
Valine 506 32
a) Abugoch et al (2008) b) Friedman and Brandon (2001)
42
Table 2-Quinoa vitamins content (mg100g)
Quinoa a-d Reference Daily Intake
Thianmin (B1) 029-038 15
Riboflavin (B2) 030-039 17
Niacin (B3) 106-152 20
Pyridoxine (B6) 0487 20
Folate (B9) 0781 04
Ascorbic acid (C) 40 60
α-Tocopherol (VE) (IU) 537 30
Β-Carotene 039 NR
a (Koziol 1992) b (Ruales and Nair 1993) c (Ranhotra et al 1993) d (USDA 2015)
43
Table 3-Quinoa minerals content (mgmg )
Whole graina RDI b
K 8257 NR
Mg 4526 400
Ca 1213 1000
P 3595 1000
Fe 95 18
Mn 37 NR
Cu 07 2
Zn 08 15
Na 13 NR
(aAndo et al 2002 bUSDA 2015)
44
Figure 1-Quinoa seed section and two-layered pericarp under perianth (Wu et al 2014)
45
Figure 2-Quinoa seed structure (Prego et al 1998)
(PE pericarp SC seed coat C cotyledons SA shoot apex H hypocotylradicle axis R radicle F funicle EN endosperm P perisperm Bar = 500 μm)
46
Chapter 3 Evaluation of Texture Differences among Varieties of
Cooked Quinoa
Published manuscript
Wu G Morris C F amp Murphy K M (2014) Evaluation of texture differences among
varieties of cooked quinoa Journal of Food Science 79(11) S2337-S2345
ABSTRACT
Texture is one of the most significant factors for consumersrsquo experience of foods Texture
differences of cooked quinoa were studied among thirteen different varieties Correlations
between the texture parameters and seed composition seed characteristics cooking quality flour
pasting properties and flour thermal properties were determined The results showed that texture
of cooked quinoa was significantly differed among varieties lsquoBlackrsquo lsquoCahuilrsquo and lsquoRed
Commercialrsquo yielded harder texture while lsquo49ALCrsquo lsquo1ESPrsquo and lsquoCol6197rsquo showed softer
texture lsquo49ALCrsquo lsquo1ESPrsquo lsquoCol6197rsquo and lsquoQQ63rsquo were more adhesive while other varieties
were not sticky The texture profile correlated to physical-chemical properties in different ways
Protein content was positively correlated with all the texture profile analysis (TPA) parameters
Seed hardness was positively correlated with TPA hardness gumminess and chewiness at P le
009 Seed density was negatively correlated with TPA hardness cohesiveness gumminess and
chewiness whereas seed coat proportion was positively correlated with these TPA parameters
Increased cooking time of quinoa was correlated with increased hardness cohesiveness
gumminess and chewiness The water uptake ratio was inversely related to TPA hardness
47
gumminess and chewiness RVA peak viscosity was negatively correlated with the hardness
gumminess and chewiness (P lt 007) breakdown was also negatively correlated with those TPA
parameters (P lt 009) final viscosity and setback were negatively correlated with the hardness
cohesiveness gumminess and chewiness (P lt 005) setback was correlated with the
adhesiveness as well (r = -063 P = 002) Onset gelatinization temperature (To) was
significantly positively correlated with all the texture profile parameters and peak temperature
(Tp) was moderately correlated with cohesiveness whereas neither conclusion temperature (Tc)
nor enthalpy correlated with the texture of cooked quinoa This study provided information for
the breeders and food industry to select quinoa with specific properties for difference use
purposes
Keywords cooked quinoa variety texture profile analysis (TPA) RVA DSC
Practical Application The research described in this paper indicates that the texture of different
quinoa varieties varies significantly The results can be used by quinoa breeders and food
processors
48
Introduction
Quinoa (Chenopodium quinoa Willd) a pseudocereal (Lindeboom et al 2007) is known as
a complete food due to its high nutritional value (Jancurovaacute et al 2009) Protein content of dry
quinoa grain ranges from 8 to 22 (Jancurovaacute et al 2009) Quinoa protein is high in nutritive
quality with an excellent balance of essential amino acids (Abugoch et al 2008) Quinoa is also a
gluten-free crop (Alvarez-Jubete et al 2010) Quinoa consumption in the US and Europe has
increased dramatically over the past decade but these regions rely on imports primarily from
Bolivia and Peru (Food and Agriculture Organization of the United Nations FAO 2013) For
these reasons greater knowledge of quinoa grain quality is needed
Quinoa is traditionally cooked as a whole grain similar to rice or milled into flour and made
into pasta and breads (Food and Agriculture Organization of the United Nations FAO 2013)
Quinoa can also be processed by extrusion drum-drying and autoclaving (Ruales et al 1993)
Commercial quinoa products include pasta bread cookies muffins cereal snacks drinks
flakes baby food and diet supplements (Ruales et al 2002 Del Castillo et al 2009 Cortez et al
2009 Demirkesen et al 2010 Schumacher et al 2010)
Texture is one of most significant properties of food that affects the consuming experience
Food texture refers to those qualities of a food that can be felt with the fingers tongue palate or
teeth (Vaclavik and Christian 2003) Cooked quinoa has a unique texture described as creamy
smooth and slightly crunchy (Abugoch 2009) Texture can be influenced by the seed structure
composition cooking quality and thermal properties However we know of no report which
documents the texture of cooked quinoa and the factors that affect it
49
Quinoa has small seeds compared to most cereals and seed size may affect the texture of
cooked quinoa Seed characteristics and structure are the significant factors potentially affecting
the textural properties of processed food Rousset et al (1995) indicated that the length and
lengthwidth ratio of rice kernels was associated with a wide range of texture attributes including
crunchy brittle elastic juicy pasty sticky and mealy which were determined by a sensory
panel The correlation between quinoa seed characteristics and cooked quinoa texture has not
been studied
Quinoa is consumed as whole grain without removing the bran unlike most rice and wheat
The insoluble fiber and non-starch polysaccharides in the seed coat can affect mouth feel and
texture Hence seed coat proportion may contribute to the texture of cooked quinoa Mohapatra
and Bal (2006) reported that the milling degree of rice positively influenced cohesiveness and
adhesiveness of cooked rice but was negatively correlated to hardness
Quinoa seed qualities such as the size hardness weight density and seed coat proportion
may influence the water binding capacity of seed during thermal processing thereby affecting
the texture of the cooked cereal (Fitzgerald et al 2003) Nevertheless correlations between seed
characteristics and texture of cooked quinoa have not been previously described
Seed composition may influence texture as well Higher protein content was reported to
cause reduced stickiness and harder texture of cooked rice (Ramesh et al 2000) Quinoa seeds
contain approximately 60 starch (Ando et al 2002) Starch granules are particularly small (05
- 3μm) Amylose content of quinoa is as low as 11 (Ahamed et al 1996) while the amylose
proportion in most cereals such as wheat is around 25 (Zeng et al 1997 BeMiller and Huber
50
2008) Amylose content of starch correlated positively with the hardness of cooked rice and
cooked white salted noodles (Ong and Blanshard 1995 Epstein et al 2002 Baik and Lee 2003)
Flour pasting properties can greatly influence the texture of cooked products Their
correlation has not been illustrated in quinoa while some research have been conducted on
cooked rice A lower peak viscosity and positive setback are associated with a harder texture
while a higher peak viscosity breakdown and lower setback are associated with a sticky texture
in cooked rice (Limpisut and Jindal 2002) Champagne et al (1999) indicated that adhesiveness
had strong correlations with Rapid Visco Analyzer (RVA) measurements Ramesh et al (2000)
reported that harder cooked rice texture was associated with a lower peak viscosity and positive
setback while sticky rice had a higher peak viscosity higher breakdown and lower setback
The gelatinization temperature of quinoa starch ranges from 54ordmC to 71ordmC (Ando et al
2002) lower than that of rice barley and wheat starches (Marshall 1994 Tang 2004 Tang et al
2005) Gelatinization temperature likely plays an important role in waxy rice quality (Perdon and
Juliano 1975 Juliano et al 1987) but was not correlated to the eating quality of normal rice
(Ramesh et al 2000) Despite a considerable amount of work having been conducted on the
thermal properties of cereal starch little is known about the relationship between quinoa flour
thermal properties and cooked quinoa texture
The correlation of quinoa cooking quality and texture has not been previously reported In
rice cooking quality exhibited strong correlations to the texture profile analysis (TPA) Cooking
time has been reported to correlate positively with hardness and negatively with adhesiveness of
cooked rice (Mohapatra and Bal 2006) Higher water uptake ratio and volume expansion ratio
were associated with softer more adhesive and more cohesive texture of cooked rice
51
(Mohapatra and Bal 2006) Cooking loss has been reported to improve firmness but decrease
juiciness (Rousset et al 1995)
There is a need to further study the texture of cooked quinoa and its determining factors
The objective of this paper is to study the texture difference among varieties of cooked quinoa
and evaluate the correlation between the texture and the seed characters and composition
cooking process flour pasting properties and thermal properties
Materials and Methods
Seed characteristics
Eleven varieties and two commercial lots of quinoa are listed in Table 1 The two grain
lots were referred as lsquoYellow Commercialrsquo and lsquoRed Commercialrsquo according to the seed color
Seed size (diameter) was determined by lining up and measuring the length of 20 seeds Average
seed diameter was calculated from three repeated measurements Bulk density of seed was
measured by the weightvolume method Seed weight was determined gravimetrically Seed
hardness was determined using the texture analyzer TAndashXT2i (Texture Technology Corp
Scarsdale NY USA) A cylinder of 10 mm in diameter compressed one seed to 90 strain at
the rate of 5 mms The force (kg) was recorded as the seed hardness Seed coat proportions were
determined by a Scanning Electron Microscope (SEM) FEI Quanta 200F (FEI Corp Hillsboro
OR USA) The seed was cross-sectioned and the SEM image was captured under 800times
magnification The seed coat proportions were measured using the software ruler in micrometers
Chemical compositions
Whole quinoa flour was prepared using a cyclone sample mill (UDY Corporation Fort
Collins CO USA) equipped with a 05 mm screen and was used for compositional analysis
52
pasting viscosity and thermal properties Ash and moisture content of quinoa flour were tested
according to the Approved Method 08-0101 and 44-1502 respectively (AACCI 2012) Protein
content was determined by a nitrogen analyzer coupled with a thermo-conductivity detector
(LECO Corporation Joseph MI USA) The factor of 625 was used to calculate the protein
content from the nitrogen content (Approved Method 46-3001 AACCI 2012) Protein and ash
were calculated on a dry weight basis
Cooking protocol
The cooking protocol of quinoa was modified from a rice cooking method (Champagne
et al 1998) Five grams of quinoa seed were soaked for 20 min in 10 mL deionized water in a
flask Soaking is required to remove the bitter saponins (Pappier et al 2008) and enhance
cooking quality (Mohapatra and Bal 2006) The mixture was then boiled for 2 min and the flask
was set in boiling water for 18 min The flask was covered to prevent water loss
Cooking quality
Two grams of quinoa seed were cooked in 20 mL deionized water for 20 min and extra
water was removed Cooking time was determined when the middle white part of the seed
completely disappeared (Mohapatra and Bal 2006) The water uptake ratio was calculated from
the seed weight ratio before and after cooking Cooking volume was the seed volume after
cooking Cooking loss was the total of soluble and insoluble matter in the cooking water
(Rousset et al 1995) Three mL of cooking water of each sample was placed on an aluminum
pan and dried at 130 ordmC overnight The weight of dry solids in the pan was used to calculate the
cooking loss
Texture profile analysis (TPA)
53
Texture profile analysis (TPA) was used to determine the texture of cooked quinoa
according to a modified method for cooked rice texture (Champagne et al 1999) Two grams of
cooked quinoa were arranged on the texture analyzer platform as close to one layer as possible
A stainless steel plate (50 mm times 40 mm times 10 mm) compressed the cooked quinoa from 5 mm to
01 mm at 5 mmsec The compression was conducted twice The texture analyzer generated a
graph with time as the x-axis and force as the y-axis Six parameters were calculated from the
graph (Epstein et al 2002) Hardness is the height of the first peak adhesiveness is the area 3
cohesiveness is area 2 divided by area 1 springiness is distance 1 divided by distance 2
gumminess is hardness multiplied by cohesiveness chewiness is gumminess multiplied by
springiness In the present study no significant differences or correlations were obtained for
springiness As such this parameter will not be included except to describe the overall result (see
below)
Flour viscosity
Quinoa flour pasting viscosity was determined using the Rapid Visco Analyzer (RVA)
RVA-4 (Newport Scientific Pty Ltd Narrabeen Australia) Quinoa flour (43 g) was added to
25 mL deionized water in an aluminum cylinder container The contents were immediately
mixed and heated following the instrument program The temperature was increased from 50 ordmC
to 93 ordmC in 8 min at a constant rate was held at 95 ordmC from 8 to 24 min cooled to 50 ordmC from 24
to 28 min and held at 50 ordmC from 29 to 40 min The program generated a graph with time against
shear force (Figure 1) expressed in RVU (cP = RVU times 12)
Two peaks representing peak viscosity and final viscosity are normally included in the
RVA graph Peak time was the time to reach the first peak Holding strength or trough is the
54
minimum viscosity after the first peak Breakdown is the viscosity difference between peak and
minimum viscosity Setback is the viscosity difference between final and minimum viscosity
Pasting temperature and the time to reach the peak were also recorded
Thermal properties using Differential Scanning Calorimetry (DSC)
Thermal properties of quinoa flour were determined by Differential Scanning
Calorimetry (DSC) Tzero Q2000 (TA instruments New Castle DE USA) The protocol was a
modification of the method of Abugoch et al (2009) Quinoa flour (02 g) was added to 200 μL
deionized water and mixed on a vortex mixer for 10 s to form a slurry Ten to twelve milligrams
of slurry was added to an aluminum pan by pipette The pan was sealed and placed at the center
of DSC platform An empty pan was used as reference The temperature was increased from 25
ordmC to 120 ordmC at 10 ordmCmin then equilibrated to 25 ordmC Gelatinization temperature and enthalpy
were determined from the graph
Statistical analysis
All experiments were repeated three times The hypothesis tests of normality and equal
variance multiple comparisons (Fisherrsquos LSD) and correlation studies were conducted by SAS
92 (SAS Institute Cary NC) A P-value of 005 is considered as the level of statistical
significance unless otherwise specified
Results
Seed characteristics and flour composition
Quinoa seed characteristics and composition are shown in Table 2 Quinoa seeds were
small compared to cereals such as rice wheat and maize Diameters of quinoa seed mostly
ranged between 19 to 22 mm except for lsquoJapanese Strainrsquo which was significantly smaller (15
55
mm) Seed hardness was significantly different among varieties ranging from 583 k g in
lsquoCol6197rsquo to 1096 kg in lsquoOro de Vallersquo Bulk seed density of quinoa varied from 063 kgL in
lsquoBlancarsquo to 081 kgL in lsquoJapanese Strainrsquo Varieties from White Mountain farm and the WSU
Organic Farm were lower in bulk density most of which were below 07 kgL The commercial
and Port Townsend samples were higher in density most of which were around 075 kgL
Thousand-seed weights of quinoa were particularly low ranging from 18 g in lsquoJapanese Strainrsquo
to 41g in lsquoRed Commercialrsquo Seed coat proportion was also significantly different among
varieties Three layers are shown in the seed coat (Figure 2) The varieties lsquoBlackrsquo and lsquoBlancarsquo
had the thickest seed coat (38 and 97 μm respectively) with coat proportions of 40 and 45
respectively lsquoYellow Commercialrsquo and lsquo1ESPrsquo had the thinnest seed coats (15 and 16 μm
respectively) with the coat proportion of 07 and 05 respectively The difference was
almost ten-fold among the varieties
Protein and ash content of quinoa flour
Protein content varied from 113 in lsquo1ESPrsquo to 170 in lsquoCahuilrsquo lsquoCherry Vanillarsquo and
lsquoOro de Vallersquo also had high protein contents of 160 and 156 respectively Ash content
ranged from 12 in the Commercial Yellow seed to 40 in lsquoQQ63rsquo comparable to that in rice
flour (Champagne 2004)
Texture of cooked quinoa
The hardness of cooked quinoa ranged from 20 g for lsquo49ALCrsquo and lsquoCol6197rsquo to 347
kg for lsquoBlackrsquo (Table 3) lsquoOro de Vallersquo and lsquoBlancarsquo were relatively hard varieties with TPA
hardness of 285 kg and 306 kg respectively whereas lsquo1ESPrsquo lsquoJapanese Strainrsquo and lsquoQQ63rsquo
were softer with a hardness of 245 kg 293 kg and 297 kg respectively
56
Adhesiveness is the extent to which seeds stick to each other the probe and the stage
lsquo49ALCrsquo lsquo1ESPrsquo lsquoCol6197rsquo and lsquoQQ63rsquo were significantly stickier with adhesiveness value
of -029 kgs -027 kgs -023 kgs and -020 kgs respectively All other varieties exhibited
lower adhesiveness with values less than 010 kgs Visual examination of the cooked samples
showed that with the more adhesive varieties the seeds stuck together as with sticky rice while
for other varieties the grains were separated
Cohesiveness of cooked lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo was
significantly higher with values from 068 to 071 respectively while those of lsquo49ALCrsquo lsquo1ESPrsquo
and lsquoCol6197rsquo were lower at 054 056 and 053 respectively Springiness is the recovery
from crushing or the elastic recovery (Tsuji 1981 Seguchi et al 1998) Cooked quinoa of all
varieties exhibited excellent elastic recovery properties with springiness values approximating
10
Gumminess is the combination of hardness and cohesiveness Chewiness is gumminess
multiplied by springiness As springiness values were all close to 10 gumminess and chewiness
of cooked quinoa were very similar in value lsquoBlackrsquo lsquoBlancarsquo and lsquoCahuilrsquo were highest in
gumminess and chewiness 24 kg 22 kg and 23 kg respectively while lsquo1ESPrsquo lsquo49ALCrsquo and
lsquoCol6197rsquo were lowest at 14 kg 11 kg and 11 kg respectively The difference among varieties
was greater than three-fold
Cooking quality
Cooking quality of quinoa is shown in Table 4 Cooking time varied from 119 min in
lsquoCol6197rsquo to 192 min in lsquoBlackrsquo cultivar and was significantly correlated with all TPA texture
parameters Longer cooking time also correlated with higher protein content (r = 052 P = 007)
57
Water uptake ratio varied from 25 to 4 fold in lsquoQQ63rsquo and lsquoCol6197rsquo respectively Water
uptake ratio was negatively correlated to seed hardness (r = 052 P = 004) Harder seeds tended
to absorb less water during cooking Cooking volume ranged from 107 mL to 137 mL and did
not significantly correlate with other properties Cooking loss ranged from 035 to 176 and
differed among varieties but was not correlated with water uptake ratio cooking time or cooking
volume
Quinoa flour pasting properties by RVA
Pasting viscosity of quinoa whole seed flour was determined using the Rapid Visco
Analyzer (RVA) The results are shown in Table 5 Peak viscosity differed among varieties
Varieties could be categorized into three groups based on peak viscosity The peak viscosity of
lsquoQQ63rsquo lsquoCol6197rsquo lsquo1ESPrsquo lsquoJapanese Strainrsquo lsquoYellow Commercialrsquo lsquoCopacabanarsquo and lsquoRed
Commercialrsquo varied from 144 to 197 RVU The peak viscosity of lsquoBlancarsquo lsquoBlackrsquo lsquo49ALCrsquo
and lsquoCahuilrsquo ranged from 98 to 116 RVU while those of lsquoOro de Vallersquo and lsquoCherry Vanillarsquo
were 59 and 66 RVU respectively
Trough viscosity namely the minimum viscosity after the first peak showed more than a
three-fold difference among varieties As in the case of peak viscosity the trough of different
varieties can be categorized into the same three groups
Breakdown is the difference between the peak and minimum viscosity lsquoQQ63rsquo lsquo1ESPrsquo
and lsquoJapanese Strainrsquo showed large breakdowns of 51 51 and 62 RVU respectively
Breakdown of lsquoCherry Vanillarsquo lsquoOro de Vallersquo and the Commercial Yellow seed were lower at
12 10 and 11 RVU respectively Breakdown of the other varieties ranged from 18 to 36 RVU
58
The final viscosity of the Commercial Yellow seed was 203 RVU the highest among all
varieties Final viscosity of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo
ranged from 56 to 82 RVU and was lower than that of other varieties which ranged from 106 to
190 RVU
Setback is the difference between final and trough viscosity Setback of lsquoRed
Commercialrsquo lsquoCahuilrsquo and lsquoBlackrsquo were all negative -62 -11 and -6 RVU respectively which
indicated that the final viscosity of these cultivars was lower than their trough viscosity Setback
of lsquoBlancarsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo were slightly positive at 2 2 and 6 RVU
respectively while those of other cultivars were much greater between 42 and 73 RVU Peak
time which is the time to reach the first peak ranged from 93 to 115 min The pasting
temperature was 93 ordmC and not different among the varieties
Thermal properties of quinoa flour using DSC
Thermal properties of quinoa flour were determined using DSC Gelatinization
temperatures (To onset temperature Tp peak temperature Tc conclusion temperature) and
gelatinization enthalpies are shown in Table 6 To of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry
Vanillarsquo and lsquoJapanese Strainrsquo were not different from each other and ranged from 645 ordmC to
659 ordmC To of lsquoOro de Vallersquo lsquoCopacabanarsquo lsquoCol6197rsquo and lsquoQQ63rsquo ranged from 605 ordmC to
631 ordmC while other varieties were lower and ranged from 544 ordmC to 589 ordmC Tp ranged from
675 ordmC in the Commercial Yellow seed to 752 ordmC in lsquoCahuilrsquo Tc ranged from 780 ordmC in lsquoRed
Commercialrsquo to 850ordmC in the lsquoJapanese Strainrsquo Enthalpy of quinoa flour differed among
varieties The range was from 11 Jg in lsquoYellow Commercialrsquo to 18 Jg in lsquoBlancarsquo
Correlations between physical-chemical properties and cooked quinoa texture
59
A summary of correlation coefficients between quinoa physical-chemical properties and
TPA texture profile parameters of cooked quinoa are shown in Table 7 Seed hardness was found
to be positively related to the TPA hardness gumminess and chewiness of cooked quinoa (P lt
009) Seed bulk density was negatively correlated to hardness cohesiveness gumminess and
chewiness while seed coat proportion was positively correlated to those parameters Protein
content of quinoa exhibited a positive relationship with TPA hardness (P = 008) and
adhesiveness cohesiveness gumminess and chewiness No significant correlation was observed
between the seed size 1000 seed weight ash content and the texture properties of cooked
quinoa
Cooking time of quinoa was highly positively correlated with all of the TPA texture
profile parameters Water uptake ratio during cooking was found to be significantly associated
with hardness gumminess and chewiness of cooked quinoa while cooking volume also showed
a modest correlation to hardness (r = -047 P = 010) Cooking loss was not correlated with any
texture parameter
Flour pasting viscosity was significantly correlated with texture of cooked quinoa Peak
viscosity and breakdown exhibited negative correlations with the hardness gumminess and
chewiness of cooked quinoa (P lt 010) Breakdown was also negatively associated with the
cohesiveness (r = -051 P lt 010) Final viscosity and setback were found to be negatively
correlated to hardness cohesiveness gumminess and chewiness while setback also exhibited a
significant correlation to adhesiveness (r = -064 P = 002)
60
Considering thermal properties To exhibited strong positive correlations with all texture
parameters Tp was found to be moderately related to cohesiveness (r = 050 P = 008) Neither
Tc nor enthalpy was significantly correlated to the TPA parameters of cooked quinoa
Discussion
Seed characteristics
Harder seed yielded harder gummier and chewier TPA texture after cooking The
varieties with lower seed bulk density or thicker seed coat yielded a firmer more cohesive
gummier and chewier texture Likely the condensed cells and non-starch polysaccharides of the
seed coat are a barrier between starch granules in the middle perisperm and water molecules
outside the seed
Seed composition
Higher protein appeared to contribute to a firmer more adhesive gummier and chewier
texture of cooked quinoa as evidenced by the TPA parameters Protein has been reported to play
a significant role in the texture of cooked rice and noodles (Ramesh et al 2000 Martin and
Fitzgerald 2002 Saleh and Meullenet 2007 Xie et al 2008 Hou et al 2013) According to the
previous studies proteins affect the food texture through three major routes (1) binding of water
(Saleh and Meullenet 2007) (2) interacting reversibly with starch bodies (Chrastil 1993) and (3)
forming networks via disulphide bonds which restrict starch granule swelling and water
hydration (Saleh and Meullenet 2007)
Cooking quality
Cooking time was found to be a key factor for cooked quinoa texture as it was closely
associated with most texture attributes Other cooking qualities such as the water uptake ratio
61
cooking volume and cooking loss were not significantly correlated to texture In the study of
rice the cooking time of rice positively correlated with hardness negatively with cohesiveness
and not significantly with adhesiveness (Mohapatra and Bal 2006) The higher water uptake ratio
and volume expansion ratio were negatively associated with softer more adhesive and more
cohesive texture This result agrees with the study on cooked rice Rousset et al (1995) study
indicated that longer cooking time greater water uptake and cooking loss related to the softer
less crunchy and more pasty texture
Flour pasting properties
The varieties with a higher peak viscosity in flour had a softer less gummy and less
chewy texture after cooking The cultivars with higher final peak viscosity yielded a softer less
cohesive less gummy and chewy texture The varieties with a greater breakdown such as
lsquoQQ63rsquo lsquo1ESPrsquo and lsquoJapanese Strainrsquo were softer in TPA parameter Breakdown has been
reported to negatively correlate with the proportion of long chain amylopectin (Han and
Hamaker 2001) Long chain amylopectin may form intra- or inter-molecular interactions with
protein and lipids and result in a firmer or harder texture (Ong and Blanshard 1995)
Quinoa varieties with a lower setback were harder after cooking compared to those with a
higher setback In rice conversely setback was positively correlated with amylose content
(Varavinit et al 2003) which would positively influence the hardness of cooked rice (Ong and
Blanshard 1995 Champagne et al 1999) Unlike rice and many other cereals where the amylose
content is approximately 25-29 the amylose proportion in quinoa starch is lower on the order
of 11 (Ahamed et al 1996) Amylose may play a different role in cooked quinoa hardness
compared to other cereals
62
Starch viscosity has been reported to significantly affect the texture of cooked rice
Champagne et al (1999) used the RVA measurements to predict TPA of cooked rice and found
that adhesiveness strongly correlated to RVA parameters Harder rice was correlated with lower
peak viscosity and positive setback while stickier rice had a higher peak viscosity breakdown
and lower setback (Ramesh et al 2000) The difference between quinoa and rice seed structure
and starch composition and the difference of texture determining methods may contribute to the
different trends in correlation
Thermal properties
The gelatinization temperature of quinoa flour ranged from 55 ordmC to 85 ordmC lower than
that of whole rice flour which was 70 ordmC to 103 ordmC (Marshall 1994) This result agrees with the
previous study on quinoa flour (Ando et al 2002) The quinoa varieties with higher To exhibited
a firmer more adhesive more cohesive gummier and chewier texture Higher Tp was associated
with increased cohesiveness The enthalpy of quinoa flour ranged from 11 to 18 Jg about one-
tenth that of whole rice flour (141 ndash 151 Jg) (Marshall 1994) indicating that it takes less
energy to cook quinoa than cook rice
Thermal properties of quinoa flour were generally correlated with flour pasting
properties Higher To and Tp were correlated with lower flour peak viscosity and lower trough
The result is comparable to the previous study of Sandhu and Singh (2007) who found that
gelatinization temperature and enthalpy of corn starch strongly influenced the peak breakdown
final and setback viscosity The thermal properties of quinoa flour were not correlated with
breakdown and setback likely was due to other composition factors in the flour such as protein
and fiber
63
Conclusions
The texture of cooked quinoa varied markedly among the different varieties indicating
that genetics management or geographic origin may all be important considerations for quinoa
quality As such differences in seed morphology and chemical composition appear to contribute
to quinoa processing parameters and cooked texture Harder seed yielded a firmer gummier and
chewier texture both lower seed density and high seed coat proportion related to a firmer more
cohesive gummier and chewier texture Seed size and weight appeared to be largely unrelated to
the texture of the cooked quinoa Protein content was a key factor apparently influencing texture
Higher protein content was related to harder more adhesive and cohesive gummier and chewier
texture Cooking time and water uptake ratio significantly affected the texture of cooked quinoa
whereas cooking volume moderately affected the hardness cooking loss was not correlated with
texture RVA peak viscosity was negatively correlated with the hardness gumminess and
chewiness breakdown was also negatively correlated with those TPA parameters Final viscosity
and setback were negatively correlated with the hardness cohesiveness gumminess and
chewiness Setback was correlated with the adhesiveness as well Gelatinization temperature To
affected all the texture profile parameters positively Tp slightly related to the cohesiveness
while Tc and enthalpy were not correlated with the texture
Acknowledgements
This project was supported by funding from the USDA Organic Research and Extension
Initiative project number NIFA GRANT11083982 The authors acknowledge Stacey Sykes and
Alecia Kiszonas for editing support
Author Contributions
64
G Wu and CF Morris designed the study together G Wu collected test data and drafted the
manuscript CF Morris and KM Murphy edited the manuscript KM Murphy provided
samples and project oversight
65
References
AACC International 2012 Approved Methods of Analysis Method 08-0101 Ash - Basic
method Approved April 13 1961 Method 44-1502 Moisture ndash Air-Oven Methods (130ordmC)
Approved October 30 1975 Method 46-3001 Crude protein ndash Combustion method
Approved November 8 1995 Reapproved November 3 1999 Available online only
AACCI St Paul MN
Abugoch LE Romero N Tapia CA Silva J Rivera M 2008 Study of some physicochemical
and functional properties of quinoa (Chenopodium quinoa Willd) protein isolates J Agric
Food Chem 564745-50
Abugoch LEJ 2009 Chapter 1 Quinoa (Chenopodium quinoa Willd) Adv Food Nutr Res
581-31
Abugoch L Castro E Tapia C Antildeoacuten MC Gajardo P Villarroel A 2009 Stability of quinoa
flour proteins (Chenopodium quinoa Willd) during storage Int J Food Sci Tech 442013-20
Ahamed NT Singhal RS Kulkami PR Palb M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 3199-103
Alvarez-Jubete L Arendt EK Gallagher E 2010 Nutritive value of pseudocereals and their
increasing use as functional gluten-free ingredients Trends in Food Sci Tech 21(2)106-13
Ando H Chen YC Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food components in
fractions of quinoa seed Food Sci Technol Res 8(1)80-4
66
Baik BK Lee MR 2003 Effects of starch amylose content of wheat on textural properties of
white salted noodles Cereal Chem 80304-9
BeMiller JN Huber KC 2008 Carbohydrates In Damdaran S Parkin KL Fennema OR editors
Food chemistry Boca Raton CRC Press p 121
Champagne ET Lyon BG Min BK Vinyard BT Bett KL Barton IIFE Webb BD Kohlwey DE
1998 Effects of postharvest processing on texture profile analysis of cooked rice Cereal
Chem 75(2)181-6
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5)764-71
Champagne ET 2004 The rice grain and its gross composition In Champagne ET editor Rice
chemistry and technology St Paul Minn American Association of Cereal Chemists p 88
Chrastil J 1993 Enzyme activities in preharvest rice grains J Agric Food Chem 41(12)2245-8
Cortez G Repo-Carrasco R Rosell CM 2009 Breadmaking use of andean crops quinoa kantildeiwa
kiwicha and tarwi Cereal Chem 86(4)386-92
Del Castillo V Lescano G Armada M 2009 Foods formulation for people with celiac disease
based on quinoa (Chenopodium quinoa) cereal flours and starches mixtures Archivos
Latinoamericanos De Nutricion 59(3)332-36
67
Demirkesen I Mert B Sumnu G Sahin S 2010 Rheological properties of gluten-free bread
formulations J Food Eng 96(2)295-303
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(Waxy) genes J Cereal Sci 3551-63
Fitzgerald MA Martin M Ward RM Park WD Shead HJ 2003 Viscosity of rice flour a
rheological and biological study J Agric Food Chem 51(8) 2295-9
Food and Agriculture Organization of the United Nations (FAO) 2013 The international year of
quinoa Available from httpwwwfaoorgquinoa-2013en Accessed 2013 February 20
Han XZ Hamaker BR 2001 Amylopectin fine structure and rice starch paste breakdown J
Cereal Sci 34(3)279-84
Hou GG Saini R Ng PKW 2013 Relationship between physicochemical properties of wheat
flour wheat protein composition and textural properties of cooked chinese white salted
noodles Cereal Chem 90(5)419-29
Jancurovaacute M Minarovicova L Dandar A 2009 Quinoa ndash a review Czech J Food Sci 27(2)71-9
Juliano BO Villareal RM Bantildeos L 1987 Varietal differences in physicochemical properties of
waxy rice starch Starch - Staumlrke 39(9)298-301
68
Limpisut P Jindal VK 2002 Comparison of rice flour pasting properties using brabender
viscoamylograph and rapid visco analyser for evaluating cooked rice texture Starch - Staumlrke
54(8)350-7
Lindeboom N Chang PR Falk KC Tyler RT 2007 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2)216-22
Marshall WE 1994 Starch gelatinization in brown and milled rice a study using differential
scanning calorimetry In Marshall WE Wadsworth IJ editors Rice science and technology
New York NY Marcel Dekker Inc p 222
Martin M Fitzgerald MA 2002 Proteins in rice grains influence cooking properties J Cereal Sci
36(3)285-94
Mohapatra D Bal S 2006 Cooking quality and instrumental textural attributes of cooked rice
for different milling fractions J Food Eng 73(3)253-9
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine stucture of amylopectin J Cereal Sci 21(3)251-60
Pappier U Fernandez Pinto V Larumbe G Vaamonde G 2008 Effect of processing for saponin
removal on fungal contamination of quinoa seeds (Chenopodium quinoa Willd) Int J Food
Microbiol 125(2)153-7
Perdon AA Juliano BO 1975 Gel and molecular properties of waxy rice starch Starch - Staumlrke
27(3)69-71
69
Ramesh M Bhattacharya KR Mitchell JR 2000 Developments in understanding the basis of
cooked-rice texture Crit Rev Food Sci Nutr 40(6)449-60
Rousset S Pons B Pilandon C 1995 Sensory texture profile grain physico-chemical
characteristics and instrumental measurements of cooked rice J Texture Stud 26(2)119-35
Ruales J Valencia S Nair B 1993 Effect of processing on the physico-chemical characteristics
of quinoa flour (Chenopodium quinoa Willd) Starch - Staumlrke 45(1)13-9
Ruales J de Grijalva Y Lopez-Jaramillo P Nair BM 2002 The nutritional quality of an infant
food from quinoa and its effect on the plasma level of insulin-like growth factor-1 (IGF-1) in
undernourished children Int J Food Sci Nutr 53(2)143-54
Saleh MI Meullenet JF 2007 Effect of protein disruption using proteolytic treatment on cooked
rice texture properties J Texture Stud 38(4)423-37
Sandhu KS Singh N 2007 Some properties of corn starches II Physicochemical gelatinization
retrogradation pasting and gel textural properties Food Chem 101(4)1499-507
Schumacher A Brandelli A Macedo F Pieta L Klug T Jong E 2010 Chemical and sensory
evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J Food
Sci Tech 47(2)202-6
Seguchi M Hayashi M Kanenaga K Ishihara C Noguchi S1998 Springiness of pancake and
its relation to binding of prime starch to tailings in stored wheat flour Cereal Chem
75(1)37-42
70
Tang H 2004 Relationship between functionality and structure in barley starches Carbohydr
Polym 57(2)145-52
Tang H Mitsunaga T Kawamura Y 2005 Functionality of starch granules in milling fractions
of normal wheat grain Carbohyd Polym 59(1)11-7
Tsuji S 1981 Texture measurement of cooked rice kernels using the multiple-point mensuration
method 1 J Texture Stud 12(2)93-105
Vaclavik VA Christian EW 2003 Evaluation of food quality In Vaclavik V Christian EW
editors Essentials of food science New York NY Kluwer AcademicPlnum Publishers p 4
Varavinit S Shobsngob S Varanyanond W Chinachoti P Naivikul O 2003 Effect of amylose
content on gelatinization retrogradation and pasting properties of flours from different
cultivars of thai rice Starch - Staumlrke 55(9)410-5
Xie L Chen N Duan B Zhu Z Liao X 2008 Impact of proteins on pasting and cooking
properties of waxy and non-waxy rice J Cereal Sci 47(2)372-9
Zeng M Morris CF Batey IL Wrigley CW 1997 Sources of variation for starch gelatinization
pasting and gelation properties in wheat Cereal Chem 7463-71
71
Table 1-Varieties of quinoa used in the experiment
Variety Original Seed Source Location
Black White Mountain Farm White Mountain Farm Colorado US
Blanca White Mountain Farm White Mountain Farm Colorado US
Cahuil White Mountain Farm White Mountain Farm Colorado US
Cherry Vanilla Wild Garden Seeds Philomath Oregon WSUa Organic Farm Pullman Washington US
Oro de Valle Wild Garden Seeds Philomath Oregon WSUa Organic Farm Pullman Washington US
49ALC USDA Port Townsend Washington US
1ESP USDA Port Townsend Washington US
Copacabana USDA Port Townsend Washington US
Col6197 USDA Port Townsend Washington US
Japanese Strain USDA Port Townsend Washington US
QQ63 USDA Port Townsend Washington US
Yellow Commercial Multi Organics company Bolivia
Red Commercial Multi Organics company Bolivia a WSU - Washington State University
72
Table 2-Seed characteristics and compositiona
Variety Diameter (mm)
Hardness (kg)
Bulk Density (gmL)
Seed Coat Proportion ()
Protein ()
Ash ()
Black 21bc 994b 0584d 37bc 143d 215hi
Blanca 22ab 608l 0672c 89a 135e 284ef
Cahuil 21abc 772e 0757a 49b 170a 260fg
Cherry Vanilla 19e 850d 0717b 41b 160b 239gh
Oro de Valle 19e 1096a 0715b 43b 156b 305de
49ALC 19de 935c 0669c 26cd 127g 348bc
1ESP 19e 664h 0672c 10f 113i 248gh
Copacabana 20cd 643i 0671c 44b 129g 361b
Col6197 19e 583m 0657c 24de 118h 291ef
Japanese Strain 15f 618k 0610d 21def 148cd 324cd
QQ63 19e 672g 0661c 45b 135f 401a
Yellow Commercial
21abc 622j 0663c 14ef 146c 198i
Red Commercial 22a 706f 0730ab 26cd 145cd 226hi a Mean values with different letters within a column are significantly different (P lt 005)
73
Table 3-Texture profile analysis (TPA)a of cooked quinoa
Variety Hardness (kg)
Adhesiveness (kgs)
Cohesiveness Gumminess (kg)
Chewiness (kg)
Black 347a -004a 069ab 24a 24a
Blanca 306bcd -003a 071a 22abc 22abc
Cahuil 327abc -003a 071a 23ab 23ab
Cherry Vanilla 278de -002a 071a 20cd 20cd
Oro de Valle 285d -001a 068ab 19cd 19cd
49ALC 209f -029c 054d 11ef 11ef
1ESP 245e -027bc 056d 14e 14e
Copacabana 305bcd -010a 068ab 21bcd 21bcd
Col6197 202f -023bc 053d 11ef 11ef
Japanese Strain 293d -008a 066bc 19cd 19cd
QQ63 297cd -020b 062c 19d 19d
Yellow Commercial 306bcd -003a 069ab 21abc 21bc
Red Commercial 338ab -005a 068ab 23ab 23ab a Mean values with different letters within a column are significantly different (P lt 005)
74
Table 4-Cooking qualitya of quinoa
Variety Optimal Cooking Time (min)
Water uptake ()
Cooking Volume (mL)
Cooking Loss ()
Black 192a 297c 109c 065f
Blanca 183abc 344b 130ab 067f
Cahuil 169de 357ab 137a 102c
Cherry Vanilla 165ef 291c 107c 102c
Oro de Valle 173cde 238d 109c 102c
49ALC 136h 359ab 126b 043g
1ESP 153g 373ab 132ab 035h
Copacabana 157fg 379ab 127b 175a
Col6197 119i 397a 126b 176a
Japanese Strain 166def 371ab 116c 106b
QQ63 177bc 244d 126b 067f
Yellow Commercial 187ab 372ab 129ab 076d
Red Commercial 155fg 276cd 132ab 071e a Mean values with different letters within a column are significantly different (P lt 005)
75
Table 5-Pasting properties of quinoa flour by RVAa
Variety Peak Viscosity (RVU)
Trough
(RVU)
Breakdown
(RVU)
Final Viscosity (RVU)
Setback (RVU)
Peak Time (min)
Black 102g 81e 21e 75g -6f 102e
Blanca 98g 80e 18e 82g 2e 99f
Cahuil 116f 85e 31d 74g -11f 104de
Cherry Vanilla
66h 54g 12f 57h 2e 97fg
Oro de Valle
59h 50g 10f 56h 6e 93h
49ALC 107fg 71f 36c 132e 62b 97fg
1ESP 161cd 110c 51b 174c 64b 98fg
Copacabana 175b 141b 34cd 190b 49c 106cd
Col6197 155de 133b 22e 177bc 44cd 108bc
Japanese Strain
172bc 109c 62a 159d 50c 96gh
QQ63 144e 94d 51b 167cd 73a 97fg
Yellow Commercial
172bc 162a 11f 203a 41d 109b
Red Commercial
197a 168a 29d 106f -62g 115a
a Mean values with different letters within a column are significantly different (P lt 005)
76
Table 6-Thermal properties of quinoa flour by Differential Scanning Calorimetry (DSC)a
Gelatinization Temperature (ordmC)
Variety To Tp Tc Enthalpy (Jg)
Black 656a 725c 818abcd 15abc
Blanca 658a 743ab 819abcd 18a
Cahuil 659a 752a 839ab 16ab
Cherry Vanilla 649ab 741ab 823abc 12c
Oro de Valle 631bc 719cd 809abcde 12bc
49ALC 579e 714d 810bcde 15abc
1ESP 544f 690f 785de 15abc
Copacabana 630c 715cd 802cde 14abc
Col6197 605d 689f 785de 15abc
Japanese Strain 645abc 740b 850a 12c
QQ63 630c 702e 784de 13bc
Yellow Commercial 570e 676g 790cde 11c
Red Commercial 589de 693ef 780e 12c a Mean values with different letters within a column are significantly different (P lt 005)
77
Table 7-Correlation coefficients between quinoa seed characteristics composition and processing parameters and TPA texture of cooked quinoaa
Hardness Adhesiveness Cohesiveness Gumminess Chewiness
Seed Hardness 051 002ns 028ns 049 049
Bulk Density -055 -044ns -063 -060 -060
Seed Coat Proportion 074 038ns 055 072 072
Protein 050 077 075 057 057
Cooking Time 077 062 074 076 076
Water Uptake Ratio -058 -025ns -046ns -056 -056
Cooking Volume -048 -014ns -032ns -046ns -046ns
Peak Viscosity -051 -014ns -041ns -053 -054
Breakdown -048 -047ns -051 -053 -053
Final Viscosity -069 -043ns -060 -070 -070
Setback -058 -064 -059 -060 -060
To 059 054 061 061 061
Tp 042ns 041ns 050 045ns 046ns a ns non-significant difference P lt 010 P lt 005 P lt 001
78
Figure 1-Rapid Visco Analyzer (RVA) graph of lsquoCherry Vanillarsquo and lsquoRed Commercialrsquo
quinoa flours ( lsquoCherry Vanillarsquo lsquoRed Commercialrsquo Temperature)
Time (min)
0 10 20 30 40
Vis
cosi
ty (R
VU
)
0
50
100
150
200
250
Tem
pera
ture
(degC
)
50
100
150
200
79
Figure 2-Seed coat image by SEM
(1 whole seed section P-perisperm C-cotyledon 2 three layers of quinoa seed coat
3 seed coat of lsquoCherry Vanillarsquo 382 microm 4 seed coat of lsquo1ESPrsquo 95microm)
4 3
2 1
P
C C
80
Chapter 4 Quinoa Starch Characteristics and Their Correlation with
Texture of Cooked Quinoa
ABSTRACT
Starch composition and physical properties strongly influence the functionality and end-
quality of cereals Here correlations between starch characteristics and seed quality cooking
properties and texture were investigated Starch characteristics differed among the eleven
experimental varieties and two commercial quinoa tested The total starch content of seed ranged
from 532 to 751 g 100 g Total starch amylose content ranged from 27 to 169 and the
degree of amylose-lipid complex ranged from 34 to 433 The quinoa samples with higher
amylose tended to yield harder stickier more cohesive more gummy and more chewy texture
after cooking With higher degree of amylose-lipid complex or amylose leaching the cooked
quinoa tended to be softer and less chewy Higher starch enthalpy correlated with firmer more
adhesive more cohesive and more chewy texture Indicating that varieties with different starch
properties should be utilized in different end-products
Keywords quinoa starch texture cooked quinoa
Practical Application The research provided the starch characteristics of different quinoa
varieties showing correlations between starch and cooked quinoa texture These results can help
breeders and food manufacturers to better understand quinoa starch properties and the use of
cultivars for different food product applications
81
Introduction
Quinoa (Chenopodium quinoa Willd) is a pseudocereal from the Andean mountains in
South America Quinoa is garnering greater attention worldwide because of its high protein
content and balanced essential amino acids As in other crops starch is one of the major
components of quinoa seed Starch content structure molecular composition pasting thermal
properties and other characteristics may influence the cooking quality and texture of cooked
quinoa
The total starch content of quinoa seed has been reported to range from 32 to 69
(Abugoch 2009) Starch granules are small (1-2μm) compared to those of rice and barley (Tari et
al 2003) Amylose content of quinoa starch was reported to range from 35 to 225 (Abugoch
2009) generally lower than that of other crops Amylose content exhibited significant influence
on the texture of cooked quinoa (Ong and Blanshard 1995) Similarly cooked rice texture was
correlated to starch amylose and chain length (Ong and Blanshard 1995 Ramesh et al 1999)
and leaching of amylose and amylopectin during cooking (Patindol et al 2010) However
amylose-lipid complex and amylose leaching properties have not been studied in quinoa cultivars
with diverse genetic backgrounds Perdon et al (1999) indicated that starch retrogradation was
positively correlated with firmness and stickiness of cooked milled rice during storage and
similar correlations would be anticipated for quinoa
Starch swelling power and water solubility influenced wheat and rice noodle quality and
texture (Crosbie 1991 McCormick et al 1991 Konik et al 1993 Ross et al 1997 Bhattacharya
et al 1999) whereas the role of starch swelling powerwater solubility in the texture of cooked
quinoa has not been reported
82
The texture of rice starch gels has been studied Gel texture was influenced by treatment
temperature incorporation of glucomannan and sugar concentration (Charoenrein et al 2011
Jiang et al 2011 Sun et al 2014) The texture of quinoa starch gel however has not been
reported
Gelatinization temperature enthalpy and pasting properties of starch were correlated
with the texture of cooked rice (Ong and Blanshard 1995 Champagne et al 1999 Limpisut and
Jindal 2002) The correlations between starch thermal properties pasting properties and cooked
quinoa texture however have also not been reported
Starch is an important component of grains and exhibits significant influence on the
texture of cooked rice noodles and other foods The texture of cooked quinoa has been studied
previously (Wu et al 2014) however the correlation of starch and cooked quinoa texture
nevertheless remained unclear The objectives of the present study were to understand 1) the
starch characteristics of different quinoa varieties and 2) the correlations between the starch
characteristics and the texture of cooked quinoa
Materials and Methods
Starch isolation
Eleven varieties and two commercial quinoa samples were included in this study (Table
1) Quinoa starch was isolated using a method modified from Lindeboom et al (2005) and Qian
et al (1999) Two hundred grams of seed were steeped in 1000 mL NaOH (03 wv) overnight
at 4 degC and rinsed with distilled water three times to remove the saponins The rinsed quinoa
was ground in a Waring blender (Conair Corp Stamford CT USA) for 15 min The slurry
was screened through a series of sieves US No 40 100 and 200 mesh sieves with openings of
83
425 150 and 74 μm respectively Distilled water was added and stirred to speed up the
filtration Filter residue was discarded whereas the filtrate was centrifuged under 2000 times g for 20
min The supernatant was decanted and the top brown layer of sediment (protein and lipids) was
gently scraped loose and discarded The remaining pellet was resuspended in distilled water and
centrifuged again This resuspension-centrifuge process was repeated three times or until the
brown topmost layer was all removed The white starch pellet was then dispersed in 95 ethanol
and centrifuged under 2000 times g for 10 min The supernatant was discarded and the starch pellet
was air-dried and gently ground using a mortar and pestle
α-amylase activity
The activity of α-amylase was determined using a Megazyme Kit (Megazyme
International Ireland Co Wicklow Ireland)
Apparent total amylose content degree of amylose-lipid complex
Apparent amylose content was determined using a cold NaOH method (Mahmood et al
2007) with modification Sample of 10 mg was weighed into a 20 mL microcentrifuge tube To
the sample was added 150 μL of 95 ethanol and 900 μL of 1M NaOH mixed vigorously and
kept on a shaker overnight at room temperature The starch solution of 200 μL was removed and
combined with 1 mL of 005 M citric acid 800 μL iodine solution (02 g I2 2 g KI in 250 mL
distilled water) and 10 mL distilled water reaching a final volume of 12 mL The solution was
chilled in a refrigerator for 20 min The absorbance at 620nm was determined using a
spectrophotometer (Shimadzu Biospec-1601 DNAProteinEnzyme Analyzer Shimadzu corp
Kyoto Japan) A standard curve was created using a dilution series of amylose amylopectin
84
proportions of 010 19 28 37 46 and 55 respectively (Sigma-Aldrich Co LLC St Louis
MO USA)
Total amylose content was determined using the same method for apparent amylose
except that lipids in the starch samples were removed in advance The starch was defatted using
hexane and ultrasonic treatment as follows One gram of starch was dissolved in 15 mL hexane
and set in an ultrasonic water bath for 2 hours The suspension was then centrifuged at 1000 times g
for 1 min The supernatant was discarded and the procedure was repeated a second time The
sample was then dried in a fume hood overnight
Degree of amylose-lipid complex = [total amylose ndash apparent amylose] total amylose times 100
Amylose leaching properties
Amylose leaching was determined using the modified method of Hoover and Ratnayake
(2002) Starch (025 g) was mixed with 5 mL distilled water and heated at 60 degC for 30 min
then cooled in ice water and centrifuged at 2000 times g for 10 min Supernatant of 1 mL was added
to 800 μL iodine solution and 102 mL distilled water to achieve the same volume of 12 mL as
in the apparent amylose test The solution was chilled in a refrigerator for 20 min and the
absorbance at 620 nm was determined The amylose leaching was expressed as mg of amylose
leached from 100 g of starch
Starch pasting properties
Starch pasting properties were determined using the Rapid Visco Analyzer RVA-4
(Newport Scientific Pty Ltd Narrabeen Australia) Starch (3 g) was added to 25 mL distilled
water mixed and heated in the RVA using the following procedure The initial temperature was
50 ordmC and increased to 93 ordmC within 8 min at a constant rate held at 95 ordmC from 8 min to 24 min
85
cooled to 50 ordmC from 24 min to 28 min and held at 50 ordmC from 29 min to 40 min The result was
expressed in RVU units (RVU = cP12)
Starch gel texture
Starch gel texture was determined using a TA-XT2i Texture Analyzer (Texture
Technologies Corp Hamilton MA USA) The starch gels were prepared in the RVA using the
same procedure as for pasting properties Then the starch gels were stored at 4 degC for 24 hours
The testing procedure followed the method of Jiang et al (2011) with modification The gel
cylinder (3 cm high and 35 cm diameter) was compressed using a TA-25 cylinder probe at the
speed of pre-test 20 mms test 05 mms and post-test 05 mms to 10 mm deformation Two
compressions were conducted with an interval time of 20 s Hardness springiness and
cohesiveness were obtained from the TPA (Texture Profile Analysis) graph (x-axis distance and
y-axis force) Hardness (g) was expressed by the maximum force of the first peak springiness
was the ratio of distance (time) to peak 2 to distance to peak 1 cohesiveness was the ratio of the
second positive area under the compression curve to that of the first positive area
Freeze-thaw stability
Freeze-thaw stability was determined using the modified method from Lindeboom et al
(2005) and Charoenrein et al (2005) Starch slurry was cooked using the RVA with 125 g
starch and 25 mL distilled water The starch suspensions were heated at 60 degC from 0 ndash 2 min
the temperature was increased to 105 degC from 3 ndash 8 min with a constant rate and held at 105 degC
from 9 - 11 min The cooked samples were stored at -18 degC for 20 hours and then kept at room
temperature for 4 hours Water was decanted and the weight difference was determined The
86
freeze-thaw cycle was repeated five times The freeze-thaw stability was expressed as water loss
after each freeze-thaw cycle
Starch thermal properties
Thermal properties of starch were determined using Differential Scanning Calorimetry
(DSC) (Lindeboom et al 2005) Starch samples of 10 mg were weighed into aluminum pans
(Perkin-Elmer Kit No 219-0062) with 20 μL distilled water The pans were sealed and the
suspensions were incubated at room temperature (25 degC) for 2 hours to achieve equilibrium The
pans were then scanned at 10 degCmin from 25 degC to 120 degC The onset temperature (To) peak
temperature (Tp) and completion temperature (Tc) were the temperature to start the peak reach
the peak and complete the peak respectively Additionally enthalpy of gelatinization was
determined by the area under the peak
Swelling power and solubility
Swelling power and water solubility of starch were obtained at 93 degC (Vandeputte et al
2003) Starch samples of 05 g were added to 12 mL distilled water and mixed vigorously The
suspensions were immediately set in a water bath with a rotating rack at 93 degC for 30 min The
suspensions were then cooled in ice water for 2 min and centrifuged at 3000 g for 15 min The
supernatant was carefully removed with a pipette and the weight of wet sediment was recorded
The removed supernatants were dried in a 105 degC oven over night The weight of dry sediment
was recorded The swelling power and water solubility were expressed using the following
equations
Swelling power = wet sediment weight [dry sample weight times (1 ndash water solubility))
Water solubility = dry sediment weight dry sample weight times 100
87
Swelling power is expressed as a unitless ratio
Statistical analysis
All experiments were repeated three times Multiple comparisons were conducted using
Fisherrsquos LSD in SAS 92 (SAS Inst Cary NC USA) Correlations were calculated using
PROC CORR code in SAS 92 A P value of 005 was considered as the level of significance
unless otherwise specified
Results
Starch content and composition
Total starch content of quinoa seeds on a dry basis ranged from 532 g 100 g in the
variety lsquoBlackrsquo to 751 g 100 g in a commercial sample named lsquoYellow Commercialrsquo (Table 2)
Varieties lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo were lower in total
starch content all below 60 g100 g The Port Townsend seeds and commercial seeds contained
higher levels of starch mostly over 70 g100 g
Apparent amylose contents ranged from 27 in lsquo49ALCrsquo to 169 in lsquoCahuilrsquo all
lower than the corn starch standard which was 264 Varieties lsquoCahuilrsquo lsquoBlackrsquo and lsquoYellow
Commercialrsquo contained higher apparent amylose 147 to 169 It is worth noting that
lsquo49ALCrsquo contained the lowest apparent and total amylose contents 27 and 47 respectively
Total amylose of the other varieties ranged from 111 in lsquoQQ63rsquo to 173 in lsquoCahuilrsquo
The degree of amylose-lipid complex differed among the samples ranging from 34 in
lsquoCahuilrsquo to 43 in lsquo49ALCrsquo and lsquoCol6197rsquo Statistically however only lsquo49ALCrsquo and
lsquoCol6197rsquo were significantly higher than lsquoCahuilrsquo in degree of amylose-lipid complex
Starch properties
88
Amylose leaching property exhibited great differences among samples (Table 3)
lsquo49ALCrsquo and lsquo1ESPrsquo showed the highest amylose leaching at 862 and 716 mg 100 g starch
respectively lsquoCahuilrsquo lsquoJapanese Stainrsquo and lsquoRed Commercialrsquo were the lowest with amylose
leaching less than 100 mg 100 g starch lsquoBlackrsquo and lsquoBlancarsquo were relatively low as well with
210 and 171 mg amylose leaching 100 g starch The other varieties were intermediate and
ranged from 349 to 552 mg 100 g starch
Water solubility of quinoa starch ranged from 07 to 45 all lower than that of corn
starch which was 79 lsquoJapanese Strainrsquo lsquoQQ63rsquo lsquoCommercial Yellowrsquo and lsquoPeruvian Redrsquo
were the highest in water solubility 26 to 45 The starch water solubility in the other varieties
was between 10 and 19
Swelling power of quinoa starch ranged from 170 to 282 all higher than that of corn
starch (89) lsquo49ALCrsquo and lsquo1ESPrsquo showed the highest swelling powers 282 and 276
respectively lsquoYellow Commercialrsquo and lsquoRed Commercialrsquo showed relatively lower swelling
power 188 and 196 respectively The remaining varieties did not exhibit differences in
swelling power with values between 253 and 263
α-Amylase activity
Activity of α-amylase in quinoa flour separated the samples to three groups (Table 3)
lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo showed high α-amylase activity from
086 CU to 116 CU (Ceralpha Unit) lsquoBlackrsquo lsquo49ALCrsquo and lsquoCopacabanarsquo were lower in α-
amylase activity 043 031 and 020 CU respectively The other varieties and commercial
samples exhibited particularly low α-amylase activities with the values lower than 01 CU
Starch gel texture
89
Texture of starch gels included hardness springiness and cohesiveness (Table 4)
Hardness of starch gel of lsquoCahuilrsquo and lsquoJapanese Strainrsquo represented the highest and the lowest
values 900 and 201 g respectively Hardness of the other varieties ranged from 333 g in
lsquo49ALCrsquo to 725 g in lsquoBlackrsquo
lsquoJapanese Strainrsquo and lsquoYellow Commercialrsquo exhibited the highest and lowest springiness
values of the starch gels 092 and 071 respectively Springiness of other starch samples ranged
from 075 to 085 and were not significantly different from each other
Cohesiveness of starch gels ranged from 053 to 089 The starch gels of lsquoJapanese
Strainrsquo lsquoCol6197rsquo and lsquoCopacabanarsquo were more cohesive at 089 083 and 078 respectively
The starch gels of lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquo1ESPrsquo were moderately cohesive
with the cohesiveness of 072 ndash 073 Other varieties exhibited less cohesive starch gels lsquoQQ63rsquo
and commercial samples showed the least cohesive starch gels 053 ndash 057 For comparison the
hardness springiness and cohesiveness of the corn starch gel was 721 084 and 073
respectively These values were among the upper-to-middle range of those counterpart values of
the texture of quinoa starch gels
Starch thermal properties
Thermal properties of quinoa starch include gelatinization temperature and enthalpy
(Table 5) Onset temperature To of quinoa starch ranged from 515 ordmC in lsquoYellow Commercialrsquo to
586 ordmC in lsquoBlancarsquo Peak temperature Tp ranged from 595 ordmC in lsquoRed Commercialrsquo to 654 ordmC
in lsquoJapanese Strainrsquo Conclusion temperature ranged from 697 ordmC in lsquoCol6197rsquo to 788 ordmC in
lsquoJapanese Strainrsquo The commercial samples exhibited lower gelatinization temperatures To Tp
90
and Tc of the corn starch were 560 626 and 743 ordmC respectively They were within the ranges
of those values of the quinoa starches
Enthalpy refers to the energy required during starch gelatinization The enthalpy of
quinoa starch ranged from 99 to 116 Jg Starch from lsquoCahuilrsquo exhibited the highest enthalpy
116 Jg higher than that of lsquo49ALCrsquo and lsquoQQ63rsquo However enthalpies of other samples were
not significantly different Corn starch enthalpy was 105 Jg comparable to those of quinoa
starches
Starch pasting properties
Starch viscosity was investigated using the RVA (Table 6) Peak viscosity of quinoa
starches ranged from 193 to 344 RVU Varieties lsquoBlancarsquo and lsquoCahuilrsquo showed the highest peak
viscosities 344 and 342 RVU respectively lsquoJapanese Strainrsquo and lsquoQQ63rsquo were lowest in starch
peak viscosity 193 and 213 RVU respectively The peak viscosity of corn starch was 255 RVU
falling within the middle range of quinoa peak viscosities
The tough is the minimum viscosity after the first peak The trrough of quinoa starch
ranged from 137 to 301 RVU The starches of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and
lsquoOro de Vallersquo showed highest trough values from 252 to 301 RVU lsquo49ALCrsquo lsquo1ESPrsquo
lsquoCopacabanarsquo lsquoJapanese Strainrsquo and lsquoQQ63rsquo were lowest in trough ranging from 137 to 186
RVU The trough of corn starch was 131 RVU lower than that of all quinoa starches
Starch breakdown of lsquo49ALCrsquo was 119 RVU higher than that of other samples except
corn starch which was 124 RVU lsquoJapanese Strainrsquo and lsquoOro de Vallersquo showed the lowest
breakdowns 12 and 17 RVU respectively Breakdown of the other samples ranged from 39 to
97 RVU
91
Final viscosity of lsquoCahuilrsquo starch was 405 RVU significantly higher than that of other
varieties At the other extreme final viscosity of lsquo49ALCrsquo starch was 225 RVU significantly
lower than that of the other varieties The final viscosity of corn starch was 283 RVU close to
that of lsquoJapanese Strainrsquo and lsquoQQ63rsquo but lower than that of the other quinoa samples
The highest setback was observed with lsquo1ESPrsquo starch (140 RVU) At the other extreme
the setback of lsquoOro de Vallersquo was 53 RVU which was lower than the other quinoa samples
Additionally setbacks of lsquoBlancarsquo lsquo49ALCrsquo and lsquoJapanese stainrsquo starches were also among the
lower range varying from 82 RVU to 88 RVU The remaining varieties exhibited higher setback
from 101 RVA to 127 RVU Setback of corn starch was 152 RVU significantly higher than all
the other quinoa starches
RVA peak times of quinoa starches varied significantly among the samples lsquoJapanese
Strainrsquo lsquoBlancarsquo lsquoCahuilrsquo and lsquoOro de Vallersquo required longer time to reach the peak viscosity
with peak times of 105 to 113 min Other varieties showed shorter peak times between 79 to
99 min The starch of lsquo49ALCrsquo however only needed 64 min to reach peak viscosity shorter
than those of other quinoa samples The peak time of corn starch was 73 min shorter than those
of quinoa starches except lsquo49ALCrsquo
Freeze-thaw stability of starch
Freeze-thaw stability of starches was expressed as the water loss () of each freeze-thaw
cycle Quinoa starch samples and corn starch showed similar trends in freeze-thaw stability
Most water loss occurred after cycles 1 and 2 Starch gels on average (excluding lsquo49ALCrsquo) lost a
cumulative total of 522 ndash 689 of water after cycle 2 and a total of 745 ndash 823 after cycle 5
Furthermore the starch gels of lsquoQQ63rsquo and lsquo1ESPrsquo lost the least water indicating higher freeze-
92
thaw stability Conversely the starch gel of lsquoJapanese Strainrsquo lost the most water in every cycle
indicating the lowest degree of freeze-thaw stability
lsquo49ALCrsquo and lsquo1ESPrsquo starches exhibited freeze-thaw behavior that was different
compared to the other samples After freezing the samples of lsquo49ALCrsquo and lsquo1ESPrsquo produced
gels that were less rigid more viscous than the other samples Further they did not lose as much
water after the first cycle The sample of lsquo1ESPrsquo however turned into a solid gel from cycle 2 to
5 And the water loss of the lsquo1ESPrsquo gel was close to that of other samples during cycles 2 and 5
Correlations between starch properties and the texture of cooked quinoa
Correlations between starch properties and texture of cooked quinoa were examined
(Table 7) using texture profile analysis (TPA) of cooked quinoa of Wu et al (2014) Total starch
content was moderately correlated with adhesiveness of cooked quinoa (r = -048 P = 009) but
was not significantly correlated with any of the other texture parameters Conversely apparent
amylose content was highly correlated with all texture parameters (067 le r le 072) Total
amylose content also exhibited significant correlations with all texture parameters (056 le r le
061) Furthermore the degree of amylose-lipid complex was negatively correlated with all
texture parameters (-070 le r le -060) and amylose leaching proportion was highly correlated
with the texture of cooked quinoa (-084 le r le -074)
Water solubility and swelling power of starch were not observed to correlate well with
any of the texture parameters Higher α-amylase activity tended to yield more adhesive (r = 055)
and more cohesive (r = 051 P = 007) texture However α-amylase activity was not correlated
with the hardness gumminess or chewiness of cooked quinoa
93
Some texture parameters of starch gels were associated with the texture parameters of
cooked quinoa The hardness of starch gels was not correlated with the hardness of cooked
quinoa but was weakly correlated with adhesiveness (r = 059) Weakly positive correlations
were found between starch gel hardness and cooked quinoa cohesiveness gumminess and
chewiness (049 le r le 051 P le 010) Springiness and cohesiveness of starch gels were not
correlated with the measured textural properties of cooked quinoa
Onset gelatinization temperature (To) of starch exhibited weak correlations with
adhesiveness (r = 049 P = 009) and cohesiveness (r = 051 P = 007) but was not correlated
with the other texture parameters Peak gelatinization temperature (Tp) of starch was correlated
with cohesiveness (r = 056) and hardness adhesiveness gumminess and chewiness (047 le r le
056 P le 010) No correlation was found with conclusion temperature (Tc) and texture Starch
enthalpy did correlate with the texture parameters (r = 064 in hardness 069 le r le 072 in other
texture parameters)
Starch viscosity measurements were variably correlated with the texture of cooked
quinoa Peak viscosity correlated adhesiveness (r = 054 P = 006) and cohesiveness (r = 047 P
= 010) but not with the other texture parameters Trough was more highly correlated with
adhesiveness cohesiveness gumminess and chewiness (r = 077 in adhesiveness 055 le r le
063 in other texture parameters)
It is interesting to note that starch breakdown only correlated with adhesiveness of
cooked quinoa (r = -060) and not with any other texture parameter Setback was not correlated
with any texture parameter These two RVA parameters breakdown and setback are usually
considered to be important indexes of end-use quality In quinoa however breakdown and
94
setback of starch apparently are not predictive of cooked quinoa texture In addition final
viscosity was also correlated with adhesiveness (r = 068) and cohesiveness (r = 058) and
correlated moderately with gumminess and chewiness (r = 053 P = 006) Peak time was
correlated with adhesiveness (r = 077) cohesiveness (r = 068) gumminess (r = 060) and
chewiness (r = 060) and to a lesser extent with hardness (r = 053 P = 006)
Correlations between starch properties and seed DSC RVA characteristics
Total starch content correlated with seed hardness (r = -073) seed coat proportion (r = -
071) and starch viscosities (peak viscosity trough and final viscosity) (-068 lt r lt -060) and
also to a lesser extent with seed density (r = 054 P = 006) and starch thermal properties (To
Tp and enthalpy) (-051 lt r lt -049 008 lt P lt009) (Table 8)
Water solubility of starch was correlated with starch viscosity such as peak viscosity (r =
-049 P = 009) and breakdown (r = -048 P = 010) Swelling power was only correlated with
peak time (r = -054 P = 006) (data not shown)
Apparent amylose content was correlated with protein content (r = 058) and optimal
cooking time (r = 056) but total amylose content did not show either of these correlations Both
apparent and total amylose contents were correlated with starch gel hardness starch enthalpy
and starch viscosity such as trough breakdown final viscosity and peak time
The degree of amylose-lipid complex exhibited negative correlations with seed protein
content (r = -07) and optimal cooking time of quinoa seed (r = -067) Moreover amylose
leaching was negatively correlated with protein content (r = -062) starch gel hardness (r = --
064) starch Tp (r = -058) and enthalpy (r = -064) optimal cooking time (r = -055) and starch
viscosities such as breakdown (r = 062) and peak time (r = -081) Additionally α-amylase
95
activity was correlated with protein content (r = 066) seed density (r = -072) seed coat
proportion (r = 055) starch To (r = 061) and starch viscosities such as peak viscosity (r =
070) trough (r = 072) and final viscosity (r = 061)
Discussion
Starch content and composition
Total starch content does influence the functional and processing properties of cereals
The total starch content of quinoa was reported to be between 32 and 69 (Abugoch 2009)
Among our varieties most of the Port Townsend varieties and commercial quinoa contained
more than 69 starch It is interesting to note that the Port Townsend samples lsquo49ALCrsquo lsquo1ESPrsquo
lsquoCol6197rsquo and lsquoQQ63rsquo were also more sticky or more adhesive after cooking than other
varieties These varieties may exhibit better performance in extrusion products or in beverages
which require high viscosity
Amylose content affects texture and gelation properties The proportion of amylose and
amylopectin impacts the functionality of cereals in this study both apparent and total amylose
contents were determined Total amylose includes those amylose molecules that are complexed
with lipids
Amylose content of quinoa was reported to range from 35 to 225 dry basis
(Abugoch 2009) generally lower than that of common cereals which is around 25 Overall
both apparent and total amylose contents of the quinoa in the present study fell within the range
which has been reported lsquo49ALCrsquo was an exception showing significantly lower apparent and
total amylose contents of 27 and 47 respectively Thus this variety is close to be being a
lsquowaxyrsquo which refers to the cereal starches that are comprised of mostly amylopectin (99) and
96
little amylose (~1) As the waxy wheat showed an excellent expansion during extrusion
(Kowalski et al 2014) lsquo49ALCrsquo is a promising variety to produce breakfast cereal or extruded
snacks
The degree of amylose-lipid complex showed great variability among the samples 34 ndash
433 whereas the value in wheat flour was reported to be 32 (Bhatnagar and Hanna 1994) or
13 to 23 (Zeng et al 1997) Degree of amylose-lipid complex showed significant and
negative correlations with all texture parameters such as hardness adhesiveness cohesiveness
gumminess and chewiness
The effect of amylose-lipid complex on product texture has been reported in previous
studies The degree of amylose-lipid complex correlated with the texture (hardness and
crispness) and quality (radial expansion) of corn-based snack (Thachil et al 2014) Wokadala et
al (2012) indicated that amylose-lipid complexes played a significant role in starch biphasic
pasting
Starch properties
Amylose leaching was also highly variable among the quinoa varieties 35 ndash 862 mg
100g starch Vandeputte et al (2003) studied amylose leaching of waxy and normal rice
starches The amylose leaching values at 65 ordmC were below 1 of starch comparable with those
in quinoa starch Pronounced increase of amylose leaching was observed at the temperatures
higher than 95 ordmC Patindol et al (2010) found that both amylose and amylopectin leached out
during cooking rice The proportion of the leached amylose and amylopectin influenced the
texture of cooked rice We found similar results indicating correlations between amylose
leaching and texture of cooked quinoa
97
Water solubility of quinoa starch was significantly lower than that of corn starch whereas
swelling power of quinoa starch was higher than that of corn starch Both water solubility and
swelling power were determined at 95 ordmC Lindeboom et al (2005) determined swelling power
and solubility of quinoa starch among eight varieties at 65 75 85 and 95 ordmC The water
solubility at 95 ordmC ranged from 01 to 47 which was lower than the corn starch standard of
100 The swelling power at 95 ordmC ranged from 164 to 526 lower than the corn starch
standard of 549 The quinoa starch in this study showed a narrower range of swelling power
170 to 282
α-Amylase activity
The quinoa in this study had significantly different α-amylase activity (003 ndash 116 CU)
Previous studies reported low α-amylase activity in quinoa compared to oat (Maumlkinen et al
2013) and traditional malting cereals (Hager et al 2014) Moreover the activity of α-amylase
indicates the degree of seed germination and the availability of sugars for fermentation In the
study of Hager et al (2014) α-amylase activity increased from 0 to 35 CU during 72 h
germination
Texture of starch gel
Starch gel texture has been previously studied on corn and rice starches but not on
quinoa starch Hardness of rice starch gel was reported to be 339 g by Charoenrein et al (2011)
and 116 g by Jiang et al (2011) Hardness of corn starch was reported to be around 100 g in the
study of Sun et al (2014) much lower than the standard corn starch hardness in this study 721
g Compared to those of rice and corn starch quinoa starch gel exhibited harder texture which
may be caused by either genetic variation or different processing procedures to form the gel
98
Additionally springiness and cohesiveness of rice starch gel were reported as 085 and 055
respectively (Jiang et al 2011) Quinoa starch gel exhibited comparable springiness and higher
cohesiveness than those of rice starch gel
Thermal properties of quinoa starch
The thermal properties of quinoa starch in this study were comparable to those of rice
starch (Cai et al 2014) The study of Lindeboom et al (2005) however found lower
gelatinization temperatures and higher enthalpies compared to the present study which may be
due to varietal difference
Furthermore correlation between thermal properties of quinoa starch and flour (Wu et al
2014) was investigated Gelatinization temperatures To Tp and Tc of starch and whole seed
flour were highly correlated especially To and Tp exhibited high r of 088 The enthalpy of
starch and flour however was not significantly correlated In this case quinoa flour can be used
to estimate quinoa starch gelatinization temperatures but not the enthalpy Additionally since
flour is easier to prepare compared to starch further studies can be conducted with a larger
number of quinoa samples to model the prediction of starch thermal properties using flour
thermal properties
Starch pasting properties
Viscosity and pasting properties of starch play a significant role in the functionality of
cereals Jane et al (1999) studied the pasting properties of starch from cereals such as maize
rice wheat barley amaranth and millet The peak viscosities ranged from 58 RVU in barley to
219 RVU in sweet rice lower than those of most quinoa starches except lsquoJapanese Strainrsquo and
lsquoQQ63rsquo Final viscosities ranged from 54 RVU in barley to 208 RVU in cattail millet all lower
99
than those of the quinoa starches in the present study Setback of cereal starches mostly ranged
from 6 RVU in waxy amaranth to 74 RVU in non-waxy maize lower than those of most quinoa
starches except lsquoOre de Vallersquo Cattail millet starch exhibited the setback of 208 RVU higher
than those of quinoa starches
The relationships between RVA pasting parameters of quinoa starch and flour were
studied by Wu et al (2014) Final viscosity of starch and flour was correlated negatively (r = -
063 P = 002) The other RVA parameters did not exhibit significant correlation between starch
and flour RVA In other words RVA of quinoa flour cannot be used to predict RVA of quinoa
starch In addition to starch the fiber and protein in whole quinoa flour may influence the
viscosity As quinoa is normally utilized as whole grain or whole grain flour instead of refined
flour the flour RVA should be a better indication on the end-use functionality
Freeze-thaw stability of starch
Quinoa starches in the present study did not show high stability during freeze and thaw
cycles Praznik et al (1999) studied freeze-thaw stability of various cereal starches Similar to
the present study Praznik et al concluded quinoa starches exhibited low freeze-thaw stability
Conversely Ahamed et al (1996) found quinoa starch exhibited excellent freeze-thaw stability
Unfortunately the variety was not indicated Overall it is reasonable to assert that for some
quinoa cultivars the starch may have better freeze-thaw stability than in other cultivars
However most quinoa varieties in published studies did not show good freeze-thaw stability
Correlations between starch characteristics and texture of cooked quinoa
The quinoa starch characteristics correlated with the texture of cooked quinoa in some
aspects Total starch content however did not show any strong correlations with TPA
100
parameters as was initially expected Since quinoa is consumed as whole grain or whole flour
fiber and bran may exhibit more influence on the texture than anticipated from the impact of
starch alone
The quinoa varieties with higher apparent and total amylose contents tended to yield a
harder stickier more cohesive more gummy and chewy texture Similar correlations are found
with cooked rice noodle and corn-based extrusion snacks The hardness of cooked rice was
positively correlated with amylose content and negatively correlated with adhesiveness (Yu et al
2009) Epstein et al (2002) reported that full waxy noodles were softer thicker less adhesive
and chewy and more cohesive and springy compared to normal noodles and partial waxy
noodles Increased amylose content in a corn-based extrusion snack resulted in higher amylose-
lipid formation and softer texture (Thachil et al 2014)
Higher levels of amylose-lipid complex in starch were associated with softer less
adhesive less cohesive and less gummy and less chewy cooked quinoa The correlation between
the degree of amylose-lipid complex and texture of cooked rice or quinoa has not been
previously reported Kaur and Singh (2000) however found that amylose-lipid complex
increased with longer cooking time of rice flour Additionally cooking time is a key factor to
determine texture ndash the longer a cereal is cooked the softer less sticky less cohesive and less
gummy and chewy the texture
Correlations were found between amylose leaching and cooked quinoa TPA parameters
especially hardness gumminess and chewiness with r of -082 Increased amylose leaching
yielded a softer gel made from potato starch (Hoover et al 1994) However the correlations of
101
amylose leaching and α-amylase activity with texture of end product for quinoa have not been
reported previously
Swelling power and water solubility were reported to influence the texture of wheat and
rice noodle (Crosbie 1991 McCormick et al 1991 Konik et al 1993 Ross et al 1997
Bhattacharya et al 1999) However in the present report no correlation was found between
swelling power water solubility and the texture of cooked quinoa Additionally the study of
Ong and Blanshard (1995) indicated a positive correlation between enthalpy and the texture of
cooked rice Similar results were found in this study
RVA is a fast and reliable way to predict flour functionality and end-use properties
Pasting properties of rice flour have been used to predict texture of cooked rice (Champagne et
al 1999 Limpisut and Jindal 2002) In our previous study cooked quinoa texture correlated
negatively with the final viscosity and setback of quinoa flour (Wu et al 2014) In this study
texture correlated with trough breakdown final viscosity and peak time of quinoa starch
However RVA of quinoa flour and starch did not correlate with each other Flour RVA might be
a convenient way to predict cooked quinoa texture
Correlations between starch properties and seed DSC RVA characteristics
Quinoa with higher total starch tended to have a thinner seed coat This makes sense
because starch protein lipids and fiber are the major components of seed An increase in one
component will result in a proportional decrease in the other component contents
Additionally the starch RVA parameters (except peak viscosity) can be used to estimate
apparent or total amylose content based on their correlations Further studies should be
conducted with a larger sample size of quinoa and a more accurate prediction model can be built
102
The samples with lower protein or those requiring shorter cooking time tended to contain
higher levels of amylose-lipid complex Additionally amylose-lipid complex was reported to
influence the texture of extrusion products (Bhatnagar and Hanna 1994 Thachil et al 2014) For
this reason protein and optimal cooking time are promising indicators of the behavior of quinoa
during extrusion
Conclusions
In summary starch content composition and characteristics were significantly different
among quinoa varieties Amylose content degree of amylose-lipid complex and amylose
leaching property of quinoa starch exhibited great variances and strong correlations with texture
of cooked quinoa Additionally starch gel texture pasting properties and thermal properties
were different among varieties and different from those of rice and corn starches Enthalpy
RVA trough final viscosity and peak time exhibited significant correlations with cooked quinoa
texture Overall starch characteristics greatly influenced the texture of cooked quinoa
Acknowledgments
This project was supported by the USDA Organic Research and Extension Initiative
(NIFAGRANT11083982) The authors acknowledge Girish Ganjyal and Shyam Sablani for
using the Differential Scanning Calorimetry (DSC) thanks to Stacey Sykes for editing support
Author Contributions
G Wu and CF Morris designed the study together and established the starch isolation
protocol G Wu collected test data and drafted the manuscript CF Morris and KM Murphy
edited the manuscript KM Murphy provided quinoa samples
103
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581-31
Ahamed NT Singhal RS Kulkarni PR Pal M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 31(1)99-103
Araujo-Farro PC Podadera G Sobral PJA Menegalli FC 2010 Development of films based on
quinoa (Chenopodium quinoa Willd) starch Carbohydr Polym 81(4)839-48
Bhatnagar S Hanna MA 1994 Amylose-lipid complex formation during single-screw extrusion
of various corn starches Cereal Chem 71(6)582-6
Bhattacharya M Zee SY Corke H 1999 Physicochemical properties related to quality of rice
noodles Cereal Chem 76(6)861-7
Cai J Yang Y Man J Huang J Wang Z Zhang C Gu M Liu Q Wei C 2014 Structural and
functional properties of alkali-treated high-amylose rice starch Food Chem 145245-53
Champagne ET 2004 The rice grain and its gross composition In Champagne ET editor Rice
chemistry and technology St Paul Minn American Association of Cereal Chemists p 88
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5)764-71
104
Charoenrein S Tatirat O Rengsutthi K Thongngam M 2011 Effect of konjac glucomannan on
syneresis textural properties and the microstructure of frozen rice starch gels Carbohydr
Polym 83(1)291-6
Crosbie GB 1991 The relationship between starch swelling properties paste viscosity and
boiled noodle quality in wheat flours J Cereal Sci 13(2)145-50
De Pilli T Derossi A Talja R Jouppila K Severini C 2012 Starchndashlipid complex formation
during extrusion-cooking of model system (rice starch and oleic acid) and real food (rice
starch and pistachio nut flour) Eur Food Res Technol 234(3)517-25
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(waxy) genes J Cereal Sci 35(1) 51-63
Hager AS Maumlkinen OE Arendt EK 2014 Amylolytic activities and starch reserve mobilization
during the germination of quinoa Eur Food Res Technol 239(4)621-7
Hoover R Ratnayake WS 2002 Starch characteristics of black bean chick pea lentil navy bean
and pinto bean cultivars grown in Canada Food Chem 78(4)489-98
Hoover R Vasanthan T Senanayake NJ Martin AM 1994 The effects of defatting and heat-
moisture treatment on the retrogradation of starch gels from wheat oat potato and lentil
Carbohydr Res 261(1)13-24
105
Jane J Chen Y Lee L McPherson A Wong K Radosavljevic M Kasemsuwan T 1999 Effects
of amylopectin branch chain length and amylose content on the gelatinization and pasting
properties of starch 1 Cereal Chem 76(5)629-37
Jiang Q Xu X Jin Z Tian Y Hu X Bai Y 2011 Physico-chemical properties of rice starch
gels Effect of different heat treatments J Food Eng 107(3)353-7
Kaur K Singh N 2000 Amylose-lipid complex formation during cooking of rice flour Food
Chem 71(4)511-7
Konik CM Miskelly DM Gras PW 1993 Starch swelling power grain hardness and protein
relationship to sensory properties of japanese noodles Starch - Staumlrke 45(4)139-44
Kowalski R Morris C Ganjyal G 2015 Extrusion characteristics thermal and rheological
properties of soft white wheat flour in comparison with regular wheat flour Cereal Chem
92(2)145-53
Limpisut P Jindal VK 2002 Comparison of rice flour pasting properties using Brabender
Viscoamylograph and Rapid Visco Analyser for evaluating cooked rice texture Starch‐
Staumlrke 54(8)350-7
Lindeboom N Chang PR Falk KC Tyler RT 2005 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2)216-22
Mahmood T Turner MA Stoddard FL 2007 Comparison of methods for colorimetric amylose
determination in cereal grains Starch‐Staumlrke 59(8)357-65
106
Maumlkinen OE Zannini E Arendt EK 2013 Germination of oat and quinoa and evaluation of the
malts as gluten free baking ingredients Plant Foods Hum Nutr 68(1)90-5
Matos M Timgren A Sjoo M Dejmek P Rayner M 2013 Preparation and encapsulation
properties of double Pickering emulsions stabilized by quinoa starch granules Colloids and
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McCormick K Panozzo J Hong S 1991 A swelling power test for selecting potential noodle
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Patindol J Gu X Wang YJ 2010 Chemometric analysis of cooked rice texture in relation to
starch fine structure and leaching characteristics Starch - Staumlrke 62(3-4)188-97
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of cooked milled rice during storage J Food Sci 64(5)828-32
107
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background of technological properties of selected starches Starch‐Staumlrke 51(6) 197-211
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starch Starch‐Staumlrke 51(4)116-20
Ramesh M Zakiuddin Ali S Bhattacharya KR 1999 Structure of rice starch and its relation to
cooked-rice texture Carbohydr Polym 38(4)337-47
Rayner M Sjoumlouml M Timgren A Dejmek P 2012 Quinoa starch granules as stabilizing particles
for production of Pickering emulsions Faraday Discuss 158(1)139-55
Ross AS Quail KJ Crosbie GB 1997 Physicochemical properties of Australian flours
influencing the texture of yellow alkaline noodles Cereal Chem 74(6)814-20
Sun Q Xing Y Qiu C Xiong L 2014 The pasting and gel textural properties of corn starch in
glucose fructose and maltose syrup PloS one 9(4)e95862
Thachil MT Chouksey MK Gudipati V 2014 Amylose-lipid complex formation during
extrusion cooking effect of added lipid type and amylose level on corn-based puffed snacks
Int J Food Sci Tech 49(2)309-16
Vandeputte GE Derycke V Geeroms J Delcour JA 2003 Rice starches II Structural aspects
provide insight into swelling and pasting properties J Cereal Sci 38(1)53-9
Wokadala OC Ray SS Emmambux MN 2012 Occurrence of amylosendashlipid complexes in teff
and maize starch biphasic pastes Carbohydr Polym 90(1)616-22
108
Wu G Morris C F Murphy K M 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79(11)2337-45
Yu S Ma Y Sun DW 2009 Impact of amylose content on starch retrogradation and texture of
cooked milled rice during storage J Cereal Sci 50(2)139-44
Zeng M Morris CF Batey IL Wrigley CW 1997 Sources of variation for starch gelatinization
pasting and gelation properties in wheat Cereal Chem 74(1)63-71
109
Table 1-Quinoa varieties tested
Variety Original Seed Source Location
Black White Mountain Farm White Mountain Farm Colo USA
Blanca White Mountain Farm White Mountain Farm Colo USA
Cahuil White Mountain Farm White Mountain Farm Colo USA
Cherry Vanilla Wild Garden Seeds Philomath Oregon
WSUa Organic Farm Pullman Wash USA
Oro de Valle Wild Garden Seeds Philomath Oregon
WSUa Organic Farm Pullman Wash USA
49ALC USDA Port Townsend Wash USA
1ESP USDA Port Townsend Wash USA
Copacabana USDA Port Townsend Wash USA
Col6197 USDA Port Townsend Wash USA
Japanese Strain USDA Port Townsend Wash USA
QQ63 USDA Port Townsend Wash USA
Yellow Commercial Multi Organics company Bolivia
Red Commercial Multi Organics company Bolivia a WSU Washington State Univ
110
Table 2-Starch content and composition
Variety Total starch
(g 100 g)
Apparent amylose
()
Total
amylose ()
Degree of amylose
lipid complex ()
Black 532f 153a 159ab 96bc
Blanca 595de 102cd 163a 361ab
Cahuil 622d 169a 173a 34c
Cherry Vanilla
590de 105cd 116bc 164abc
Oro de Valle 573ef 114bcd 166a 300abc
49ALC 674c 27e 47d 426a
1ESP 705bc 86d 152abc 389ab
Copacabana 734ab 120bc 153abc 222abc
Col6197 725ab 102cd 140abc 433a
Japanese Strain
723ab 116bcd 165ab 305abc
QQ63 713abc 84d 111c 241abc
Yellow Commercial
751a 147ab 150abc 118abc
Red Commercial
691bc 100cd 164a 375ab
Corn starch - 264 - -
111
Table 3-Starch properties and α-amylase activity
Variety Amylose leaching (mg 100 g starch)
Water solubility ()
Swelling power
α-Amylase activity (CU)
Black 210ef 16de 260bcd 043d
Blanca 171efg 10de 260bcd 086c
Cahuil 97fg 16cde 253cd 106b
Cherry Vanilla 394d 15de 253cd 116a
Oro de Valle 420d 16de 245d 103b
49ALC 862a 07e 282a 031e
1ESP 716b 13de 276ab 003g
Copacabana 438cd 14de 263bc 020f
Col6197 552c 19cd 257cd 009g
Japanese Strain 31fg 45a 170f 005g
QQ63 315de 26bc 262bc 008g
Yellow Commercial
349d 32b 188e 005g
Red Commercial 35g 26bc 196e 003g
Corn starch - 79 89 -
112
Table 4-Texture of starch gel
Variety Hardness (g) Springiness Cohesiveness
Black 725ab 082ab 064cd
Blanca 649abc 083ab 072bc
Cahuil 900a 085ab 072bc
Cherry Vanilla 607abc 078bc 072bc
Oro de Valle 448abc 078bc 064cd
49ALC 333bc 081bc 061cd
1ESP 341bc 081bc 073bc
Copacabana 402bc 084ab 078ab
Col6197 534abc 083ab 083ab
Japanese Strain 765ab 092a 089a
QQ63 201c 078bc 053d
Yellow Commercial 436bc 071c 057d
Red Commercial 519abc 075bc 055d
Corn starch 721 084 073
113
Table 5-Thermal properties of starch
Variety Gelatinization temperature Enthalpy (Jg)
To (ordmC) Tp (ordmC) Tc (ordmC)
Black 560b 639bc 761bc 112abc
Blanca 586a 652ab 754bcd 113abc
Cahuil 582a 648ab 755bcd 116a
Cherry Vanilla 563b 627cd 747bcd 111abc
Oro de Valle 562b 623d 739cd 106abc
49ALC 524ef 598f 747bcd 101bc
1ESP 530de 608ef 738cd 103abc
Copacabana 565b 622d 731de 106abc
Col6197 540cd 598f 697f 105abc
Japanese Strain 579a 654a 788a 104abc
QQ63 545c 616de 766ab 99c
Yellow Commercial 515f 599f 708ef 107abc
Red Commercial 520ef 595f 700 f 116ab
Corn starch 560 626 743 105
114
Table 6-Pasting properties of starch
Variety Peak viscosity
(RVU)a
Trough
(RVU)
Breakdown
(RVU)
Final viscosity
(RVU)
Setback
(RVU)
Peak time
(min)
Black 293abc 252abc 41efg 363ab 111abcd 92e
Blanca 344a 301a 42defg 384ab 82de 111ab
Cahuil 342ab 297a 45def 405a 108abcd 106bc
Cherry Vanilla 313abc 263abc 50de 369ab 106abcd 99d
Oro de Valle 294abc 277ab 17fg 330abc 53e 105c
49ALC 256cde 137f 119a 225d 88cde 64i
1ESP 269bcd 172ef 97ab 313bc 140a 79h
Copacabana 258cde 186def 72bcd 308bc 122abc 81gh
Col6197 270bcd 231bcd 39efg 347ab 116abcd 86fg
Japanese Strain 193e 181def 12g 264cd 83de 113a
QQ63 213de 152f 60cde 254cd 101bcd 88ef
Yellow Commercial
290abc 223cde 67bcde 350ab 127ab 93de
Red Commercial 327abc 242bc 85bc 366ab 125ab 92ef
Corn 255 131 124 283 152 73 aRVU = cP12
115
Table 7-Correlation coefficients between starch properties and texture of cooked quinoaa
Hardness Adhesiveness Cohesiveness Gumminess Chewiness
Total starch content
-032ns -048 -043ns -039ns -039ns
Apparent amylose content
069 072 069 072 072
Actual amylose content
061 062 056 061 061
Degree of amylose-lipid complex
-065 -060 -070 -070 -070
Amylose leaching
-082 -075 -074 -082 -082
α-Amylase activity
018ns 055 051 032ns 032ns
Starch gel hardness
042ns 059 051 049 049
DSC
To 034ns 049 051 041ns 041ns
Tp 047 052 056 052 052
ΔH 064 072 069 070 070
RVA
Peak viscosity 031ns 054 047 041ns 041ns
Trough 044ns 077 063 055 055
Breakdown -034ns -060 -044ns -038ns -038ns
Final viscosity 045ns 068 058 053 053
Peak time 053 077 068 060 060
ns non-significant difference P lt 010 P lt 005 P lt 001 aTPA is the Texture Profile Analysis of cooked quinoa data were presented in Wu et al (2014)
116
Table 8-Correlations between starch properties and seed DSC RVA characteristicsa
Total
starch content
Water solubility
Apparent amylose content
Total amylose content
Degree of amylose-lipid complex
Amylose leaching
α-Amylase activity
Protein -047ns 023ns 058 031ns -069 -062 066
Seed hardness
-073 -041ns -003ns -021ns -020ns 019ns 053
Bulk density
054 049 -020ns -015ns 031ns 019ns -072
Seed coat proportion
-071 -041ns 027ns 021ns -028ns -038ns 055
Starch gel hardness
-045ns 017 ns 065 053 -044ns -064 046ns
Starch DSC
To -049 -004ns 041ns 043ns -033ns -049 061
Tp -050 010ns 047ns 045ns -042ns -058 052
Enthalpy -051 -011ns 059 055 -041ns -064 049
Starch viscosity
Peak viscosity
-066 -049 028ns 027ns -020ns -023ns 070
Trough -068 -017ns 056 057 -031ns -052 072
Breakdown
022ns -048 -061 -067 027ns 062 -025ns
Final viscosity
-060 -022ns 063 060 -037ns -046ns 061
Peak time -032ns 045ns 058 072 -029ns -081 043ns
117
Cooking quality
Optimal cooking time
-043ns 019ns 056 040ns -067 -055 029ns
ns non-significant difference P lt 010 P lt 005 P lt 001 aSeed characteristics data were presented in Wu et al (2014)
118
Chapter 5 Quinoa Seed Quality Response to Sodium Chloride and
Sodium Sulfate Salinity
Submitted to the Frontiers in Plant Science
Research Topic Protein crops Food and feed for the future
Abstract
Quinoa (Chenopodium quinoa Willd) is an Andean grain with an edible seed that both contains
high protein content and provides high quality protein with a balanced amino acid profile
Quinoa is a halophyte adapted to harsh environments with highly saline soil In this study four
quinoa varieties were grown under six salinity treatments and two levels of fertilization and then
evaluated for quinoa seed quality characteristics including protein content seed hardness and
seed density Concentrations of 8 16 and 32 dS m-1 of NaCl and Na2SO4 as well as a no-salt
control were applied to the soil medium across low (1 g N 029 g P 029 g K per pot) and high
(3 g N 085 g P 086 g K per pot) fertilizer treatments Seed protein content differed across soil
salinity treatments varieties and fertilization levels Protein content of quinoa grown under
salinized soil ranged from 130 to 167 comparable to that from normal conditions NaCl
and Na2SO4 exhibited different impacts on protein content Whereas the different concentrations
of NaCl did not show differential effects on protein content the seed from 32 dS m-1 Na2SO4
contained the highest protein content Seed hardness differed among varieties and was
moderately influenced by salinity level (P = 009) Seed density was affected significantly by
119
variety and Na2SO4 concentration but was unaffected by NaCl concentration The plants from 8
dS m-1 Na2SO4 soil had lower density (066 gcm3) than those from 16 dS m-1 and 32 dS m-1
Na2SO4 074 and 072gcm3 respectively This paper identifies changes in critical seed quality
traits of quinoa as influenced by soil salinity and fertility and offers insights into variety
response and choice across different abiotic stresses in the field environment
Key words quinoa soil salinity protein content hardness density
120
Introduction
Quinoa (Chenopodium quinoa Willd) has garnered much attention in recent years
because it is an excellent source of plant-based protein and is highly tolerance of soil salinity
Because soil salinity affects between 20 to 50 of irrigated arable land worldwide (Pitman and
Lauchli 2002) the question of how salinity affects seed quality in a halophytic crop like quinoa
needs to be addressed Protein content in most quinoa accessions has been reported to range from
12 to 17 depending on variety environment and inputs (Rojas et al 2015) This range
tends to be higher than the protein content of wheat barley and rice which were reported to be
105- 14 8-14 and 6-7 respectively (Shih 2006 Orth and Shellenberger1988 Cai et
al 2013) Additionally quinoa has a well-balanced complement of essential amino acids
Specifically quinoa is rich in lysine which is considered the first limiting essential amino acid in
cereals (Taylor and Parker 2002) Protein quality such as Protein Efficiency Ratio is similar to
that of casein (Ranhotra et al 1993) Furthermore with a lack of gluten protein quinoa can be
safely consumed by gluten sensitiveintolerant population (Zevallos et al 2014)
Quinoa shows exceptional adaption to harsh environments such as drought and salinity
(Gonzaacutelez et al 2015) Soil salinity reduces crop yields and is a worldwide problem In the
United States approximately 54 million acres of cropland in forty-eight States were occupied by
saline soils while another 762 million acres are at risk of becoming saline (USDA 2011) The
salinity issue leads producers to grow more salt-tolerant crops such as quinoa
Many studies have focused on quinoarsquos tolerance to soil salinity with a particular
emphasis on plant physiology (Ruiz-Carrasco et al 2011 Adolf et al 2012 Cocozza et al
121
2013 Shabala et al 2013) and agronomic characteristics such as germination rate plant height
and yield (Prado et al 2000 Chilo et al 2009 Peterson and Murphy 2015 Razzaghi et al
2012) For instance Razzaghi et al (2012) showed that the seed number per m2 and seed yield
did not decrease as salinity increased from 20 to 40 dS m-1 in the variety Titicaca Ruiz-Carrasco
et al (2011) reported that under 300 mM NaCl germination and shoot length were significantly
reduced whereas root length was inhibited in variety BO78 variety PRJ biomass was less
affected and exhibited the greatest increase in proline concentration Jacobsen et al (2000)
suggested that stomatal conductance leaf area and plant height were the characters in quinoa
most sensitive to salinity Wilson et al (2002) examined salinity stress of salt mixtures of
MgSO4 Na2SO4 NaCl and CaCl2 (3 ndash 19 dS m-1) No significant reduction in plant height and
fresh weight were observed In a comparison of the effects of NaCl and Na2SO4 on seed yield
quinoa exhibited greater tolerance to Na2SO4 than to NaCl (Peterson and Murphy 2015)
Few studies have focused on the influence of salinity on seed quality in quinoa Karyotis
et al (2003) conducted a field experiment in Greece (80 m above sea level latitude 397degN)
With the exception of Chilean variety lsquoNo 407rsquo seven other varieties exhibited significant
increases in protein (13 to 33) under saline-sodic soil with electrical conductivity (EC) of
65 dS m-1 Mineral contents of phosphorous iron copper and boron did not decrease under
saline conditions Koyro and Eisa (2008) found a significant increase in protein and a decrease in
total carbohydrates under high salinity (500 mM) Pulvento et al (2012) indicated that fiber and
saponin contents increased under saline conditions with well watersea water ratio of 11
compared to those under normal soil
122
Protein is one of the most important nutritional components of quinoa seed The content
and quality of protein contribute to the nutritional value of quinoa Additionally seed hardness is
an important trait in crops such as wheat and soybeans For instance kernel hardness highly
influences wheat end-use quality (Morris 2002) and correlates with other seed quality
parameters such as ash content semolina yield and flour protein content (Hruškovaacute and Švec
2009) Hardness of soybean influenced water absorption seed coat permeability cookability
and overall texture (Zhang et al 2008) Quinoa seed hardness was correlated with the texture of
cooked quinoa influencing hardness chewiness and gumminess and potentially consumer
experience (Wu et al 2014) Furthermore seed density is also a quality index and is negatively
correlated with the texture of cooked quinoa such as hardness cohesiveness chewiness and
gumminess (Wu et al 2014)
Chilean lowland varieties have been shown to be the most well-adapted to temperate
latitudes (Bertero 2003) and therefore they have been extensively utilized in quinoa breeding
programs in both Colorado State University and Washington State University (Peterson and
Murphy 2015) For these reasons Chilean lowland varieties were evaluated in the present study
The objectives of this study were to 1) examine the effect of soil salinity on the protein content
seed hardness and density of quinoa varieties 2) determine the effect of different levels of two
agronomically important soil salts NaCl and Na2SO4 on seed quality and 3) test the influence
of fertilization levels on salinity tolerance of quinoa The present study illustrates the different
influence of NaCl and Na2SO4 on quinoa seed quality and provides better guidance for variety
selection and agronomic planning in highly saline environments
Materials and Methods
123
Genetic material
Quinoa germplasms were obtained from Dr David Brenner at the USDA-ARS North
Central Regional Plant Introduction Station in Ames Iowa The four quinoa varieties CO407D
(PI 596293) UDEC-1 (PI 634923) Baer (PI 634918) and QQ065 (PI 614880) were originally
sourced from lowland Chile CO407D was released by Colorado State University in 1987
UDEC-1 Baer and QQ065 were varieties from northern central and southern locations in Chile
with latitudes of 3463deg S 3870deg S and 4250deg S respectively
Experimental design
A controlled environment greenhouse study was conducted using a split-split-plot
randomized complete block design with three replicates per treatment Factors included four
quinoa varieties two fertility levels and seven salinity treatments (three concentration levels
each of NaCl and Na2SO4) Three subsamples each representing a single plant were evaluated
for each treatment combination Quinoa variety was treated as the main plot salinity level as the
sub-plot and fertilization as the sub-sub-plot Salinity levels included 8 16 and 32 dS m-1 of
NaCl and Na2SO4 The details of controlling salinity levels were described by Peterson and
Murphy (2015) In brief fertilization was provided by a mixture of alfalfa meal
monoammonium phosphate and feather meal Low fertilization level referred to 1 g of N 029 g
of P and 029 g of K in each pot and high fertilization level referred to 3 g of N 086 g of P and
086 g of K in each pot Each pot contained about 1 L of Sunshine Mix 1 (Sun Gro Horticulture
Bellevue WA) (dry density of 100 gL water holding capacity of ca 480 gL potting mix) The
124
entire experiment was conducted twice with the planting dates of September 10th 2011 and
October 7th 2011
Seed quality tests
Protein content of quinoa was determined using the Dumas combustion nitrogen method
(LECO Corp Joseph Mich USA) (AACCI Method 46-3001) A factor of 625 was used to
convert nitrogen to protein Seed hardness was determined using the Texture Analyzer (TA-
XT2i) (Texture Technologies Corp Scarsdale NY) and a modified rice kernel hardness method
(Krishnamurthy and Giroux 2001) A single quinoa kernel was compressed until the point of
fracture using a 1 cm2 cylinder probe traveling at 5 mms Repeat measurements were taken on 9
random kernels The seed hardness was recorded as the average peak force (Kg) of the repeated
measures
Seed density was determined using a pycnometer (Pentapyc 5200e Quantachrome
Instruments Boynton Beach FL) Quinoa seed was placed in a closed micro container and
compressed nitrogen was suffused in the container Pressure in the container was recorded both
with and without nitrogen The volume of the quinoa sample was calculated by comparing the
standard pressure obtained with a stainless steel ball Density was the seed weight divided by the
displaced volume Seed density was collected on only the second greenhouse experiment
Statistical analysis
Data were analyzed using the PROC GLM procedure in SAS (SAS Institute Cary NC)
Greenhouse experiment repetition was treated as a random factor in protein content and seed
hardness analysis Variety salinity and fertilization were treated as fixed factors Fisherrsquos LSD
125
Test was used to access multiple comparisons Pearson correlation coefficients between protein
hardness and density were obtained via PROC CORR procedure in SAS using the treatment
means
Results
Protein
Variety salinity and fertilization all exhibited highly significant effects on protein
content (P lt 0001) (Table 1) The greatest contribution to variation in seed protein was due to
fertilization (F = 40247) In contrast salinity alone had a relatively minor effect and the
varieties responded similarly to salinity as evidenced by a non-significant interaction The
interactions however were found in variety x fertilization as well as in salinity x fertilization
both of which were addressed in later paragraphs It is worth noting that the two experiments
produced different seed protein contents (F = 4809 P lt0001) experiment x variety interaction
was observed (F = 1494 P lt0001) (data not shown) Upon closer examination this interaction
was caused by variety QQ065 which produced an overall mean protein content of 129 in
experiment 1 and 149 in experiment 2 Protein contents of the other three varieties were
essentially consistent across the two experiments
Across all salinity and fertilization treatments the variety protein means ranged from
130 to 167 (data not shown) As expected high fertilization resulted in an increase in
protein content across all varieties The mean protein contents under high and low fertilization
were 158 and 136 respectively (Table 2) The means of Baer and CO407D were the
126
highest 151 and 149 respectively QQ065 contained 141 protein significantly lower
than the other varieties
Even though salinity effects were relatively smaller than fertilization and variety effects
salinity still had a significant effect on protein content (Table 1) The two types of salt exhibited
different impacts on protein (Table 2) Protein content did not differ according to different
concentrations of NaCl with means (across varieties and fertilization levels) from 147 to
149 Seed from 32 dS m-1 Na2SO4 however contained higher protein (152) than that from
8 dS m-1 and 16 dS m-1 Na2SO4 (144 and 142 respectively)
A significant interaction of salinity x fertilization was detected indicating that salinity
differentially impacted seed protein content under high and low fertilization level (Figure 1)
Within the high fertilizer treatment protein content in the seed from 32dS m-1 Na2SO4 was
significantly higher (167) than all other samples which did not differ from each other (~13)
Within the low fertilizer treatment protein content of seeds from 8 dS m-1 and 16 dS m-1
Na2SO4 were significantly lower than those from the NaCl treatments and 32dS m-1 Na2SO4
The significant interaction between variety and fertilization (Table 1) was due to the
different response of QQ065 Protein mean of QQ065 from high fertilization was 144 lower
than the other varieties CO407D UDEC-1 and Baer exhibited a decline of 16 - 18 in
protein under low fertilization while QQ065 dropped only 5
Hardness
Variety exhibited the greatest influence on seed hardness (F = 21059 P lt0001)
whereas fertilization did not show any significant effect (Table 1) Salinity exhibited a moderate
127
effect (F = 200 P = 009) Varieties responded consistently to salinity under various fertilization
levels since neither variety x salinity nor salinity x fertilization interaction was significant
However a variety x fertilization interaction was observed which will be discussed in a later
paragraph Similar to the situation in protein content experiment repetition exhibited a
significant influence on seed hardness Whereas the hardness of CO407D was consistent across
the two greenhouse experiments the hardness of other three varieties all decreased by 8 to 9
Mean hardness was significantly different among varieties CO407D had the hardest
seeds with hardness mean of 100 kg (Table 3) UDEC-1 was softer at 94 kg whereas Baer and
QQ065 were the softest and with similar hardness means of 77 kg and 74 kg respectively
Salinity exhibited a moderate impact on seed hardness (P = 009) The highest hardness
mean was observed under 16 dS m-1 Na2SO4 whereas the lowest was under 8 dS m-1 NaCl with
means of 89 and 83 kg respectively
A significant fertilization x variety interaction was found for seed hardness The hardness
of UDEC-1 and Baer did not differ across fertilization level whereas CO407D was harder under
low fertilization and QQ065 was harder under high fertilization
Seed density
Variety and salinity both significantly affected seed density whereas fertilization did not
show a significant influence (Table 1) The greatest contribution to variation in seed density was
due to variety (F = 2282) Salinity exhibited a relatively smaller effect yet still significant (F =
282 P lt005) Neither variety x salinity interaction nor salinity x fertilization interaction was
observed which indicated that varieties similarly responded to salinity under high and low
128
fertilization levels An interaction of variety x fertilization was found and the details were
presented later
Across all salinity and fertilization treatments CO407D had the highest mean density
080 gcm3 followed by Baer with 069 gcm3 (Table 4) UDEC-1 and QQ065 had the lowest and
similar densities (~065 gcm3)
With regard to salinity effect the Na2SO4 treatments exhibited differential influence on
seed density Density means did not significantly change due to the increased concentration of
NaCl ranging from 068 to 071 gcm3 (Table 4) The samples from 8 dS m-1 Na2SO4 soil had
lower density (066 gcm3) than those from 16 dS m-1 and 32 dS m-1 Na2SO4 074 and
072gcm3 respectively
A significant variety x fertilization interaction was found With closer examination
UDEC-1 and Baer yielded higher density seeds under high fertilization whereas CO407D and
QQ065 did not differ in density between fertilization treatments
Correlations of protein hardness and density
Correlation coefficients among seed protein content hardness and density are shown in
Table 5 No significant correlation was detected between protein content and seed hardness
However both protein content and hardness were correlated with seed density The overall
correlation coefficient was low (r = 019 P = 003) between density and protein A marginally
significant correlation was found between density and protein content of the seeds from NaCl
salinized soil under low fertilization No correlation was found between density and protein
content of the seeds from NaCl salinized soil under high fertilization or Na2SO4 salinized soil
129
The overall correlation coefficient was 038 (P lt 00001) between density and hardness
The low fertilization samples from both NaCl and Na2SO4 soil showed significant correlations
between density and hardness with coefficients of 051 and 047 (both P lt 0005) The high
fertility quinoa did not exhibit any correlation between density and hardness
Correlation with yield leaf greenness index plant height and seed minerals contents
Correlation between seed quality and yield leaf greenness index plant height and seed
mineral concentration were obtained using data from Peterson and Murphy (2015) (Table 6)
Seed hardness significantly correlated with yield and plant height (r = 035 and 031
respectively) Protein content and density however did not correlate with yield leaf greenness
or plant height Correlations were found between quality indices and the concentration of
different minerals Protein was negatively correlated with Cu and Mg (r = -052 and -050
respectively) Hardness was negatively correlated with Cu P and Zn (r = -037 -056 -029
respectively) but was positively correlated with Mn (r = 057) Density was negatively
correlated with Cu (r = -035)
Discussion
Protein
Although salinity exhibited a significant effect on seed protein content the impact was
relatively minor compared to fertilization and variety effects In another words over a wide
range of saline soil quinoa can grow and yield seeds with stable protein content
130
Protein content of quinoa growing under salinized soil ranged from 127 to 167 (data
not shown) within the general range of protein content under non-saline conditions which was
12 to 17 (Rojas et al 2015) Saline soil did not cause a significant decrease in seed protein
It is interesting to notice that the samples from 32 dS m-1 Na2SO4 tended to contain the highest
protein especially in variety QQ065 The studies of Koyro and Eisa (2008) and Karyotis et al
(2003) also indicated that protein content significantly increased under high salinity (NaCl)
whereas total carbohydrates decreased In contrast Ruffino et al (2009) found that quinoa
protein decreased under 250 mM NaCl salinity in a growth chamber experiment It is reasonable
to conclude that salinity exhibits contrasting effects on different quinoa genotypes QQ065 and
CO407D both significantly increased in protein under 32 dS m-1 Na2SO4 however the yield
decline was 519 and 245 respectively (Peterson and Murphy 2015) This result indicted
that CO407D was the variety most optimally adapted to severe sodic saline soil tested in this
study
Na2SO4 level exhibited a significant influence on protein content whereas NaCl level did
not In the study of Koyro and Eisa (2008) however seed protein of the quinoa variety Hualhuas
(origin from Peru) increased under the highest salinity level of 500 mM NaCl compared to lower
NaCl levels (0 ndash 400 mM) This disagreement of NaCl influence may be due to diversity of
genotypes It is worth noting that quinoa protein contents in this paper were primarily above 13
based on wet weight (as-is-moisture of approximately ~8 -10) even under saline soil and low
fertilization level This protein content is generally equal to or higher than that of other crops
such as barley and rice (Wu 2015) In conclusion quinoa maintained high and stable protein
content under salinity stress
131
Hardness
Quinoa seed hardness was only moderately affected by salinity (P = 009) indicating that
quinoa primarily maintained seed texture when growing under a wide range of saline soil
CO407D exhibited the hardest seed (100 kg) whereas Baer and QQ065 were relatively soft (74
ndash 77 kg) A previous study indicated a hardness range of 58 ndash 109 kg among 11 quinoa
varieties and 2 commercial samples (Wu et al 2014) The commercial samples had hardness
values of 62 kg and 71 kg Since commercial samples generally maintain stable quality and
indicate an acceptable level for consumers seed hardness around 7 kg as in Baer and QQ065
should be considered as acceptable quality The hardness of CO407D was close to that of the
colored variety lsquoBlackrsquo (100 kg) which had a thicker seed coat than that of the yellow seeded
varieties It was reported that a thicker seed coat is related to harder texture (Fraczek et al 2005)
Even though the greenhouse is a highly controlled environment and the two experiments
were conducted in similar seasons (planted in September and October respectively) seed protein
and hardness were still different across the two experiments However ANOVA indicated
modest-to-no significant interactions with salinity and fertilization such that responses to salinity
and fertilization were consistent with little or no change in rank order Even though experiment x
variety was significant the F-values were relatively low compared to the major effects such as
variety and fertilization and neither of them was crossing interaction This is a particularly
noteworthy result for breeders farmers and processors
Density
132
The range of seed density under salinity 055 ndash 089 gcm3 was comparable to the
density range of 13 quinoa samples (058 ndash 076 gcm3 ) (Wu et al 2014) Generally CO407D
had higher seed density (071 ndash 089 gcm3) which indicated that seed density in this variety was
affected by salinity stress In contrast the density of QQ065 did not change according to salinity
type or concentration which indicated a stable quality under saline soil
Correlations
The correlation between seed hardness and density was only significant under low fertilization
but not under high fertilization The high fertilization level in the greenhouse experiment
exceeded the amount of fertilizer that would normally be applied in field environments whereas
the low fertilization level is closer to the field situation Therefore correlation between hardness
and density may still exist in field trials
Conclusions
Under saline soil conditions quinoa did not show any marked decrease in seed quality
such as protein content hardness and density Protein content even increased under high Na2SO4
concentration (32 dS m-1) Varieties exhibited great differential reactions to fertilization and
salinity levels QQ065 maintained a similar level of hardness and density whereas seed of
CO407D was both harder and higher density under salinity stress If only seed quality is
considered then QQ065 is the most well-adapted variety in this study
The influences of NaCl and Na2SO4 were different The higher concentration of Na2SO4
tended to increase protein content and seed density whereas NaCl concentration did not exhibit
any significant difference on those quality indexes
133
Acknowledgement
The research was funded by USDA Organic Research and Extension Initiative project
number NIFAGRANT11083982 The authors acknowledge Alecia Kiszonas for assisting in the
data analysis
Author contributions
Peterson AJ set up the experiment design in the greenhouse and grew harvested and
processed quinoa samples Wu G collected seed quality data such as protein content seed
hardness and density Peterson AJ and Wu G together processed the data Wu G also drafted the
manuscript Murphy KM and Morris CF edited the manuscript
Conflict of interest statement
The authors declared to have no conflict of interest
134
References
AACC International Approved Methods of Analysis Method 46-3001 Crude protein ndash
Combustion method Approved November 8 1995 Reapproved November 3 1999
Availablenline only AACCI St Paul MN
Adolf VI Shabala S Andersen MN Razzaghi F Jacobsen SE 2012 Varietal differences of
quinoas tolerance to saline conditions Plant Soil 357 117ndash29
Bertero HD 2003 Response of developmental processes to temperature and photoperiod in
quinoa (Chenopodium quinoa Willd) Food Rev Int 19 87ndash97
Cai S Yu G Chen X Huang Y Jiang X Zhang G Jin X 2013 Grain protein content variation
and its association analysis in barley BMC Plant Boil 13 35
Chilo G Molina MV Carabajal R Ochoa M 2009 Temperature and salinity effects on
germination and seedling growth on two varieties of Chenopodium quinoa Agri-Scientia 26
15ndash22
Cocozza C Pulvento C Lavini A Riccardi M dAndria R Tognetti R 2013 Effects of
increasing salinity stress and decreasing water availability on ecophysiological traits of
quinoa (Chenopodium quinoa Willd) grown in a mediterranean-type agroecosystem J Agron
Crop Sci 199 229ndash40
Fraczek J Hebda T Slipek Z Kurpaska S 2005 Effect of seed coat thickness on seed hardness
Can Biosyst Eng 47 41ndash5
135
Gonzaacutelez JA Eisa SSS Hussin SAES Prado FE 2015 Quinoa an Incan crop to face global
changes in agriculture In Murphy KM Matanguihan J editors Quinoa Improvement and
Sustainable Production Hoboken NJ John Wiley Sons p 7ndash11
Hruškovaacute M Švec I 2009 Wheat hardness in relation to other quality factors Czech J Food Sci
27 240ndash8
Jacobsen S Quispe H Mujica A 2000 Quinoa an alternative crop for saline soils in the Andes
in Scientist and Farmer Partners in Research for the 21st Century (Program Report 1999-
2000) ed International Potato Center (Peru) 403ndash8
Jancurovaacute M Minarovicovaacute L Dandar A 2009 Quinoandasha review Czech J Food Sci 27 71ndash9
Karyotis T Iliadis C Noulas C Mitsibonas T 2003 Preliminary research on seed production
and nutrient content for certain quinoa varieties in a salinendashsodic soil J Agron Crop Sci 189
402ndash8
Koyro HW Eisa S 2008 Effect of salinity on composition viability and germination of seeds of
Chenopodium quinoa Willd Plant Soil 302 79-90
Krishnamurthy K Giroux MJ 2001 Expression of wheat puroindoline genes in transgenic rice
enhances grain softness Nat Biotechnol 19 162ndash6
Morris CF 2002 Puroindolines the molecular genetic basis of wheat grain hardness Plant mol
Biol 48 633ndash47
136
Orth RA Shellenberger JA 1988 Chapter 1 Origin production and utilization of wheat In
Pomeranz Y editor Wheat Chemistry and Technology 3th edition St Paul MN American
Association of Cereal Chemists Inc p 11ndash2
Peterson A Murphy K 2015 Tolerance of lowland quinoa cultivars to sodium chloride and
sodium sulfate salinity Crop Sci 55 331ndash8
Pitman MG Laumluchli A 2002 Global impact of salinity and agricultural ecosystems In Laumluchli
A Luumlttge U editors Netherlands Springer p 3ndash20
Prado FE Boero C Gallardo M Gonzaacutelez JA 2000 Effect of NaCl on germination growth and
soluble sugar content in Chenopodium quinoa Willd seeds Bot Bull Acad Sinica 41 27ndash34
Pulvento C Riccardi M Lavini A Iafelice G Marconi E dAndria R 2012 Yield and quality
characteristics of quinoa grown in open field under different saline and non-saline irrigation
regimes J Agron Crop Sci 198 254ndash63
Ranhotra G Gelroth J Glaser B Lorenz K Johnson D 1993 Composition and protein
nutritional quality of quinoa Cereal Chem 70 303ndash5
Razzaghi F Ahmadi SH Jacobsen SE Jensen CR Andersen MN 2012 Effects of salinity and
soilndashdrying on radiation use efficiency water productivity and yield of quinoa (Chenopodium
quinoa Willd) J Agron Crop Sci 198 173ndash84
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile D
137
Bertero D Nieto C editors State of the Art Report of Quinoa in the World in 2013 Rome
FAO amp CIRAD p 67-8
Ruffino A Rosa M Hilal M Gonzaacutelez J Prado F 2010 The role of cotyledon metabolism in the
establishment of quinoa (Chenopodium quinoa)seedlings growing under salinity Plant Soil
326 213ndash24
Ruiz-Carrasco K Antognoni F Coulibaly A K Lizardi S Covarrubias A Martiacutenez E A
Shabala S Hariadi Y Jacobsen SE 2013 Genotypic difference in salinity tolerance in quinoa is
determined by differential control of xylem Na+ loading and stomatal density J Plant Physiol
170 906ndash14
Shih FF 2006 Chapter 6 Rice protein In Champagne ET editor Rice Chemistry and
Technology 3rd edition St Paul MN American Association of Cereal Chemists Inc p
143-4
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Taylor JRN Parker ML editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science amp Business Media p 96-101
USDA (United States Department of Agriculture) 2011 Soil and water resources conservation
act (RCA) P 31 Access from
httpwwwnrcsusdagovInternetFSE_DOCUMENTSstelprdb1044939pdf
Wilson C Read J Abo-Kassem E 2002 Effect of mixed-salt salinity on growth and ion
relations of a quinoa and a wheat variety J Plant Nutri 25 2689ndash704
138
Wu G Morris CF Murphy KM 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79 2337ndash45
Wu G 2015 Chapter 11 Nutritional properties of quinoa In Murphy KM Matanguihan J
editors Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp
Sons Inc p 193-205
Zhang B Chen P Chen CY Wang D Shi A Hou A Ishibashi T 2008 Quantitative trait loci
mapping of seed hardness in soybean Crop Sci 48 1341ndash9
Zevallos VF Herencia LI Chang F Donnelly S Ellis HJ Ciclitira PJ 2014 Gastrointestinal
effects of eating quinoa (Chenopodium quinoa Willd) in celiac patients Am J Gastroenterol
109 270ndash8
Zurita-Silva A 2011 Variation in salinity tolerance of four lowland genotypes of quinoa
(Chenopodium quinoa Willd) as assessed by growth physiological traits and sodium
transporter gene expression Plant Physiol Bioch 49 1333ndash41
139
Table 1-Analysis of variance with F-values for protein content hardness and density of quinoa seed
Effect F-values
Protein Hardness Density
Model 524 360 245
Variety 2463 21059 2282
Salinity 975 200dagger 282
Fertilization 40247 107 260
Variety x Salinity 096 098 036
Variety x Fertilization 2062 1094 460
Salinity x Fertilization 339 139 071
Variety x Salinity x Fertilization 083 161dagger 155
dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the 001 probability level Significant at the lt0001 probability level
140
Table 2-Salinity variety and fertilization effects on quinoa seed protein content ()
Salinity Protein content ()
Variety Protein content ()
Fertilization Protein content ()
8 dS m-1 NaCl 147bc1 CO407D 149ab High 158a
16 dS m-1 NaCl 148ab UDEC-1 147b Low 136b
32 dS m-1 NaCl 149ab Baer 151a
8 dS m-1 Na2SO4 144cd QQ065 141c
16 dS m-1 Na2SO4 142d
32 dS m-1 Na2SO4 152a 1Different letters in a given column indicate significant differences (P lt 005)
141
Table 3-Salinity variety and fertilization effects on quinoa seed hardness (kg)
Salinity Hardness (kg)1 Variety Hardness (kg)
8 dS m-1 NaCl 83 CO407D 100a2
16 dS m-1 NaCl 87 UDEC-1 94b
32 dS m-1 NaCl 85 Baer 77c
8 dS m-1 Na2SO4 87 QQ065 74c
16 dS m-1 Na2SO4 89
32 dS m-1 Na2SO4 88 1Hardness was significant at the 009 probability level 2Different letters in a given column indicate significant differences (P lt 005)
142
Table 4-Salinity variety and fertilization effects on quinoa seed density (g cm3)
Salinity density (g cm3) Variety density (g cm3)
8 dS m-1 NaCl 069bc1 CO407D 080a
16 dS m-1 NaCl 068bc UDEC-1 066bc
32 dS m-1 NaCl 071abc Baer 069b
8 dS m-1 Na2SO4 066c QQ065 065c
16 dS m-1 Na2SO4 074a
32 dS m-1 Na2SO4 072ab 1Different letters in a given column indicate significant differences (P lt 005)
143
Table 5-Correlation coefficients of protein hardness and density of quinoa seed
Correlation All NaCl Na2SO4
High fertilization
Low fertilization
High fertilization
Low fertilization
Protein -Density 019 013ns 029dagger 026ns 019ns
Hardness - Density 038 027ns 051 022ns 047
ns Not significant dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the lt0001 probability level
144
Table 6-Correlation coefficients of quinoa seed quality and agronomic performance and seed mineral content
Protein Hardness Density
Yield 004 035 006
Plant Height -004 031 011
Cu -052 -037 -035
Mg -050 004 0
Mn -006 057 025dagger
P -001 -056 -015
Zn -004 -029 -028dagger
dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the 001 probability level Significant at the lt0001 probability level
145
Figure 1-Protein content () of quinoa in response to combined fertility and salinity treatments
146
Chapter 6 Lexicon development and consumer acceptance
of cooked quinoa
ABSTRACT
Quinoa is becoming increasingly popular with an expanding number of varieties being
commercially available In order to compare the sensory properties of these quinoa varieties a
common sensory lexicon needs to be developed Thus the objective of this study was to develop
a lexicon of cooked quinoa and examine consumer acceptance of various varieties A trained
panel (n = 9) developed appropriate aroma tasteflavor texture and color descriptors to describe
cooked quinoa and evaluated 21 quinoa varieties Additionally texture of the cooked quinoa was
determined using a texture analyzer Results indicated panelists using this developed lexicon
could distinguish among these quinoa varieties showing significant differences in aromas
tasteflavors and textures Specifically quinoa variety effects were observed for the aromas of
caramel nutty buttery grassy earthy and woody tasteflavor of sweet bitter grain-like nutty
earthy and toasty and texture of firm cohesive pasty adhesive crunchy chewy astringent and
moist The varieties lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Drsquo exhibited adhesive texture that has not
been seen in any commercialized quinoa Subsequent consumer evaluation (n = 102) on 6
selected samples found that the lsquoPeruvian Redrsquo was the most accepted overall while the least
accepted was lsquoQQ74rsquo Partial least squares analysis on the consumer and trained panel data
indicated that overall consumer liking was driven by higher intensities of grassy aroma and firm
and crunchy texture The attributes of pasty moist and adhesive were less accepted by
consumers This overall liking was highly correlated with consumer liking of texture (r = 096)
147
tasteflavor (r = 095) and appearance (r = 091) of cooked quinoa From the present study the
quinoa lexicon and key drivers of consumer acceptance can be utilized in the industry to evaluate
quinoa product quality and processing procedures
Keywords quinoa lexicon sensory evaluation
Practical application The lexicon of cooked quinoa can be used by breeders to screen quinoa
varieties Furthermore the lexicon will useful in the food industry to evaluate quinoa ingredients
from multiple farms harvest years processing procedures and product development
148
Introduction
Quinoa is classified as a pseudocereal like amaranth and buckwheat With its high
protein content and balanced essential amino acid profile quinoa is becoming popular
worldwide From 1992 to 2012 quinoa exports increased dramatically from 600 tons to 37000
tons (Furche et al 2015) Quinoa price in retail stores increased from $9kg in 2013 to $13kg -
$20kg in 2015 (Arco 2015) Quinoa has been incorporated into numerous products including
bread cookies pasta cakes and chocolates (Pop et al 2014 Alencar et al 2015 Casas Moreno
et al 2015 Wang et al 2015) Some of these products are gluten-free foods thus targeting the
gluten-sensitive market segment (Wang et al 2015)
Popularity of quinoa inspired US researchers to breed varieties that are compatible with
local weather and soil conditions which greatly differ from quinoarsquos original land the Andean
mountain region Since 2010 Washington State University has been breeding quinoa in the
Pacific Northwest region of United States Of the quinoa varieties evaluated in the breeding
program agronomic attributes of interest include high yield consistent performance over years
and tolerance to drought salinity heat and diseases (Peterson and Murphy 2013 Peterson
2013) However beyond agronomic attributes the grain sensory profiles of these quinoa
varieties are also important to assist in breeding decisions as well as screening
genotypescultivars for various food applications
In order to provide a complete descriptive profile of the cooked quinoa a trained sensory
evaluation should be used along with a complete lexicon of the sensory attributes of importance
Currently no quinoa lexicon is available and descriptions of quinoa sensory properties are
149
limited From currently published research papers attributes describing quinoa taste have been
limited to bitter sweet earthy and nutty (Koziol 1991 Lorenz and Coulter 1991 Repo-Carrasco
et al 2003 Stikic et al 2012 Foumlste M et al 2014) and texture of cooked quinoa has been
described as creamy smooth and crunchy (Abugoch 2009) Thus to address the lack of quinoa
lexicon one objective of this study is to develop a lexicon describing the sensory properties of
quinoa
Beyond developing a lexicon to describe quinoa consumer preference of the different
quinoa varieties is also of great interest Most previous sensory studies in quinoa focused on
acceptance of quinoa-containing products while consumer acceptance on plain grain of quinoa
varieties has not been studied Because of the lack of cooked quinoa studies with consumers rice
may be considered as a model to study quinoa because of their similar cooking process Tomlins
et al (2005) found consumer preference of rice was driven by the attributes of uniform clean
bright translucent and cream with consumers not liking the brown color of cooked rice and
unshelled paddy in raw rice In another study Suwannaporn et al (2008) found consumer
acceptance of rice products was significantly influenced by convenience grain variety and
traditionnaturalness
This study presenting a quinoa lexicon along with consumer acceptance of quinoa
varieties provides critical information for both the breeding programs and food industry
researchers Given the predicted importance of texture in consumer acceptance of quinoa texture
analysis was conducted to evaluate the parameters of hardness adhesiveness cohesiveness
chewiness and gumminess in quinoa samples
150
This lexicon describing the sensory attributes of cooked quinoa will be a useful tool to
evaluate quinoa varieties compare samples from different farms harvest years seed quality and
cleaning processing procedures Finally the sensory attributes driving consumersrsquo liking can be
utilized to evaluate optimal quinoa quality and target different consumers based on preference
Materials and methods
Quinoa samples
The present study included twenty-one quinoa samples harvested in 2014 which included
sixteen varieties from Finnriver Organic Farm (Finnriver WA) and five commercial samples
from Bolivia and Peru (Table 1)
Quinoa preparation
Following harvest the samples from Finnriver Farm were cleaned in a Clipper Office
Tester (Seedburo Des Plainies IL USA) to separate mixed weed seeds and threshed materials
Furthermore the samples were soaked for 30 min rubbed manually under running water and
dried at 43 ordmC until the moisture reached lt 11 Generally a moisture of 12 - 14 is
considered safe for grain storage (Hoseney 1989)
To prepare quinoa samples for sensory evaluation samples were soaked for 30 min and
mixed with water at a 12 ratio These mixtures were brought to a boil and simmered for 20 min
Following cooking the quinoa was cooled to room temperature Samples of cooked quinoa (10
g) were served in 30 mL plastic containers with lids (SOLO Lakeforest IL USA) Quinoa
151
samples were cooked and placed in covered cups within 2 h before evaluation Unsalted
crackers plastic cups used as cuspidors and napkins were provided to each panelist
Trained sensory evaluation panel
This project was approved by the Institutional Review Board of Washington State
University Sensory panelists (n = 9) were recruited via email announcements Panelists were
selected based on their interest in quinoa and availability All participants signed the Informed
Consent Form They received non-monetary incentives for each training session and a large non-
monetary reward at the completion of the formal evaluation
Demographic information was collected using a questionnaire Panelists included 4
females and 5 males ranging in age from 21 to 60 (mean age of 35) Regarding quinoa
consumption frequency four panelists frequently consumed quinoa (few times per month to
everyday) whereas five panelists rarely consumed quinoa As quinoa is a novel crop to most of
the world this was expected Since rice is a comparable model of quinoa frequency of rice
consumption was also considered with all panelists being frequent rice consumers
Sensory training and lexicon development
The training consisted of 12 sessions of 15 hours totaling 18 hours In the early stages
of the panel training attribute terms and references were discussed Panelists were first presented
with samples in covered plastic containers The samples widely varied in their sensory attributes
and included the varieties of lsquoBlackrsquo lsquoBolivian Redrsquo and lsquoBolivian Whitersquo The panelists
developed terms to describe the appearance aroma flavor taste and texture of the samples
Additionally the same samples were evaluated by an experienced sensory evaluation panel with
152
terms collected from this set of evaluators Terms were collected from panelists professionals
and literature describing rice (Meilgaard et al 2007 Limpawattana and Shewfelt 2010) The
term list was presented and discussed with panelist consensus being used to determine which
sensory terms appeared in the final lexicon
The final lexicon and associated definitions are presented in Table 2 This lexicon
included the sensory attributes of color (black red yellow) aroma (caramel grain-like bean-
like nutty buttery starchy grassygreen earthymusty woody) tasteflavor (sweet bitter grain-
like bean-like nutty earthy and toasted) and texture (soft-firm separate-cohesive pasty
adhesivenesssticky crunchycrumblycrisp chewygummy astringent and waterymoist)
References standards for each attribute were introduced The references were discussed and
modified until the panelists were in agreement Panelists reviewed the reference standards at the
beginning of each training session Since aroma varies over time all aroma references were
prepared 1-2 h before training During training three to four quinoa samples were evaluated and
discussed in each session The ability to detect attribute differences and the reproducibility of
panelists were both monitored and visualized using spider graphs and line graphs Using this
feedback panelists were calibrated paying extra attention to those attributes that were outside of
the panel standard deviation Practice sessions were continued until the panelists accurately and
consistently assessed varietal differences of quinoa
The protocols applied to evaluate samples and references were consistent among
panelists At the start of the evaluation the sample cup was shaken to allow the aroma to
accumulate in the headspace Panelists then lifted the cover and immediately took three short
sharp sniffs to evaluate the aroma Panelists then determined the color and its intensity Finally
153
panelists used the spoon to place the sample in-mouth and evaluate the tasteflavor and texture
Between each sample panelists rinsed their palate using water and unsalted crackers A 15-cm
line scale with 15-cm indentations on each end was used to determine the intensity of attributes
The values of 15 and 135 represented the extremely low and high intensity respectively Using
the lexicon panelists were trained to sense and quantify the attributes of cooked quinoa on
aroma color tasteflavor and texture
Following the development of the lexicon formal evaluations were conducted in the
sensory booths under white lights Compusensereg Five (Guelph Ontario Canada) provided scales
and programs for evaluation and collected results Panelists followed the protocol and used the
lexicon and 15-cm scales to evaluate the sensory attributes of the cooked quinoa samples
Twenty-one quinoa samples were tested in duplicate Panelists attended one session per day and
four sessions in total During each session panelists evaluated 10 or 11 samples with a 30 s
break after each sample and a 10 min break after the fifth sample Each variety was assigned
with a random three-digit code and the serving order was randomized
Consumer acceptance panel
From the 21 samples evaluated by the trained panelists six were selected for consumer
evaluation These six samples selected were diverse in color tasteflavor and texture as defined
by the trained panel results Consumers (n = 102) were recruited from Pullman WA Of the
consumers 49 were male and 52 were female with age ranging from 19 to 64 (mean age of 33)
The consumers showed different familiarity with quinoa with 29 indicating that they were
154
familiar with quinoa 40 having tried quinoa a few times and 32 having never tried quinoa
before All consumers had consumed rice before
The project was approved by the Institutional Review Board of Washington State
University Each consumer signed an Informed Consent Form and received a non-monetary
incentive at the end of evaluation The evaluation was conducted in the sensory booths under
white light Six quinoa samples were assigned with three-digit code and randomly presented to
each consumer using monadic presentation Quinoa samples were cooked and distributed in
evaluation cups and lidded (~10 gcup) the day before stored at 4 degC overnight and placed at
room temperature (25 degC) for 1 h prior to evaluation
During evaluation consumers followed the protocol instructions and indicated the degree
of acceptance of aroma color appearance tasteflavor texture and overall liking using a 7-point
hedonic scale (1 = dislike extremely 7 = like extremely) provided by Compusensereg Five
(Guelph Ontario Canada) A comments section was provided at the end of each sample
evaluation to gather additional opinions and information Between samples panelists took a 30 s
break and cleansed their palates using unsalted crackers and water
Texture Profile Analysis by instrument (TPA)
The texture of 21 cooked quinoa samples were conducted using a TA-XT2i Texture
Analyzer (Texture Technologies Corp Hamilton MA USA) (Wu et al 2014) Samples were
cooked using the same procedure as in the trained panel evaluation and cooled to room
temperature prior to evaluation
Statistical analysis
155
Sample characteristics and trained panel results were analyzed using three-way ANOVA
and mean separation (Fisherrsquos LSD) PCA was performed on the trained panel data Using
trained panel data and consumer evaluation data partial least square regression analysis was
performed Additionally correlations between instrument tests and panel evaluation on texture
and tasteflavor were determined XLSTAT 2013 (Addinsoft Paris France) was used for all data
analysis
Results and Discussion
Lexicon Development
A lexicon was created to describe the sensory attributes of cooked quinoa (Table 2) A
total of 27 attributes were included in the lexicon based on color (black red yellow) aroma
(caramel grain-like bean-like nutty buttery starchy grassygreen earthymusty and woody)
tasteflavor (sweet bitter grain-like bean-like nutty earthy and toasted) and texture (firm
cohesive pasty adhesivenesssticky crunchy chewygummy astringent and waterymoist)
Rice is considered as a good model of quinoa lexicon developments since both products
have common preparation methods The lexicon for cooked rice has been developed for the
aroma tasteflavor and texture properties of rice (Lyon et al 1999 Meullenet et al 2000
Limpawattana and Shewfelt 2010) Many attributes from these previously developed rice
lexicons can be applied to cooked quinoa For instance rice aroma and flavor notes such as
starchy woody grain nutty buttery earthy sweet bitter and astringent are also present in
quinoa Hence those notes were also included in the lexicon of cooked quinoa in present study
with quinoa varieties showing differences in these attributes
156
This present lexicon presents some sensory attributes not found to be significantly
different among the quinoa varieties These attributes include grain-like bean-like and starchy
aroma bean-like flavor and chewy texture Even though the trained panel did not detect
differences in this study future studies may find differences among other quinoa varieties for
these attributes so they were kept in the lexicon For instance the flavoraroma notes of
lsquorancidoxidizedrsquo lsquosourrsquo lsquometallicrsquo may also be present in other quinoa varieties or have these
attributes develop during storage as has been shown in rice (Meullenet et al 2000)
The lexicon also expanded the vocabularies to describe quinoa This lexicon is a
valuable tool with multiple practical applications such as describing and screening quinoa
varieties in breeding and evaluating post-harvest process and cooking methods
Lexicon Application Evaluation of the 21 quinoa samples
The effects of panelist replicate and quinoa variety on aroma tasteflavor and texture of
cooked quinoa were evaluated (n = 9) (Table 3) The quinoa variety exhibited significant
influences on most attributes listed in the lexicon (P lt 005) except for grain-like bean-like and
starchy aroma and bean-like flavor Generally quinoa variety effects were greater in the
perceived texture of cooked quinoa than in the aroma and flavor attributes however bitterness
was also highly significant among varieties Although panelists were trained over 18 h and
references were used for calibration significant panelist effects were still observed Based on the
inherent variation of human subjects such panelist effects commonly occur in sensory evaluation
of a complex product (Muntildeoz 2003) In future studies increased training and practice to further
clarify attribute definitions may reduce panelist effects (Muntildeoz 2003)
157
Examining the details of aroma attributes quinoa variety effect significantly influenced
the aroma attributes of caramel nutty buttery grassy earthy and woody (Figure 1) Principal
Components Analysis (PCA) was performed in order to visualize differences among the
varieties For aroma the first two components described 669 of the variation among quinoa
samples PC1 was primarily defined by the grassy and woody aromas while PC2 was primarily
described by more starchy and grain-like aromas The proximity of the attributes to a specific
quinoa sample reflected its degree of association For instance lsquoCalifornia Tricolorrsquo was most
commonly described by earthy woody grassy bean-like and nutty aroma lsquoTemukorsquo exhibited
sweet and grain-like aroma Yellowwhite quinoa such as lsquoTiticacarsquo lsquoRed Headrsquo lsquoQuF9P39-51rsquo
and lsquoPeruvian Whitersquo showed significantly more nutty (6) aroma compared to brown and red
quinoa varieties (48 ndash 51) (Table 1S) lsquoBlackrsquo lsquoCahuilrsquo and lsquoPeruvian Redrsquo exhibited more
grassy aroma (47 ndash 49) compared to lsquoTiticacarsquo lsquoLinaresrsquo and lsquoNL-6rsquo (38 ndash 39) lsquoBlackrsquo
showed the most earthy aroma (54) among all varieties
PCA was also performed to show how the varieties differed in their flavortaste
properties (Figure 2) The first two components described 646 of the varietal differences The
lsquoBlackrsquo variety was found to have more bitter and earthy flavors lsquoPeruvian Whitersquo was most
commonly described by sweet and nutty flavor and lack of earthy flavors lsquoTemukorsquo was mostly
defined by its bitter taste and lack of sweetness nutty grain-like and toasty flavors Overall
sweet and bitter taste and grain-like nutty earthy and toasty flavor exhibited significant
difference among quinoa varieties (plt005) The lsquoQuF9P39-51rsquo lsquoKaslaearsquo lsquoBolivian Whitersquo
and lsquoPeruvian Whitersquo were assigned the highest values in sweet taste (46 ndash 47) significantly
sweeter than lsquoBlackrsquo lsquoCherry Vanillarsquo lsquoTemukorsquo lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCalifornia Tricolorrsquo
158
(36 ndash 40)(Table 4) lsquoTemukorsquo and lsquoCherry Vanillarsquo were the most bitter samples (56 and 52
respectively) It is worth noting that the commercial samples were assigned the lowest bitterness
scores ranging from 22 ndash 27 significantly lower than the field trial varieties (34 ndash 56) Similar
to earthy aroma lsquoBlackrsquo also exhibited the earthiest flavor (52) Additionally lsquoCahuilrsquo and
lsquoCalifornia Tricolorrsquo showed high scores in earthy flavor (both 48) Toasty flavor varied from
38 in lsquoLinaresrsquo and lsquoQuF9P1-20rsquo to 51 in lsquoCahuilrsquo
Quinoa bitterness is caused by saponin compounds present on the seed coat It has been
reported that saponin can be removed by abrasion pearling and rinsing (Taylor and Parker
2002) However in the present study despite two cleaning process steps (airscreen and rinsing)
there was still bitter flavor remained Besides processing genetic background can also affect
saponin content Some sweet quinoa varieties (lsquoSajamarsquo lsquoKurmirsquo lsquoAynoqrsquoarsquo lsquoKrsquoosuntildearsquo and
lsquoBlanquitarsquo in Bolivia and lsquoBlancade Juninrsquo in Peru) have been developed with total seed
saponin content lower than 110 mg100 g (Quiroga et al 2015) However these varieties are not
adapted to the growing conditions in the Pacific Northwest (Peterson and Murphy 2015) The
quinoa varieties in WSU breeding program are primarily from Chilean lowland and those
varieties are more highly adapted to temperate areas In this case sweet quinoa varieties from
Bolivia and Peru were not included in this study However in 2015 a saponin-free quinoa
variety lsquoJessiersquo was grown in different locations of Washington State with a comparable yield
to bitter varieties The sensory evaluation of this new variety lsquoJessiersquo would be meaningful
Earthy which may be referred to as moldy and musty is caused by geosmin (a bicyclic
alcohol with formula C12H22O) which produced by actinobacteria (Gerber 1968) Samples with a
dark color (lsquoBlackrsquo lsquoCalifornia Tricolorrsquo and lsquoCahuilrsquo) tended to exhibit more earthy aroma and
159
flavor Possibly the pericarpseed coat composition of dark quinoa favors the actinobacteria-
producing geosmin
Overall texture attributes of cooked quinoa exhibited greater differences in values
(Figure 3) Among commercial quinoa varieties the red quinoa was firmer more gummy and
more chewy in texture compared to the yellowwhite commercial quinoa Several WSU field trial
varieties (lsquoQQ74rsquo lsquoLinaresrsquo and CO407D) exhibited greater variation in adhesiveness The first
two PCA factors explained 817 of the variation among samples lsquoPeruvian Redrsquo was most
accurately described by firm and crunchy texture and a lack of pasty sticky and cohesive
texture In contrast lsquoLinaresrsquo lsquoCO407Daversquo and lsquoQQ74rsquo were mostly described as pasty sticky
and cohesive yet lacking in firmness and crunchiness Mixed color or red color samples
(lsquoPeruvian Redrsquo lsquoBlackrsquo lsquoCahuilrsquo and lsquoCalifornia Tricolorrsquo) tended to be both firmer and
crunchier compared to the samples with light color However some yellow samples such as
lsquoTiticacarsquo and lsquoKU-2rsquo also had hard texture The varieties lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Daversquo
had the softest texture and also exhibited the least crunchy but the most pasty sticky and moist
texture Additionally compared to field trial varieties commercial samples tended to be lower in
intensity for the attributes of cohesiveness pastiness adhesiveness and astringency Moreover
astringent is the dry and puckering mouth feeling which is caused by the combination of tannins
and salivary proteins The differences found in this study among quinoa varieties may be caused
by processing protocols (removal of tannins to various degrees) or diverse genetic backgrounds
Consumer acceptance
160
Consumers evaluated six selected quinoa samples including the field trial varieties of
lsquoBlackrsquo lsquoTiticacarsquo lsquoQQ74rsquo and the commercial samples of lsquoPeruvian Redrsquo lsquoBolivian Redrsquo and
lsquoBolivian Whitersquo The selected samples were diverse in color texture and included both WSU
field trial varieties and commercial quinoa Among the field trial varieties the lsquoBlackrsquo variety
exhibited more grassy aroma earthy flavor and chewy texture lsquoTiticacarsquo had more caramel
aroma and lsquoQQ74rsquo was more adhesive than the other samples
The quinoa varieties varied significantly in consumer acceptance of color appearance
taste flavor texture and overall acceptance (P lt 0001) (Table 5) Overall lsquoPeruvian Redrsquo was
more accepted by consumers compared to lsquoTiticacarsquo and lsquoQQ74rsquo lsquoBlackrsquo received a similar
level of acceptance with all the commercial samples and the acceptance of lsquoTiticacarsquo did not
differ from lsquoBolivian Redrsquo and lsquoBolivian Whitersquo In aroma acceptance no significant difference
was found among the varieties In color lsquoPeruvian Redrsquo and lsquoBolivian Redrsquo received
significantly higher scores In appearance lsquoPeruvian Redrsquo was rated higher than all other
varieties except lsquoBolivian Redrsquo while lsquoQQ74rsquo gained the lowest rate Additionally lsquoQQ74rsquo was
less accepted in tasteflavor than all commercial samples but did not differ from other field trial
varieties lsquoBlackrsquo and lsquoTiticacarsquo Furthermore the texture of lsquoQQ74rsquo was the least accepted and
other varieties did not show any significant differences
However low acceptance in adhesive texture of cooked quinoa does not indicate the
adhesive quinoa varieties will not have market potential Adhesiveness in cooked rice is
correlated with high amylopectin and low amylose (Mossman et al 1983 Sowbhagya et al
1987) Hence adhesive quinoa may also contain low amylose Additionally previous studies
found waxy cereal or starch (0 amylose and 100 amylopectin) exhibited excellent
161
performance in extrusion Kowalski et al (2014) found that waxy wheat extrudates exhibited
nearly twice the expansion ratio as that of normal wheat Koumlksel et al (2004) found hulless waxy
barley to be promising for extrusion using low shear screw configuration Van Soest et al (1996)
reported high elongation (500) in extruded maize starch Consequently the adhesive quinoa
varieties have great potential to apply in extruded or other puffed foods
Consumer preference of the sensory attributes was analyzed using Partial Least Square
Regression (PLS) (Figure 4) The attributes presented by lsquoPeruvian Redrsquo including lsquograssyrsquo
aroma lsquograinyrsquo flavors and lsquofirmrsquo and lsquocrunchyrsquo textures were preferred among consumers The
less preferred attributes included lsquopastyrsquo lsquowaterymoistrsquo lsquoadhesiversquo and lsquocohesiversquo all attributes
used to describe the lsquoQQ74rsquo variety Overall acceptance was driven by crunchy texture (r =
090) but negatively correlated with lsquocohesiversquo lsquopastyrsquo and lsquoadhesiversquo texture (r = -096 -087
and -089 respectively) Specifically aroma acceptance of cooked quinoa was negatively
correlated with lsquowoodyrsquo (r = -083) Texture acceptance was positively correlated with lsquofirmrsquo(r =
084) and lsquocrunchyrsquo (r = 094) but was negatively correlated with lsquocohesiversquo (r = -096) lsquopastyrsquo
(r = -095) lsquoadhesiversquo (r = -096) and lsquomoistrsquo (r = -085) Even though lsquoearthyrsquo is a common
attribute in foods such as mushroom and beets this study on quinoa indicated that earthy aroma
and flavor were not the attributes driving consumersrsquo liking of cooked quinoa Color and
appearance did not exhibit significant correlation with color intensity of cooked quinoa
however the varieties with red or dark colors (lsquoPeruvian Redrsquo lsquoBolivian Redrsquo and lsquoBlackrsquo)
were more highly accepted by consumers compared to samples with light color (lsquoTiticacarsquo
lsquoBolivian Whitersquo lsquoQQ74rsquo) In sum consumers preferred cooked quinoa with grassy aroma firm
and crunchy texture and lack of woody aroma and low cohesive pasty or adhesive texture
162
The variety lsquoBlackrsquo was accepted at a similar level as commercial samples in aroma
tasteflavor texture and overall evaluation With a closer examination of the consumer
demographic consumers who were more familiar with quinoa rated the lsquoBlackrsquo quinoa variety
with higher scores (average of 7) compared to those panelists less familiar with quinoa who
assigned lower average scores (59) (Figure 1S) This tricolor quinoa (browndark mixture) is not
as common as red and yellowwhite quinoa in the US market However the potential of tricolor
quinoa may be great due to the relative high consumer acceptance as well as high gain yield in
the field
Instrumental Texture Profile Analysis (TPA)
The physical properties of cooked quinoa were determined using the texture analyzer
(Table 6) Samples differed in all six texture parameters lsquoNL-6rsquo lsquoPeruvian Redrsquo lsquoBolivian Redrsquo
and lsquoCalifornia Tricolorrsquo exhibited the hardest texture while lsquoTemukorsquo lsquoQQ74rsquo lsquoIslugarsquo
lsquoLinaresrsquo and lsquoCO407Daversquo displayed the lowest hardness values Consistent with trained panel
evaluation lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Daversquo were more adhesive than all other varieties
lsquoTiticacarsquo was the springiest variety while lsquoKaslaearsquo and lsquoQuF9P1-20rsquo were the least springy
varieties The commercial samples with the exception of lsquoPeruvian Whitersquo exhibited a more
gummy texture lsquoTiticacarsquo and lsquoBolivian Whitersquo were the chewiest samples In contrast varieties
of lsquoTemukorsquo lsquoQQ74rsquo lsquoIslugarsquo lsquoLinaresrsquo lsquoQuF9P1-20rsquo and lsquoCO407Daversquo showed the least
gummy and chewy texture The result was comparable to an earlier study (Wu et al 2014)
Similarly quinoa varieties with darker color (orangeredbrowndark) tended to yield harder
texture compared to the varieties with light color (whiteyellow) which is caused by the thicker
seed coat in dark colored quinoa In this study adhesive quinoa varieties lsquoQQ74rsquo lsquoLinaresrsquo and
163
lsquoCO407Daversquo were found to have higher adhesiveness values (-17 kgs to -13 kgs) compared
to other varieties previously reported (-029 kgs to 0) (Wu et al 2014)
Correlations of instrumental tests and trained panel evaluations of texture were
significant for hardness and adhesiveness (r = 070 and -063 respectively) (Table 7) Since
adhesiveness was calculated from the first negative peak area of the TPA graph a negative
correlation coefficient was observed but still indicating a high level of agreement between
instrumental and panel tests Springiness tested by TPA was not correlated with texture
attributes
Cohesiveness from the instrumental test was negatively correlated with cohesiveness
from the trained panel texture evaluation (r = -066) Instrumental cohesiveness also exhibited
positive correlations with the trained panel evaluation of firmness and crunchiness (r = 080 and
076 respectively) and negative correlations with pastiness adhesiveness moistness (r = -072
-075 and -082 respectively) Upon a closer examination of the definitions in the instrumental
test cohesiveness was defined as lsquohow well the product withstands a second deformation relative
to its resistance under the first deformationrsquo and is calculated as the ratio of second peak area to
first peak area (Wiles et al 2004) In the sensory lexicon cohesiveness was defined as lsquodegree
to which a substance is compressed between the teeth before it breaksrsquo (Szczesniak 2002) These
differential definitions or explanations of these attributes may have caused the different results
Additionally the gumminess and chewiness from the instrumental evaluation were not
significantly correlated with their counterpart notes from the trained panel evaluations but
correlated with other sensory attributes evaluated by the trained panel Instrumental gumminess
164
was positively correlated with firm and crunchy textures(r = 079 and 078 respectively) but
negatively correlated with cohesive pasty adhesive and moist (r = -067 -068 -075 and -
078 respectively) Additionally a positive correlation was found between instrumental
chewiness and firmness from the panel evaluation (r = 057) whereas negative correlations were
found between instrumental chewiness and panel evaluated cohesiveness pastiness
adhesiveness and moistness (r = -043 -045 -055 and -052 respectively) In the instrumental
texture profile gumminess is calculated by hardness multiplied by cohesiveness and chewiness
is calculated by gumminess multiplied by springiness (Epstein et al 2002) Hence gumminess
was significantly correlated with hardness and cohesiveness and chewiness was significantly
correlated with gumminess In another study of Lyon et al (2000) pasty and adhesive were
expressed as lsquoinitial starchy coatingrsquo and lsquoself-adhesivenessrsquo respectively in cooked rice and
were both negatively correlated with instrumental hardness Generally the instrument test is
more accurate and stable but the parameter or sensory attributes were relatively limited Sensory
panels are able to use various vocabularies to describe the food however accuracy and precision
of panel evaluations were lower than for the instrument Consequently both tools can be
important in sensory evaluation depending on the objectives and resources availability
Future Studies
A lexicon of cooked quinoa was firstly developed in this paper Further discussion and
improvement of the lexicon are necessary and require cooperation with industry and chefs The
lexicon is not only useful in categorizing varieties but also can be used to evaluate post-harvest
practice cooking protocols and other quinoa foodsdishes Additionally quinoa seed quality
varies among years and locations and sensory properties also change over different
165
environments To validate the sensory profile of varieties especially adhesiveness evaluation
should be repeated on the samples from other years and locations Finally multiple dishes food
types should be included in future consumer evaluation studies to identify the best application of
different varieties
Conclusion
A lexicon of cooked quinoa was developed based on aroma tastefavor texture and
color Using the lexicon the trained panel conducted descriptive analysis evaluation on 16
quinoa varieties from field trials and 5 commercial samples Many sensory attributes exhibited
significant differences among quinoa samples especially texture attributes
Consumer evaluations (n = 102) were conducted on six selected samples with diverse
color texture and origin Commercial samples and the variety lsquoBlackrsquo were better accepted by
consumers The adhesive variety lsquoQQ74rsquo was the least accepted quinoa variety in the plain
cooked quinoa dish However because of its cohesive texture lsquoQQ74rsquo shows possible
application in other dishes and foods such as quinoa sushi and extruded snacks Furtherly Partial
Least Square Regression indicated the consumerrsquos preferred attributes were grassy aroma and
firm and crunchy texture while the attributes of pasty adhesive and cohesive were not liked by
consumers
Correlations of panel evaluation and instrumental test were observed in hardness and
adhesiveness However chewiness and gumminess were not significant correlated between panel
test and instrumental test Further training should be addressed to clarify the definitions of
sensory attributes With the assistance and calibration from instruments such as the texture
166
analyzer and electronic tongue panel training can be more efficient and panelists can be more
accurate at evaluation
Acknowledgements
The study was funded by the USDA Organic Research and Extension Initiative
(NIFAGRANT11083982) The authors acknowledge Washington State University Sensory
Facility and their technicians Beata Vixie and Karen Weller The authors also acknowledge
Sergio Nunez de Arco and Sarah Connolly to provide commercial samples Thanks to Raymond
Kinney Max Wood and Hanna Walters who managed the plants harvested the seeds and
collected the data of yield and 1000-seed weight on field trial quinoa varieties Thanks also go to
the USDA-ARS Western Wheat Quality Lab which provided equipment for protein and ash tests
and the texture analyzer
Author contributions
CF Ross and G Wu together designed the study G Wu conducted panel training
collected and processed data and drafted the manuscript KM Murphyrsquos research group provided
the quinoa samples and assisted cleaning process CF Ross CF Morris and KM Murphy edited
the manuscript
167
References
Abugoch LEJ 2009 Chapter 1 quinoa (Chenopodium quinoa Willd) Adv Food Nutr Res
581ndash31
Arco SND Quinoas Calling In Murphy KM Matanguihan J editors Quinoa improvement
and sustainable production Hoboken NJ John Wiley amp Sons Inc p 211
Casas Moreno MM Barreto-Palacios V Gonzalez-Carrascosa R Iborra-Bernad C Andres-Bello
A Martiacutenez-Monzoacute J Garciacutea-Segovia P 2015 Evaluation of textural and sensory properties
on typical spanish small cakes designed using alternative flours J Culinary Sci Technol 13
19-28
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(Waxy) genes J Cereal Sci 35 51-63
Foumlste M Nordlohne SD Elgeti D Linden MH Heinz V Jekle M Becker T Impact of quinoa
bran on gluten-free dough and bread characteristics Eur Food Res Technol 2014 239 767-
75
Furche C Salcedo S Krivonos E Rabczuk P Jara B Fernaacutendez D Correa F 2015 Chapter 41
International quinoa trade In Bazile D Bertero D Nieto C editors State of the art report
on quinoa in 2013 Rome FAO amp CIRAD p 317 ndash 20
Gerber NN1968 Geosmin from microorganisms is trans-1 10-dimethyl-trans-9-decalol
Tetrahedron Lett 9 2971-4
168
Koumlksel H Ryu GH Basman A Demiralp H Ng PK 2004 Effects of extrusion variables on the
properties of waxy hulless barley extrudates FoodNahrung 48 19-24
Kowalski RJ Morris CF Ganjyal GM 2015 Waxy soft white wheat extrusion characteristics
and thermal and rheological propertiesCereal Chem 92 145-53
Koziol MJ 1991 Afrosimetric estimation of threshold saponin concentration for bitterness in
quinoa (Chenopodium quinoa Willd) J Sci Food Agr 54 211-9
Limpawattana M Shewfelt R 2010 Flavor lexicon for sensory descriptive profiling of different
rice types J Food Sci 75 199-205
Lorenz K Coulter L Quinoa flour in baked products Plant Food Hum Nutr 1991 41 213-23
Lyon BG Champagne ET Vinyard BT Windham WR Barton FE Webb BD McKenzie KS
1999 Effects of degree of milling drying condition and final moisture content on sensory
texture of cooked rice Cereal Chem 76 56-62
Lyon BG Champagne ET Vinyard BT Windham WR 2000 Sensory and instrumental
relationships of texture of cooked rice from selected cultivars and postharvest handling
practices Cereal Chem 77 64-9
Meilgaad MC Civille GV Carr BT 2007 Chapter 11 The spectrum descriptive analysis
method In Meilgaad MC Civille GV Carr BT Sensory evaluation techniques Boca Raton
FL CRC Press p 225 ndash 32
169
Meullenet JF Marks BP Hankins JA Griffin VK Daniels MJ 2000 Sensory quality of cooked
long-grain rice as affected by rough rice moisture content storage temperature and storage
duration Cereal Chem 77 259 ndash 63
Mossman AP Fellers DA Suzuki H 1983 Rice stickiness I Determination of rice stickiness
with an Instron tester Cereal Chem 60 286ndash92
Muntildeoz AM 2003 Training time in descriptive analysis In Moskowitz HR Muntildeoz AM and
Gacula MC editors Viewpoints and controversies in sensory science and consumer product
testing Trumbull Food amp Nutrition Press Inc p 351 ndash 6
Peterson AJ Murphy KM 2015 Quinoa cultivation for temperate North America
considerations and areas for investigation In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 173-92
Palmer GH 1994 Chapter 5 Storage In Hoseney RC editor Cereal science and technology
2nd edition St Paul MN American Association of Cereal Chemisty Inc p 107
Pop A Muste S Man S Mureșan C 2014 Improvement of tagliatelle quality by addition of red
quinoa flour Bulletin UASVM Food Sci Tech 71 225-6
Pulvento C Riccardia M Biondib S Orsinic F Jacobsend SE Ragabe R DrsquoAndriaa R Lavinia
A 2015 Chapter 613 Quinoa in Italy research and perspectives In Bazile D Bertero D
Nieto C editors State of the art report on quinoa in 2013 Rome FAO amp CIRAD p 460
Quiroga C Escalera R Aroni G Bonifacio A Gonzaacutelez JA Villca M Saravia R Ruiz A 2015
Chapter 31 Traditional processes and technological innovations in quinoa harvesting
170
processing and industrialization In Bazile D Bertero D Nieto C editors State of the art
report of quinoa in the world in 2013 Rome FAO amp CIRAD p 231
Repo-Carrasco R Espinoza C Jacobsen SE 2003 Nutritional value and use of the Andean
crops quinoa (Chenopodium quinoa) and kantildeiwa (Chenopodium pallidicaule) Food Rev Int
19 179-89
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile
D Bertero D Nieto C editors State of the art report on quinoa in 2013 Rome FAO amp
CIRAD p 67
Sowbhagya CM Ramesh BS Bhattacharya KR 1987 The relationship between cooked-rice
texture and physicochemical characteristics of rice J Cereal Sci 5 287ndash97
Suwannaporn P Linnemann A and Chaveesuk R 2008 Consumer preference mapping for rice
product concepts Brit Food J 110 595-606
Stikic R Glamoclija D Demin M Vucelic-Radovic B Jovanovic Z Milojkovic-Opsenica D
Milovanovic M 2012 Agronomical and nutritional evaluation of quinoa seeds
(Chenopodium quinoa Willd) as an ingredient in bread formulations J Cereal Sci 55 132-8
Szczesniak AS 2002 Texture is a sensory property Food Qual Prefer 13 215-25
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Belton PS JRN Taylor editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science Business Media p 108 ndash 10
171
Tomlins KI Manful JT Larwer P and Hammond L 2005 Urban consumer preferences and
sensory evaluation of locally produced and imported rice in West Africa Food Qual Prefer
16 79-89
Van Soest JJG De Wit D Vliegenthart JFG 1996 Mechanical properties of thermoplastic waxy
maize starch J Appl Polym Sci 61 1927-37
Wang S Opassathavorn A Zhu F 2015 Influence of quinoa flour on quality characteristics of
cookie bread and Chinese steamed bread J Texture Stud 46 281-92
Wiles JL Green BW Bryant R 2004 Texture profile analysis and composition of a minced
catfish product J Texture Stud 35 325-37
Wu G Morris C F Murphy K M 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79 2337-45
172
Table 1-Quinoa samples
Varietya Color Source
Titicaca Yellowwhite Denmark
Black Blackbrown mixture White Mountain Farm Colorado USA
KU-2 Yellowwhite Washington USA
Cahuil Brownorange mixture White Mountain Farm Colorado USA
Red Head Yellowwhite Wild Garden Seed Oregon USA
Cherry Vanilla Yellowwhite Wild Garden Seed Oregon USA
Temuko Yellowwhite Washington USA
QuF9P39-51 Yellowwhite Washington USA
Kaslaea Yellowwhite MN USA
QQ74 Yellowwhite Chile
Isluga Yellowwhite Chile
Linares Yellowwhite Washington USA
Puno Yellowwhite Denmark
QuF9P1-20 Yellowwhite Washington USA
NL-6 Yellowwhite Washington USA
CO407Dave Yellowwhite White Mountain Farm Colorado USA
Bolivian White White Bolivia
Bolivian Red Red Bolivia
California Tricolor
Blackbrown mixture California USA
Peruvian Red Red Peru
Peruvian White White Peru aThe first 16 varieties (Tititcaca ndash CO407Dave) were grown in Chimacum WA
173
Table 2-Lexicon of cooked quinoa as developed by the trained panelists (n = 9)
Attribute Intensitya Reference Definition
Aroma
Caramel 10 1 piece of caramel candy (Kraft) (81 g) in 100 mL water
Aromatics associated with caramel tastes
Grain-like 10 Cooked brown rice (15 g) (Great Value)
Rice like wheaty sorghum like
Bean-like 8 Cooked red bean (10 g) (Great Value)
Aromatics associated with cooked beans or bean protein
Nutty 10 Dry roasted peanuts (10 g) (Planters)c
Aromatics associated with roasted nuts
Buttery 10 Unsalted butter (1cm1cm01cm) (Tillamook)c
Aromatics associated with natural fresh butter
Starchy 10 Wheat flour water (11 ww) (Great Value)c
Aromatics associated with the starch
Grassygreen 9 Fresh cut grass collected 1 h before usingc
Aromatics associated with grass
Earthymusty 8 Sliced raw button mushrooms (fresh cut)c
Aromatic reminiscent of decaying vegetative matters and damp black soil root like
Woody 7 Toothpicks (20)c Aromatics reminiscent of dry cut wood cardboard
TasteFlavor
Sweet 3 9 2 and 5 (ww) sucrose solution (CampH pure cane sugar)b
Basic taste sensation elicited by sugar
Bitter 5 8 mgL quinine sulfate acid (Sigma)
Basic taste sensation elicited by caffeine
174
Grain-like 10 Cooked brown rice (Great Value)
Tasted associated with cooked grain such as rice
Bean-like 10 Cooked red beans (Great Value)
Beans bean protein
Nutty 10 Dry roasted peanut (Planters)c Taste associated with roasted nuts
Earthy 7 Sliced raw button mushrooms (fresh)
Taste associated with decaying vegetative matters and damp black soil
Toasted 10 Toasted English muffin (at 6 of a toaster) (Franze Original English Muffin)
Taste associated with toast
Texturee
Soft - Firm 3
7
Firm tofu (Azumaya)b
Brown rice (Great Value)
Force required to compress a substance between molar teeth (in the case of solids) or between tongue and palate (in the case of semi-solids)d
Separate - Cohesive
15
7
Cracker (Premium unsalted cracker)
Cake (Sponge cake Walmart Bakery)
Degree to which a substance is compressed between the teeth before it breaks
Pasty
10 Mashed potato (Great Value Mashed Potatoes powder)
Smooth creamy pulpy slippery
Adhesiveness sticky
10
3
Sticky rice (Koda Farms Premium Sweet Rice)
Brown rice (Great Value)
Force required to remove the material that adheres to the mouth (the palate and teeth) during the normal eating process
Crunchy 13 Thick cut potato chip (Tostitos Restaurant Style
Force with which a sample crumbles cracks or shatters
175
Tortilla Chips)b
Chewygummy
15
7
Gummy Bear (Haribo Gold-Bears mixed flavor)
Brown rice (Great Value)
Length of time (in sec) required to masticate the sample at a constant rate of force application to reduce it to a consistency suitable for swallowing
Astringent 12
6
Tannic acid (2gL)
Tannic acid (1gL) (Sigma)
Puckering or tingling sensation elicited by grape juice
Waterymoist 10
3
Salad tomato (Natural Sweet Cherubs)
Brown rice (Great Value)
Degree of wet or dry
Color
Red 4 9
N-W8M Board Walke
N-W16N Ballet Barree
Yellow 3 10
15B-2U Sandy Toese 15B-7
N Summer Harveste
Black 3 10
N-C32N Strong Influencee N-C4M Trench Coate
aReference intensities were based on a 15-cm scale with 0 = extremely low and 15 = extremely high bMeilgaad et al (2007) cLimpawattana and Shewfelt (2010) dTexture definitions in Szczesniak (2002) were used eAce Hardware color chip
176
Table 3-Significance and F-value of the effects of panelist replicate and quinoa variety on aroma flavor and texture of cooked quinoa as determined using a trained panel (n = 9)
Attribute Panelist Replicate Quinoa Variety PanelistVariety
Aroma
Caramel 26548 093 317 174
Grain-like 7338 000 125 151
Bean-like 7525 029 129 135
Nutty 6274 011 322 118
Buttery 21346 003 301 104
Starchy 12094 1102 094 135
Grassy 17058 379dagger 282 162
Earthy 12946 239 330 198
Woody 13178 039 269 131
TasteFlavor
Sweet 6745 430 220 137
Bitter 9368 1290 2059 236
Grain-like 7681 392 222 206
Bean-like 7039 122 142 141
Nutty 7209 007 169 153
Earthy 9313 131 330 177
Toasted 10975 015 373 184
Texture
Firm 1803 022 1587 141
Cohesive 14750 011 656 208
Pasty 3919 2620 1832 205
Adhesive 2439 287dagger 5740 183
177
Crunchy 13649 001 1871 167
Chewy 3170 870 150dagger 167
Astringent 10183 544 791 252
Waterymoist 10281 369dagger 1809 164
daggerP lt 010 P lt 005 P lt 001 P lt 0001
178
Table 4-Mean separation of significant tasteflavor attributes of cooked quinoa determined by the trained panel Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Sweet Bitter Grain-like Nutty Earthy Toasty
Titicaca 40cdef1 39bcde 73abc 51abcdef 44bcdef 47abcd
Black 36f 42bcd 69bcde 49def 52a 46abcd
KU2 41bcdef 38cde 73abc 52abcdef 40fg 44bcdefg
Cahuil 41abcdef 44b 70bcde 50abcdef 48abc 51a
Red Head 42abcd 43bc 72abcd 51abcdef 42defg 44bcdefg
Cherry Vanilla 40def 52a 66e 48ef 44bcdef 40fghi
Temuko 36ef 56a 68cde 47f 43cdef 40ghi
QuF9P39-51 47a 34e 73abc 48def 40efg 46abcde
Kaslaea 47ab 39bcde 70bcde 55ab 44bcdef 45bcdefg
QQ74 40def 38cde 66e 50abcdef 45bcde 42defghi
Isluga 41bcdef 41bcd 69cde 55a 46bcd 47abcd
Linares 39def 40bcd 65e 49cdef 43def 38i
Puno 44abcd 39bcde 72abcd 51abcdef 45bcde 43cdefghi
QuF9P1-20 42abcdef 43bc 69bcde 53abcd 45bcde 38i
NL-6 38def 37de 72abcd 55a 45bcd 44bcdefgh
CO 407 Dave 41bcdef 40bcd 67de 51abcdef 41defg 39hi
Bolivian White 47ab 22f 69bcde 50bcdef 42def 41efghi
Bolivian Red 42abcde 24f 72abcd 53abcdef 43cdef 46bcde
California Tricolor 40def 27f 74ab 53abcde 48ab 48ab
Peruvian Red 43abcd 25f 75a 48ef 45bcde 47abc
Peruvian White 46abc 26f 70bcde 55abc 37g 45bcdef
179
Table 5-Mean separation of consumer preference Different letters within a column indicate consumer evaluation scores were different among quinoa samples at P lt 005
Samples Aroma Color Appearance TasteFlavor Texture Overall
Black 56a 63b 61bc 61abc 65a 63ab
QQ74 61a 56c 53d 56c 53b 53c
Titicaca 60a 57bc 56cd 58bc 63a 59bc
Peruvian Red 60a 72a 70a 65a 68a 67a
Bolivian Red 60a 69a 66ab 64ab 67a 64ab
Bolivian White 57a 59bc 58c 62ab 63a 62ab
180
Table 6-Hardness adhesiveness cohesiveness springiness gumminess and chewiness of the cooked quinoa samples as determined using Texture Profile Analysis (TPA)
Variety Hardness
(kg)
Adhesiveness
(kgs)
Cohesiveness Springiness Gumminess
(kg)
Chewiness
(kg)
Titicaca 505abc1 -02ab 08abc 15a 384bc 599a
Black 545ab -01a 07bcd 10abc 404abc 404ab
KU-2 490abcd -01a 07bcd 09abc 363bcd 332abc
Cahuil 464bcde -01a 07bcd 08abc 344cd 281bc
Red Head 412defg -03ab 06ef 09abc 246ef 225bc
Cherry Vanilla 391efgh -02ab 05fgh 08abc 208fg 178bc
Temuko 328gh -09c 04hi 08abc 147g 120c
QuF9P39-51 451cde -02ab 07de 10abc 297de 272bc
Kaslaea 493abcd -02ab 07bcd 06c 359cd 227bc
QQ74 312h -17e 04i 09abc 132g 119c
Isluga 362fgh -05b 05ghi 08abc 171fg 137bc
Linares 337gh -16de 05ghi 09abc 159g 146bc
Puno 504abc -01a 06ef 10abc 301de 301bc
QuF9P1-20 438cdef -02ab 06fg 05c 242ef 137bc
NL-6 555a -01a 07cde 09abc 376bcd 350abc
CO407Dave 357fgh -13d 04hi 09abc 160g 141bc
Bolivian White 441cdef -01ab 05fg 14ab 242ef 340abc
Bolivian Red 572a -01ab 08ab 14ab 440ab 593a
California Tricolor
572a -01a 08a 08bc 477a 361abc
Peruvian Red 568a 00a 08ab 08abc 439ab 342abc
Peruvian White 459bcde -01a 08abc 11abc 347cd 394abc
181
Table 7-Correlation of trained panel texture evaluation data and instrumental TPA over the 21 quinoa varieties
Variables Hardness Adhesiveness Cohesiveness Gumminess Chewiness Firm 070 059 080 079 057 Cohesive -060 -051 -066 -067 -043 Pasty -060 -070 -072 -068 -045 Adhesive -067 -063 -075 -075 -055 Crunchy 072 054 076 078 055 Moist -066 -066 -082 -078 -052
daggerP lt 01 P lt 005 P lt 001 P lt 0001
182
Figure 1-Principal component Analysis (PCA) biplot of aroma evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil Red Head
Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white Kaslaea
QQ74
Isluga
Linares
Puno
QuF9P1-20 NL-6
CO 407 Dave
Bolivia white
Bolivia red California Tricolor
Caramel Grain-like
Bean-like Nutty
Buttery Starchy
Grassy
Earthy
Woody
-25
-2
-15
-1
-05
0
05
1
15
2
-3 -25 -2 -15 -1 -05 0 05 1 15 2 25 3 35 4
F2 (2
455
)
F1 (4234 )
183
Figure 2-Principal component Analysis (PCA) biplot of tasteflavor evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil
Red Head Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white
Kaslaea
QQ74 Isluga
Linares
Puno
QuF9P1-20
NL-6
CO 407 Dave
Bolivia white
Bolivia red
California Tricolor
Sweet
Bitter Grain-like
Bean-like
Nutty
Earthy
Toasted
-3
-2
-1
0
1
2
3
-4 -3 -2 -1 0 1 2 3 4 5
F2 (3
073
)
F1 (3391 )
184
Figure 3-Principal component Analysis (PCA) biplot of texturemouthfeel evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil
Red Head Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white
Kaslaea
QQ74 Isluga
Linares
Puno
QuF9P1-20
NL-6
CO 407 Dave
Bolivia white
Bolivia red California Tricolor
Firm Cohesive
Pasty
Adhesive
Crunchy
Chewy Astringent
Moist
-2
-15
-1
-05
0
05
1
15
2
25
-3 -25 -2 -15 -1 -05 0 05 1 15 2 25 3 35
F2 (2
212
)
F1 (5959 )
185
Figure 4-Partial Least Squares (PLS) biplot correlating aroma color appearance tasteflavor texture and overall attributes evaluated by the trained panel (n = 9) to the consumer panel (n = 102) for 6 cooked quinoa samples (Consumer acceptances are in bold italics)
Grainy aroma
Beany aroma
Nutty aroma
Buttery
Starchy
Grassy
Earthy
Woody
Sweet
Bitter grainy flavor
Beany flavor
Earthy flavor Nutty flavor
Toasty
Firm Cohesive
Pasty
Adhesive
Crunchy
Chewy
Astringent
Waterymoist
Aroma
Color Appearance TasteFlavor
Texture Overall
Black
Bolivia red
QQ74
Bolivia white
Commercial Red
Titicaca
-1
-075
-05
-025
0
025
05
075
1
-1 -075 -05 -025 0 025 05 075 1
t2
t1
186
Supplementary tables
Table 1S-Mean separation of significant aroma attributes of cooked quinoa determined by the trained panel (n = 9) Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Caramel Nutty Buttery Green Earthy Woody
Titicaca 59a1 60a 45abc 39fg 42defgh 37cdef
Black 46g 50efg 38ef 47abc 54a 46a
KU2 50efg 51defg 41cdef 40efg 38h 35ef
Cahuil 56abc 53bcdefg 43abcd 49a 48b 39bcde
Red Head 55abcd 60a 45abc 44bcde 46bcd 41bc
Cherry Vanilla 52cdef 54bcdef 43abcde 43bcdef 46bcdef 37bcdef
Temuko 55abcd 56abcde 44abc 40defg 41efgh 37bcdef
QuF9P39-51 58ab 60a 46ab 42bcdefg 44bcdefg 36def
Kaslaea 53bcde 55abcde 42abcde 41defg 40gh 37bcdef
QQ74 50efg 48fg 39def 42defg 45bcdef 38bcdef
Isluga 52cdef 57abc 43abcd 43bcdefg 46bcde 39bcde
Linares 52cdef 54bcdef 42bcde 38g 44bcdefg 37cdef
Puno 56abc 56abcde 46ab 42cdefg 46bcdef 38bcdef
QuF9P1-20 53bcdef 58ab 44abcd 42cdefg 44bcdefg 40bcd
NL-6 57abc 53bcdefg 44abcd 39fg 44bcdefg 35def
CO 407 Dave 51def 54abcde 46ab 40efg 42defgh 34f
Bolivian White 53bcde 57abcd 46ab 43bcdef 43cdefgh 39bcd
Bolivian Red 52cdef 51defg 42bcde 43bcdefg 44bcdefg 37bcdef
California Tricolor 54abcde 51cdefg 38ef 44abcd 48bc 41ab
Peruvian Red 48fg 48g 36f 47ab 46bcdef 38bcdef
Peruvian White 54abcde 60a 48a 45abcd 41fgh 40bc
187
Table 2S-Mean separation of significant texture attributes of cooked quinoa determined by the trained panel Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Firm Cohesive Pasty Adhesive Crunchy Astringent Moist
Titicaca 70ab 63efgh 37ghi 37ghi 56bc 47d 38hij
Black 71ab 63efgh 32i 38ghi 58b 55abc 35jk
KU2 66bcd 64efg 38fghi 37ghi 49de 46de 38hij
Cahuil 68abc 61fghi 37ghi 36hi 56bc 55ab 37ij
Red Head 57fgh 68bcde 46cde 49d 45ef 55ab 48de
Cherry Vanilla 56gh 65cdef 49c 44def 43fg 55ab 49de
Temuko 49ij 70abcd 56b 57c 39gh 59a 51cd
QuF9P39-51 61defg 65def 47cd 40efgh 48def 48cd 42fgh
Kaslaea 60defg 62fghi 40defgh 40fgh 51cd 51bcd 42gh
QQ74 44j 70abc 60ab 81ab 37hi 46def 57ab
Isluga 52hi 66cdef 43cdef 55c 44efg 50bcd 48de
Linares 45j 75a 65a 86a 33i 47d 61a
Puno 58efgh 60fghij 41defg 43efg 52cd 47d 47def
QuF9P1-20 52hi 65def 43cdefg 46de 44fg 55ab 47defg
NL-6 64cde 61fghi 40efgh 41efgh 51cd 46de 46efg
CO 407 Dave 45j 72ab 59ab 80b 35hi 47d 55bc
Bolivian White 56gh 61fghi 38fghi 41efgh 50de 34g 48de
Bolivian Red 62cdef 59hij 34hi 36hi 56bc 38g 42fgh
California Tricolor 68abc 56j 32i 33i 60ab 39efg 39hij
Peruvian Red 74a 57ij 35hi 33i 64a 39fg 31k
Peruvian White 60defg 59ghij 38fghi 37hi 48def 34g 40hi
188
Figure-1S Demographic influence on preference of variety lsquoBlackrsquo
75a
66ab 61bc
54c
61bc
0
1
2
3
4
5
6
7
8
75 50 25 None Other
Liking score of lsquoBlackrsquo
Proportion of organic food consumption
52b
64a 65a 69a 70a
57ab 59ab
0
1
2
3
4
5
6
7
8
Everyday 4-5 timesper week
2-3 timesper week
Once aweek
A fewtimes per
month
Aboutevery 6months
Other
Liking score of lsquoBlackrsquo
Frequency of rice consumption
189
Chapter 7 Conclusions
Quinoa quality is a complex topic with seed composition influencing sensory and
physical properties This dissertation evaluated the seed characteristics composition flour
properties and cooking quality of 13 quinoa samples Differences in seed morphology and
composition contributed to the texture of cooked quinoa The seeds with higher raw seed
hardness lower bulk density or higher seed coat proportion yielded a firmer gummier and
chewier texture after cooking Higher protein content correlated with harder more adhesive
more cohesive gummier and chewier texture of cooked quinoa Additionally flour peak
viscosity breakdown final viscosity and setback exhibited influence on different texture
parameters Cooking time and water uptake ratio also significantly influence the texture whereas
cooking loss did not show any correlation with texture Starch characteristics also significantly
differed among quinoa varieties (Chapter 3) Amylose content ranged from 27 to 169
among 13 quinoa samples The quinoa samples with higher amylose proportion or higher starch
enthalpy tended to yield harder stickier more cohesive and chewier quinoa These studies on
seed quality seed characteristics compositions and cooking quality provided useful information
to food industry professionals to use in the development of quinoa products using appropriate
quinoa varieties Indices such protein content and flour viscosity (RVA) can be quickly
determined and exhibited strong correlations with cooked quinoa texture Furthur study should
develop a prediction model using protein content or RVA parameters to predict the texture of
cooked quinoa In this way food manufactures can quickly predict the texture or functionality of
quinoa varieties and then determine their specific application Moreover many of the test
methods were using the methods used in rice such as kernel hardness texture of cooked quinoa
190
thermal properties (DSC) and cooking qualities Such methods should be standardized in near
future as those defined by AACC (American Association of Cereal Chemists) The development
of standard methods allows for easier comparisons among different studies In Chapter 4 the
seed quality response to soil salinity and fertilization was studied Quinoa protein content
increased under high Na2SO4 concentration (32 dS m-1) The variety lsquoQQ065rsquo maintained similar
levels of hardness and density under salinity stress and is considered to be the best adapted
variety among four varieties The variety can be applied in salinity affected areas Future studies
can be applied on salinity drought influence on quinoa amino acids profile starch composition
fiber content and saponins content
Sensory evaluation of cooked quinoa was further examined in Chapter 5 Using a trained
panel the lexicon for cooked quinoa was developed Using this lexicon the sensory profiles of
16 field trial varieties and 5 commercial quinoa samples were generated Varietal differences
were observed in the aromas of caramel nutty buttery grassy earthy and woody tasteflavor of
sweet bitter grain-like nutty earthy and toasty and texture of firm cohesive pasty adhesive
crunchy chewy astringent and moist Subsequent consumer evaluation on 6 selected quinoa
samples indicated lsquoPeruvian Redrsquo was the most accepted overall whereas a sticky variety lsquoQQ74rsquo
was the least accepted Partial least square analysis using trained panel data and consumer
acceptance data indicated that overall consumer liking was driven by grassy aroma and firm and
crunchy texture The lexicon and the attributes driving consumer-liking can be utilized by
breeders and farmers to evaluate their quinoa varieties and products The information is also
useful to the food industry to evaluate ingredients from different locations and years improve
processing procedures and develop products
191
Overall the dissertation provided significant information of quinoa seed quality and
sensory characteristics among different varieties including both commercialized samples and
field trial samples not yet available in market Several quinoa varieties increasingly grown in
US were included in the studies The variety lsquoCherry Vanillarsquo and lsquoTiticacarsquo are among the
varieties gaining the best yields in US Their seed characteristics and sensory attributes
described in this dissertation should be helpful for industry professionals in their research and
product development Varieties include lsquoTiticacarsquo lsquoCherry Vanillarsquo and lsquoBlackrsquo Additionally
important tools were developed in quinoa evaluation including texture analysis using TPA and
the lexicon of cooked quinoa
As with any set of studies other research questions arise to be addressed in future
research First saponins the compounds introducing bitter taste in quinoa require further study
Sweet quinoa varieties (saponins content lt 011) should be bred and adapted to the US
Although many consumers may like the bitter taste and especially the potential health benefits of
saponins it is important to provide consumers choices of both bitter and non-bitter quinoa types
To assist the breeding of sweet quinoa genetic markers can be developed and associated with the
phenotype of saponin content As for the methods testing saponin content the foam method is
quick but not accurate whereas the GC method is accurate but requires long sample preparation
time and high capital investment An accurate more affordable and more efficient method such
as one using a spectrophotometer should be developed
Second one important nutritional value of quinoa is the balanced essential amino acids
The essential amino acids profiles change according to environment (drought and saline soil)
quinoa variety and processing (cleaning milling and cooking) and these changes should be
192
further studied It is important to prove quinoa seed maintains the rich essential amino acids even
growing under marginal conditions or being subjected to cleaning processes such as abrasion
and washing
Third betalains are the compounds contributing to the color of quinoa seed and providing
potential health benefits Betalain content type (relate to diverse colors) and their genetic loci in
quinoa can be further investigated Color diversity is one of the attractive properties in quinoa
seeds However the commercialized quinoa samples are in white or red color while more quinoa
varieties present orange purple brown and gray colors More choices of quinoa colorstypes
may attract more consumers
Finally sensory evaluation of quinoa varieties should be applied to the samples from
multiple years and locations since environment can significantly influence the sensory attributes
Also in addition to plain cooked quinoa more quinoa dishes can be involved in consumer
acceptance studies as different quinoa varieties may be suitable for various dishes
copy Copyright by GEYANG WU 2016 All Rights Reserved
ii
To the Faculty of Washington State University
The members of the Committee appointed to examine the dissertation of GEYANG WU find it satisfactory and recommend that it be accepted
_________________________________ Carolyn F Ross PhD Co-Chair
_________________________________
Craig F Morris PhD Co-Chair
_________________________________ Barbara Rasco PhD
_________________________________
Kevin M Murphy PhD
iii
ACKNOWLEDGMENT
This dissertation is accomplished with a lot of collaborations of Food Science USDA-
ARS Western Wheat Quality Lab and Crop Science I gained significant advice and help from
my co-chairs and co-advisors Dr Craig Morris and Dr Carolyn Ross as well as my committee
members Dr Barbara Rasco and Dr Kevin Murphy Working with them on research proposals
experiments data processing and editing manuscripts I learned so much from scientific
philosophy critical thinking and efficient argument to scientific writing skills This dissertation
could never have been accomplished without their professional patient and persistent work
Additionally I owe thanks to many lab members who provided important help with the
experiments From the USDA-ARS Western Wheat Quality Lab Bozena Paszczynska who is no
longer with us trained me on most of the flour testing equipment Patrick Fuerst Alecia
Kiszonas Douglas Engle and Eric Wegner helped with experimental methods manuscript
preparation milling and equipment maintenance From the WSU Sensory Evaluation Lab Beata
Vixie Karen Weller Charles Diako and Ben Bernhard provided help in sensory study
preparation and serving From the WSU Sustainable Seed System Lab Max Wood Janet
Matanguihan Hannah Walters Adam Peterson Raymond Kinney Cedric Habiyaremye
Leonardo Hinojosa and Kristofor Ludvigson helped with quinoa field work (planting weeding
harvesting) post-harvest cleaning and greenhouse management I feel grateful to have met so
many brilliant and kind people and it is a pleasant journey to work with them and develop
friendships with them
Finally thanks to my family and friends Their understanding and support helped me
sincerely enjoy life and work during the past four years
iv
QUINOA SEED QUALITY AND SENSORY EVALUATION
Abstract
by Geyang Wu PhD Washington State University
May 2016
Co-Chairs Carolyn F Ross Craig F Morris
Quinoa is a grain that has garnered increasing interest in recent years from global
markets as well as in academic research The studies in this dissertation focused on quinoa seed
quality and sensory evaluation among diverse quinoa varieties with potential adaptation to
growing conditions in Washington State The objectives in the dissertation were to study quinoa
seed quality as well as the sensory attributes of cooked quinoa as defined by both trained and
consumer panelists Regarding quinoa seed quality we investigated seed characteristics
(diameter weight density hardness seed coat proportion) seed composition (protein and ash
content) flour viscosity and thermal properties quinoa cooking quality and texture of cooked
quinoa Additionally the functional characteristics of quinoa were studied including the
determination of amylose content starch swelling power and water solubility texture of starch
gel and starch thermal properties Results indicated texture of cooked quinoa was significantly
influenced by protein content flour viscosity quinoa cooking quality amylose content and
starch enthalpy In addition the influences of soil salinity and fertility on quinoa seed quality
were evaluated The variety lsquoQQ065rsquo exhibited increased protein content and maintained similar
levels of hardness and density under salinity stress and is considered to be the best adapted
v
variety among four varieties Finally sensory evaluation studies on cooked quinoa were
conducted A lexicon of cooked quinoa was developed including the sensory attributes of aroma
tasteflavor texture and color Results from the trained and consumer panel indicated that
consumer liking of quinoa was positively influenced by grassy aroma and firm and crunchy
texture These results represent valuable information to quinoa breeders in the determination of
seed quality of diverse quinoa varieties In the food industry the results of seed quality and
sensory studies (lexicon and consumer-liking) can be utilized to evaluate quinoa ingredients from
multiple locations or years determine the efficiency of post-harvest processing and develop
appropriate products according to the properties of the specific quinoa variety Overall this
dissertation contributed to the growing body of research describing the chemical physical and
sensory properties of quinoa
vi
TABLE OF CONTENTS
Page
ACKNOWLEDGMENTS iii
ABSTRACT iv-v
LIST OF TABLES ix-xi
LIST OF FIGURES xii-xiii
CHAPTERS
1 Introduction 1
References 6
2 Literature review 9
References 26
Tables 41
Figures44
3 Evaluation of texture differences among varieties of cooked quinoa 46
Abstract 46
Introduction 48
Materials and Methods 51
Results 54
Discussion 60
vii
Conclusion 63
References 65
Tables 71
Figures78
4 Quinoa starch characteristics and their correlation with
texture of cooked quinoa 80
Abstract 80
Introduction 81
Materials and Methods 82
Results 87
Discussion 95
Conclusion 102
References 103
Tables 109
5 Quinoa seed quality response to sodium chloride and
Sodium sulfate salinity 118
Abstract 118
Introduction 120
Materials and Methods 122
Results 125
Discussion 123
viii
Conclusion 132
References 134
Tables 139
Figure 145
6 Lexicon development and sensory attributes of cooked quinoa 146
Abstract 146
Introduction 148
Materials and Methods 150
Results and Discussion 155
Conclusion 165
References 167
Tables 172
Figures183
7 Conclusions 189
ix
LIST OF TABLES
Page
CHAPTER 2
Table 1 Essential amino acid of quinoa protein and FAOWHO suggested requirement (mgg
protein) 41
Table 2 Quinoa vitamin content (mg100g) 42
Table 3 Quinoa mineral content (mgmg ) 43
CHAPTER 3
Table 1 Varieties of quinoa used in the experimenthelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip71
Table 2 Seed characteristics and composition 72
Table 3 Texture profile analysis (TPA) of cooked quinoa 73
Table 4 Cooking quality of quinoa 74
Table 5 Pasting properties of quinoa flour by RVA 75
Table 6 Thermal properties of quinoa flour by Differential Scanning Calorimetry (DSC) 76
Table 7 Correlation coefficients between quinoa seed characteristics composition and
processing parameters and TPA texture of cooked quinoa 77
CHAPTER 4
Table 1 Quinoa varieties tested 109
Table 2 Starch content and composition 110
Table 3 Starch properties and α-amylase activity 111
Table 4 Texture of starch gel 112
Table 5 Thermal properties of starch 113
x
Table 6 Pasting properties of starch 114
Table 7 Correlation coefficients between starch properties and texture of cooked quinoa 115
Table 8 Correlations between starch properties and seed DSC RVA characteristics 116
CHAPTER 5
Table 1 Analysis of variance with F-values for protein content hardness and density of quinoa
seed 139
Table 2 Salinity variety and fertilization effects on quinoa seed protein content () 140
Table 3 Salinity variety and fertilization effects on quinoa seed hardness (kg) 141
Table 4 Salinity variety and fertilization effects on quinoa seed density (g cm3) 142
Table 5 Correlation coefficients of protein hardness and density of quinoa seed 143
Table 6 Correlation coefficients of quinoa seed quality and agronomic performance and seed
mineral content144
CHAPTER 6
Table 1 Quinoa samples 172
Table 2 Lexicon of cooked quinoa as developed by the trained panelists (n = 9) 173
Table 3 Significance and F-value of the effects of panelist replicate and quinoa variety on
aroma flavor and texture of cooked quinoa as determined using a trained panel (n = 9) 176
Table 4 Mean separation of significant tasteflavor attributes of cooked quinoa determined by
the trained panel Different letters within a column indicate attribute intensities were different
among quinoa samples at P lt 005 as determined using Fisherrsquos LSD 178
Table 5 Mean separation of consumer preference Different letters within a column indicate
consumer evaluation scores were different among quinoa samples at P lt 005 179
xi
Table 6 Hardness adhesiveness cohesiveness springiness gumminess and chewiness of the
cooked quinoa samples as determined using Texture Profile Analysis (TPA) Different letters
within a column indicate attribute intensities were different among quinoa samples at P lt 005
180
Table 7 Correlation of trained panel texture evaluation data and instrumental TPA over the 21
quinoa varieties 181
Table 1S Mean separation of significant aroma attributes of cooked quinoa determined by the
trained panel (n = 9) Different letters within a column indicate attribute intensities were different
among quinoa samples at P lt 005 as determined using Fisherrsquos LSD 186
Table 2S Mean separation of significant texture attributes of cooked quinoa determined by the
trained panel Different letters within a column indicate attribute intensities were different among
quinoa samples at P lt 005 as determined using Fisherrsquos LSD 187
xii
LIST OF FIGURES
Page
CHAPTER 2
Figure 1 Quinoa seed section and two-layered pericarp under perianth (Wu et al 2014) 44
Figure 2 Figure 2-Quinoa seed structure (Prego et al 1998) 45
CHAPTER 3
Figure 1 Rapid Visco Analyzer (RVA) graph of lsquoCherry Vanillarsquo and lsquoRed Commercialrsquo quinoa
flours 78
Figure 2 Seed coat image by SEM 79
CHAPTER 5
Figure 1 Protein content () of quinoa in response to combined fertility and
salinity treatments 145
CHAPTER 6
Figure 1 Principal component Analysis (PCA) biplot of aroma evaluations by the trained
sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 182
Figure 2 Principal component Analysis (PCA) biplot of tasteflavor evaluations by the trained
sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 183
xiii
Figure 3 Principal component Analysis (PCA) biplot of texturemouthfeel evaluations by the
trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 184
Figure 4 Partial Least Squares (PLS) biplot correlating aroma color appearance tasteflavor
texture and overall attributes evaluated by the trained panel (n = 9) to the consumer panel (n =
102) for 6 quinoa samples (Consumer acceptances are in bold italics) 185
Figure-1S Demographic influence on preference of variety lsquoBlackrsquo 188
xiv
Dedication
This dissertation is dedicated to those who are interested in quinoa
the beautiful small grain providing nutrition and fun
1
Chapter 1 Introduction
Quinoa is growing rapidly in the global market largely due to its high nutritional value
and potential application in a wide range of products Bolivia and Peru are the major producers
and exporters of quinoa In Peru production increased from 31824 MT (Metric Ton) in 2007 to
108000 MT in 2015 (USDA 2015) In 2013 organic quinoa from Bolivia and Peru were sold at
averages of $8000MT and $7000MT respectively (Nuntildeez de Acro 2015) Of all countries the
US and Canada import the most quinoa and comprise 53 and 15 of the global imports
respectively (Carimentrand et al 2015) Quinoa yield is on average 600 kgha with yield
varying greatly and among varieties and environments (Garcia et al 2004) The total production
cost is $720ha in the southern Altiplano region of Bolivia and the farm-gate price reached
$60kg in 2013 (Nuntildeez de Acro 2015) With 2600 kg annual quinoa yield in a small 3 ha farm
the revenue would be $15390 which could potentially raise a family out of poverty (Nuntildeez de
Acro 2015)
Quinoa possesses many sensory properties Food texture refers to those qualities of a
food that can be felt with the fingers tongue palate or teeth (Sahin and Sumnu 2006) Texture is
one of most significant properties of food products Quinoa has unique texture ndash creamy smooth
and a little crunchy (James 2009) The texture of cooked quinoa is not only influenced by seed
structure but also determined by compounds such as starch and protein However publications
describing the texture of cooked quinoa are limited
Seed characteristics and structure are important factors influencing the textual properties
of cooked quinoa seed Quinoa is a dicotyledonous plant species very different from
2
monocotyledonous cereal grains The majority of the seed is the middle perisperm of which cells
have very thin walls and angular-shaped starch grains (Prego et al 1998) The two-layer
endosperm of the quinoa seed consists of living thick-walled cells rich in proteins and lipids but
without starch The protein bodies found in the embryo and endosperm lack crystalloids and
contain one or more globoids of phytin (Prego 1998) Given the structure of quinoa the seed
properties such as seed size hardness and seed coat proportion may influence the texture of the
cooked quinoa Nevertheless correlations between seed characteristics seed structure and
texture of cooked quinoa have not been performed
Beside the physical properties of seed the seed composition will influence the texture as
well Protein and starch are the major components in quinoa while their correlation to texture
has not been studied Starch characteristics and structures significantly influence the texture of
the end product Starch granules of quinoa is very small (1-2μm) compared to that of rice and
barley (Tari et al 2003) Quinoa starch is lower in amylose content (11 of starch) (Ahamed
1996) which may yield the hard texture Chain length of amylopectin also influences hardness of
food product (Ong and Blanshard 1995) In sum the influence of quinoa seed composition and
characteristics on cooked product should be studied
In addition to seed quality and characteristics the sensory attributes of quinoa are also
significant as they influence consumer acceptance and the application of the quinoa variety
However there is a lack of lexicon to describe the sensory attributes of cooked quinoa Rice is
considered as a model when studying quinoa sensory attributes because they are cooked in
similar ways The lexicon of cooked rice were developed and defined in the study of Champagne
3
et al (2004) Sewer floral starchygrain hay-likemusty popcorn green beans sweet taste
sour and astringent were among those attributes
Consumer acceptance is of great interested to breeders farmers and the food industry
Acceptability of quinoa bread was studied by Rosell et al (2009) and Chlopicka et al (2012)
Gluten free quinoa spaghetti (Chillo et al 2008) and dark chocolate with 20 quinoa
(Schumacher et al 2010) were evaluated using a sensory panel However cooked quinoa the
most common way of consuming quinoa has not been studied for its sensory properties and
consumer preference Additionally consumer acceptance of quinoa may be influenced by the
panelistsrsquo demographic such as origin food culture familiarity with less common grains and
quinoa and opinion of a healthy diet Furthermore compared to instrumental tests sensory
evaluation tests are generally more expensive and time consuming hence correlations of sensory
panel and instrumental data are of interest If correlations exist instrumental analyses can be
used to substitute or complement sensory panel evaluation
Based on the above discussion this dissertation focused on the study of seed
characteristics quality and texture of cooked quinoa and starch characteristics among various
quinoa varieties Seed quality under saline soil conditions was also investigated To develop the
sensory profiles of cooked quinoa a trained panel developed and validated a lexicon for cooked
quinoa while a consumer panel evaluated their acceptance of different quinoa varieties From
these data the drivers of consumer liking were determined
The dissertation is divided into 7 chapters Chapter 1 is an introduction of the topic and
overall objectives of the studies Chapter 2 provides a literature review of recent progress in
4
quinoa studies including quinoa seed structure and compositions physical properties flour
properties health benefits and quinoa products Chapter 3 was published in Journal of Food
Science under the title of lsquoEvaluation of texture differences among varieties of cooked quinoarsquo
The objectives of Chapter 3 were to study the texture difference among varieties of cooked
quinoa and evaluate the correlation between the texture and the seed characters and
composition cooking process flour pasting properties and thermal properties
Chapter 4 includes the manuscript entitled lsquoQuinoa starch characteristics and their
correlation with texture of cooked quinoarsquo The objectives of Chapter 4 were to determine starch
characteristics of quinoa among different varieties and investigate the correlations between the
starch characteristics and cooking quality of quinoa
Chapter 5 has been submitted to Frontier in Plant Science under the title lsquoQuinoa seed
quality response to sodium chloride and sodium sulfate salinityrsquo In Chapter 5 quinoa seed
quality grown under salinity stress was assessed Four quinoa varieties were grown under six
salinity treatments and two levels of fertilization and then quinoa seed quality characteristics
such as protein content seed hardness and seed density were evaluated
Chapter 6 is the manuscript entitled lsquoLexicon development and sensory attributes of
cooked quinoarsquo In Chapter 6 a lexicon of cooked quinoa was developed using a trained panel
The lexicon provided descriptions of the sensory attributes of aroma tasteflavor texture and
color with references developed for each attribute The trained panel then applied this lexicon to
the evaluation of 16 field trial quinoa varieties from WSU and 5 commercial quinoa samples
from Bolivia and Peru A consumer panel also evaluated their acceptance of 6 selected quinoa
5
samples Using data from the trained panel and the consumer panel the key sensory attributes
driving consumer liking were determined Finally Chapter 7 presents the conclusions and
recommendations for future studies
6
References
Nuntildeez de Acro Chapter 12 Quinoarsquos calling In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 211 ndash 25
Ahamed NT Singhal RS Kulkarni PR Pal M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 31 99-103
Ando H Chen Y Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food Components in
Fractions of Quinoa Seed Food Sci Technol Res 8(1) 80-4
Carimentrand A Baudoin A Lacroix P Bazile D Chia E 2015 Chapter 41 International
quinoa trade In D Bazile D Bertero and C Nieto editors State of the Art Report of
Quinoa in the World in 2013 Rome FAO amp CIRAD p 316 ndash 29
Champagne ET Bett-Garber KL McClung AM Bergman C 2004 Sensory characteristics of
diverse rice cultivars as influenced by genetic and environmental factors Cereal Chem 81
237-43
Chillo S Civica V Iannetti M Mastromatteo M Suriano N Del Nobile M 2010 Influence of
repeated extrusions on some properties of non-conventional spaghetti J Food Eng 100 329-
35
Chlopicka J Pasko P Gorinstein S Jedryas A Zagrodzki P 2012 Total phenolic and total
flavonoid content antioxidant activity and sensory evaluation of pseudocereal breads LWT-
Food Sci Technol 46 548-55
7
Garcia M Raes D Allen R Herbas C 2004 Dynamics of reference evapotranspiration in the
Bolivian highlands (Altiplano) Agr Forest Meteorol 125(1) 67-82
James LEA 2009 Quinoa (Chenopodium quinoa Willd) composition chemistry nutritional
and functional properties Adv Food Nutr Res 58 1-31
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine structure of amylopectin J Cereal Sci 21 251-60
Perdon AA Siebenmorgen TJ Buescher RW Gbur EE 1999 Starch retrogradation and texture
of cooked milled rice during storage J Food Sci 64 828-32
Prego I Maldonado S Otegui M 1998 Seed structure and localization of reserves in
Chenopodium quinoa Ann Bot 82(4) 481-8
Ramesh M Ali SZ Bhattacharya KR1999 Structure of rice starch and its relation to cooked-
rice texture Carbohydr Polym 38 337-47
Rosell CM Cortez G Repo-Carrasco R 2009 Bread making use of Andean crops quinoa
kantildeiwa kiwicha and tarwi Cereal Chem 86 386-92
Sahin S Sumnu SG 2006 Physical properties of foods Springer Science amp Business Media
P39 ndash 109
Schumacher AB Brandelli A Macedo FC Pieta L Klug TV de Jong EV 2010 Chemical and
sensory evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J
Food Sci Technol 47 202-6
8
Tari TA Annapure US Singhal RS Kulkarni PR 2003 Starch-based spherical aggregates
screening of small granule sized starches for entrapment of a model flavouring compound
vanillin Carbohydr Polym 53 45-51
USDA US Department of Agriculture 2015a Peru Quinoa outlook Access from
httpwwwfasusdagovdataperu-quinoa-outlook
9
Chapter 2 Literature Review
Introduction
Quinoa (Chenopodium quinoa Willd) is a dicotyledonous pseudocereal from the Andean
region of South America The plant belongs to a complex of allotetraploid taxa (2n = 4x = 36)
which includes Chenopodium berlandieri subsp berlandieri Chenopodium berlandieri subsp
nuttalliae Chenopodium hircinum and Chenopodium quinoa (Gomez-Pando 2015 Matanguihan
et al 2015) Closely related species include the weed lambsquarter (Chenopodium album)
amaranth (Amaranth palmeri) sugar beet (Beta vulgaris L) and spinach (Spinacea oleracea L)
(Maughan et al 2004) Quinoa plant is C3 specie with 90 self-pollenating (Gonzalez et al
2011) Quinoa was domesticated approximately 5000 ndash 7000 years ago in the Lake Titicaca area
in Bolivia and Peru (Gonzalez et al 2015) Quinoa produces small oval-shaped seeds with a
diameter of 2 mm and a weight of 2 g ndash 46 g 1000-seed (Wu et al 2014) The seed color varies
and can be white yellow orange red purple brown or gray White and red quinoas are the most
common commercially available varietals in the US marketplace (Data from online resources
and local stores in Pullman WA) With such small seeds quinoa provides excellent nutritional
value such as high protein content balanced essential amino acids high proportion of
unsaturated fatty acids rich vitamin B complex vitamin E and minerals antioxidants such as
phenolics and betalains and rich dietary fibers (Wu 2015) For these reasons quinoa is
recognized as a ldquocompleterdquo food (Taverna et al 2012)
10
This chapter reviewed publications in quinoa varieties global development seed
structure and constituents quinoa health benefits physical properties and thermal properties
quinoa flour characteristics processing and quinoa products
Quinoa varieties
There are 16422 quinoa accessions or genetypes conserved worldwide 14502 of which
are conserved in genebanks from the Andean region (Rojas et al 2013) Bolivia and Peru
manage 13023 quinoa accessions (80 of world total accessions) in 140 genebanks (Rojas and
Pinto 2015)
Based on genetic diversity adaptation and morphological characteristics five ecotypes
of quinoa have been identified in the Andean region including valley quinoa Altiplano quinoa
salar quinoa sea level quinoa and subtropical quinoa (Tapia et al 1980) The sea-level ecotype
or Chilean lowland ecotype is the best adapted to temperate climate and high summer
temperature (Peterson and Murphy 2015a)
Adaptation
Quinoa has shown excellent adaptation to marginal or extreme environments and such
adaptation was summarized by Gonzalez et al (2015) Quinoa growing areas range from sea
level to 4200 masl (meters above sea level) with growing temperature rangeing from -4 to 38 ordmC
The plant has adapted to drought-stressed environments but can also grow in areas with
humidity ranging from 40 to 88 Quinoa can grow in marginal soil conditions such as dry
(Garcia et al 2003) infertile (Sanchez et al 2003) and with wide pH range from acidic to basic
(Jacobsen and Stolen 1993) Quinoa has also adapted to high salinity soil (equal to sea salt level
11
or 40 dSm) (Koyro and Eisa 2008 Hariadi et al 2011 Peterson and Murphy 2015b)
Furthermore quinoa has shown tolerance to frost at -8 to -4 ordmC (Jacobsen et al 2005)
Even though quinoa varieties are remarkably diverse and able to adapt to extreme
conditions time and resources are required to breed the high-yielding varieties that are adapted
to regional environments in North America Challenges to achieving strong performance include
yield waterlogging pre-harvest sprouting weed control and tolerance to disease insect pests
and animal stress (Peterson and Murphy 2015a) The breeding work not only needs the effort
from breeders and researchers but also demands the participation and collaboration of local
farmers
In addition to being widely grown in South America quinoa has also recently been
grown in North America Europe Australia Africa and Asia In US quinoa cultivation and
breeding started in the 1980s by the efforts from seed companies private individuals and
Colorado State University (Peterson and Murphy 2015a) Since 2010 Washington State
University has been breeding quinoa in the Pacific Northwest to suit the diverse environmental
conditions including rainfall and temperature Peterson and Murphy (2015a) found the major
challenges in North America included heat susceptibility downy mildew (Plasmopara viticola)
saponin removal weed stress and insect stress (such as aphids and Lygus sp)
With high nutritional value quinoa is recognized as significant in food security and
treating malnutrition issue in developing countries (Rojas 2011) Maliro and Guwela (2015)
reviewed quinoa breeding in Africa Initial experiments showed quinoa can grow well in Malawi
and Kenya in both warm and cool areas The quinoa grain yields in Malawi and Kenya are 3-4
12
tonha which are comparable to the yields in South America However the challenge remains to
adopt quinoa into the local diet and cultivate a quinoa consuming market
Physical Properties of Quinoa
Physical properties of seed refer to seed morphology size gravimetric properties
(weight density and porosity) aerodynamic properties and hardness which are critical to
technology and equipment designed for post-harvest process such as seed cleaning
classification aeration drying and storage (Vilche et al 2003)
The quinoa seed is oval-shaped with a diameter of approximately 18 to 22 mm (Bertero
et al 2004 Wu et al 2014) Mean 1000-seed weight of quinoa is around 27 g (Bhargava et al
2006) and a range of 15 g to 45 g has been observed among varieties (Wu et al 2014)
Commercial quinoa from Bolivia tends to have higher 1000-seed weight of 38 g to 45 g
Additionally bulk density ranges from 066 gmL to 075 gmL in most varieties (Wu et al
2014) Porosity refers to the fraction of space in bulk seed which is not occupied by the seed
(Thompson and Isaac 1976) The porosity of quinoa is 23 (Vilche et al 2003) while that of
rice is 50 to 60 (Kunze et al 2004)
Terminal velocity is the air velocity at which seeds remain in suspension This parameter
is important in cleaning quinoa to remove impurities such as dockage hollow and immature
kernels and mixed weed seeds Vilche et al (2003) reported the terminal velocity of 081 ms-1
while the value of rice was 6 ms-1 to 77 ms-1 (Razavi and Farahmandfar 2008)
Seed hardness or crushing strength is used as a rough estimation of moisture content in
rice (Kunze et al 2004) The hardness of quinoa seed can be tested using a texture analyzer (Wu
13
et al 2014) A stainless cylinder (10 mm in diameter) compressed one quinoa seed to 90 strain
at the rate of 5 mms Because of hardness variation among individual seeds at least six
measurements were required Among the thirteen quinoa samples that were tested hardness
ranged from 58 kg to 110 kg (Wu et al 2014)
Quinoa Seed Structure
Grain structure of quinoa was described in detail by Taylor and Parker (2002) On the
outside of grain is a perianth which can be easily removed during cleaning or rubbing
Sometimes betalain pigments concentrate on this perianth layer and the seed shows bright purple
or golden colors However this color will disappear with the removal of the perianth Inside the
perianth is two-layered pericarp with papillose surface (Figure 1) Beneath the pericarp a seed
coat or episperm is located The seed coat can be white yellow orange red brown or black
Red and white quinoa share the largest market share with consumers exhibiting increasing
interest in brownblack mixed products such as lsquoCalifornia Tricolorrsquo(data from Google
Shopping Amazon and local stores in Pullman WA)
The main seed is enveloped in outside layers and the structure was depicted by Prego et
al (1998) (Figure 2) The embryo (two cotyledons and radicle) coils around a center pericarp
which occupies ~40 of seed volume (Fleming and Galwey 1998) Protein and lipid bodies are
primarily present in the embryo whereas starch granules provide storage in the thin-walled
perisperm Minerals of phosphorus potassium and magnesium are concentrated in phytin
globoids located in the embryo and calcium is located in the pericarp (Konishi et al 2004)
Quinoa Seed Constituents
14
Quinoa is known as a lsquocomplete foodrsquo (James 2009) The seed composition was recently
reviewed by Wu (2015) and Maradini Filho et al (2015) In sum the high nutritional value of
quinoa arises from its high protein content complete and balanced essential amino acids high
proportion of unsaturated fatty acids high concentrations of vitamin B complex vitamin E and
minerals and high phenolic and betalain content
A protein range of 12 to 17 in quinoa has been reported by most studies (Rojas et al
2015) This protein content is higher than wheat (8 to 14 ww) (Halverson and Zeleny 1988)
and rice (4 - 105 ww) (Champagne et al 2004) Additionally quinoa contains all essential
amino acids at concentrations exceeding the suggested requirements from FAOWHO (Table 1)
Quinoa is also gluten-free because it is lacking in prolamins Prolamins are a group of
storage proteins that are rich in proline Prolamins can interact with water and form the gluten
structure which cannot be tolerated by those with celiac disease (Fasano et al 2003) Quinoa and
rice both contain low prolamins (72 and 89 of total protein respectively) and are
considered gluten-free crops Prolamins in wheat (called gliadin) comprise 285 of its total
protein and in maize this concentration of prolamin is 245 (Koziol 1992)
The protein quality of quinoa protein was reported by Ruales and Nair (1992) In raw
quinoa the net protein utilization (NPU) was 757 biological value (BV) was 826 and
digestibility (TD) was 917 all of which were slightly lower than those of casein The
digestibility of quinoa protein is comparable to that of other high quality food proteins such as
soy beans and skim milk (Taylor and Parker 2002) The Protein Efficiency Ratio (PER) in
quinoa ranges from 195 to 31 and is similar to that of casein (Gross et al 1989 Guzmaacuten-
15
Maldonado and Paredes-Lopez 2002) Regarding functional properties of quinoa protein isolates
Eugenia et al (2015) found Bolivian quinoa exhibited the highest thermal stability oil binding
capacity and water binding capacity at acidic pH The Peruvian samples showed the highest
water binding capacity at basic pH and the best foaming capacity at pH 5
Quinoa starch content ranges from 58 to 64 of the dry seed weight (Vega‐Gaacutelvez et
al 2010) Quinoa possesses a small granule size of 06 to 2 μm similar to that of amaranth (1 to
2 μm) and much smaller than those of other grains such as rice wheat oat barley and
buckwheat (2 to 36 μm) (Lindeboom et al 2004) The amylose content in quinoa starch tends to
be lower than found in common grains A range of 3 to 20 was reported by Lindeboom et al
(2005) whereas amylose content is around 25 in cereals As in most cereals quinoa starch is
type A in X-ray diffraction pattern (Ando et al 2002) Li et al (2016) found significant variation
among 26 commercial quinoa samples in the physicochemical properties of starch such as gel
texture thermal and pasting parameters which were strongly affected by apparent amylose
content
Quinoa lipids comprise 55 to 71 of dry seed weight in most reports (Maradini Filho
et al 2015) Ando et al (2002) found quinoa (cultivar Real TKW from Bolivia) perisperm and
embryo contained 50 and 102 total fatty acids respectively Among these fatty acids
unsaturated fatty acids such as oleic linoleic and linolenic comprised 875 Ogungbenle
(2003) reported the properties of quinoa lipids The values of acid iodine peroxide and
saponification were 05 54 24 and 192 respectively
16
Quinoa micronutrients of vitamins and minerals and the relative lsquoreference daily intakersquo
are summarized in Table 2 and 3 respectively Compared to Daily Intake References quinoa
provides a good source of Vitamin B1 B2 and B9 and Vitamin E as well as minerals such as
magnesium phosphorous iron and copper
Quinoa is one of the crops representing diversity in color including white vanilla
yellow orange red brown gray and dark Besides the anthocyannins in dark quinoa (Paśko et
al 2009) the major pigment in quinoa is betalain primarily presenting in seed coat and the
compounds can be subdivided into red-violet betacyannins and yellow-orange betaxanthins
(Tang et al 2015) Betalain is a water-soluble pigment which is permitted quantum satis as a
natural food colorant and applied in fruit yogurt ice cream jams chewing gum sauces and
soups (Esatbeyoglu et al 2015) Additionally betalain potentially offers health benefits such as
antioxidant activity anti-inflammation activity preventing low-density lipoprotein (LDL)
oxidation and DNA damage (Benavente-Garcia and Castillo 2008 Esatbeyoglu et al 2015)
Saponins
Saponins are compounds on the seed coat of quinoa that confer a bitter taste The
compounds are considered to be a defense system against herbivores and pathogens Regarding
chemical structure saponins are a group of glycosides consisting of a hydrophilic carbohydrate
chain (such as arabinose glucose galactose xylose and rhamnose) and a hydrophobic aglycone
(Kuljanabhagavad and Wink 2009) Chemical structures of aglycones were summarized by
Kuljanabhagavad and Wink (2009)
17
Saponins have been considered as anti-nutrient because of haemolytic activity which
refers to the breakdown of red blood cells (Khalil and El-Adawy 1994) However saponins
exhibited health benefit functions such as anti-inflammation (Yao et al 2009) antibacterial
antimicrobial activity (Killeen et al 1998) anti-tumor activity (Shao et al 1996) and
antioxidant activity (Guumllccedilin et al 2006) Furthermore saponins have medicinal use Sun et al
(2009) reported saponins can activate immune system and were used as vaccine adjuvants
Saponins also exhibited anti-cancer activity (Man et al 2010)
Even though saponins have potential health benefits their bitter taste is not pleasant to
consumers To address the bitterness found in bitter quinoa varieties (gt 011 saponin content)
sweet quinoa varieties were bred through conventional genetic selection to contain a lower
saponin content (lt 011 saponin content) For instance lsquoSajamarsquo lsquoKurmirsquo lsquoAynoqarsquo
lsquoKosunarsquo and lsquoBlanquitarsquo in Bolivia lsquoBlanca de Juninrsquo in Peru and lsquoTunkahuanrsquo in Ecuador are
considered sweet quinoa varieties (Quiroga et al 2015) Unfortunately varieties from Bolivia
Peru and Ecuador do not adapt to temperate climates such as those found in the Pacific
Northwest in US and Europe A sweet variety called lsquoJessiersquo exhibits acceptable yield in Pacific
Northwest and has a great market potential Further development of sweet quinoa varieties
adapted to local climate will happen in near future
To remove saponins both dry and wet processing methods have been developed The wet
method or moist method refers to washing quinoa while rubbing the grain with hands or by a
stone Repo-Carrasco et al (2003) suggested the best washing conditions of 20 min soaking 20
min stirring with a water temperature of 70 degC The wet method becomes costly due to the
required drying process Additionally quinoa grain may begin to germinate during wet cleaning
18
The dry method or abrasive dehulling uses mechanical abrasion to polish the grain and
remove the saponins A dehulling process was reported by Reichert et al (1986) using Tanential
Abrasive Dehulling Device (TADD) and removal of 6 - 15 of kernel was required to reduce
the saponins content to lower than 011 Additionally a TM-05 Taka-Yama testing mill was
used in the quinoa pearling process (to 20 - 30 pearling degree) (Goacutemez-Caravaca et al
2014) The dry method is relatively cheaper than wet method and does not generate saponin
waste water The saponin removal efficiency of the dry and washing methods were reported to be
87 and 72 respectively (Reichert et al 1986 Gee et al 1993) A combination of dry and wet
methods was recommended to obtain the efficient cleaning (Repo-Carrasco et al 2003)
Since quinoa is such an expensive crop a 25 to 30 weight lost during the cleaning
process represents a substantial loss on an industrial scale In addition mineral phenolic and
fiber content may dramatically decrease during processing resulting in a loss of nutritional
value Hence cleaning process should be further optimized to reach lower grain weight loss
while maintain an efficient saponins elimination
Removed saponins can be utilized as side products Since saponins also have excellent
foaming property they can be applied in cosmetics and foods as foam-stabilizing and
emulsifying agents (Yang et al 2010) detergents (Chen et al 2010) and preservatives
(Taormina et al 2006)
Saponin content is important to analyze since it highly influences the taste of quinoa
Traditionally the afrosimetric method or foam method was used to estimate saponins content In
this method saponon content is calculated from foam height after shaking quinoa and water
19
mixture for a specific time (Koziol 1991) This afrosimetric method is fast and affordable and
can be used by farmers as a quick estimation of saponin content however the method is not very
accurate The foam stability varies among samples A more accurate method was developed
using Gas Chromatography (GC) (Ridout et al 1991) Using this method quinoa flour was first
defatted using a Soxhlet extraction and then hydrolyzed in reflux for 3 h with a methanol
solution of HCl (2 N) The hydrolysis product sapogenins were extracted with ethyl acetate and
derivatized with bis-(trimethylsilyl) trifluoroacetamide (BSTFA) and dry pyridine and then
tested using GC Generally GC method is a more solid and accurate method compared to foam
method however GC also requires high capital investment as well as long and complex sample
preparation For quinoa farmers and food manufactures fast and affordable methods to test
saponins content in quinoa need to be developed
Saponins have been an important topic in quinoa research Future studies in this area can
include 1) breeding and commercialization of saponin-free or sweet quinoa varieties with high
yield and high agronomy performance (resistance to biotic and abiotic stresses) 2) development
of quick and low cost detection method of saponin content and 3) application of saponin in
medicine foods and cosmetics can be further explored
Health benefits
Simnadis et al (2015) performed a meta-analysis of 18 studies which used animal models
to assess the physiological effects associated with quinoa consumption From these studies
purported physiological effects of quinoa consumption included decreased weight gain
improved lipid profile (decrease LDL and cholesterol) and improved capacity to respond to
20
oxidative stress Simnadis et al (2015) pointed out that the presence of saponins protein and
20-hydroxyecdysone (affects energy homeostasis and intestinal fat absorption) contributed to
those benefit effects
Furthermore Ruales et al (2002) found increased plasma levels of IGF-1 (insulin-like
growth factor) in 50-65 month-old boys after consuming a quinoa infant food for 15 days This
result implicated the potential of quinoa to reduce childhood malnutrition In another study of 22
students (aged 18 to 45) the daily consumption of a quinoa cereal bar for 30 days significantly
decreased triglycerides cholesterol and LDL compared to those parameters prior to quinoa
consumption These results suggest that quinoa intake may reduce the risk of developing
cardiovascular disease (Farinazzi-Machado et al 2012) De Carvalho et al (2014) studied the
influence of quinoa on over-weight postmenopausal women Consumption of quinoa flakes (25
gd for 4 weeks) was found to reduce serum triglycerides and TBARS (thiobarbituric acid
reactive substances) and increase GSH (glutathione) and urinary excretion of enterolignans
compared to those indexes before consuming quinoa flakes
Quinoa flour properties
Functional properties of quinoa flour were determined by Ogungbenle (2003) Quinoa
flour has high water absorption capacity (147) and low foaming capacity (9) and stability
(2) Water absorption capacity was determined by the volume of water retained per gram of
quinoa flour during 30-min mixing at 24 ordmC (Beuchat 1977) The water absorption of quinoa was
higher than that of fluted pumpkin seed (85) soy flour (130) and pigeon pea flour (138)
which implies the potential use of quinoa flour in viscous foods such as soups doughs and
21
baked products Additionally foaming capacity was determined by the foam volumes before and
after whipping of 8 protein solution at pH 70 (Coffmann and Garciaj 1977) Then foam
samples were inverted and dripped though 2 mm wire screen in to beakers The foam stability
was determined by the weight of liquid released from foam after a specific time and the original
weight of foam (Coffmann and Garciaj 1977) Furthermore minimum protein solubility was
observed at pH 60 similar to that of pearl millet and higher than pigeon pea (pH 50) and fluted
pumpkin seed (pH 40) Relatively high solubility of quinoa protein in acidic condition implies
the potential application of quinoa protein in acidic food and carbonated beverages
Wu et al (2014) studied flour viscosity among 13 quinoa samples with large variations
reported among samples The ranges of peak viscosity final viscosity and setback were 59
RVU ndash 197 RVU 56 RVU ndash 203 RVU and -62 RVU ndash 73 RVU respectively which were
comparable to those of rice flour (Zhou et al 2003) Flour viscosity significantly influence
texture of quinoa and rice (Champagne et al 1998 Wu et al 2014)
Ruales et al (1993) studied processing influence on the physico-chemical characteristics
of quinoa flour The process included cooking and autoclaving of the seeds drum drying of
flour and extrusion of the grits Autoclaved quinoa samples exhibited the lowest degree of starch
gelatinization (325) whereas precookeddrum dried quinoa samples were 974 Higher
polymer degradation was found in the cooked samples compared to the autoclaved samples
Water solubility in cooked samples (54 to 156) and autoclaved samples (70 to 96) increased
with the processing time (30 to 60 min cooking and 10 to 30 min autoclaving)
Thermal Properties of quinoa
22
Thermal properties of quinoa flour (both starch and protein) have been determined using
Differential Scanning Calorimetry (DSC) (Abugoch et al 2009) A quinoa flour suspension was
prepared in 20 (ww) concentration The testing temperature was raised from 27 to 120 degC at a
rate of 10 degCmin Two peaks in the DSC graph referenced the starch gelatinization temperature
at 657 degC and protein denaturalization at 989 degC Enthalpy refers to the energy required to
complete starch gelatinization or protein denaturazition In the study of Abugoch et al (2009)
the enthalpy was 59 Jg for starch and 22 Jg for proteins in quinoa
Product development with quinoa
Quinoa has been used in different products such as spaghetti bread and cookies to
enhance nutritional value including a higher protein content and more balanced amino acid
profile Chillo et al (2008) evaluated the quality of spaghetti from amaranth and quinoa flour
Compared to durum semolina spaghetti the spaghetti with amaranth and quinoa flour exhibited
equal breakage susceptibility higher cooking loss and lower instrumental stickiness The
sensory acceptance scores were not different from the control The solid loss weight increase
volume increase adhesiveness and moisture of a corn and quinoa mixed spaghetti were 162thinspg
kgminus1 23 times 26 times 20907thinspg and 384thinspg kgminus1 respectively (Caperuto et al 2001)
Schoenlechner et al (2010) found the optimal combination of 60 buckwheat 20 amaranth
and 20 quinoa yielded an improved dough matrix compared to other flour combinations With
the addition of 6 egg white powder and 12 emulsifier (distilled monoglycerides) this gluten-
free pasta exhibited acceptable firmness and cooking quality compared to wheat pasta
23
Stikic et al (2012) added 20 quinoa seeds in bread formulations which resulted in the
similar dough development time and stability compared to those of wheat dough even though
the bread specific volume was lower (63 mLg) compared to wheat bread (67 mLg) The
protein content of bread increased by 2 (ww) and sensory characteristics were lsquoexcellentrsquo as
evaluated by five trained expert panelists Iglesias-Puig et al (2015) found 25g100 g quinoa
flour substitution in wheat bread showed small depreciation in bread quality in terms of loaf
volume crumb firmness and acceptability whereas the nutritional value increased in dietary
fiber minerals protein and healthy fats Rizzello et al (2016) selected strains (lactic acid
bacteria) to develop a quinoa sourdough A wheat bread with 20 (ww) quinoa sourdough
exhibited improved nutritional (such as protein digestibility and quality) textural and sensory
features Quinoa leaves were also applied to bread making (Świeca et al 2014) With the
replacement of wheat flour by 1 to 5 (ww) quinoa leaves the bread crumb exhibited increased
firmness cohesiveness and gumminess Antioxidant activity and phenolic contents both
significantly increased compared to wheat bread
Pagamunici et al (2014) developed three gluten-free cookies with rice and quinoa flour
with 15 26 and 36 (ww) quinoa flour proportions respectively The formulation with
36 quinoa flour had the highest alpha-linolenic acid and mineral content and the cookie
displayed excellent sensory characteristics as evaluated by 80 non-trained consumer panelists
Another study optimized a gluten-free quinoa formulation with 30 quinoa flour 25 quinoa
flakes and 45 corn starch (Brito et al 2015) The cookie was characterized as a product rich in
essential amino acids linolenic acid minerals and dietary fiber This cookie was among those
24
products using the highest quinoa flour content (55 ww) while still received acceptable
sensory scores
Repo-Carrasco-Valencia and Serna (2011) introduced an extrusion process in Peru
Quinoa flour was tempered to 12 moisture for extrusion During extrusion total and insoluble
dietary fiber decreased by 5 to 17 and 13 to 29 respectively whereas the soluble dietary
fiber significantly increased by 38 to 71 Additionally the radical scavenging activity was
also increased in extruded quinoa compared to raw quinoa
Schumacher et al (2010) developed a dark chocolate with addition of 20 quinoa An
improved nutritional value was observed in 9 (ww) increase in vitamin E 70 - 104
increases in amino acids of cysteine tyrosine and methionine This quinoa dark chocolate
received over 70 acceptance index from sensory panel
Gluten-free beer is of increasing interest in the market (Dezelak et al 2014) Ogungbenle
(2003) found quinoa has high D-xylose and maltose and low glucose and fructose content
suggesting its potential use in malted drink de Meo et al (2011) applied alkaline steeping to
pseudocereal and found its positive effects on pseudocereals malt production by increasing total
soluble nitrogen and free amino nitrogen Kamelgard (2012) patented a method to create a
quinoa-based beverage fermented by a yeast Saccharomyces cerevisiae The beverage can be
distilled and aged to form gluten-free liquor Dezelak et al (2014) processed a quinoa beer-like
beverage (fermented with Saccharomyces pastorianus TUM 3470) resulting in a product with a
nutty aroma low alcohol content and rich in minerals and amino acids However further
development of the brewing procedure was necessary since the beverage showed a less attractive
25
appearance (near to black color and greyish foam) and astringent mouthfeel Compared to barley
brewing attributes of quinoa exhibited lower malt extracts longer saccharification times higher
values in total protein fermentable amino nitrogen content and iodine test
Processing quinoa grain to dried edible product and sweet quinoa product were developed
by Scanlin and Burnett (2010) The edible quinoa product was processed through pre-
conditioning (abrasion and washing) moist heating (steam cooking and pressure cooking) dry
heating (baking toasting and dehydrating) and post-production treatment As for sweet quinoa
product germination and malting processing were applied Caceres et al (2014) patented a
process to extract peptides and maltodextrins from quinoa flour and the extracts were applied in
a gel-format food as a supplement during and after physical activity
26
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27
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73
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101
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
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28
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29
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34
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biological effects on intestinal mucosal tissue J Sci Food Agric 63(2) 201-9
Goacutemez-Caravaca AM Iafelice G Verardo V Marconi E Caboni MF 2014 Influence of
pearling process on phenolic and saponin content in quinoa (Chenopodium quinoa Willd)
Food Chem 157 174-8
Gomez-Pando L 2015 Chapter 6 Quinoa breeding In Murphy KM Matanguihan J editors
Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p
87 ndash 97
Gonzaacutelez JA Bruno M Valoy M Prado FE 2011 Genotypic variation of gas exchange
parameters and leaf stable carbon and nitrogen isotopes in ten quinoa cultivars grown under
drought J Agron Crop Sci 197(2) 81-93
30
Gonzaacutelez JA Eisa SSS Hussin SAES and Prado FE 2015 Chapter 1 Quinoa An Incan Crop
to Face Global Changes in Agriculture In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 182-6
Graf BL Rojas-Silva P Rojo LE Delatorre-Herrera J Baldeoacuten ME Raskin I 2015 Innovations
in health value and functional food development of quinoa (Chenopodium quinoa Willd)
Comp Rev Food Sci Food Safety 14(4) 431-45
Gross R Koch F Malaga I de Miranda A Schoeneberger H Trugo L 1989 Chemical
composition and protein quality of some local Andean food sources Food Chem 34(1) 25-
34
Guumllccedilin İ Mshvildadze V Gepdiremen A Elias R 2006 The antioxidant activity of a
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Guzmaacuten-Maldonado S Paredes-Lopez O 2002 Functional products of plants indigenous to
Latin America amaranth quinoa common beans and botanicals In Shi J Mazza G
Maguer ML editors Functional foods Biochemical and processing aspects CRC Press p
293-328
Halverson J Zeleny L 1988 Chapter 2 Criteria of wheat quality In Pomeranz Y editor
Wheat Chemistry and Technology 3rd edition St Paul MN American Association of
Cereal Chemists Inc p 25 ndash 6
31
Hariadi Y Marandon K Tian Y Jacobsen SE Shabala S 2011 Ionic and osmotic relations in
quinoa (Chenopodium quinoa Willd) plants grown at various salinity levels J Exp Bot
62(1) 185-93
Iglesias-Puig E Monedero V Haros M 2015 Bread with whole quinoa flour and bifidobacterial
phytases increases dietary mineral intake and bioavailability LWT-Food Sci Technol 60(1)
71-7
Jacobsen SE Monteros C Christiansen J Bravo L Corcuera L Mujica A 2005 Plant responses
of quinoa (Chenopodium quinoa Willd) to frost at various phenological stages Eur J Agron
22(2) 131-9
Jacobsen SE Stoslashlen O 1993 Quinoa-morphology phenology and prospects for its production as
a new crop in Europe Eur J Agron 2(1) 19-29
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and functional properties Adv Food Nutr Res 58 1-31
Kamelgard JI 2012 Quinoa-based beverages and method of creating quinoa-based beverages
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Killeen GF Madigan CA Connolly CR Walsh GA Clark C Hynes MJ Power RF 1998
Antimicrobial saponins of Yucca schidigera and the implications of their in vitro properties
for their in vivo impact J Agric Food Chem 46(8) 3178-86
32
Konishi Y Hirano S Tsuboi H Wada M 2004 Distribution of minerals in quinoa
(Chenopodium quinoa Willd) seeds Biotechnol Appl Biochem 68(1) 231-4
Koyro HW Eisa SS 2008 Effect of salinity on composition viability and germination of seeds
of Chenopodium quinoa Willd Plant Soil 302(1-2) 79-90
Kozioł M1992 Chemical composition and nutritional evaluation of quinoa (Chenopodium
quinoa Willd) J Food Compost Anal 5(1) 35-68
Kuljanabhagavad T Wink M 2009 Biological activities and chemistry of saponins from
Chenopodium quinoa Willd Phytochem Rev 8(2) 473-90
Kunze OR Lan Y and Wratten FT 2004 Chapter 8 Physical and mechanical properties of rice
In Champagne ET editor Rice Chemistry and Technology 3rd edition St Paul MN
American Association of Cereal Chemists Inc p 193 ndash 211
Li G Wang S Zhu F 2016 Physicochemical properties of quinoa starch Carbohydr Polym 137
328-38
Lindeboom N Chang PR Falk KC Tyler RT 2005 Characteristics of starch from eight quinoa
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Lindeboom N Chang PR Tyler RT 2004 Analytical biochemical and physicochemical aspects
of starch granule size with emphasis on small granule starches a review Starch-Staumlrke 56(3-
4) 89-99
Man S Gao W Zhang Y Huang L Liu C 2010 Chemical study and medical application of
saponins as anti-cancer agents Fitoterapia 81(7) 703-14
33
Maradini Filho AM Pirozi MR Da Silva Borges JT Pinheiro SantAna HM Paes Chaves JB
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Rev Food Sci Nutr (just-accepted)
Matanguihan JB Jellen EN and Kolano A 2015 Chapter 7 Quinoa cytogenetics molecular
genetics and diversity In Murphy KM Matanguihan J editors Quinoa Improvement and
Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 109-24
Maughan PJ Bonifacio A Jellen EN Stevens MR Coleman CE Ricks M Mason SL Jarvis
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Cereals and Pseudo-Cereals for Gluten-Free Beer Production J Inst Brew 117(4) 541-6
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quinoa) flour Int J Food Sci Nutr 54(2) 153-8
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Chapter 31 Traditional processes and Technological Innovations in Quinoa Harvesting
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34
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35
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13
Rojas W 2011 Quinoa an ancient crop to contribute to world food security Santiago Chile
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Murphy KM Matanguihan J editors Quinoa Improvement and Sustainable Production
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37
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Arumuganathan K Bonifacio A Fairbanks DJ Jellen EN Stevens JJ 2006 Construction of
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encoding seed storage proteins Theor Appl Genet 112(8) 1593-600
Stikic R Glamoclija D Demin M Vucelic-Radovic B Jovanovic Z Milojkovic-Opsenica D
Jacobsen SE Milovanovic M 2012 Agronomical and nutritional evaluation of quinoa seeds
38
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132-8
Sun HX Xie Y Ye YP 2009 Advances in saponin-based adjuvants Vaccine 27(12) 1787-96
Świeca M Sęczyk Ł Gawlik-Dziki U Dziki D 2014 Bread enriched with quinoa leaves - The
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Chem 162 54-62
Tang Y Li X Zhang B Chen PX Liu R Tsao R 2015 Characterisation of phenolics betanins
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Taormina PJ Simpson PG Bertera EA Komitopoulou E 2006 Beverage preservatives Google
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Tapia M Mujica A Canahua A 1980 Origen y distribucion geografica y sistemas de
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Tecnica del Altiplano
Taverna LG Leonel M Mischan MM 2012 Changes in physical properties of extruded sour
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Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Taylor JRN Parker ML editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science amp Business Media p 96-9
39
Thompson R Isaacs G 1967 Porosity determinations of grains and seeds with an air-
comparison pycnometer T ASAE 10(5) 693-6
Vega-Gaacutelvez A Miranda M Vergara J Uribe E Puente L Martiacutenez EA 2010 Nutrition facts
and functional potential of quinoa (Chenopodium quinoa willd) an ancient Andean grain a
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USDA US Department of Agriculture Agricultrual Research Service 2015 USDA national
nutrient database for standard reference Release 18 Nutrient Data Laboratory Home Page
Available from httpwwwarsusdagovServicesdocshtmdocid=8964
Vilche C Gely M Santalla E 2003 Physical Properties of Quinoa Seeds Biosyst Eng 86(1) 59-
65
Wu G Morris CF Murphy KM 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79(11) 2337-45
Wu G Chapter 11 Nutritional properties of quinoa In Murphy KM Matanguihan J editors
Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc
p193 ndash 205
Yang CH Huang YC Chen YF Chang MH 2010 Foam properties detergent abilities and long-
term preservative efficacy of the saponins from J Food Drug Anal 18(3) 4417-25
Yao Y Yang X Shi Z Ren G 2014 Anti-inflammatory activity of saponins from quinoa
(Chenopodium quinoa Willd) Seeds in lipopolysaccharide-stimulated raw 2647
Macrophages Cells J Food Sci 79(5) 1018-23
40
Zhou Z Robards K Helliwell S Blanchard C 2003 Effect of rice storage on pasting properties
of rice flour Food Res Int 36(6) 625-34
41
Table 1-Essential amino acid of quinoa protein and FAOWHO suggested requirement (mgg protein)
Essential amino acid Quinoa protein a FAOWHO suggested requirement b
Histidine 258 18
Isoleucine 433 25
Leucine 736 55
Lysine 525 51
Methionine amp Cysteine 273 25
Phenylalanine amp Tyrosine 803 47
Threonine 439 27
Tryptophan 385 7
Valine 506 32
a) Abugoch et al (2008) b) Friedman and Brandon (2001)
42
Table 2-Quinoa vitamins content (mg100g)
Quinoa a-d Reference Daily Intake
Thianmin (B1) 029-038 15
Riboflavin (B2) 030-039 17
Niacin (B3) 106-152 20
Pyridoxine (B6) 0487 20
Folate (B9) 0781 04
Ascorbic acid (C) 40 60
α-Tocopherol (VE) (IU) 537 30
Β-Carotene 039 NR
a (Koziol 1992) b (Ruales and Nair 1993) c (Ranhotra et al 1993) d (USDA 2015)
43
Table 3-Quinoa minerals content (mgmg )
Whole graina RDI b
K 8257 NR
Mg 4526 400
Ca 1213 1000
P 3595 1000
Fe 95 18
Mn 37 NR
Cu 07 2
Zn 08 15
Na 13 NR
(aAndo et al 2002 bUSDA 2015)
44
Figure 1-Quinoa seed section and two-layered pericarp under perianth (Wu et al 2014)
45
Figure 2-Quinoa seed structure (Prego et al 1998)
(PE pericarp SC seed coat C cotyledons SA shoot apex H hypocotylradicle axis R radicle F funicle EN endosperm P perisperm Bar = 500 μm)
46
Chapter 3 Evaluation of Texture Differences among Varieties of
Cooked Quinoa
Published manuscript
Wu G Morris C F amp Murphy K M (2014) Evaluation of texture differences among
varieties of cooked quinoa Journal of Food Science 79(11) S2337-S2345
ABSTRACT
Texture is one of the most significant factors for consumersrsquo experience of foods Texture
differences of cooked quinoa were studied among thirteen different varieties Correlations
between the texture parameters and seed composition seed characteristics cooking quality flour
pasting properties and flour thermal properties were determined The results showed that texture
of cooked quinoa was significantly differed among varieties lsquoBlackrsquo lsquoCahuilrsquo and lsquoRed
Commercialrsquo yielded harder texture while lsquo49ALCrsquo lsquo1ESPrsquo and lsquoCol6197rsquo showed softer
texture lsquo49ALCrsquo lsquo1ESPrsquo lsquoCol6197rsquo and lsquoQQ63rsquo were more adhesive while other varieties
were not sticky The texture profile correlated to physical-chemical properties in different ways
Protein content was positively correlated with all the texture profile analysis (TPA) parameters
Seed hardness was positively correlated with TPA hardness gumminess and chewiness at P le
009 Seed density was negatively correlated with TPA hardness cohesiveness gumminess and
chewiness whereas seed coat proportion was positively correlated with these TPA parameters
Increased cooking time of quinoa was correlated with increased hardness cohesiveness
gumminess and chewiness The water uptake ratio was inversely related to TPA hardness
47
gumminess and chewiness RVA peak viscosity was negatively correlated with the hardness
gumminess and chewiness (P lt 007) breakdown was also negatively correlated with those TPA
parameters (P lt 009) final viscosity and setback were negatively correlated with the hardness
cohesiveness gumminess and chewiness (P lt 005) setback was correlated with the
adhesiveness as well (r = -063 P = 002) Onset gelatinization temperature (To) was
significantly positively correlated with all the texture profile parameters and peak temperature
(Tp) was moderately correlated with cohesiveness whereas neither conclusion temperature (Tc)
nor enthalpy correlated with the texture of cooked quinoa This study provided information for
the breeders and food industry to select quinoa with specific properties for difference use
purposes
Keywords cooked quinoa variety texture profile analysis (TPA) RVA DSC
Practical Application The research described in this paper indicates that the texture of different
quinoa varieties varies significantly The results can be used by quinoa breeders and food
processors
48
Introduction
Quinoa (Chenopodium quinoa Willd) a pseudocereal (Lindeboom et al 2007) is known as
a complete food due to its high nutritional value (Jancurovaacute et al 2009) Protein content of dry
quinoa grain ranges from 8 to 22 (Jancurovaacute et al 2009) Quinoa protein is high in nutritive
quality with an excellent balance of essential amino acids (Abugoch et al 2008) Quinoa is also a
gluten-free crop (Alvarez-Jubete et al 2010) Quinoa consumption in the US and Europe has
increased dramatically over the past decade but these regions rely on imports primarily from
Bolivia and Peru (Food and Agriculture Organization of the United Nations FAO 2013) For
these reasons greater knowledge of quinoa grain quality is needed
Quinoa is traditionally cooked as a whole grain similar to rice or milled into flour and made
into pasta and breads (Food and Agriculture Organization of the United Nations FAO 2013)
Quinoa can also be processed by extrusion drum-drying and autoclaving (Ruales et al 1993)
Commercial quinoa products include pasta bread cookies muffins cereal snacks drinks
flakes baby food and diet supplements (Ruales et al 2002 Del Castillo et al 2009 Cortez et al
2009 Demirkesen et al 2010 Schumacher et al 2010)
Texture is one of most significant properties of food that affects the consuming experience
Food texture refers to those qualities of a food that can be felt with the fingers tongue palate or
teeth (Vaclavik and Christian 2003) Cooked quinoa has a unique texture described as creamy
smooth and slightly crunchy (Abugoch 2009) Texture can be influenced by the seed structure
composition cooking quality and thermal properties However we know of no report which
documents the texture of cooked quinoa and the factors that affect it
49
Quinoa has small seeds compared to most cereals and seed size may affect the texture of
cooked quinoa Seed characteristics and structure are the significant factors potentially affecting
the textural properties of processed food Rousset et al (1995) indicated that the length and
lengthwidth ratio of rice kernels was associated with a wide range of texture attributes including
crunchy brittle elastic juicy pasty sticky and mealy which were determined by a sensory
panel The correlation between quinoa seed characteristics and cooked quinoa texture has not
been studied
Quinoa is consumed as whole grain without removing the bran unlike most rice and wheat
The insoluble fiber and non-starch polysaccharides in the seed coat can affect mouth feel and
texture Hence seed coat proportion may contribute to the texture of cooked quinoa Mohapatra
and Bal (2006) reported that the milling degree of rice positively influenced cohesiveness and
adhesiveness of cooked rice but was negatively correlated to hardness
Quinoa seed qualities such as the size hardness weight density and seed coat proportion
may influence the water binding capacity of seed during thermal processing thereby affecting
the texture of the cooked cereal (Fitzgerald et al 2003) Nevertheless correlations between seed
characteristics and texture of cooked quinoa have not been previously described
Seed composition may influence texture as well Higher protein content was reported to
cause reduced stickiness and harder texture of cooked rice (Ramesh et al 2000) Quinoa seeds
contain approximately 60 starch (Ando et al 2002) Starch granules are particularly small (05
- 3μm) Amylose content of quinoa is as low as 11 (Ahamed et al 1996) while the amylose
proportion in most cereals such as wheat is around 25 (Zeng et al 1997 BeMiller and Huber
50
2008) Amylose content of starch correlated positively with the hardness of cooked rice and
cooked white salted noodles (Ong and Blanshard 1995 Epstein et al 2002 Baik and Lee 2003)
Flour pasting properties can greatly influence the texture of cooked products Their
correlation has not been illustrated in quinoa while some research have been conducted on
cooked rice A lower peak viscosity and positive setback are associated with a harder texture
while a higher peak viscosity breakdown and lower setback are associated with a sticky texture
in cooked rice (Limpisut and Jindal 2002) Champagne et al (1999) indicated that adhesiveness
had strong correlations with Rapid Visco Analyzer (RVA) measurements Ramesh et al (2000)
reported that harder cooked rice texture was associated with a lower peak viscosity and positive
setback while sticky rice had a higher peak viscosity higher breakdown and lower setback
The gelatinization temperature of quinoa starch ranges from 54ordmC to 71ordmC (Ando et al
2002) lower than that of rice barley and wheat starches (Marshall 1994 Tang 2004 Tang et al
2005) Gelatinization temperature likely plays an important role in waxy rice quality (Perdon and
Juliano 1975 Juliano et al 1987) but was not correlated to the eating quality of normal rice
(Ramesh et al 2000) Despite a considerable amount of work having been conducted on the
thermal properties of cereal starch little is known about the relationship between quinoa flour
thermal properties and cooked quinoa texture
The correlation of quinoa cooking quality and texture has not been previously reported In
rice cooking quality exhibited strong correlations to the texture profile analysis (TPA) Cooking
time has been reported to correlate positively with hardness and negatively with adhesiveness of
cooked rice (Mohapatra and Bal 2006) Higher water uptake ratio and volume expansion ratio
were associated with softer more adhesive and more cohesive texture of cooked rice
51
(Mohapatra and Bal 2006) Cooking loss has been reported to improve firmness but decrease
juiciness (Rousset et al 1995)
There is a need to further study the texture of cooked quinoa and its determining factors
The objective of this paper is to study the texture difference among varieties of cooked quinoa
and evaluate the correlation between the texture and the seed characters and composition
cooking process flour pasting properties and thermal properties
Materials and Methods
Seed characteristics
Eleven varieties and two commercial lots of quinoa are listed in Table 1 The two grain
lots were referred as lsquoYellow Commercialrsquo and lsquoRed Commercialrsquo according to the seed color
Seed size (diameter) was determined by lining up and measuring the length of 20 seeds Average
seed diameter was calculated from three repeated measurements Bulk density of seed was
measured by the weightvolume method Seed weight was determined gravimetrically Seed
hardness was determined using the texture analyzer TAndashXT2i (Texture Technology Corp
Scarsdale NY USA) A cylinder of 10 mm in diameter compressed one seed to 90 strain at
the rate of 5 mms The force (kg) was recorded as the seed hardness Seed coat proportions were
determined by a Scanning Electron Microscope (SEM) FEI Quanta 200F (FEI Corp Hillsboro
OR USA) The seed was cross-sectioned and the SEM image was captured under 800times
magnification The seed coat proportions were measured using the software ruler in micrometers
Chemical compositions
Whole quinoa flour was prepared using a cyclone sample mill (UDY Corporation Fort
Collins CO USA) equipped with a 05 mm screen and was used for compositional analysis
52
pasting viscosity and thermal properties Ash and moisture content of quinoa flour were tested
according to the Approved Method 08-0101 and 44-1502 respectively (AACCI 2012) Protein
content was determined by a nitrogen analyzer coupled with a thermo-conductivity detector
(LECO Corporation Joseph MI USA) The factor of 625 was used to calculate the protein
content from the nitrogen content (Approved Method 46-3001 AACCI 2012) Protein and ash
were calculated on a dry weight basis
Cooking protocol
The cooking protocol of quinoa was modified from a rice cooking method (Champagne
et al 1998) Five grams of quinoa seed were soaked for 20 min in 10 mL deionized water in a
flask Soaking is required to remove the bitter saponins (Pappier et al 2008) and enhance
cooking quality (Mohapatra and Bal 2006) The mixture was then boiled for 2 min and the flask
was set in boiling water for 18 min The flask was covered to prevent water loss
Cooking quality
Two grams of quinoa seed were cooked in 20 mL deionized water for 20 min and extra
water was removed Cooking time was determined when the middle white part of the seed
completely disappeared (Mohapatra and Bal 2006) The water uptake ratio was calculated from
the seed weight ratio before and after cooking Cooking volume was the seed volume after
cooking Cooking loss was the total of soluble and insoluble matter in the cooking water
(Rousset et al 1995) Three mL of cooking water of each sample was placed on an aluminum
pan and dried at 130 ordmC overnight The weight of dry solids in the pan was used to calculate the
cooking loss
Texture profile analysis (TPA)
53
Texture profile analysis (TPA) was used to determine the texture of cooked quinoa
according to a modified method for cooked rice texture (Champagne et al 1999) Two grams of
cooked quinoa were arranged on the texture analyzer platform as close to one layer as possible
A stainless steel plate (50 mm times 40 mm times 10 mm) compressed the cooked quinoa from 5 mm to
01 mm at 5 mmsec The compression was conducted twice The texture analyzer generated a
graph with time as the x-axis and force as the y-axis Six parameters were calculated from the
graph (Epstein et al 2002) Hardness is the height of the first peak adhesiveness is the area 3
cohesiveness is area 2 divided by area 1 springiness is distance 1 divided by distance 2
gumminess is hardness multiplied by cohesiveness chewiness is gumminess multiplied by
springiness In the present study no significant differences or correlations were obtained for
springiness As such this parameter will not be included except to describe the overall result (see
below)
Flour viscosity
Quinoa flour pasting viscosity was determined using the Rapid Visco Analyzer (RVA)
RVA-4 (Newport Scientific Pty Ltd Narrabeen Australia) Quinoa flour (43 g) was added to
25 mL deionized water in an aluminum cylinder container The contents were immediately
mixed and heated following the instrument program The temperature was increased from 50 ordmC
to 93 ordmC in 8 min at a constant rate was held at 95 ordmC from 8 to 24 min cooled to 50 ordmC from 24
to 28 min and held at 50 ordmC from 29 to 40 min The program generated a graph with time against
shear force (Figure 1) expressed in RVU (cP = RVU times 12)
Two peaks representing peak viscosity and final viscosity are normally included in the
RVA graph Peak time was the time to reach the first peak Holding strength or trough is the
54
minimum viscosity after the first peak Breakdown is the viscosity difference between peak and
minimum viscosity Setback is the viscosity difference between final and minimum viscosity
Pasting temperature and the time to reach the peak were also recorded
Thermal properties using Differential Scanning Calorimetry (DSC)
Thermal properties of quinoa flour were determined by Differential Scanning
Calorimetry (DSC) Tzero Q2000 (TA instruments New Castle DE USA) The protocol was a
modification of the method of Abugoch et al (2009) Quinoa flour (02 g) was added to 200 μL
deionized water and mixed on a vortex mixer for 10 s to form a slurry Ten to twelve milligrams
of slurry was added to an aluminum pan by pipette The pan was sealed and placed at the center
of DSC platform An empty pan was used as reference The temperature was increased from 25
ordmC to 120 ordmC at 10 ordmCmin then equilibrated to 25 ordmC Gelatinization temperature and enthalpy
were determined from the graph
Statistical analysis
All experiments were repeated three times The hypothesis tests of normality and equal
variance multiple comparisons (Fisherrsquos LSD) and correlation studies were conducted by SAS
92 (SAS Institute Cary NC) A P-value of 005 is considered as the level of statistical
significance unless otherwise specified
Results
Seed characteristics and flour composition
Quinoa seed characteristics and composition are shown in Table 2 Quinoa seeds were
small compared to cereals such as rice wheat and maize Diameters of quinoa seed mostly
ranged between 19 to 22 mm except for lsquoJapanese Strainrsquo which was significantly smaller (15
55
mm) Seed hardness was significantly different among varieties ranging from 583 k g in
lsquoCol6197rsquo to 1096 kg in lsquoOro de Vallersquo Bulk seed density of quinoa varied from 063 kgL in
lsquoBlancarsquo to 081 kgL in lsquoJapanese Strainrsquo Varieties from White Mountain farm and the WSU
Organic Farm were lower in bulk density most of which were below 07 kgL The commercial
and Port Townsend samples were higher in density most of which were around 075 kgL
Thousand-seed weights of quinoa were particularly low ranging from 18 g in lsquoJapanese Strainrsquo
to 41g in lsquoRed Commercialrsquo Seed coat proportion was also significantly different among
varieties Three layers are shown in the seed coat (Figure 2) The varieties lsquoBlackrsquo and lsquoBlancarsquo
had the thickest seed coat (38 and 97 μm respectively) with coat proportions of 40 and 45
respectively lsquoYellow Commercialrsquo and lsquo1ESPrsquo had the thinnest seed coats (15 and 16 μm
respectively) with the coat proportion of 07 and 05 respectively The difference was
almost ten-fold among the varieties
Protein and ash content of quinoa flour
Protein content varied from 113 in lsquo1ESPrsquo to 170 in lsquoCahuilrsquo lsquoCherry Vanillarsquo and
lsquoOro de Vallersquo also had high protein contents of 160 and 156 respectively Ash content
ranged from 12 in the Commercial Yellow seed to 40 in lsquoQQ63rsquo comparable to that in rice
flour (Champagne 2004)
Texture of cooked quinoa
The hardness of cooked quinoa ranged from 20 g for lsquo49ALCrsquo and lsquoCol6197rsquo to 347
kg for lsquoBlackrsquo (Table 3) lsquoOro de Vallersquo and lsquoBlancarsquo were relatively hard varieties with TPA
hardness of 285 kg and 306 kg respectively whereas lsquo1ESPrsquo lsquoJapanese Strainrsquo and lsquoQQ63rsquo
were softer with a hardness of 245 kg 293 kg and 297 kg respectively
56
Adhesiveness is the extent to which seeds stick to each other the probe and the stage
lsquo49ALCrsquo lsquo1ESPrsquo lsquoCol6197rsquo and lsquoQQ63rsquo were significantly stickier with adhesiveness value
of -029 kgs -027 kgs -023 kgs and -020 kgs respectively All other varieties exhibited
lower adhesiveness with values less than 010 kgs Visual examination of the cooked samples
showed that with the more adhesive varieties the seeds stuck together as with sticky rice while
for other varieties the grains were separated
Cohesiveness of cooked lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo was
significantly higher with values from 068 to 071 respectively while those of lsquo49ALCrsquo lsquo1ESPrsquo
and lsquoCol6197rsquo were lower at 054 056 and 053 respectively Springiness is the recovery
from crushing or the elastic recovery (Tsuji 1981 Seguchi et al 1998) Cooked quinoa of all
varieties exhibited excellent elastic recovery properties with springiness values approximating
10
Gumminess is the combination of hardness and cohesiveness Chewiness is gumminess
multiplied by springiness As springiness values were all close to 10 gumminess and chewiness
of cooked quinoa were very similar in value lsquoBlackrsquo lsquoBlancarsquo and lsquoCahuilrsquo were highest in
gumminess and chewiness 24 kg 22 kg and 23 kg respectively while lsquo1ESPrsquo lsquo49ALCrsquo and
lsquoCol6197rsquo were lowest at 14 kg 11 kg and 11 kg respectively The difference among varieties
was greater than three-fold
Cooking quality
Cooking quality of quinoa is shown in Table 4 Cooking time varied from 119 min in
lsquoCol6197rsquo to 192 min in lsquoBlackrsquo cultivar and was significantly correlated with all TPA texture
parameters Longer cooking time also correlated with higher protein content (r = 052 P = 007)
57
Water uptake ratio varied from 25 to 4 fold in lsquoQQ63rsquo and lsquoCol6197rsquo respectively Water
uptake ratio was negatively correlated to seed hardness (r = 052 P = 004) Harder seeds tended
to absorb less water during cooking Cooking volume ranged from 107 mL to 137 mL and did
not significantly correlate with other properties Cooking loss ranged from 035 to 176 and
differed among varieties but was not correlated with water uptake ratio cooking time or cooking
volume
Quinoa flour pasting properties by RVA
Pasting viscosity of quinoa whole seed flour was determined using the Rapid Visco
Analyzer (RVA) The results are shown in Table 5 Peak viscosity differed among varieties
Varieties could be categorized into three groups based on peak viscosity The peak viscosity of
lsquoQQ63rsquo lsquoCol6197rsquo lsquo1ESPrsquo lsquoJapanese Strainrsquo lsquoYellow Commercialrsquo lsquoCopacabanarsquo and lsquoRed
Commercialrsquo varied from 144 to 197 RVU The peak viscosity of lsquoBlancarsquo lsquoBlackrsquo lsquo49ALCrsquo
and lsquoCahuilrsquo ranged from 98 to 116 RVU while those of lsquoOro de Vallersquo and lsquoCherry Vanillarsquo
were 59 and 66 RVU respectively
Trough viscosity namely the minimum viscosity after the first peak showed more than a
three-fold difference among varieties As in the case of peak viscosity the trough of different
varieties can be categorized into the same three groups
Breakdown is the difference between the peak and minimum viscosity lsquoQQ63rsquo lsquo1ESPrsquo
and lsquoJapanese Strainrsquo showed large breakdowns of 51 51 and 62 RVU respectively
Breakdown of lsquoCherry Vanillarsquo lsquoOro de Vallersquo and the Commercial Yellow seed were lower at
12 10 and 11 RVU respectively Breakdown of the other varieties ranged from 18 to 36 RVU
58
The final viscosity of the Commercial Yellow seed was 203 RVU the highest among all
varieties Final viscosity of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo
ranged from 56 to 82 RVU and was lower than that of other varieties which ranged from 106 to
190 RVU
Setback is the difference between final and trough viscosity Setback of lsquoRed
Commercialrsquo lsquoCahuilrsquo and lsquoBlackrsquo were all negative -62 -11 and -6 RVU respectively which
indicated that the final viscosity of these cultivars was lower than their trough viscosity Setback
of lsquoBlancarsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo were slightly positive at 2 2 and 6 RVU
respectively while those of other cultivars were much greater between 42 and 73 RVU Peak
time which is the time to reach the first peak ranged from 93 to 115 min The pasting
temperature was 93 ordmC and not different among the varieties
Thermal properties of quinoa flour using DSC
Thermal properties of quinoa flour were determined using DSC Gelatinization
temperatures (To onset temperature Tp peak temperature Tc conclusion temperature) and
gelatinization enthalpies are shown in Table 6 To of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry
Vanillarsquo and lsquoJapanese Strainrsquo were not different from each other and ranged from 645 ordmC to
659 ordmC To of lsquoOro de Vallersquo lsquoCopacabanarsquo lsquoCol6197rsquo and lsquoQQ63rsquo ranged from 605 ordmC to
631 ordmC while other varieties were lower and ranged from 544 ordmC to 589 ordmC Tp ranged from
675 ordmC in the Commercial Yellow seed to 752 ordmC in lsquoCahuilrsquo Tc ranged from 780 ordmC in lsquoRed
Commercialrsquo to 850ordmC in the lsquoJapanese Strainrsquo Enthalpy of quinoa flour differed among
varieties The range was from 11 Jg in lsquoYellow Commercialrsquo to 18 Jg in lsquoBlancarsquo
Correlations between physical-chemical properties and cooked quinoa texture
59
A summary of correlation coefficients between quinoa physical-chemical properties and
TPA texture profile parameters of cooked quinoa are shown in Table 7 Seed hardness was found
to be positively related to the TPA hardness gumminess and chewiness of cooked quinoa (P lt
009) Seed bulk density was negatively correlated to hardness cohesiveness gumminess and
chewiness while seed coat proportion was positively correlated to those parameters Protein
content of quinoa exhibited a positive relationship with TPA hardness (P = 008) and
adhesiveness cohesiveness gumminess and chewiness No significant correlation was observed
between the seed size 1000 seed weight ash content and the texture properties of cooked
quinoa
Cooking time of quinoa was highly positively correlated with all of the TPA texture
profile parameters Water uptake ratio during cooking was found to be significantly associated
with hardness gumminess and chewiness of cooked quinoa while cooking volume also showed
a modest correlation to hardness (r = -047 P = 010) Cooking loss was not correlated with any
texture parameter
Flour pasting viscosity was significantly correlated with texture of cooked quinoa Peak
viscosity and breakdown exhibited negative correlations with the hardness gumminess and
chewiness of cooked quinoa (P lt 010) Breakdown was also negatively associated with the
cohesiveness (r = -051 P lt 010) Final viscosity and setback were found to be negatively
correlated to hardness cohesiveness gumminess and chewiness while setback also exhibited a
significant correlation to adhesiveness (r = -064 P = 002)
60
Considering thermal properties To exhibited strong positive correlations with all texture
parameters Tp was found to be moderately related to cohesiveness (r = 050 P = 008) Neither
Tc nor enthalpy was significantly correlated to the TPA parameters of cooked quinoa
Discussion
Seed characteristics
Harder seed yielded harder gummier and chewier TPA texture after cooking The
varieties with lower seed bulk density or thicker seed coat yielded a firmer more cohesive
gummier and chewier texture Likely the condensed cells and non-starch polysaccharides of the
seed coat are a barrier between starch granules in the middle perisperm and water molecules
outside the seed
Seed composition
Higher protein appeared to contribute to a firmer more adhesive gummier and chewier
texture of cooked quinoa as evidenced by the TPA parameters Protein has been reported to play
a significant role in the texture of cooked rice and noodles (Ramesh et al 2000 Martin and
Fitzgerald 2002 Saleh and Meullenet 2007 Xie et al 2008 Hou et al 2013) According to the
previous studies proteins affect the food texture through three major routes (1) binding of water
(Saleh and Meullenet 2007) (2) interacting reversibly with starch bodies (Chrastil 1993) and (3)
forming networks via disulphide bonds which restrict starch granule swelling and water
hydration (Saleh and Meullenet 2007)
Cooking quality
Cooking time was found to be a key factor for cooked quinoa texture as it was closely
associated with most texture attributes Other cooking qualities such as the water uptake ratio
61
cooking volume and cooking loss were not significantly correlated to texture In the study of
rice the cooking time of rice positively correlated with hardness negatively with cohesiveness
and not significantly with adhesiveness (Mohapatra and Bal 2006) The higher water uptake ratio
and volume expansion ratio were negatively associated with softer more adhesive and more
cohesive texture This result agrees with the study on cooked rice Rousset et al (1995) study
indicated that longer cooking time greater water uptake and cooking loss related to the softer
less crunchy and more pasty texture
Flour pasting properties
The varieties with a higher peak viscosity in flour had a softer less gummy and less
chewy texture after cooking The cultivars with higher final peak viscosity yielded a softer less
cohesive less gummy and chewy texture The varieties with a greater breakdown such as
lsquoQQ63rsquo lsquo1ESPrsquo and lsquoJapanese Strainrsquo were softer in TPA parameter Breakdown has been
reported to negatively correlate with the proportion of long chain amylopectin (Han and
Hamaker 2001) Long chain amylopectin may form intra- or inter-molecular interactions with
protein and lipids and result in a firmer or harder texture (Ong and Blanshard 1995)
Quinoa varieties with a lower setback were harder after cooking compared to those with a
higher setback In rice conversely setback was positively correlated with amylose content
(Varavinit et al 2003) which would positively influence the hardness of cooked rice (Ong and
Blanshard 1995 Champagne et al 1999) Unlike rice and many other cereals where the amylose
content is approximately 25-29 the amylose proportion in quinoa starch is lower on the order
of 11 (Ahamed et al 1996) Amylose may play a different role in cooked quinoa hardness
compared to other cereals
62
Starch viscosity has been reported to significantly affect the texture of cooked rice
Champagne et al (1999) used the RVA measurements to predict TPA of cooked rice and found
that adhesiveness strongly correlated to RVA parameters Harder rice was correlated with lower
peak viscosity and positive setback while stickier rice had a higher peak viscosity breakdown
and lower setback (Ramesh et al 2000) The difference between quinoa and rice seed structure
and starch composition and the difference of texture determining methods may contribute to the
different trends in correlation
Thermal properties
The gelatinization temperature of quinoa flour ranged from 55 ordmC to 85 ordmC lower than
that of whole rice flour which was 70 ordmC to 103 ordmC (Marshall 1994) This result agrees with the
previous study on quinoa flour (Ando et al 2002) The quinoa varieties with higher To exhibited
a firmer more adhesive more cohesive gummier and chewier texture Higher Tp was associated
with increased cohesiveness The enthalpy of quinoa flour ranged from 11 to 18 Jg about one-
tenth that of whole rice flour (141 ndash 151 Jg) (Marshall 1994) indicating that it takes less
energy to cook quinoa than cook rice
Thermal properties of quinoa flour were generally correlated with flour pasting
properties Higher To and Tp were correlated with lower flour peak viscosity and lower trough
The result is comparable to the previous study of Sandhu and Singh (2007) who found that
gelatinization temperature and enthalpy of corn starch strongly influenced the peak breakdown
final and setback viscosity The thermal properties of quinoa flour were not correlated with
breakdown and setback likely was due to other composition factors in the flour such as protein
and fiber
63
Conclusions
The texture of cooked quinoa varied markedly among the different varieties indicating
that genetics management or geographic origin may all be important considerations for quinoa
quality As such differences in seed morphology and chemical composition appear to contribute
to quinoa processing parameters and cooked texture Harder seed yielded a firmer gummier and
chewier texture both lower seed density and high seed coat proportion related to a firmer more
cohesive gummier and chewier texture Seed size and weight appeared to be largely unrelated to
the texture of the cooked quinoa Protein content was a key factor apparently influencing texture
Higher protein content was related to harder more adhesive and cohesive gummier and chewier
texture Cooking time and water uptake ratio significantly affected the texture of cooked quinoa
whereas cooking volume moderately affected the hardness cooking loss was not correlated with
texture RVA peak viscosity was negatively correlated with the hardness gumminess and
chewiness breakdown was also negatively correlated with those TPA parameters Final viscosity
and setback were negatively correlated with the hardness cohesiveness gumminess and
chewiness Setback was correlated with the adhesiveness as well Gelatinization temperature To
affected all the texture profile parameters positively Tp slightly related to the cohesiveness
while Tc and enthalpy were not correlated with the texture
Acknowledgements
This project was supported by funding from the USDA Organic Research and Extension
Initiative project number NIFA GRANT11083982 The authors acknowledge Stacey Sykes and
Alecia Kiszonas for editing support
Author Contributions
64
G Wu and CF Morris designed the study together G Wu collected test data and drafted the
manuscript CF Morris and KM Murphy edited the manuscript KM Murphy provided
samples and project oversight
65
References
AACC International 2012 Approved Methods of Analysis Method 08-0101 Ash - Basic
method Approved April 13 1961 Method 44-1502 Moisture ndash Air-Oven Methods (130ordmC)
Approved October 30 1975 Method 46-3001 Crude protein ndash Combustion method
Approved November 8 1995 Reapproved November 3 1999 Available online only
AACCI St Paul MN
Abugoch LE Romero N Tapia CA Silva J Rivera M 2008 Study of some physicochemical
and functional properties of quinoa (Chenopodium quinoa Willd) protein isolates J Agric
Food Chem 564745-50
Abugoch LEJ 2009 Chapter 1 Quinoa (Chenopodium quinoa Willd) Adv Food Nutr Res
581-31
Abugoch L Castro E Tapia C Antildeoacuten MC Gajardo P Villarroel A 2009 Stability of quinoa
flour proteins (Chenopodium quinoa Willd) during storage Int J Food Sci Tech 442013-20
Ahamed NT Singhal RS Kulkami PR Palb M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 3199-103
Alvarez-Jubete L Arendt EK Gallagher E 2010 Nutritive value of pseudocereals and their
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Ando H Chen YC Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food components in
fractions of quinoa seed Food Sci Technol Res 8(1)80-4
66
Baik BK Lee MR 2003 Effects of starch amylose content of wheat on textural properties of
white salted noodles Cereal Chem 80304-9
BeMiller JN Huber KC 2008 Carbohydrates In Damdaran S Parkin KL Fennema OR editors
Food chemistry Boca Raton CRC Press p 121
Champagne ET Lyon BG Min BK Vinyard BT Bett KL Barton IIFE Webb BD Kohlwey DE
1998 Effects of postharvest processing on texture profile analysis of cooked rice Cereal
Chem 75(2)181-6
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5)764-71
Champagne ET 2004 The rice grain and its gross composition In Champagne ET editor Rice
chemistry and technology St Paul Minn American Association of Cereal Chemists p 88
Chrastil J 1993 Enzyme activities in preharvest rice grains J Agric Food Chem 41(12)2245-8
Cortez G Repo-Carrasco R Rosell CM 2009 Breadmaking use of andean crops quinoa kantildeiwa
kiwicha and tarwi Cereal Chem 86(4)386-92
Del Castillo V Lescano G Armada M 2009 Foods formulation for people with celiac disease
based on quinoa (Chenopodium quinoa) cereal flours and starches mixtures Archivos
Latinoamericanos De Nutricion 59(3)332-36
67
Demirkesen I Mert B Sumnu G Sahin S 2010 Rheological properties of gluten-free bread
formulations J Food Eng 96(2)295-303
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
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(Waxy) genes J Cereal Sci 3551-63
Fitzgerald MA Martin M Ward RM Park WD Shead HJ 2003 Viscosity of rice flour a
rheological and biological study J Agric Food Chem 51(8) 2295-9
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Han XZ Hamaker BR 2001 Amylopectin fine structure and rice starch paste breakdown J
Cereal Sci 34(3)279-84
Hou GG Saini R Ng PKW 2013 Relationship between physicochemical properties of wheat
flour wheat protein composition and textural properties of cooked chinese white salted
noodles Cereal Chem 90(5)419-29
Jancurovaacute M Minarovicova L Dandar A 2009 Quinoa ndash a review Czech J Food Sci 27(2)71-9
Juliano BO Villareal RM Bantildeos L 1987 Varietal differences in physicochemical properties of
waxy rice starch Starch - Staumlrke 39(9)298-301
68
Limpisut P Jindal VK 2002 Comparison of rice flour pasting properties using brabender
viscoamylograph and rapid visco analyser for evaluating cooked rice texture Starch - Staumlrke
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Lindeboom N Chang PR Falk KC Tyler RT 2007 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2)216-22
Marshall WE 1994 Starch gelatinization in brown and milled rice a study using differential
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New York NY Marcel Dekker Inc p 222
Martin M Fitzgerald MA 2002 Proteins in rice grains influence cooking properties J Cereal Sci
36(3)285-94
Mohapatra D Bal S 2006 Cooking quality and instrumental textural attributes of cooked rice
for different milling fractions J Food Eng 73(3)253-9
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine stucture of amylopectin J Cereal Sci 21(3)251-60
Pappier U Fernandez Pinto V Larumbe G Vaamonde G 2008 Effect of processing for saponin
removal on fungal contamination of quinoa seeds (Chenopodium quinoa Willd) Int J Food
Microbiol 125(2)153-7
Perdon AA Juliano BO 1975 Gel and molecular properties of waxy rice starch Starch - Staumlrke
27(3)69-71
69
Ramesh M Bhattacharya KR Mitchell JR 2000 Developments in understanding the basis of
cooked-rice texture Crit Rev Food Sci Nutr 40(6)449-60
Rousset S Pons B Pilandon C 1995 Sensory texture profile grain physico-chemical
characteristics and instrumental measurements of cooked rice J Texture Stud 26(2)119-35
Ruales J Valencia S Nair B 1993 Effect of processing on the physico-chemical characteristics
of quinoa flour (Chenopodium quinoa Willd) Starch - Staumlrke 45(1)13-9
Ruales J de Grijalva Y Lopez-Jaramillo P Nair BM 2002 The nutritional quality of an infant
food from quinoa and its effect on the plasma level of insulin-like growth factor-1 (IGF-1) in
undernourished children Int J Food Sci Nutr 53(2)143-54
Saleh MI Meullenet JF 2007 Effect of protein disruption using proteolytic treatment on cooked
rice texture properties J Texture Stud 38(4)423-37
Sandhu KS Singh N 2007 Some properties of corn starches II Physicochemical gelatinization
retrogradation pasting and gel textural properties Food Chem 101(4)1499-507
Schumacher A Brandelli A Macedo F Pieta L Klug T Jong E 2010 Chemical and sensory
evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J Food
Sci Tech 47(2)202-6
Seguchi M Hayashi M Kanenaga K Ishihara C Noguchi S1998 Springiness of pancake and
its relation to binding of prime starch to tailings in stored wheat flour Cereal Chem
75(1)37-42
70
Tang H 2004 Relationship between functionality and structure in barley starches Carbohydr
Polym 57(2)145-52
Tang H Mitsunaga T Kawamura Y 2005 Functionality of starch granules in milling fractions
of normal wheat grain Carbohyd Polym 59(1)11-7
Tsuji S 1981 Texture measurement of cooked rice kernels using the multiple-point mensuration
method 1 J Texture Stud 12(2)93-105
Vaclavik VA Christian EW 2003 Evaluation of food quality In Vaclavik V Christian EW
editors Essentials of food science New York NY Kluwer AcademicPlnum Publishers p 4
Varavinit S Shobsngob S Varanyanond W Chinachoti P Naivikul O 2003 Effect of amylose
content on gelatinization retrogradation and pasting properties of flours from different
cultivars of thai rice Starch - Staumlrke 55(9)410-5
Xie L Chen N Duan B Zhu Z Liao X 2008 Impact of proteins on pasting and cooking
properties of waxy and non-waxy rice J Cereal Sci 47(2)372-9
Zeng M Morris CF Batey IL Wrigley CW 1997 Sources of variation for starch gelatinization
pasting and gelation properties in wheat Cereal Chem 7463-71
71
Table 1-Varieties of quinoa used in the experiment
Variety Original Seed Source Location
Black White Mountain Farm White Mountain Farm Colorado US
Blanca White Mountain Farm White Mountain Farm Colorado US
Cahuil White Mountain Farm White Mountain Farm Colorado US
Cherry Vanilla Wild Garden Seeds Philomath Oregon WSUa Organic Farm Pullman Washington US
Oro de Valle Wild Garden Seeds Philomath Oregon WSUa Organic Farm Pullman Washington US
49ALC USDA Port Townsend Washington US
1ESP USDA Port Townsend Washington US
Copacabana USDA Port Townsend Washington US
Col6197 USDA Port Townsend Washington US
Japanese Strain USDA Port Townsend Washington US
QQ63 USDA Port Townsend Washington US
Yellow Commercial Multi Organics company Bolivia
Red Commercial Multi Organics company Bolivia a WSU - Washington State University
72
Table 2-Seed characteristics and compositiona
Variety Diameter (mm)
Hardness (kg)
Bulk Density (gmL)
Seed Coat Proportion ()
Protein ()
Ash ()
Black 21bc 994b 0584d 37bc 143d 215hi
Blanca 22ab 608l 0672c 89a 135e 284ef
Cahuil 21abc 772e 0757a 49b 170a 260fg
Cherry Vanilla 19e 850d 0717b 41b 160b 239gh
Oro de Valle 19e 1096a 0715b 43b 156b 305de
49ALC 19de 935c 0669c 26cd 127g 348bc
1ESP 19e 664h 0672c 10f 113i 248gh
Copacabana 20cd 643i 0671c 44b 129g 361b
Col6197 19e 583m 0657c 24de 118h 291ef
Japanese Strain 15f 618k 0610d 21def 148cd 324cd
QQ63 19e 672g 0661c 45b 135f 401a
Yellow Commercial
21abc 622j 0663c 14ef 146c 198i
Red Commercial 22a 706f 0730ab 26cd 145cd 226hi a Mean values with different letters within a column are significantly different (P lt 005)
73
Table 3-Texture profile analysis (TPA)a of cooked quinoa
Variety Hardness (kg)
Adhesiveness (kgs)
Cohesiveness Gumminess (kg)
Chewiness (kg)
Black 347a -004a 069ab 24a 24a
Blanca 306bcd -003a 071a 22abc 22abc
Cahuil 327abc -003a 071a 23ab 23ab
Cherry Vanilla 278de -002a 071a 20cd 20cd
Oro de Valle 285d -001a 068ab 19cd 19cd
49ALC 209f -029c 054d 11ef 11ef
1ESP 245e -027bc 056d 14e 14e
Copacabana 305bcd -010a 068ab 21bcd 21bcd
Col6197 202f -023bc 053d 11ef 11ef
Japanese Strain 293d -008a 066bc 19cd 19cd
QQ63 297cd -020b 062c 19d 19d
Yellow Commercial 306bcd -003a 069ab 21abc 21bc
Red Commercial 338ab -005a 068ab 23ab 23ab a Mean values with different letters within a column are significantly different (P lt 005)
74
Table 4-Cooking qualitya of quinoa
Variety Optimal Cooking Time (min)
Water uptake ()
Cooking Volume (mL)
Cooking Loss ()
Black 192a 297c 109c 065f
Blanca 183abc 344b 130ab 067f
Cahuil 169de 357ab 137a 102c
Cherry Vanilla 165ef 291c 107c 102c
Oro de Valle 173cde 238d 109c 102c
49ALC 136h 359ab 126b 043g
1ESP 153g 373ab 132ab 035h
Copacabana 157fg 379ab 127b 175a
Col6197 119i 397a 126b 176a
Japanese Strain 166def 371ab 116c 106b
QQ63 177bc 244d 126b 067f
Yellow Commercial 187ab 372ab 129ab 076d
Red Commercial 155fg 276cd 132ab 071e a Mean values with different letters within a column are significantly different (P lt 005)
75
Table 5-Pasting properties of quinoa flour by RVAa
Variety Peak Viscosity (RVU)
Trough
(RVU)
Breakdown
(RVU)
Final Viscosity (RVU)
Setback (RVU)
Peak Time (min)
Black 102g 81e 21e 75g -6f 102e
Blanca 98g 80e 18e 82g 2e 99f
Cahuil 116f 85e 31d 74g -11f 104de
Cherry Vanilla
66h 54g 12f 57h 2e 97fg
Oro de Valle
59h 50g 10f 56h 6e 93h
49ALC 107fg 71f 36c 132e 62b 97fg
1ESP 161cd 110c 51b 174c 64b 98fg
Copacabana 175b 141b 34cd 190b 49c 106cd
Col6197 155de 133b 22e 177bc 44cd 108bc
Japanese Strain
172bc 109c 62a 159d 50c 96gh
QQ63 144e 94d 51b 167cd 73a 97fg
Yellow Commercial
172bc 162a 11f 203a 41d 109b
Red Commercial
197a 168a 29d 106f -62g 115a
a Mean values with different letters within a column are significantly different (P lt 005)
76
Table 6-Thermal properties of quinoa flour by Differential Scanning Calorimetry (DSC)a
Gelatinization Temperature (ordmC)
Variety To Tp Tc Enthalpy (Jg)
Black 656a 725c 818abcd 15abc
Blanca 658a 743ab 819abcd 18a
Cahuil 659a 752a 839ab 16ab
Cherry Vanilla 649ab 741ab 823abc 12c
Oro de Valle 631bc 719cd 809abcde 12bc
49ALC 579e 714d 810bcde 15abc
1ESP 544f 690f 785de 15abc
Copacabana 630c 715cd 802cde 14abc
Col6197 605d 689f 785de 15abc
Japanese Strain 645abc 740b 850a 12c
QQ63 630c 702e 784de 13bc
Yellow Commercial 570e 676g 790cde 11c
Red Commercial 589de 693ef 780e 12c a Mean values with different letters within a column are significantly different (P lt 005)
77
Table 7-Correlation coefficients between quinoa seed characteristics composition and processing parameters and TPA texture of cooked quinoaa
Hardness Adhesiveness Cohesiveness Gumminess Chewiness
Seed Hardness 051 002ns 028ns 049 049
Bulk Density -055 -044ns -063 -060 -060
Seed Coat Proportion 074 038ns 055 072 072
Protein 050 077 075 057 057
Cooking Time 077 062 074 076 076
Water Uptake Ratio -058 -025ns -046ns -056 -056
Cooking Volume -048 -014ns -032ns -046ns -046ns
Peak Viscosity -051 -014ns -041ns -053 -054
Breakdown -048 -047ns -051 -053 -053
Final Viscosity -069 -043ns -060 -070 -070
Setback -058 -064 -059 -060 -060
To 059 054 061 061 061
Tp 042ns 041ns 050 045ns 046ns a ns non-significant difference P lt 010 P lt 005 P lt 001
78
Figure 1-Rapid Visco Analyzer (RVA) graph of lsquoCherry Vanillarsquo and lsquoRed Commercialrsquo
quinoa flours ( lsquoCherry Vanillarsquo lsquoRed Commercialrsquo Temperature)
Time (min)
0 10 20 30 40
Vis
cosi
ty (R
VU
)
0
50
100
150
200
250
Tem
pera
ture
(degC
)
50
100
150
200
79
Figure 2-Seed coat image by SEM
(1 whole seed section P-perisperm C-cotyledon 2 three layers of quinoa seed coat
3 seed coat of lsquoCherry Vanillarsquo 382 microm 4 seed coat of lsquo1ESPrsquo 95microm)
4 3
2 1
P
C C
80
Chapter 4 Quinoa Starch Characteristics and Their Correlation with
Texture of Cooked Quinoa
ABSTRACT
Starch composition and physical properties strongly influence the functionality and end-
quality of cereals Here correlations between starch characteristics and seed quality cooking
properties and texture were investigated Starch characteristics differed among the eleven
experimental varieties and two commercial quinoa tested The total starch content of seed ranged
from 532 to 751 g 100 g Total starch amylose content ranged from 27 to 169 and the
degree of amylose-lipid complex ranged from 34 to 433 The quinoa samples with higher
amylose tended to yield harder stickier more cohesive more gummy and more chewy texture
after cooking With higher degree of amylose-lipid complex or amylose leaching the cooked
quinoa tended to be softer and less chewy Higher starch enthalpy correlated with firmer more
adhesive more cohesive and more chewy texture Indicating that varieties with different starch
properties should be utilized in different end-products
Keywords quinoa starch texture cooked quinoa
Practical Application The research provided the starch characteristics of different quinoa
varieties showing correlations between starch and cooked quinoa texture These results can help
breeders and food manufacturers to better understand quinoa starch properties and the use of
cultivars for different food product applications
81
Introduction
Quinoa (Chenopodium quinoa Willd) is a pseudocereal from the Andean mountains in
South America Quinoa is garnering greater attention worldwide because of its high protein
content and balanced essential amino acids As in other crops starch is one of the major
components of quinoa seed Starch content structure molecular composition pasting thermal
properties and other characteristics may influence the cooking quality and texture of cooked
quinoa
The total starch content of quinoa seed has been reported to range from 32 to 69
(Abugoch 2009) Starch granules are small (1-2μm) compared to those of rice and barley (Tari et
al 2003) Amylose content of quinoa starch was reported to range from 35 to 225 (Abugoch
2009) generally lower than that of other crops Amylose content exhibited significant influence
on the texture of cooked quinoa (Ong and Blanshard 1995) Similarly cooked rice texture was
correlated to starch amylose and chain length (Ong and Blanshard 1995 Ramesh et al 1999)
and leaching of amylose and amylopectin during cooking (Patindol et al 2010) However
amylose-lipid complex and amylose leaching properties have not been studied in quinoa cultivars
with diverse genetic backgrounds Perdon et al (1999) indicated that starch retrogradation was
positively correlated with firmness and stickiness of cooked milled rice during storage and
similar correlations would be anticipated for quinoa
Starch swelling power and water solubility influenced wheat and rice noodle quality and
texture (Crosbie 1991 McCormick et al 1991 Konik et al 1993 Ross et al 1997 Bhattacharya
et al 1999) whereas the role of starch swelling powerwater solubility in the texture of cooked
quinoa has not been reported
82
The texture of rice starch gels has been studied Gel texture was influenced by treatment
temperature incorporation of glucomannan and sugar concentration (Charoenrein et al 2011
Jiang et al 2011 Sun et al 2014) The texture of quinoa starch gel however has not been
reported
Gelatinization temperature enthalpy and pasting properties of starch were correlated
with the texture of cooked rice (Ong and Blanshard 1995 Champagne et al 1999 Limpisut and
Jindal 2002) The correlations between starch thermal properties pasting properties and cooked
quinoa texture however have also not been reported
Starch is an important component of grains and exhibits significant influence on the
texture of cooked rice noodles and other foods The texture of cooked quinoa has been studied
previously (Wu et al 2014) however the correlation of starch and cooked quinoa texture
nevertheless remained unclear The objectives of the present study were to understand 1) the
starch characteristics of different quinoa varieties and 2) the correlations between the starch
characteristics and the texture of cooked quinoa
Materials and Methods
Starch isolation
Eleven varieties and two commercial quinoa samples were included in this study (Table
1) Quinoa starch was isolated using a method modified from Lindeboom et al (2005) and Qian
et al (1999) Two hundred grams of seed were steeped in 1000 mL NaOH (03 wv) overnight
at 4 degC and rinsed with distilled water three times to remove the saponins The rinsed quinoa
was ground in a Waring blender (Conair Corp Stamford CT USA) for 15 min The slurry
was screened through a series of sieves US No 40 100 and 200 mesh sieves with openings of
83
425 150 and 74 μm respectively Distilled water was added and stirred to speed up the
filtration Filter residue was discarded whereas the filtrate was centrifuged under 2000 times g for 20
min The supernatant was decanted and the top brown layer of sediment (protein and lipids) was
gently scraped loose and discarded The remaining pellet was resuspended in distilled water and
centrifuged again This resuspension-centrifuge process was repeated three times or until the
brown topmost layer was all removed The white starch pellet was then dispersed in 95 ethanol
and centrifuged under 2000 times g for 10 min The supernatant was discarded and the starch pellet
was air-dried and gently ground using a mortar and pestle
α-amylase activity
The activity of α-amylase was determined using a Megazyme Kit (Megazyme
International Ireland Co Wicklow Ireland)
Apparent total amylose content degree of amylose-lipid complex
Apparent amylose content was determined using a cold NaOH method (Mahmood et al
2007) with modification Sample of 10 mg was weighed into a 20 mL microcentrifuge tube To
the sample was added 150 μL of 95 ethanol and 900 μL of 1M NaOH mixed vigorously and
kept on a shaker overnight at room temperature The starch solution of 200 μL was removed and
combined with 1 mL of 005 M citric acid 800 μL iodine solution (02 g I2 2 g KI in 250 mL
distilled water) and 10 mL distilled water reaching a final volume of 12 mL The solution was
chilled in a refrigerator for 20 min The absorbance at 620nm was determined using a
spectrophotometer (Shimadzu Biospec-1601 DNAProteinEnzyme Analyzer Shimadzu corp
Kyoto Japan) A standard curve was created using a dilution series of amylose amylopectin
84
proportions of 010 19 28 37 46 and 55 respectively (Sigma-Aldrich Co LLC St Louis
MO USA)
Total amylose content was determined using the same method for apparent amylose
except that lipids in the starch samples were removed in advance The starch was defatted using
hexane and ultrasonic treatment as follows One gram of starch was dissolved in 15 mL hexane
and set in an ultrasonic water bath for 2 hours The suspension was then centrifuged at 1000 times g
for 1 min The supernatant was discarded and the procedure was repeated a second time The
sample was then dried in a fume hood overnight
Degree of amylose-lipid complex = [total amylose ndash apparent amylose] total amylose times 100
Amylose leaching properties
Amylose leaching was determined using the modified method of Hoover and Ratnayake
(2002) Starch (025 g) was mixed with 5 mL distilled water and heated at 60 degC for 30 min
then cooled in ice water and centrifuged at 2000 times g for 10 min Supernatant of 1 mL was added
to 800 μL iodine solution and 102 mL distilled water to achieve the same volume of 12 mL as
in the apparent amylose test The solution was chilled in a refrigerator for 20 min and the
absorbance at 620 nm was determined The amylose leaching was expressed as mg of amylose
leached from 100 g of starch
Starch pasting properties
Starch pasting properties were determined using the Rapid Visco Analyzer RVA-4
(Newport Scientific Pty Ltd Narrabeen Australia) Starch (3 g) was added to 25 mL distilled
water mixed and heated in the RVA using the following procedure The initial temperature was
50 ordmC and increased to 93 ordmC within 8 min at a constant rate held at 95 ordmC from 8 min to 24 min
85
cooled to 50 ordmC from 24 min to 28 min and held at 50 ordmC from 29 min to 40 min The result was
expressed in RVU units (RVU = cP12)
Starch gel texture
Starch gel texture was determined using a TA-XT2i Texture Analyzer (Texture
Technologies Corp Hamilton MA USA) The starch gels were prepared in the RVA using the
same procedure as for pasting properties Then the starch gels were stored at 4 degC for 24 hours
The testing procedure followed the method of Jiang et al (2011) with modification The gel
cylinder (3 cm high and 35 cm diameter) was compressed using a TA-25 cylinder probe at the
speed of pre-test 20 mms test 05 mms and post-test 05 mms to 10 mm deformation Two
compressions were conducted with an interval time of 20 s Hardness springiness and
cohesiveness were obtained from the TPA (Texture Profile Analysis) graph (x-axis distance and
y-axis force) Hardness (g) was expressed by the maximum force of the first peak springiness
was the ratio of distance (time) to peak 2 to distance to peak 1 cohesiveness was the ratio of the
second positive area under the compression curve to that of the first positive area
Freeze-thaw stability
Freeze-thaw stability was determined using the modified method from Lindeboom et al
(2005) and Charoenrein et al (2005) Starch slurry was cooked using the RVA with 125 g
starch and 25 mL distilled water The starch suspensions were heated at 60 degC from 0 ndash 2 min
the temperature was increased to 105 degC from 3 ndash 8 min with a constant rate and held at 105 degC
from 9 - 11 min The cooked samples were stored at -18 degC for 20 hours and then kept at room
temperature for 4 hours Water was decanted and the weight difference was determined The
86
freeze-thaw cycle was repeated five times The freeze-thaw stability was expressed as water loss
after each freeze-thaw cycle
Starch thermal properties
Thermal properties of starch were determined using Differential Scanning Calorimetry
(DSC) (Lindeboom et al 2005) Starch samples of 10 mg were weighed into aluminum pans
(Perkin-Elmer Kit No 219-0062) with 20 μL distilled water The pans were sealed and the
suspensions were incubated at room temperature (25 degC) for 2 hours to achieve equilibrium The
pans were then scanned at 10 degCmin from 25 degC to 120 degC The onset temperature (To) peak
temperature (Tp) and completion temperature (Tc) were the temperature to start the peak reach
the peak and complete the peak respectively Additionally enthalpy of gelatinization was
determined by the area under the peak
Swelling power and solubility
Swelling power and water solubility of starch were obtained at 93 degC (Vandeputte et al
2003) Starch samples of 05 g were added to 12 mL distilled water and mixed vigorously The
suspensions were immediately set in a water bath with a rotating rack at 93 degC for 30 min The
suspensions were then cooled in ice water for 2 min and centrifuged at 3000 g for 15 min The
supernatant was carefully removed with a pipette and the weight of wet sediment was recorded
The removed supernatants were dried in a 105 degC oven over night The weight of dry sediment
was recorded The swelling power and water solubility were expressed using the following
equations
Swelling power = wet sediment weight [dry sample weight times (1 ndash water solubility))
Water solubility = dry sediment weight dry sample weight times 100
87
Swelling power is expressed as a unitless ratio
Statistical analysis
All experiments were repeated three times Multiple comparisons were conducted using
Fisherrsquos LSD in SAS 92 (SAS Inst Cary NC USA) Correlations were calculated using
PROC CORR code in SAS 92 A P value of 005 was considered as the level of significance
unless otherwise specified
Results
Starch content and composition
Total starch content of quinoa seeds on a dry basis ranged from 532 g 100 g in the
variety lsquoBlackrsquo to 751 g 100 g in a commercial sample named lsquoYellow Commercialrsquo (Table 2)
Varieties lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo were lower in total
starch content all below 60 g100 g The Port Townsend seeds and commercial seeds contained
higher levels of starch mostly over 70 g100 g
Apparent amylose contents ranged from 27 in lsquo49ALCrsquo to 169 in lsquoCahuilrsquo all
lower than the corn starch standard which was 264 Varieties lsquoCahuilrsquo lsquoBlackrsquo and lsquoYellow
Commercialrsquo contained higher apparent amylose 147 to 169 It is worth noting that
lsquo49ALCrsquo contained the lowest apparent and total amylose contents 27 and 47 respectively
Total amylose of the other varieties ranged from 111 in lsquoQQ63rsquo to 173 in lsquoCahuilrsquo
The degree of amylose-lipid complex differed among the samples ranging from 34 in
lsquoCahuilrsquo to 43 in lsquo49ALCrsquo and lsquoCol6197rsquo Statistically however only lsquo49ALCrsquo and
lsquoCol6197rsquo were significantly higher than lsquoCahuilrsquo in degree of amylose-lipid complex
Starch properties
88
Amylose leaching property exhibited great differences among samples (Table 3)
lsquo49ALCrsquo and lsquo1ESPrsquo showed the highest amylose leaching at 862 and 716 mg 100 g starch
respectively lsquoCahuilrsquo lsquoJapanese Stainrsquo and lsquoRed Commercialrsquo were the lowest with amylose
leaching less than 100 mg 100 g starch lsquoBlackrsquo and lsquoBlancarsquo were relatively low as well with
210 and 171 mg amylose leaching 100 g starch The other varieties were intermediate and
ranged from 349 to 552 mg 100 g starch
Water solubility of quinoa starch ranged from 07 to 45 all lower than that of corn
starch which was 79 lsquoJapanese Strainrsquo lsquoQQ63rsquo lsquoCommercial Yellowrsquo and lsquoPeruvian Redrsquo
were the highest in water solubility 26 to 45 The starch water solubility in the other varieties
was between 10 and 19
Swelling power of quinoa starch ranged from 170 to 282 all higher than that of corn
starch (89) lsquo49ALCrsquo and lsquo1ESPrsquo showed the highest swelling powers 282 and 276
respectively lsquoYellow Commercialrsquo and lsquoRed Commercialrsquo showed relatively lower swelling
power 188 and 196 respectively The remaining varieties did not exhibit differences in
swelling power with values between 253 and 263
α-Amylase activity
Activity of α-amylase in quinoa flour separated the samples to three groups (Table 3)
lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo showed high α-amylase activity from
086 CU to 116 CU (Ceralpha Unit) lsquoBlackrsquo lsquo49ALCrsquo and lsquoCopacabanarsquo were lower in α-
amylase activity 043 031 and 020 CU respectively The other varieties and commercial
samples exhibited particularly low α-amylase activities with the values lower than 01 CU
Starch gel texture
89
Texture of starch gels included hardness springiness and cohesiveness (Table 4)
Hardness of starch gel of lsquoCahuilrsquo and lsquoJapanese Strainrsquo represented the highest and the lowest
values 900 and 201 g respectively Hardness of the other varieties ranged from 333 g in
lsquo49ALCrsquo to 725 g in lsquoBlackrsquo
lsquoJapanese Strainrsquo and lsquoYellow Commercialrsquo exhibited the highest and lowest springiness
values of the starch gels 092 and 071 respectively Springiness of other starch samples ranged
from 075 to 085 and were not significantly different from each other
Cohesiveness of starch gels ranged from 053 to 089 The starch gels of lsquoJapanese
Strainrsquo lsquoCol6197rsquo and lsquoCopacabanarsquo were more cohesive at 089 083 and 078 respectively
The starch gels of lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquo1ESPrsquo were moderately cohesive
with the cohesiveness of 072 ndash 073 Other varieties exhibited less cohesive starch gels lsquoQQ63rsquo
and commercial samples showed the least cohesive starch gels 053 ndash 057 For comparison the
hardness springiness and cohesiveness of the corn starch gel was 721 084 and 073
respectively These values were among the upper-to-middle range of those counterpart values of
the texture of quinoa starch gels
Starch thermal properties
Thermal properties of quinoa starch include gelatinization temperature and enthalpy
(Table 5) Onset temperature To of quinoa starch ranged from 515 ordmC in lsquoYellow Commercialrsquo to
586 ordmC in lsquoBlancarsquo Peak temperature Tp ranged from 595 ordmC in lsquoRed Commercialrsquo to 654 ordmC
in lsquoJapanese Strainrsquo Conclusion temperature ranged from 697 ordmC in lsquoCol6197rsquo to 788 ordmC in
lsquoJapanese Strainrsquo The commercial samples exhibited lower gelatinization temperatures To Tp
90
and Tc of the corn starch were 560 626 and 743 ordmC respectively They were within the ranges
of those values of the quinoa starches
Enthalpy refers to the energy required during starch gelatinization The enthalpy of
quinoa starch ranged from 99 to 116 Jg Starch from lsquoCahuilrsquo exhibited the highest enthalpy
116 Jg higher than that of lsquo49ALCrsquo and lsquoQQ63rsquo However enthalpies of other samples were
not significantly different Corn starch enthalpy was 105 Jg comparable to those of quinoa
starches
Starch pasting properties
Starch viscosity was investigated using the RVA (Table 6) Peak viscosity of quinoa
starches ranged from 193 to 344 RVU Varieties lsquoBlancarsquo and lsquoCahuilrsquo showed the highest peak
viscosities 344 and 342 RVU respectively lsquoJapanese Strainrsquo and lsquoQQ63rsquo were lowest in starch
peak viscosity 193 and 213 RVU respectively The peak viscosity of corn starch was 255 RVU
falling within the middle range of quinoa peak viscosities
The tough is the minimum viscosity after the first peak The trrough of quinoa starch
ranged from 137 to 301 RVU The starches of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and
lsquoOro de Vallersquo showed highest trough values from 252 to 301 RVU lsquo49ALCrsquo lsquo1ESPrsquo
lsquoCopacabanarsquo lsquoJapanese Strainrsquo and lsquoQQ63rsquo were lowest in trough ranging from 137 to 186
RVU The trough of corn starch was 131 RVU lower than that of all quinoa starches
Starch breakdown of lsquo49ALCrsquo was 119 RVU higher than that of other samples except
corn starch which was 124 RVU lsquoJapanese Strainrsquo and lsquoOro de Vallersquo showed the lowest
breakdowns 12 and 17 RVU respectively Breakdown of the other samples ranged from 39 to
97 RVU
91
Final viscosity of lsquoCahuilrsquo starch was 405 RVU significantly higher than that of other
varieties At the other extreme final viscosity of lsquo49ALCrsquo starch was 225 RVU significantly
lower than that of the other varieties The final viscosity of corn starch was 283 RVU close to
that of lsquoJapanese Strainrsquo and lsquoQQ63rsquo but lower than that of the other quinoa samples
The highest setback was observed with lsquo1ESPrsquo starch (140 RVU) At the other extreme
the setback of lsquoOro de Vallersquo was 53 RVU which was lower than the other quinoa samples
Additionally setbacks of lsquoBlancarsquo lsquo49ALCrsquo and lsquoJapanese stainrsquo starches were also among the
lower range varying from 82 RVU to 88 RVU The remaining varieties exhibited higher setback
from 101 RVA to 127 RVU Setback of corn starch was 152 RVU significantly higher than all
the other quinoa starches
RVA peak times of quinoa starches varied significantly among the samples lsquoJapanese
Strainrsquo lsquoBlancarsquo lsquoCahuilrsquo and lsquoOro de Vallersquo required longer time to reach the peak viscosity
with peak times of 105 to 113 min Other varieties showed shorter peak times between 79 to
99 min The starch of lsquo49ALCrsquo however only needed 64 min to reach peak viscosity shorter
than those of other quinoa samples The peak time of corn starch was 73 min shorter than those
of quinoa starches except lsquo49ALCrsquo
Freeze-thaw stability of starch
Freeze-thaw stability of starches was expressed as the water loss () of each freeze-thaw
cycle Quinoa starch samples and corn starch showed similar trends in freeze-thaw stability
Most water loss occurred after cycles 1 and 2 Starch gels on average (excluding lsquo49ALCrsquo) lost a
cumulative total of 522 ndash 689 of water after cycle 2 and a total of 745 ndash 823 after cycle 5
Furthermore the starch gels of lsquoQQ63rsquo and lsquo1ESPrsquo lost the least water indicating higher freeze-
92
thaw stability Conversely the starch gel of lsquoJapanese Strainrsquo lost the most water in every cycle
indicating the lowest degree of freeze-thaw stability
lsquo49ALCrsquo and lsquo1ESPrsquo starches exhibited freeze-thaw behavior that was different
compared to the other samples After freezing the samples of lsquo49ALCrsquo and lsquo1ESPrsquo produced
gels that were less rigid more viscous than the other samples Further they did not lose as much
water after the first cycle The sample of lsquo1ESPrsquo however turned into a solid gel from cycle 2 to
5 And the water loss of the lsquo1ESPrsquo gel was close to that of other samples during cycles 2 and 5
Correlations between starch properties and the texture of cooked quinoa
Correlations between starch properties and texture of cooked quinoa were examined
(Table 7) using texture profile analysis (TPA) of cooked quinoa of Wu et al (2014) Total starch
content was moderately correlated with adhesiveness of cooked quinoa (r = -048 P = 009) but
was not significantly correlated with any of the other texture parameters Conversely apparent
amylose content was highly correlated with all texture parameters (067 le r le 072) Total
amylose content also exhibited significant correlations with all texture parameters (056 le r le
061) Furthermore the degree of amylose-lipid complex was negatively correlated with all
texture parameters (-070 le r le -060) and amylose leaching proportion was highly correlated
with the texture of cooked quinoa (-084 le r le -074)
Water solubility and swelling power of starch were not observed to correlate well with
any of the texture parameters Higher α-amylase activity tended to yield more adhesive (r = 055)
and more cohesive (r = 051 P = 007) texture However α-amylase activity was not correlated
with the hardness gumminess or chewiness of cooked quinoa
93
Some texture parameters of starch gels were associated with the texture parameters of
cooked quinoa The hardness of starch gels was not correlated with the hardness of cooked
quinoa but was weakly correlated with adhesiveness (r = 059) Weakly positive correlations
were found between starch gel hardness and cooked quinoa cohesiveness gumminess and
chewiness (049 le r le 051 P le 010) Springiness and cohesiveness of starch gels were not
correlated with the measured textural properties of cooked quinoa
Onset gelatinization temperature (To) of starch exhibited weak correlations with
adhesiveness (r = 049 P = 009) and cohesiveness (r = 051 P = 007) but was not correlated
with the other texture parameters Peak gelatinization temperature (Tp) of starch was correlated
with cohesiveness (r = 056) and hardness adhesiveness gumminess and chewiness (047 le r le
056 P le 010) No correlation was found with conclusion temperature (Tc) and texture Starch
enthalpy did correlate with the texture parameters (r = 064 in hardness 069 le r le 072 in other
texture parameters)
Starch viscosity measurements were variably correlated with the texture of cooked
quinoa Peak viscosity correlated adhesiveness (r = 054 P = 006) and cohesiveness (r = 047 P
= 010) but not with the other texture parameters Trough was more highly correlated with
adhesiveness cohesiveness gumminess and chewiness (r = 077 in adhesiveness 055 le r le
063 in other texture parameters)
It is interesting to note that starch breakdown only correlated with adhesiveness of
cooked quinoa (r = -060) and not with any other texture parameter Setback was not correlated
with any texture parameter These two RVA parameters breakdown and setback are usually
considered to be important indexes of end-use quality In quinoa however breakdown and
94
setback of starch apparently are not predictive of cooked quinoa texture In addition final
viscosity was also correlated with adhesiveness (r = 068) and cohesiveness (r = 058) and
correlated moderately with gumminess and chewiness (r = 053 P = 006) Peak time was
correlated with adhesiveness (r = 077) cohesiveness (r = 068) gumminess (r = 060) and
chewiness (r = 060) and to a lesser extent with hardness (r = 053 P = 006)
Correlations between starch properties and seed DSC RVA characteristics
Total starch content correlated with seed hardness (r = -073) seed coat proportion (r = -
071) and starch viscosities (peak viscosity trough and final viscosity) (-068 lt r lt -060) and
also to a lesser extent with seed density (r = 054 P = 006) and starch thermal properties (To
Tp and enthalpy) (-051 lt r lt -049 008 lt P lt009) (Table 8)
Water solubility of starch was correlated with starch viscosity such as peak viscosity (r =
-049 P = 009) and breakdown (r = -048 P = 010) Swelling power was only correlated with
peak time (r = -054 P = 006) (data not shown)
Apparent amylose content was correlated with protein content (r = 058) and optimal
cooking time (r = 056) but total amylose content did not show either of these correlations Both
apparent and total amylose contents were correlated with starch gel hardness starch enthalpy
and starch viscosity such as trough breakdown final viscosity and peak time
The degree of amylose-lipid complex exhibited negative correlations with seed protein
content (r = -07) and optimal cooking time of quinoa seed (r = -067) Moreover amylose
leaching was negatively correlated with protein content (r = -062) starch gel hardness (r = --
064) starch Tp (r = -058) and enthalpy (r = -064) optimal cooking time (r = -055) and starch
viscosities such as breakdown (r = 062) and peak time (r = -081) Additionally α-amylase
95
activity was correlated with protein content (r = 066) seed density (r = -072) seed coat
proportion (r = 055) starch To (r = 061) and starch viscosities such as peak viscosity (r =
070) trough (r = 072) and final viscosity (r = 061)
Discussion
Starch content and composition
Total starch content does influence the functional and processing properties of cereals
The total starch content of quinoa was reported to be between 32 and 69 (Abugoch 2009)
Among our varieties most of the Port Townsend varieties and commercial quinoa contained
more than 69 starch It is interesting to note that the Port Townsend samples lsquo49ALCrsquo lsquo1ESPrsquo
lsquoCol6197rsquo and lsquoQQ63rsquo were also more sticky or more adhesive after cooking than other
varieties These varieties may exhibit better performance in extrusion products or in beverages
which require high viscosity
Amylose content affects texture and gelation properties The proportion of amylose and
amylopectin impacts the functionality of cereals in this study both apparent and total amylose
contents were determined Total amylose includes those amylose molecules that are complexed
with lipids
Amylose content of quinoa was reported to range from 35 to 225 dry basis
(Abugoch 2009) generally lower than that of common cereals which is around 25 Overall
both apparent and total amylose contents of the quinoa in the present study fell within the range
which has been reported lsquo49ALCrsquo was an exception showing significantly lower apparent and
total amylose contents of 27 and 47 respectively Thus this variety is close to be being a
lsquowaxyrsquo which refers to the cereal starches that are comprised of mostly amylopectin (99) and
96
little amylose (~1) As the waxy wheat showed an excellent expansion during extrusion
(Kowalski et al 2014) lsquo49ALCrsquo is a promising variety to produce breakfast cereal or extruded
snacks
The degree of amylose-lipid complex showed great variability among the samples 34 ndash
433 whereas the value in wheat flour was reported to be 32 (Bhatnagar and Hanna 1994) or
13 to 23 (Zeng et al 1997) Degree of amylose-lipid complex showed significant and
negative correlations with all texture parameters such as hardness adhesiveness cohesiveness
gumminess and chewiness
The effect of amylose-lipid complex on product texture has been reported in previous
studies The degree of amylose-lipid complex correlated with the texture (hardness and
crispness) and quality (radial expansion) of corn-based snack (Thachil et al 2014) Wokadala et
al (2012) indicated that amylose-lipid complexes played a significant role in starch biphasic
pasting
Starch properties
Amylose leaching was also highly variable among the quinoa varieties 35 ndash 862 mg
100g starch Vandeputte et al (2003) studied amylose leaching of waxy and normal rice
starches The amylose leaching values at 65 ordmC were below 1 of starch comparable with those
in quinoa starch Pronounced increase of amylose leaching was observed at the temperatures
higher than 95 ordmC Patindol et al (2010) found that both amylose and amylopectin leached out
during cooking rice The proportion of the leached amylose and amylopectin influenced the
texture of cooked rice We found similar results indicating correlations between amylose
leaching and texture of cooked quinoa
97
Water solubility of quinoa starch was significantly lower than that of corn starch whereas
swelling power of quinoa starch was higher than that of corn starch Both water solubility and
swelling power were determined at 95 ordmC Lindeboom et al (2005) determined swelling power
and solubility of quinoa starch among eight varieties at 65 75 85 and 95 ordmC The water
solubility at 95 ordmC ranged from 01 to 47 which was lower than the corn starch standard of
100 The swelling power at 95 ordmC ranged from 164 to 526 lower than the corn starch
standard of 549 The quinoa starch in this study showed a narrower range of swelling power
170 to 282
α-Amylase activity
The quinoa in this study had significantly different α-amylase activity (003 ndash 116 CU)
Previous studies reported low α-amylase activity in quinoa compared to oat (Maumlkinen et al
2013) and traditional malting cereals (Hager et al 2014) Moreover the activity of α-amylase
indicates the degree of seed germination and the availability of sugars for fermentation In the
study of Hager et al (2014) α-amylase activity increased from 0 to 35 CU during 72 h
germination
Texture of starch gel
Starch gel texture has been previously studied on corn and rice starches but not on
quinoa starch Hardness of rice starch gel was reported to be 339 g by Charoenrein et al (2011)
and 116 g by Jiang et al (2011) Hardness of corn starch was reported to be around 100 g in the
study of Sun et al (2014) much lower than the standard corn starch hardness in this study 721
g Compared to those of rice and corn starch quinoa starch gel exhibited harder texture which
may be caused by either genetic variation or different processing procedures to form the gel
98
Additionally springiness and cohesiveness of rice starch gel were reported as 085 and 055
respectively (Jiang et al 2011) Quinoa starch gel exhibited comparable springiness and higher
cohesiveness than those of rice starch gel
Thermal properties of quinoa starch
The thermal properties of quinoa starch in this study were comparable to those of rice
starch (Cai et al 2014) The study of Lindeboom et al (2005) however found lower
gelatinization temperatures and higher enthalpies compared to the present study which may be
due to varietal difference
Furthermore correlation between thermal properties of quinoa starch and flour (Wu et al
2014) was investigated Gelatinization temperatures To Tp and Tc of starch and whole seed
flour were highly correlated especially To and Tp exhibited high r of 088 The enthalpy of
starch and flour however was not significantly correlated In this case quinoa flour can be used
to estimate quinoa starch gelatinization temperatures but not the enthalpy Additionally since
flour is easier to prepare compared to starch further studies can be conducted with a larger
number of quinoa samples to model the prediction of starch thermal properties using flour
thermal properties
Starch pasting properties
Viscosity and pasting properties of starch play a significant role in the functionality of
cereals Jane et al (1999) studied the pasting properties of starch from cereals such as maize
rice wheat barley amaranth and millet The peak viscosities ranged from 58 RVU in barley to
219 RVU in sweet rice lower than those of most quinoa starches except lsquoJapanese Strainrsquo and
lsquoQQ63rsquo Final viscosities ranged from 54 RVU in barley to 208 RVU in cattail millet all lower
99
than those of the quinoa starches in the present study Setback of cereal starches mostly ranged
from 6 RVU in waxy amaranth to 74 RVU in non-waxy maize lower than those of most quinoa
starches except lsquoOre de Vallersquo Cattail millet starch exhibited the setback of 208 RVU higher
than those of quinoa starches
The relationships between RVA pasting parameters of quinoa starch and flour were
studied by Wu et al (2014) Final viscosity of starch and flour was correlated negatively (r = -
063 P = 002) The other RVA parameters did not exhibit significant correlation between starch
and flour RVA In other words RVA of quinoa flour cannot be used to predict RVA of quinoa
starch In addition to starch the fiber and protein in whole quinoa flour may influence the
viscosity As quinoa is normally utilized as whole grain or whole grain flour instead of refined
flour the flour RVA should be a better indication on the end-use functionality
Freeze-thaw stability of starch
Quinoa starches in the present study did not show high stability during freeze and thaw
cycles Praznik et al (1999) studied freeze-thaw stability of various cereal starches Similar to
the present study Praznik et al concluded quinoa starches exhibited low freeze-thaw stability
Conversely Ahamed et al (1996) found quinoa starch exhibited excellent freeze-thaw stability
Unfortunately the variety was not indicated Overall it is reasonable to assert that for some
quinoa cultivars the starch may have better freeze-thaw stability than in other cultivars
However most quinoa varieties in published studies did not show good freeze-thaw stability
Correlations between starch characteristics and texture of cooked quinoa
The quinoa starch characteristics correlated with the texture of cooked quinoa in some
aspects Total starch content however did not show any strong correlations with TPA
100
parameters as was initially expected Since quinoa is consumed as whole grain or whole flour
fiber and bran may exhibit more influence on the texture than anticipated from the impact of
starch alone
The quinoa varieties with higher apparent and total amylose contents tended to yield a
harder stickier more cohesive more gummy and chewy texture Similar correlations are found
with cooked rice noodle and corn-based extrusion snacks The hardness of cooked rice was
positively correlated with amylose content and negatively correlated with adhesiveness (Yu et al
2009) Epstein et al (2002) reported that full waxy noodles were softer thicker less adhesive
and chewy and more cohesive and springy compared to normal noodles and partial waxy
noodles Increased amylose content in a corn-based extrusion snack resulted in higher amylose-
lipid formation and softer texture (Thachil et al 2014)
Higher levels of amylose-lipid complex in starch were associated with softer less
adhesive less cohesive and less gummy and less chewy cooked quinoa The correlation between
the degree of amylose-lipid complex and texture of cooked rice or quinoa has not been
previously reported Kaur and Singh (2000) however found that amylose-lipid complex
increased with longer cooking time of rice flour Additionally cooking time is a key factor to
determine texture ndash the longer a cereal is cooked the softer less sticky less cohesive and less
gummy and chewy the texture
Correlations were found between amylose leaching and cooked quinoa TPA parameters
especially hardness gumminess and chewiness with r of -082 Increased amylose leaching
yielded a softer gel made from potato starch (Hoover et al 1994) However the correlations of
101
amylose leaching and α-amylase activity with texture of end product for quinoa have not been
reported previously
Swelling power and water solubility were reported to influence the texture of wheat and
rice noodle (Crosbie 1991 McCormick et al 1991 Konik et al 1993 Ross et al 1997
Bhattacharya et al 1999) However in the present report no correlation was found between
swelling power water solubility and the texture of cooked quinoa Additionally the study of
Ong and Blanshard (1995) indicated a positive correlation between enthalpy and the texture of
cooked rice Similar results were found in this study
RVA is a fast and reliable way to predict flour functionality and end-use properties
Pasting properties of rice flour have been used to predict texture of cooked rice (Champagne et
al 1999 Limpisut and Jindal 2002) In our previous study cooked quinoa texture correlated
negatively with the final viscosity and setback of quinoa flour (Wu et al 2014) In this study
texture correlated with trough breakdown final viscosity and peak time of quinoa starch
However RVA of quinoa flour and starch did not correlate with each other Flour RVA might be
a convenient way to predict cooked quinoa texture
Correlations between starch properties and seed DSC RVA characteristics
Quinoa with higher total starch tended to have a thinner seed coat This makes sense
because starch protein lipids and fiber are the major components of seed An increase in one
component will result in a proportional decrease in the other component contents
Additionally the starch RVA parameters (except peak viscosity) can be used to estimate
apparent or total amylose content based on their correlations Further studies should be
conducted with a larger sample size of quinoa and a more accurate prediction model can be built
102
The samples with lower protein or those requiring shorter cooking time tended to contain
higher levels of amylose-lipid complex Additionally amylose-lipid complex was reported to
influence the texture of extrusion products (Bhatnagar and Hanna 1994 Thachil et al 2014) For
this reason protein and optimal cooking time are promising indicators of the behavior of quinoa
during extrusion
Conclusions
In summary starch content composition and characteristics were significantly different
among quinoa varieties Amylose content degree of amylose-lipid complex and amylose
leaching property of quinoa starch exhibited great variances and strong correlations with texture
of cooked quinoa Additionally starch gel texture pasting properties and thermal properties
were different among varieties and different from those of rice and corn starches Enthalpy
RVA trough final viscosity and peak time exhibited significant correlations with cooked quinoa
texture Overall starch characteristics greatly influenced the texture of cooked quinoa
Acknowledgments
This project was supported by the USDA Organic Research and Extension Initiative
(NIFAGRANT11083982) The authors acknowledge Girish Ganjyal and Shyam Sablani for
using the Differential Scanning Calorimetry (DSC) thanks to Stacey Sykes for editing support
Author Contributions
G Wu and CF Morris designed the study together and established the starch isolation
protocol G Wu collected test data and drafted the manuscript CF Morris and KM Murphy
edited the manuscript KM Murphy provided quinoa samples
103
References
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581-31
Ahamed NT Singhal RS Kulkarni PR Pal M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 31(1)99-103
Araujo-Farro PC Podadera G Sobral PJA Menegalli FC 2010 Development of films based on
quinoa (Chenopodium quinoa Willd) starch Carbohydr Polym 81(4)839-48
Bhatnagar S Hanna MA 1994 Amylose-lipid complex formation during single-screw extrusion
of various corn starches Cereal Chem 71(6)582-6
Bhattacharya M Zee SY Corke H 1999 Physicochemical properties related to quality of rice
noodles Cereal Chem 76(6)861-7
Cai J Yang Y Man J Huang J Wang Z Zhang C Gu M Liu Q Wei C 2014 Structural and
functional properties of alkali-treated high-amylose rice starch Food Chem 145245-53
Champagne ET 2004 The rice grain and its gross composition In Champagne ET editor Rice
chemistry and technology St Paul Minn American Association of Cereal Chemists p 88
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5)764-71
104
Charoenrein S Tatirat O Rengsutthi K Thongngam M 2011 Effect of konjac glucomannan on
syneresis textural properties and the microstructure of frozen rice starch gels Carbohydr
Polym 83(1)291-6
Crosbie GB 1991 The relationship between starch swelling properties paste viscosity and
boiled noodle quality in wheat flours J Cereal Sci 13(2)145-50
De Pilli T Derossi A Talja R Jouppila K Severini C 2012 Starchndashlipid complex formation
during extrusion-cooking of model system (rice starch and oleic acid) and real food (rice
starch and pistachio nut flour) Eur Food Res Technol 234(3)517-25
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(waxy) genes J Cereal Sci 35(1) 51-63
Hager AS Maumlkinen OE Arendt EK 2014 Amylolytic activities and starch reserve mobilization
during the germination of quinoa Eur Food Res Technol 239(4)621-7
Hoover R Ratnayake WS 2002 Starch characteristics of black bean chick pea lentil navy bean
and pinto bean cultivars grown in Canada Food Chem 78(4)489-98
Hoover R Vasanthan T Senanayake NJ Martin AM 1994 The effects of defatting and heat-
moisture treatment on the retrogradation of starch gels from wheat oat potato and lentil
Carbohydr Res 261(1)13-24
105
Jane J Chen Y Lee L McPherson A Wong K Radosavljevic M Kasemsuwan T 1999 Effects
of amylopectin branch chain length and amylose content on the gelatinization and pasting
properties of starch 1 Cereal Chem 76(5)629-37
Jiang Q Xu X Jin Z Tian Y Hu X Bai Y 2011 Physico-chemical properties of rice starch
gels Effect of different heat treatments J Food Eng 107(3)353-7
Kaur K Singh N 2000 Amylose-lipid complex formation during cooking of rice flour Food
Chem 71(4)511-7
Konik CM Miskelly DM Gras PW 1993 Starch swelling power grain hardness and protein
relationship to sensory properties of japanese noodles Starch - Staumlrke 45(4)139-44
Kowalski R Morris C Ganjyal G 2015 Extrusion characteristics thermal and rheological
properties of soft white wheat flour in comparison with regular wheat flour Cereal Chem
92(2)145-53
Limpisut P Jindal VK 2002 Comparison of rice flour pasting properties using Brabender
Viscoamylograph and Rapid Visco Analyser for evaluating cooked rice texture Starch‐
Staumlrke 54(8)350-7
Lindeboom N Chang PR Falk KC Tyler RT 2005 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2)216-22
Mahmood T Turner MA Stoddard FL 2007 Comparison of methods for colorimetric amylose
determination in cereal grains Starch‐Staumlrke 59(8)357-65
106
Maumlkinen OE Zannini E Arendt EK 2013 Germination of oat and quinoa and evaluation of the
malts as gluten free baking ingredients Plant Foods Hum Nutr 68(1)90-5
Matos M Timgren A Sjoo M Dejmek P Rayner M 2013 Preparation and encapsulation
properties of double Pickering emulsions stabilized by quinoa starch granules Colloids and
Surfaces A 423147-53
McCormick K Panozzo J Hong S 1991 A swelling power test for selecting potential noodle
quality wheats Aust J Agric Res 42(3)317-23
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine structure of amylopectin J Cereal Sci 21(3)251-60
Ong MH Blanshard JMV 1995 Texture determinants of cooked parboiled rice II
Physicochemical properties and leaching behaviour of rice J Cereal Sci 21(3)261-9
Pagno CH Costa TMH de Menezes EW Benvenutti EV Hertz PF Matte CR Tosati JV
Monteiro AR Rios AO Flores SH 2015 Development of active biofilms of quinoa
(Chenopodium quinoa W) starch containing gold nanoparticles and evaluation of
antimicrobial activity Food Chem 173755-62
Patindol J Gu X Wang YJ 2010 Chemometric analysis of cooked rice texture in relation to
starch fine structure and leaching characteristics Starch - Staumlrke 62(3-4)188-97
Perdon AA Siebenmorgen TJ Buescher RW Gbur EE 1999 Starch retrogradation and texture
of cooked milled rice during storage J Food Sci 64(5)828-32
107
Praznik W Mundigler N Kogler A Pelzl B Huber A Wollendorfer M 1999 Molecular
background of technological properties of selected starches Starch‐Staumlrke 51(6) 197-211
Qian J Kuhn M 1999 Characterization of Amaranthus cruentus and Chenopodium quinoa
starch Starch‐Staumlrke 51(4)116-20
Ramesh M Zakiuddin Ali S Bhattacharya KR 1999 Structure of rice starch and its relation to
cooked-rice texture Carbohydr Polym 38(4)337-47
Rayner M Sjoumlouml M Timgren A Dejmek P 2012 Quinoa starch granules as stabilizing particles
for production of Pickering emulsions Faraday Discuss 158(1)139-55
Ross AS Quail KJ Crosbie GB 1997 Physicochemical properties of Australian flours
influencing the texture of yellow alkaline noodles Cereal Chem 74(6)814-20
Sun Q Xing Y Qiu C Xiong L 2014 The pasting and gel textural properties of corn starch in
glucose fructose and maltose syrup PloS one 9(4)e95862
Thachil MT Chouksey MK Gudipati V 2014 Amylose-lipid complex formation during
extrusion cooking effect of added lipid type and amylose level on corn-based puffed snacks
Int J Food Sci Tech 49(2)309-16
Vandeputte GE Derycke V Geeroms J Delcour JA 2003 Rice starches II Structural aspects
provide insight into swelling and pasting properties J Cereal Sci 38(1)53-9
Wokadala OC Ray SS Emmambux MN 2012 Occurrence of amylosendashlipid complexes in teff
and maize starch biphasic pastes Carbohydr Polym 90(1)616-22
108
Wu G Morris C F Murphy K M 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79(11)2337-45
Yu S Ma Y Sun DW 2009 Impact of amylose content on starch retrogradation and texture of
cooked milled rice during storage J Cereal Sci 50(2)139-44
Zeng M Morris CF Batey IL Wrigley CW 1997 Sources of variation for starch gelatinization
pasting and gelation properties in wheat Cereal Chem 74(1)63-71
109
Table 1-Quinoa varieties tested
Variety Original Seed Source Location
Black White Mountain Farm White Mountain Farm Colo USA
Blanca White Mountain Farm White Mountain Farm Colo USA
Cahuil White Mountain Farm White Mountain Farm Colo USA
Cherry Vanilla Wild Garden Seeds Philomath Oregon
WSUa Organic Farm Pullman Wash USA
Oro de Valle Wild Garden Seeds Philomath Oregon
WSUa Organic Farm Pullman Wash USA
49ALC USDA Port Townsend Wash USA
1ESP USDA Port Townsend Wash USA
Copacabana USDA Port Townsend Wash USA
Col6197 USDA Port Townsend Wash USA
Japanese Strain USDA Port Townsend Wash USA
QQ63 USDA Port Townsend Wash USA
Yellow Commercial Multi Organics company Bolivia
Red Commercial Multi Organics company Bolivia a WSU Washington State Univ
110
Table 2-Starch content and composition
Variety Total starch
(g 100 g)
Apparent amylose
()
Total
amylose ()
Degree of amylose
lipid complex ()
Black 532f 153a 159ab 96bc
Blanca 595de 102cd 163a 361ab
Cahuil 622d 169a 173a 34c
Cherry Vanilla
590de 105cd 116bc 164abc
Oro de Valle 573ef 114bcd 166a 300abc
49ALC 674c 27e 47d 426a
1ESP 705bc 86d 152abc 389ab
Copacabana 734ab 120bc 153abc 222abc
Col6197 725ab 102cd 140abc 433a
Japanese Strain
723ab 116bcd 165ab 305abc
QQ63 713abc 84d 111c 241abc
Yellow Commercial
751a 147ab 150abc 118abc
Red Commercial
691bc 100cd 164a 375ab
Corn starch - 264 - -
111
Table 3-Starch properties and α-amylase activity
Variety Amylose leaching (mg 100 g starch)
Water solubility ()
Swelling power
α-Amylase activity (CU)
Black 210ef 16de 260bcd 043d
Blanca 171efg 10de 260bcd 086c
Cahuil 97fg 16cde 253cd 106b
Cherry Vanilla 394d 15de 253cd 116a
Oro de Valle 420d 16de 245d 103b
49ALC 862a 07e 282a 031e
1ESP 716b 13de 276ab 003g
Copacabana 438cd 14de 263bc 020f
Col6197 552c 19cd 257cd 009g
Japanese Strain 31fg 45a 170f 005g
QQ63 315de 26bc 262bc 008g
Yellow Commercial
349d 32b 188e 005g
Red Commercial 35g 26bc 196e 003g
Corn starch - 79 89 -
112
Table 4-Texture of starch gel
Variety Hardness (g) Springiness Cohesiveness
Black 725ab 082ab 064cd
Blanca 649abc 083ab 072bc
Cahuil 900a 085ab 072bc
Cherry Vanilla 607abc 078bc 072bc
Oro de Valle 448abc 078bc 064cd
49ALC 333bc 081bc 061cd
1ESP 341bc 081bc 073bc
Copacabana 402bc 084ab 078ab
Col6197 534abc 083ab 083ab
Japanese Strain 765ab 092a 089a
QQ63 201c 078bc 053d
Yellow Commercial 436bc 071c 057d
Red Commercial 519abc 075bc 055d
Corn starch 721 084 073
113
Table 5-Thermal properties of starch
Variety Gelatinization temperature Enthalpy (Jg)
To (ordmC) Tp (ordmC) Tc (ordmC)
Black 560b 639bc 761bc 112abc
Blanca 586a 652ab 754bcd 113abc
Cahuil 582a 648ab 755bcd 116a
Cherry Vanilla 563b 627cd 747bcd 111abc
Oro de Valle 562b 623d 739cd 106abc
49ALC 524ef 598f 747bcd 101bc
1ESP 530de 608ef 738cd 103abc
Copacabana 565b 622d 731de 106abc
Col6197 540cd 598f 697f 105abc
Japanese Strain 579a 654a 788a 104abc
QQ63 545c 616de 766ab 99c
Yellow Commercial 515f 599f 708ef 107abc
Red Commercial 520ef 595f 700 f 116ab
Corn starch 560 626 743 105
114
Table 6-Pasting properties of starch
Variety Peak viscosity
(RVU)a
Trough
(RVU)
Breakdown
(RVU)
Final viscosity
(RVU)
Setback
(RVU)
Peak time
(min)
Black 293abc 252abc 41efg 363ab 111abcd 92e
Blanca 344a 301a 42defg 384ab 82de 111ab
Cahuil 342ab 297a 45def 405a 108abcd 106bc
Cherry Vanilla 313abc 263abc 50de 369ab 106abcd 99d
Oro de Valle 294abc 277ab 17fg 330abc 53e 105c
49ALC 256cde 137f 119a 225d 88cde 64i
1ESP 269bcd 172ef 97ab 313bc 140a 79h
Copacabana 258cde 186def 72bcd 308bc 122abc 81gh
Col6197 270bcd 231bcd 39efg 347ab 116abcd 86fg
Japanese Strain 193e 181def 12g 264cd 83de 113a
QQ63 213de 152f 60cde 254cd 101bcd 88ef
Yellow Commercial
290abc 223cde 67bcde 350ab 127ab 93de
Red Commercial 327abc 242bc 85bc 366ab 125ab 92ef
Corn 255 131 124 283 152 73 aRVU = cP12
115
Table 7-Correlation coefficients between starch properties and texture of cooked quinoaa
Hardness Adhesiveness Cohesiveness Gumminess Chewiness
Total starch content
-032ns -048 -043ns -039ns -039ns
Apparent amylose content
069 072 069 072 072
Actual amylose content
061 062 056 061 061
Degree of amylose-lipid complex
-065 -060 -070 -070 -070
Amylose leaching
-082 -075 -074 -082 -082
α-Amylase activity
018ns 055 051 032ns 032ns
Starch gel hardness
042ns 059 051 049 049
DSC
To 034ns 049 051 041ns 041ns
Tp 047 052 056 052 052
ΔH 064 072 069 070 070
RVA
Peak viscosity 031ns 054 047 041ns 041ns
Trough 044ns 077 063 055 055
Breakdown -034ns -060 -044ns -038ns -038ns
Final viscosity 045ns 068 058 053 053
Peak time 053 077 068 060 060
ns non-significant difference P lt 010 P lt 005 P lt 001 aTPA is the Texture Profile Analysis of cooked quinoa data were presented in Wu et al (2014)
116
Table 8-Correlations between starch properties and seed DSC RVA characteristicsa
Total
starch content
Water solubility
Apparent amylose content
Total amylose content
Degree of amylose-lipid complex
Amylose leaching
α-Amylase activity
Protein -047ns 023ns 058 031ns -069 -062 066
Seed hardness
-073 -041ns -003ns -021ns -020ns 019ns 053
Bulk density
054 049 -020ns -015ns 031ns 019ns -072
Seed coat proportion
-071 -041ns 027ns 021ns -028ns -038ns 055
Starch gel hardness
-045ns 017 ns 065 053 -044ns -064 046ns
Starch DSC
To -049 -004ns 041ns 043ns -033ns -049 061
Tp -050 010ns 047ns 045ns -042ns -058 052
Enthalpy -051 -011ns 059 055 -041ns -064 049
Starch viscosity
Peak viscosity
-066 -049 028ns 027ns -020ns -023ns 070
Trough -068 -017ns 056 057 -031ns -052 072
Breakdown
022ns -048 -061 -067 027ns 062 -025ns
Final viscosity
-060 -022ns 063 060 -037ns -046ns 061
Peak time -032ns 045ns 058 072 -029ns -081 043ns
117
Cooking quality
Optimal cooking time
-043ns 019ns 056 040ns -067 -055 029ns
ns non-significant difference P lt 010 P lt 005 P lt 001 aSeed characteristics data were presented in Wu et al (2014)
118
Chapter 5 Quinoa Seed Quality Response to Sodium Chloride and
Sodium Sulfate Salinity
Submitted to the Frontiers in Plant Science
Research Topic Protein crops Food and feed for the future
Abstract
Quinoa (Chenopodium quinoa Willd) is an Andean grain with an edible seed that both contains
high protein content and provides high quality protein with a balanced amino acid profile
Quinoa is a halophyte adapted to harsh environments with highly saline soil In this study four
quinoa varieties were grown under six salinity treatments and two levels of fertilization and then
evaluated for quinoa seed quality characteristics including protein content seed hardness and
seed density Concentrations of 8 16 and 32 dS m-1 of NaCl and Na2SO4 as well as a no-salt
control were applied to the soil medium across low (1 g N 029 g P 029 g K per pot) and high
(3 g N 085 g P 086 g K per pot) fertilizer treatments Seed protein content differed across soil
salinity treatments varieties and fertilization levels Protein content of quinoa grown under
salinized soil ranged from 130 to 167 comparable to that from normal conditions NaCl
and Na2SO4 exhibited different impacts on protein content Whereas the different concentrations
of NaCl did not show differential effects on protein content the seed from 32 dS m-1 Na2SO4
contained the highest protein content Seed hardness differed among varieties and was
moderately influenced by salinity level (P = 009) Seed density was affected significantly by
119
variety and Na2SO4 concentration but was unaffected by NaCl concentration The plants from 8
dS m-1 Na2SO4 soil had lower density (066 gcm3) than those from 16 dS m-1 and 32 dS m-1
Na2SO4 074 and 072gcm3 respectively This paper identifies changes in critical seed quality
traits of quinoa as influenced by soil salinity and fertility and offers insights into variety
response and choice across different abiotic stresses in the field environment
Key words quinoa soil salinity protein content hardness density
120
Introduction
Quinoa (Chenopodium quinoa Willd) has garnered much attention in recent years
because it is an excellent source of plant-based protein and is highly tolerance of soil salinity
Because soil salinity affects between 20 to 50 of irrigated arable land worldwide (Pitman and
Lauchli 2002) the question of how salinity affects seed quality in a halophytic crop like quinoa
needs to be addressed Protein content in most quinoa accessions has been reported to range from
12 to 17 depending on variety environment and inputs (Rojas et al 2015) This range
tends to be higher than the protein content of wheat barley and rice which were reported to be
105- 14 8-14 and 6-7 respectively (Shih 2006 Orth and Shellenberger1988 Cai et
al 2013) Additionally quinoa has a well-balanced complement of essential amino acids
Specifically quinoa is rich in lysine which is considered the first limiting essential amino acid in
cereals (Taylor and Parker 2002) Protein quality such as Protein Efficiency Ratio is similar to
that of casein (Ranhotra et al 1993) Furthermore with a lack of gluten protein quinoa can be
safely consumed by gluten sensitiveintolerant population (Zevallos et al 2014)
Quinoa shows exceptional adaption to harsh environments such as drought and salinity
(Gonzaacutelez et al 2015) Soil salinity reduces crop yields and is a worldwide problem In the
United States approximately 54 million acres of cropland in forty-eight States were occupied by
saline soils while another 762 million acres are at risk of becoming saline (USDA 2011) The
salinity issue leads producers to grow more salt-tolerant crops such as quinoa
Many studies have focused on quinoarsquos tolerance to soil salinity with a particular
emphasis on plant physiology (Ruiz-Carrasco et al 2011 Adolf et al 2012 Cocozza et al
121
2013 Shabala et al 2013) and agronomic characteristics such as germination rate plant height
and yield (Prado et al 2000 Chilo et al 2009 Peterson and Murphy 2015 Razzaghi et al
2012) For instance Razzaghi et al (2012) showed that the seed number per m2 and seed yield
did not decrease as salinity increased from 20 to 40 dS m-1 in the variety Titicaca Ruiz-Carrasco
et al (2011) reported that under 300 mM NaCl germination and shoot length were significantly
reduced whereas root length was inhibited in variety BO78 variety PRJ biomass was less
affected and exhibited the greatest increase in proline concentration Jacobsen et al (2000)
suggested that stomatal conductance leaf area and plant height were the characters in quinoa
most sensitive to salinity Wilson et al (2002) examined salinity stress of salt mixtures of
MgSO4 Na2SO4 NaCl and CaCl2 (3 ndash 19 dS m-1) No significant reduction in plant height and
fresh weight were observed In a comparison of the effects of NaCl and Na2SO4 on seed yield
quinoa exhibited greater tolerance to Na2SO4 than to NaCl (Peterson and Murphy 2015)
Few studies have focused on the influence of salinity on seed quality in quinoa Karyotis
et al (2003) conducted a field experiment in Greece (80 m above sea level latitude 397degN)
With the exception of Chilean variety lsquoNo 407rsquo seven other varieties exhibited significant
increases in protein (13 to 33) under saline-sodic soil with electrical conductivity (EC) of
65 dS m-1 Mineral contents of phosphorous iron copper and boron did not decrease under
saline conditions Koyro and Eisa (2008) found a significant increase in protein and a decrease in
total carbohydrates under high salinity (500 mM) Pulvento et al (2012) indicated that fiber and
saponin contents increased under saline conditions with well watersea water ratio of 11
compared to those under normal soil
122
Protein is one of the most important nutritional components of quinoa seed The content
and quality of protein contribute to the nutritional value of quinoa Additionally seed hardness is
an important trait in crops such as wheat and soybeans For instance kernel hardness highly
influences wheat end-use quality (Morris 2002) and correlates with other seed quality
parameters such as ash content semolina yield and flour protein content (Hruškovaacute and Švec
2009) Hardness of soybean influenced water absorption seed coat permeability cookability
and overall texture (Zhang et al 2008) Quinoa seed hardness was correlated with the texture of
cooked quinoa influencing hardness chewiness and gumminess and potentially consumer
experience (Wu et al 2014) Furthermore seed density is also a quality index and is negatively
correlated with the texture of cooked quinoa such as hardness cohesiveness chewiness and
gumminess (Wu et al 2014)
Chilean lowland varieties have been shown to be the most well-adapted to temperate
latitudes (Bertero 2003) and therefore they have been extensively utilized in quinoa breeding
programs in both Colorado State University and Washington State University (Peterson and
Murphy 2015) For these reasons Chilean lowland varieties were evaluated in the present study
The objectives of this study were to 1) examine the effect of soil salinity on the protein content
seed hardness and density of quinoa varieties 2) determine the effect of different levels of two
agronomically important soil salts NaCl and Na2SO4 on seed quality and 3) test the influence
of fertilization levels on salinity tolerance of quinoa The present study illustrates the different
influence of NaCl and Na2SO4 on quinoa seed quality and provides better guidance for variety
selection and agronomic planning in highly saline environments
Materials and Methods
123
Genetic material
Quinoa germplasms were obtained from Dr David Brenner at the USDA-ARS North
Central Regional Plant Introduction Station in Ames Iowa The four quinoa varieties CO407D
(PI 596293) UDEC-1 (PI 634923) Baer (PI 634918) and QQ065 (PI 614880) were originally
sourced from lowland Chile CO407D was released by Colorado State University in 1987
UDEC-1 Baer and QQ065 were varieties from northern central and southern locations in Chile
with latitudes of 3463deg S 3870deg S and 4250deg S respectively
Experimental design
A controlled environment greenhouse study was conducted using a split-split-plot
randomized complete block design with three replicates per treatment Factors included four
quinoa varieties two fertility levels and seven salinity treatments (three concentration levels
each of NaCl and Na2SO4) Three subsamples each representing a single plant were evaluated
for each treatment combination Quinoa variety was treated as the main plot salinity level as the
sub-plot and fertilization as the sub-sub-plot Salinity levels included 8 16 and 32 dS m-1 of
NaCl and Na2SO4 The details of controlling salinity levels were described by Peterson and
Murphy (2015) In brief fertilization was provided by a mixture of alfalfa meal
monoammonium phosphate and feather meal Low fertilization level referred to 1 g of N 029 g
of P and 029 g of K in each pot and high fertilization level referred to 3 g of N 086 g of P and
086 g of K in each pot Each pot contained about 1 L of Sunshine Mix 1 (Sun Gro Horticulture
Bellevue WA) (dry density of 100 gL water holding capacity of ca 480 gL potting mix) The
124
entire experiment was conducted twice with the planting dates of September 10th 2011 and
October 7th 2011
Seed quality tests
Protein content of quinoa was determined using the Dumas combustion nitrogen method
(LECO Corp Joseph Mich USA) (AACCI Method 46-3001) A factor of 625 was used to
convert nitrogen to protein Seed hardness was determined using the Texture Analyzer (TA-
XT2i) (Texture Technologies Corp Scarsdale NY) and a modified rice kernel hardness method
(Krishnamurthy and Giroux 2001) A single quinoa kernel was compressed until the point of
fracture using a 1 cm2 cylinder probe traveling at 5 mms Repeat measurements were taken on 9
random kernels The seed hardness was recorded as the average peak force (Kg) of the repeated
measures
Seed density was determined using a pycnometer (Pentapyc 5200e Quantachrome
Instruments Boynton Beach FL) Quinoa seed was placed in a closed micro container and
compressed nitrogen was suffused in the container Pressure in the container was recorded both
with and without nitrogen The volume of the quinoa sample was calculated by comparing the
standard pressure obtained with a stainless steel ball Density was the seed weight divided by the
displaced volume Seed density was collected on only the second greenhouse experiment
Statistical analysis
Data were analyzed using the PROC GLM procedure in SAS (SAS Institute Cary NC)
Greenhouse experiment repetition was treated as a random factor in protein content and seed
hardness analysis Variety salinity and fertilization were treated as fixed factors Fisherrsquos LSD
125
Test was used to access multiple comparisons Pearson correlation coefficients between protein
hardness and density were obtained via PROC CORR procedure in SAS using the treatment
means
Results
Protein
Variety salinity and fertilization all exhibited highly significant effects on protein
content (P lt 0001) (Table 1) The greatest contribution to variation in seed protein was due to
fertilization (F = 40247) In contrast salinity alone had a relatively minor effect and the
varieties responded similarly to salinity as evidenced by a non-significant interaction The
interactions however were found in variety x fertilization as well as in salinity x fertilization
both of which were addressed in later paragraphs It is worth noting that the two experiments
produced different seed protein contents (F = 4809 P lt0001) experiment x variety interaction
was observed (F = 1494 P lt0001) (data not shown) Upon closer examination this interaction
was caused by variety QQ065 which produced an overall mean protein content of 129 in
experiment 1 and 149 in experiment 2 Protein contents of the other three varieties were
essentially consistent across the two experiments
Across all salinity and fertilization treatments the variety protein means ranged from
130 to 167 (data not shown) As expected high fertilization resulted in an increase in
protein content across all varieties The mean protein contents under high and low fertilization
were 158 and 136 respectively (Table 2) The means of Baer and CO407D were the
126
highest 151 and 149 respectively QQ065 contained 141 protein significantly lower
than the other varieties
Even though salinity effects were relatively smaller than fertilization and variety effects
salinity still had a significant effect on protein content (Table 1) The two types of salt exhibited
different impacts on protein (Table 2) Protein content did not differ according to different
concentrations of NaCl with means (across varieties and fertilization levels) from 147 to
149 Seed from 32 dS m-1 Na2SO4 however contained higher protein (152) than that from
8 dS m-1 and 16 dS m-1 Na2SO4 (144 and 142 respectively)
A significant interaction of salinity x fertilization was detected indicating that salinity
differentially impacted seed protein content under high and low fertilization level (Figure 1)
Within the high fertilizer treatment protein content in the seed from 32dS m-1 Na2SO4 was
significantly higher (167) than all other samples which did not differ from each other (~13)
Within the low fertilizer treatment protein content of seeds from 8 dS m-1 and 16 dS m-1
Na2SO4 were significantly lower than those from the NaCl treatments and 32dS m-1 Na2SO4
The significant interaction between variety and fertilization (Table 1) was due to the
different response of QQ065 Protein mean of QQ065 from high fertilization was 144 lower
than the other varieties CO407D UDEC-1 and Baer exhibited a decline of 16 - 18 in
protein under low fertilization while QQ065 dropped only 5
Hardness
Variety exhibited the greatest influence on seed hardness (F = 21059 P lt0001)
whereas fertilization did not show any significant effect (Table 1) Salinity exhibited a moderate
127
effect (F = 200 P = 009) Varieties responded consistently to salinity under various fertilization
levels since neither variety x salinity nor salinity x fertilization interaction was significant
However a variety x fertilization interaction was observed which will be discussed in a later
paragraph Similar to the situation in protein content experiment repetition exhibited a
significant influence on seed hardness Whereas the hardness of CO407D was consistent across
the two greenhouse experiments the hardness of other three varieties all decreased by 8 to 9
Mean hardness was significantly different among varieties CO407D had the hardest
seeds with hardness mean of 100 kg (Table 3) UDEC-1 was softer at 94 kg whereas Baer and
QQ065 were the softest and with similar hardness means of 77 kg and 74 kg respectively
Salinity exhibited a moderate impact on seed hardness (P = 009) The highest hardness
mean was observed under 16 dS m-1 Na2SO4 whereas the lowest was under 8 dS m-1 NaCl with
means of 89 and 83 kg respectively
A significant fertilization x variety interaction was found for seed hardness The hardness
of UDEC-1 and Baer did not differ across fertilization level whereas CO407D was harder under
low fertilization and QQ065 was harder under high fertilization
Seed density
Variety and salinity both significantly affected seed density whereas fertilization did not
show a significant influence (Table 1) The greatest contribution to variation in seed density was
due to variety (F = 2282) Salinity exhibited a relatively smaller effect yet still significant (F =
282 P lt005) Neither variety x salinity interaction nor salinity x fertilization interaction was
observed which indicated that varieties similarly responded to salinity under high and low
128
fertilization levels An interaction of variety x fertilization was found and the details were
presented later
Across all salinity and fertilization treatments CO407D had the highest mean density
080 gcm3 followed by Baer with 069 gcm3 (Table 4) UDEC-1 and QQ065 had the lowest and
similar densities (~065 gcm3)
With regard to salinity effect the Na2SO4 treatments exhibited differential influence on
seed density Density means did not significantly change due to the increased concentration of
NaCl ranging from 068 to 071 gcm3 (Table 4) The samples from 8 dS m-1 Na2SO4 soil had
lower density (066 gcm3) than those from 16 dS m-1 and 32 dS m-1 Na2SO4 074 and
072gcm3 respectively
A significant variety x fertilization interaction was found With closer examination
UDEC-1 and Baer yielded higher density seeds under high fertilization whereas CO407D and
QQ065 did not differ in density between fertilization treatments
Correlations of protein hardness and density
Correlation coefficients among seed protein content hardness and density are shown in
Table 5 No significant correlation was detected between protein content and seed hardness
However both protein content and hardness were correlated with seed density The overall
correlation coefficient was low (r = 019 P = 003) between density and protein A marginally
significant correlation was found between density and protein content of the seeds from NaCl
salinized soil under low fertilization No correlation was found between density and protein
content of the seeds from NaCl salinized soil under high fertilization or Na2SO4 salinized soil
129
The overall correlation coefficient was 038 (P lt 00001) between density and hardness
The low fertilization samples from both NaCl and Na2SO4 soil showed significant correlations
between density and hardness with coefficients of 051 and 047 (both P lt 0005) The high
fertility quinoa did not exhibit any correlation between density and hardness
Correlation with yield leaf greenness index plant height and seed minerals contents
Correlation between seed quality and yield leaf greenness index plant height and seed
mineral concentration were obtained using data from Peterson and Murphy (2015) (Table 6)
Seed hardness significantly correlated with yield and plant height (r = 035 and 031
respectively) Protein content and density however did not correlate with yield leaf greenness
or plant height Correlations were found between quality indices and the concentration of
different minerals Protein was negatively correlated with Cu and Mg (r = -052 and -050
respectively) Hardness was negatively correlated with Cu P and Zn (r = -037 -056 -029
respectively) but was positively correlated with Mn (r = 057) Density was negatively
correlated with Cu (r = -035)
Discussion
Protein
Although salinity exhibited a significant effect on seed protein content the impact was
relatively minor compared to fertilization and variety effects In another words over a wide
range of saline soil quinoa can grow and yield seeds with stable protein content
130
Protein content of quinoa growing under salinized soil ranged from 127 to 167 (data
not shown) within the general range of protein content under non-saline conditions which was
12 to 17 (Rojas et al 2015) Saline soil did not cause a significant decrease in seed protein
It is interesting to notice that the samples from 32 dS m-1 Na2SO4 tended to contain the highest
protein especially in variety QQ065 The studies of Koyro and Eisa (2008) and Karyotis et al
(2003) also indicated that protein content significantly increased under high salinity (NaCl)
whereas total carbohydrates decreased In contrast Ruffino et al (2009) found that quinoa
protein decreased under 250 mM NaCl salinity in a growth chamber experiment It is reasonable
to conclude that salinity exhibits contrasting effects on different quinoa genotypes QQ065 and
CO407D both significantly increased in protein under 32 dS m-1 Na2SO4 however the yield
decline was 519 and 245 respectively (Peterson and Murphy 2015) This result indicted
that CO407D was the variety most optimally adapted to severe sodic saline soil tested in this
study
Na2SO4 level exhibited a significant influence on protein content whereas NaCl level did
not In the study of Koyro and Eisa (2008) however seed protein of the quinoa variety Hualhuas
(origin from Peru) increased under the highest salinity level of 500 mM NaCl compared to lower
NaCl levels (0 ndash 400 mM) This disagreement of NaCl influence may be due to diversity of
genotypes It is worth noting that quinoa protein contents in this paper were primarily above 13
based on wet weight (as-is-moisture of approximately ~8 -10) even under saline soil and low
fertilization level This protein content is generally equal to or higher than that of other crops
such as barley and rice (Wu 2015) In conclusion quinoa maintained high and stable protein
content under salinity stress
131
Hardness
Quinoa seed hardness was only moderately affected by salinity (P = 009) indicating that
quinoa primarily maintained seed texture when growing under a wide range of saline soil
CO407D exhibited the hardest seed (100 kg) whereas Baer and QQ065 were relatively soft (74
ndash 77 kg) A previous study indicated a hardness range of 58 ndash 109 kg among 11 quinoa
varieties and 2 commercial samples (Wu et al 2014) The commercial samples had hardness
values of 62 kg and 71 kg Since commercial samples generally maintain stable quality and
indicate an acceptable level for consumers seed hardness around 7 kg as in Baer and QQ065
should be considered as acceptable quality The hardness of CO407D was close to that of the
colored variety lsquoBlackrsquo (100 kg) which had a thicker seed coat than that of the yellow seeded
varieties It was reported that a thicker seed coat is related to harder texture (Fraczek et al 2005)
Even though the greenhouse is a highly controlled environment and the two experiments
were conducted in similar seasons (planted in September and October respectively) seed protein
and hardness were still different across the two experiments However ANOVA indicated
modest-to-no significant interactions with salinity and fertilization such that responses to salinity
and fertilization were consistent with little or no change in rank order Even though experiment x
variety was significant the F-values were relatively low compared to the major effects such as
variety and fertilization and neither of them was crossing interaction This is a particularly
noteworthy result for breeders farmers and processors
Density
132
The range of seed density under salinity 055 ndash 089 gcm3 was comparable to the
density range of 13 quinoa samples (058 ndash 076 gcm3 ) (Wu et al 2014) Generally CO407D
had higher seed density (071 ndash 089 gcm3) which indicated that seed density in this variety was
affected by salinity stress In contrast the density of QQ065 did not change according to salinity
type or concentration which indicated a stable quality under saline soil
Correlations
The correlation between seed hardness and density was only significant under low fertilization
but not under high fertilization The high fertilization level in the greenhouse experiment
exceeded the amount of fertilizer that would normally be applied in field environments whereas
the low fertilization level is closer to the field situation Therefore correlation between hardness
and density may still exist in field trials
Conclusions
Under saline soil conditions quinoa did not show any marked decrease in seed quality
such as protein content hardness and density Protein content even increased under high Na2SO4
concentration (32 dS m-1) Varieties exhibited great differential reactions to fertilization and
salinity levels QQ065 maintained a similar level of hardness and density whereas seed of
CO407D was both harder and higher density under salinity stress If only seed quality is
considered then QQ065 is the most well-adapted variety in this study
The influences of NaCl and Na2SO4 were different The higher concentration of Na2SO4
tended to increase protein content and seed density whereas NaCl concentration did not exhibit
any significant difference on those quality indexes
133
Acknowledgement
The research was funded by USDA Organic Research and Extension Initiative project
number NIFAGRANT11083982 The authors acknowledge Alecia Kiszonas for assisting in the
data analysis
Author contributions
Peterson AJ set up the experiment design in the greenhouse and grew harvested and
processed quinoa samples Wu G collected seed quality data such as protein content seed
hardness and density Peterson AJ and Wu G together processed the data Wu G also drafted the
manuscript Murphy KM and Morris CF edited the manuscript
Conflict of interest statement
The authors declared to have no conflict of interest
134
References
AACC International Approved Methods of Analysis Method 46-3001 Crude protein ndash
Combustion method Approved November 8 1995 Reapproved November 3 1999
Availablenline only AACCI St Paul MN
Adolf VI Shabala S Andersen MN Razzaghi F Jacobsen SE 2012 Varietal differences of
quinoas tolerance to saline conditions Plant Soil 357 117ndash29
Bertero HD 2003 Response of developmental processes to temperature and photoperiod in
quinoa (Chenopodium quinoa Willd) Food Rev Int 19 87ndash97
Cai S Yu G Chen X Huang Y Jiang X Zhang G Jin X 2013 Grain protein content variation
and its association analysis in barley BMC Plant Boil 13 35
Chilo G Molina MV Carabajal R Ochoa M 2009 Temperature and salinity effects on
germination and seedling growth on two varieties of Chenopodium quinoa Agri-Scientia 26
15ndash22
Cocozza C Pulvento C Lavini A Riccardi M dAndria R Tognetti R 2013 Effects of
increasing salinity stress and decreasing water availability on ecophysiological traits of
quinoa (Chenopodium quinoa Willd) grown in a mediterranean-type agroecosystem J Agron
Crop Sci 199 229ndash40
Fraczek J Hebda T Slipek Z Kurpaska S 2005 Effect of seed coat thickness on seed hardness
Can Biosyst Eng 47 41ndash5
135
Gonzaacutelez JA Eisa SSS Hussin SAES Prado FE 2015 Quinoa an Incan crop to face global
changes in agriculture In Murphy KM Matanguihan J editors Quinoa Improvement and
Sustainable Production Hoboken NJ John Wiley Sons p 7ndash11
Hruškovaacute M Švec I 2009 Wheat hardness in relation to other quality factors Czech J Food Sci
27 240ndash8
Jacobsen S Quispe H Mujica A 2000 Quinoa an alternative crop for saline soils in the Andes
in Scientist and Farmer Partners in Research for the 21st Century (Program Report 1999-
2000) ed International Potato Center (Peru) 403ndash8
Jancurovaacute M Minarovicovaacute L Dandar A 2009 Quinoandasha review Czech J Food Sci 27 71ndash9
Karyotis T Iliadis C Noulas C Mitsibonas T 2003 Preliminary research on seed production
and nutrient content for certain quinoa varieties in a salinendashsodic soil J Agron Crop Sci 189
402ndash8
Koyro HW Eisa S 2008 Effect of salinity on composition viability and germination of seeds of
Chenopodium quinoa Willd Plant Soil 302 79-90
Krishnamurthy K Giroux MJ 2001 Expression of wheat puroindoline genes in transgenic rice
enhances grain softness Nat Biotechnol 19 162ndash6
Morris CF 2002 Puroindolines the molecular genetic basis of wheat grain hardness Plant mol
Biol 48 633ndash47
136
Orth RA Shellenberger JA 1988 Chapter 1 Origin production and utilization of wheat In
Pomeranz Y editor Wheat Chemistry and Technology 3th edition St Paul MN American
Association of Cereal Chemists Inc p 11ndash2
Peterson A Murphy K 2015 Tolerance of lowland quinoa cultivars to sodium chloride and
sodium sulfate salinity Crop Sci 55 331ndash8
Pitman MG Laumluchli A 2002 Global impact of salinity and agricultural ecosystems In Laumluchli
A Luumlttge U editors Netherlands Springer p 3ndash20
Prado FE Boero C Gallardo M Gonzaacutelez JA 2000 Effect of NaCl on germination growth and
soluble sugar content in Chenopodium quinoa Willd seeds Bot Bull Acad Sinica 41 27ndash34
Pulvento C Riccardi M Lavini A Iafelice G Marconi E dAndria R 2012 Yield and quality
characteristics of quinoa grown in open field under different saline and non-saline irrigation
regimes J Agron Crop Sci 198 254ndash63
Ranhotra G Gelroth J Glaser B Lorenz K Johnson D 1993 Composition and protein
nutritional quality of quinoa Cereal Chem 70 303ndash5
Razzaghi F Ahmadi SH Jacobsen SE Jensen CR Andersen MN 2012 Effects of salinity and
soilndashdrying on radiation use efficiency water productivity and yield of quinoa (Chenopodium
quinoa Willd) J Agron Crop Sci 198 173ndash84
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile D
137
Bertero D Nieto C editors State of the Art Report of Quinoa in the World in 2013 Rome
FAO amp CIRAD p 67-8
Ruffino A Rosa M Hilal M Gonzaacutelez J Prado F 2010 The role of cotyledon metabolism in the
establishment of quinoa (Chenopodium quinoa)seedlings growing under salinity Plant Soil
326 213ndash24
Ruiz-Carrasco K Antognoni F Coulibaly A K Lizardi S Covarrubias A Martiacutenez E A
Shabala S Hariadi Y Jacobsen SE 2013 Genotypic difference in salinity tolerance in quinoa is
determined by differential control of xylem Na+ loading and stomatal density J Plant Physiol
170 906ndash14
Shih FF 2006 Chapter 6 Rice protein In Champagne ET editor Rice Chemistry and
Technology 3rd edition St Paul MN American Association of Cereal Chemists Inc p
143-4
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Taylor JRN Parker ML editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science amp Business Media p 96-101
USDA (United States Department of Agriculture) 2011 Soil and water resources conservation
act (RCA) P 31 Access from
httpwwwnrcsusdagovInternetFSE_DOCUMENTSstelprdb1044939pdf
Wilson C Read J Abo-Kassem E 2002 Effect of mixed-salt salinity on growth and ion
relations of a quinoa and a wheat variety J Plant Nutri 25 2689ndash704
138
Wu G Morris CF Murphy KM 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79 2337ndash45
Wu G 2015 Chapter 11 Nutritional properties of quinoa In Murphy KM Matanguihan J
editors Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp
Sons Inc p 193-205
Zhang B Chen P Chen CY Wang D Shi A Hou A Ishibashi T 2008 Quantitative trait loci
mapping of seed hardness in soybean Crop Sci 48 1341ndash9
Zevallos VF Herencia LI Chang F Donnelly S Ellis HJ Ciclitira PJ 2014 Gastrointestinal
effects of eating quinoa (Chenopodium quinoa Willd) in celiac patients Am J Gastroenterol
109 270ndash8
Zurita-Silva A 2011 Variation in salinity tolerance of four lowland genotypes of quinoa
(Chenopodium quinoa Willd) as assessed by growth physiological traits and sodium
transporter gene expression Plant Physiol Bioch 49 1333ndash41
139
Table 1-Analysis of variance with F-values for protein content hardness and density of quinoa seed
Effect F-values
Protein Hardness Density
Model 524 360 245
Variety 2463 21059 2282
Salinity 975 200dagger 282
Fertilization 40247 107 260
Variety x Salinity 096 098 036
Variety x Fertilization 2062 1094 460
Salinity x Fertilization 339 139 071
Variety x Salinity x Fertilization 083 161dagger 155
dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the 001 probability level Significant at the lt0001 probability level
140
Table 2-Salinity variety and fertilization effects on quinoa seed protein content ()
Salinity Protein content ()
Variety Protein content ()
Fertilization Protein content ()
8 dS m-1 NaCl 147bc1 CO407D 149ab High 158a
16 dS m-1 NaCl 148ab UDEC-1 147b Low 136b
32 dS m-1 NaCl 149ab Baer 151a
8 dS m-1 Na2SO4 144cd QQ065 141c
16 dS m-1 Na2SO4 142d
32 dS m-1 Na2SO4 152a 1Different letters in a given column indicate significant differences (P lt 005)
141
Table 3-Salinity variety and fertilization effects on quinoa seed hardness (kg)
Salinity Hardness (kg)1 Variety Hardness (kg)
8 dS m-1 NaCl 83 CO407D 100a2
16 dS m-1 NaCl 87 UDEC-1 94b
32 dS m-1 NaCl 85 Baer 77c
8 dS m-1 Na2SO4 87 QQ065 74c
16 dS m-1 Na2SO4 89
32 dS m-1 Na2SO4 88 1Hardness was significant at the 009 probability level 2Different letters in a given column indicate significant differences (P lt 005)
142
Table 4-Salinity variety and fertilization effects on quinoa seed density (g cm3)
Salinity density (g cm3) Variety density (g cm3)
8 dS m-1 NaCl 069bc1 CO407D 080a
16 dS m-1 NaCl 068bc UDEC-1 066bc
32 dS m-1 NaCl 071abc Baer 069b
8 dS m-1 Na2SO4 066c QQ065 065c
16 dS m-1 Na2SO4 074a
32 dS m-1 Na2SO4 072ab 1Different letters in a given column indicate significant differences (P lt 005)
143
Table 5-Correlation coefficients of protein hardness and density of quinoa seed
Correlation All NaCl Na2SO4
High fertilization
Low fertilization
High fertilization
Low fertilization
Protein -Density 019 013ns 029dagger 026ns 019ns
Hardness - Density 038 027ns 051 022ns 047
ns Not significant dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the lt0001 probability level
144
Table 6-Correlation coefficients of quinoa seed quality and agronomic performance and seed mineral content
Protein Hardness Density
Yield 004 035 006
Plant Height -004 031 011
Cu -052 -037 -035
Mg -050 004 0
Mn -006 057 025dagger
P -001 -056 -015
Zn -004 -029 -028dagger
dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the 001 probability level Significant at the lt0001 probability level
145
Figure 1-Protein content () of quinoa in response to combined fertility and salinity treatments
146
Chapter 6 Lexicon development and consumer acceptance
of cooked quinoa
ABSTRACT
Quinoa is becoming increasingly popular with an expanding number of varieties being
commercially available In order to compare the sensory properties of these quinoa varieties a
common sensory lexicon needs to be developed Thus the objective of this study was to develop
a lexicon of cooked quinoa and examine consumer acceptance of various varieties A trained
panel (n = 9) developed appropriate aroma tasteflavor texture and color descriptors to describe
cooked quinoa and evaluated 21 quinoa varieties Additionally texture of the cooked quinoa was
determined using a texture analyzer Results indicated panelists using this developed lexicon
could distinguish among these quinoa varieties showing significant differences in aromas
tasteflavors and textures Specifically quinoa variety effects were observed for the aromas of
caramel nutty buttery grassy earthy and woody tasteflavor of sweet bitter grain-like nutty
earthy and toasty and texture of firm cohesive pasty adhesive crunchy chewy astringent and
moist The varieties lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Drsquo exhibited adhesive texture that has not
been seen in any commercialized quinoa Subsequent consumer evaluation (n = 102) on 6
selected samples found that the lsquoPeruvian Redrsquo was the most accepted overall while the least
accepted was lsquoQQ74rsquo Partial least squares analysis on the consumer and trained panel data
indicated that overall consumer liking was driven by higher intensities of grassy aroma and firm
and crunchy texture The attributes of pasty moist and adhesive were less accepted by
consumers This overall liking was highly correlated with consumer liking of texture (r = 096)
147
tasteflavor (r = 095) and appearance (r = 091) of cooked quinoa From the present study the
quinoa lexicon and key drivers of consumer acceptance can be utilized in the industry to evaluate
quinoa product quality and processing procedures
Keywords quinoa lexicon sensory evaluation
Practical application The lexicon of cooked quinoa can be used by breeders to screen quinoa
varieties Furthermore the lexicon will useful in the food industry to evaluate quinoa ingredients
from multiple farms harvest years processing procedures and product development
148
Introduction
Quinoa is classified as a pseudocereal like amaranth and buckwheat With its high
protein content and balanced essential amino acid profile quinoa is becoming popular
worldwide From 1992 to 2012 quinoa exports increased dramatically from 600 tons to 37000
tons (Furche et al 2015) Quinoa price in retail stores increased from $9kg in 2013 to $13kg -
$20kg in 2015 (Arco 2015) Quinoa has been incorporated into numerous products including
bread cookies pasta cakes and chocolates (Pop et al 2014 Alencar et al 2015 Casas Moreno
et al 2015 Wang et al 2015) Some of these products are gluten-free foods thus targeting the
gluten-sensitive market segment (Wang et al 2015)
Popularity of quinoa inspired US researchers to breed varieties that are compatible with
local weather and soil conditions which greatly differ from quinoarsquos original land the Andean
mountain region Since 2010 Washington State University has been breeding quinoa in the
Pacific Northwest region of United States Of the quinoa varieties evaluated in the breeding
program agronomic attributes of interest include high yield consistent performance over years
and tolerance to drought salinity heat and diseases (Peterson and Murphy 2013 Peterson
2013) However beyond agronomic attributes the grain sensory profiles of these quinoa
varieties are also important to assist in breeding decisions as well as screening
genotypescultivars for various food applications
In order to provide a complete descriptive profile of the cooked quinoa a trained sensory
evaluation should be used along with a complete lexicon of the sensory attributes of importance
Currently no quinoa lexicon is available and descriptions of quinoa sensory properties are
149
limited From currently published research papers attributes describing quinoa taste have been
limited to bitter sweet earthy and nutty (Koziol 1991 Lorenz and Coulter 1991 Repo-Carrasco
et al 2003 Stikic et al 2012 Foumlste M et al 2014) and texture of cooked quinoa has been
described as creamy smooth and crunchy (Abugoch 2009) Thus to address the lack of quinoa
lexicon one objective of this study is to develop a lexicon describing the sensory properties of
quinoa
Beyond developing a lexicon to describe quinoa consumer preference of the different
quinoa varieties is also of great interest Most previous sensory studies in quinoa focused on
acceptance of quinoa-containing products while consumer acceptance on plain grain of quinoa
varieties has not been studied Because of the lack of cooked quinoa studies with consumers rice
may be considered as a model to study quinoa because of their similar cooking process Tomlins
et al (2005) found consumer preference of rice was driven by the attributes of uniform clean
bright translucent and cream with consumers not liking the brown color of cooked rice and
unshelled paddy in raw rice In another study Suwannaporn et al (2008) found consumer
acceptance of rice products was significantly influenced by convenience grain variety and
traditionnaturalness
This study presenting a quinoa lexicon along with consumer acceptance of quinoa
varieties provides critical information for both the breeding programs and food industry
researchers Given the predicted importance of texture in consumer acceptance of quinoa texture
analysis was conducted to evaluate the parameters of hardness adhesiveness cohesiveness
chewiness and gumminess in quinoa samples
150
This lexicon describing the sensory attributes of cooked quinoa will be a useful tool to
evaluate quinoa varieties compare samples from different farms harvest years seed quality and
cleaning processing procedures Finally the sensory attributes driving consumersrsquo liking can be
utilized to evaluate optimal quinoa quality and target different consumers based on preference
Materials and methods
Quinoa samples
The present study included twenty-one quinoa samples harvested in 2014 which included
sixteen varieties from Finnriver Organic Farm (Finnriver WA) and five commercial samples
from Bolivia and Peru (Table 1)
Quinoa preparation
Following harvest the samples from Finnriver Farm were cleaned in a Clipper Office
Tester (Seedburo Des Plainies IL USA) to separate mixed weed seeds and threshed materials
Furthermore the samples were soaked for 30 min rubbed manually under running water and
dried at 43 ordmC until the moisture reached lt 11 Generally a moisture of 12 - 14 is
considered safe for grain storage (Hoseney 1989)
To prepare quinoa samples for sensory evaluation samples were soaked for 30 min and
mixed with water at a 12 ratio These mixtures were brought to a boil and simmered for 20 min
Following cooking the quinoa was cooled to room temperature Samples of cooked quinoa (10
g) were served in 30 mL plastic containers with lids (SOLO Lakeforest IL USA) Quinoa
151
samples were cooked and placed in covered cups within 2 h before evaluation Unsalted
crackers plastic cups used as cuspidors and napkins were provided to each panelist
Trained sensory evaluation panel
This project was approved by the Institutional Review Board of Washington State
University Sensory panelists (n = 9) were recruited via email announcements Panelists were
selected based on their interest in quinoa and availability All participants signed the Informed
Consent Form They received non-monetary incentives for each training session and a large non-
monetary reward at the completion of the formal evaluation
Demographic information was collected using a questionnaire Panelists included 4
females and 5 males ranging in age from 21 to 60 (mean age of 35) Regarding quinoa
consumption frequency four panelists frequently consumed quinoa (few times per month to
everyday) whereas five panelists rarely consumed quinoa As quinoa is a novel crop to most of
the world this was expected Since rice is a comparable model of quinoa frequency of rice
consumption was also considered with all panelists being frequent rice consumers
Sensory training and lexicon development
The training consisted of 12 sessions of 15 hours totaling 18 hours In the early stages
of the panel training attribute terms and references were discussed Panelists were first presented
with samples in covered plastic containers The samples widely varied in their sensory attributes
and included the varieties of lsquoBlackrsquo lsquoBolivian Redrsquo and lsquoBolivian Whitersquo The panelists
developed terms to describe the appearance aroma flavor taste and texture of the samples
Additionally the same samples were evaluated by an experienced sensory evaluation panel with
152
terms collected from this set of evaluators Terms were collected from panelists professionals
and literature describing rice (Meilgaard et al 2007 Limpawattana and Shewfelt 2010) The
term list was presented and discussed with panelist consensus being used to determine which
sensory terms appeared in the final lexicon
The final lexicon and associated definitions are presented in Table 2 This lexicon
included the sensory attributes of color (black red yellow) aroma (caramel grain-like bean-
like nutty buttery starchy grassygreen earthymusty woody) tasteflavor (sweet bitter grain-
like bean-like nutty earthy and toasted) and texture (soft-firm separate-cohesive pasty
adhesivenesssticky crunchycrumblycrisp chewygummy astringent and waterymoist)
References standards for each attribute were introduced The references were discussed and
modified until the panelists were in agreement Panelists reviewed the reference standards at the
beginning of each training session Since aroma varies over time all aroma references were
prepared 1-2 h before training During training three to four quinoa samples were evaluated and
discussed in each session The ability to detect attribute differences and the reproducibility of
panelists were both monitored and visualized using spider graphs and line graphs Using this
feedback panelists were calibrated paying extra attention to those attributes that were outside of
the panel standard deviation Practice sessions were continued until the panelists accurately and
consistently assessed varietal differences of quinoa
The protocols applied to evaluate samples and references were consistent among
panelists At the start of the evaluation the sample cup was shaken to allow the aroma to
accumulate in the headspace Panelists then lifted the cover and immediately took three short
sharp sniffs to evaluate the aroma Panelists then determined the color and its intensity Finally
153
panelists used the spoon to place the sample in-mouth and evaluate the tasteflavor and texture
Between each sample panelists rinsed their palate using water and unsalted crackers A 15-cm
line scale with 15-cm indentations on each end was used to determine the intensity of attributes
The values of 15 and 135 represented the extremely low and high intensity respectively Using
the lexicon panelists were trained to sense and quantify the attributes of cooked quinoa on
aroma color tasteflavor and texture
Following the development of the lexicon formal evaluations were conducted in the
sensory booths under white lights Compusensereg Five (Guelph Ontario Canada) provided scales
and programs for evaluation and collected results Panelists followed the protocol and used the
lexicon and 15-cm scales to evaluate the sensory attributes of the cooked quinoa samples
Twenty-one quinoa samples were tested in duplicate Panelists attended one session per day and
four sessions in total During each session panelists evaluated 10 or 11 samples with a 30 s
break after each sample and a 10 min break after the fifth sample Each variety was assigned
with a random three-digit code and the serving order was randomized
Consumer acceptance panel
From the 21 samples evaluated by the trained panelists six were selected for consumer
evaluation These six samples selected were diverse in color tasteflavor and texture as defined
by the trained panel results Consumers (n = 102) were recruited from Pullman WA Of the
consumers 49 were male and 52 were female with age ranging from 19 to 64 (mean age of 33)
The consumers showed different familiarity with quinoa with 29 indicating that they were
154
familiar with quinoa 40 having tried quinoa a few times and 32 having never tried quinoa
before All consumers had consumed rice before
The project was approved by the Institutional Review Board of Washington State
University Each consumer signed an Informed Consent Form and received a non-monetary
incentive at the end of evaluation The evaluation was conducted in the sensory booths under
white light Six quinoa samples were assigned with three-digit code and randomly presented to
each consumer using monadic presentation Quinoa samples were cooked and distributed in
evaluation cups and lidded (~10 gcup) the day before stored at 4 degC overnight and placed at
room temperature (25 degC) for 1 h prior to evaluation
During evaluation consumers followed the protocol instructions and indicated the degree
of acceptance of aroma color appearance tasteflavor texture and overall liking using a 7-point
hedonic scale (1 = dislike extremely 7 = like extremely) provided by Compusensereg Five
(Guelph Ontario Canada) A comments section was provided at the end of each sample
evaluation to gather additional opinions and information Between samples panelists took a 30 s
break and cleansed their palates using unsalted crackers and water
Texture Profile Analysis by instrument (TPA)
The texture of 21 cooked quinoa samples were conducted using a TA-XT2i Texture
Analyzer (Texture Technologies Corp Hamilton MA USA) (Wu et al 2014) Samples were
cooked using the same procedure as in the trained panel evaluation and cooled to room
temperature prior to evaluation
Statistical analysis
155
Sample characteristics and trained panel results were analyzed using three-way ANOVA
and mean separation (Fisherrsquos LSD) PCA was performed on the trained panel data Using
trained panel data and consumer evaluation data partial least square regression analysis was
performed Additionally correlations between instrument tests and panel evaluation on texture
and tasteflavor were determined XLSTAT 2013 (Addinsoft Paris France) was used for all data
analysis
Results and Discussion
Lexicon Development
A lexicon was created to describe the sensory attributes of cooked quinoa (Table 2) A
total of 27 attributes were included in the lexicon based on color (black red yellow) aroma
(caramel grain-like bean-like nutty buttery starchy grassygreen earthymusty and woody)
tasteflavor (sweet bitter grain-like bean-like nutty earthy and toasted) and texture (firm
cohesive pasty adhesivenesssticky crunchy chewygummy astringent and waterymoist)
Rice is considered as a good model of quinoa lexicon developments since both products
have common preparation methods The lexicon for cooked rice has been developed for the
aroma tasteflavor and texture properties of rice (Lyon et al 1999 Meullenet et al 2000
Limpawattana and Shewfelt 2010) Many attributes from these previously developed rice
lexicons can be applied to cooked quinoa For instance rice aroma and flavor notes such as
starchy woody grain nutty buttery earthy sweet bitter and astringent are also present in
quinoa Hence those notes were also included in the lexicon of cooked quinoa in present study
with quinoa varieties showing differences in these attributes
156
This present lexicon presents some sensory attributes not found to be significantly
different among the quinoa varieties These attributes include grain-like bean-like and starchy
aroma bean-like flavor and chewy texture Even though the trained panel did not detect
differences in this study future studies may find differences among other quinoa varieties for
these attributes so they were kept in the lexicon For instance the flavoraroma notes of
lsquorancidoxidizedrsquo lsquosourrsquo lsquometallicrsquo may also be present in other quinoa varieties or have these
attributes develop during storage as has been shown in rice (Meullenet et al 2000)
The lexicon also expanded the vocabularies to describe quinoa This lexicon is a
valuable tool with multiple practical applications such as describing and screening quinoa
varieties in breeding and evaluating post-harvest process and cooking methods
Lexicon Application Evaluation of the 21 quinoa samples
The effects of panelist replicate and quinoa variety on aroma tasteflavor and texture of
cooked quinoa were evaluated (n = 9) (Table 3) The quinoa variety exhibited significant
influences on most attributes listed in the lexicon (P lt 005) except for grain-like bean-like and
starchy aroma and bean-like flavor Generally quinoa variety effects were greater in the
perceived texture of cooked quinoa than in the aroma and flavor attributes however bitterness
was also highly significant among varieties Although panelists were trained over 18 h and
references were used for calibration significant panelist effects were still observed Based on the
inherent variation of human subjects such panelist effects commonly occur in sensory evaluation
of a complex product (Muntildeoz 2003) In future studies increased training and practice to further
clarify attribute definitions may reduce panelist effects (Muntildeoz 2003)
157
Examining the details of aroma attributes quinoa variety effect significantly influenced
the aroma attributes of caramel nutty buttery grassy earthy and woody (Figure 1) Principal
Components Analysis (PCA) was performed in order to visualize differences among the
varieties For aroma the first two components described 669 of the variation among quinoa
samples PC1 was primarily defined by the grassy and woody aromas while PC2 was primarily
described by more starchy and grain-like aromas The proximity of the attributes to a specific
quinoa sample reflected its degree of association For instance lsquoCalifornia Tricolorrsquo was most
commonly described by earthy woody grassy bean-like and nutty aroma lsquoTemukorsquo exhibited
sweet and grain-like aroma Yellowwhite quinoa such as lsquoTiticacarsquo lsquoRed Headrsquo lsquoQuF9P39-51rsquo
and lsquoPeruvian Whitersquo showed significantly more nutty (6) aroma compared to brown and red
quinoa varieties (48 ndash 51) (Table 1S) lsquoBlackrsquo lsquoCahuilrsquo and lsquoPeruvian Redrsquo exhibited more
grassy aroma (47 ndash 49) compared to lsquoTiticacarsquo lsquoLinaresrsquo and lsquoNL-6rsquo (38 ndash 39) lsquoBlackrsquo
showed the most earthy aroma (54) among all varieties
PCA was also performed to show how the varieties differed in their flavortaste
properties (Figure 2) The first two components described 646 of the varietal differences The
lsquoBlackrsquo variety was found to have more bitter and earthy flavors lsquoPeruvian Whitersquo was most
commonly described by sweet and nutty flavor and lack of earthy flavors lsquoTemukorsquo was mostly
defined by its bitter taste and lack of sweetness nutty grain-like and toasty flavors Overall
sweet and bitter taste and grain-like nutty earthy and toasty flavor exhibited significant
difference among quinoa varieties (plt005) The lsquoQuF9P39-51rsquo lsquoKaslaearsquo lsquoBolivian Whitersquo
and lsquoPeruvian Whitersquo were assigned the highest values in sweet taste (46 ndash 47) significantly
sweeter than lsquoBlackrsquo lsquoCherry Vanillarsquo lsquoTemukorsquo lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCalifornia Tricolorrsquo
158
(36 ndash 40)(Table 4) lsquoTemukorsquo and lsquoCherry Vanillarsquo were the most bitter samples (56 and 52
respectively) It is worth noting that the commercial samples were assigned the lowest bitterness
scores ranging from 22 ndash 27 significantly lower than the field trial varieties (34 ndash 56) Similar
to earthy aroma lsquoBlackrsquo also exhibited the earthiest flavor (52) Additionally lsquoCahuilrsquo and
lsquoCalifornia Tricolorrsquo showed high scores in earthy flavor (both 48) Toasty flavor varied from
38 in lsquoLinaresrsquo and lsquoQuF9P1-20rsquo to 51 in lsquoCahuilrsquo
Quinoa bitterness is caused by saponin compounds present on the seed coat It has been
reported that saponin can be removed by abrasion pearling and rinsing (Taylor and Parker
2002) However in the present study despite two cleaning process steps (airscreen and rinsing)
there was still bitter flavor remained Besides processing genetic background can also affect
saponin content Some sweet quinoa varieties (lsquoSajamarsquo lsquoKurmirsquo lsquoAynoqrsquoarsquo lsquoKrsquoosuntildearsquo and
lsquoBlanquitarsquo in Bolivia and lsquoBlancade Juninrsquo in Peru) have been developed with total seed
saponin content lower than 110 mg100 g (Quiroga et al 2015) However these varieties are not
adapted to the growing conditions in the Pacific Northwest (Peterson and Murphy 2015) The
quinoa varieties in WSU breeding program are primarily from Chilean lowland and those
varieties are more highly adapted to temperate areas In this case sweet quinoa varieties from
Bolivia and Peru were not included in this study However in 2015 a saponin-free quinoa
variety lsquoJessiersquo was grown in different locations of Washington State with a comparable yield
to bitter varieties The sensory evaluation of this new variety lsquoJessiersquo would be meaningful
Earthy which may be referred to as moldy and musty is caused by geosmin (a bicyclic
alcohol with formula C12H22O) which produced by actinobacteria (Gerber 1968) Samples with a
dark color (lsquoBlackrsquo lsquoCalifornia Tricolorrsquo and lsquoCahuilrsquo) tended to exhibit more earthy aroma and
159
flavor Possibly the pericarpseed coat composition of dark quinoa favors the actinobacteria-
producing geosmin
Overall texture attributes of cooked quinoa exhibited greater differences in values
(Figure 3) Among commercial quinoa varieties the red quinoa was firmer more gummy and
more chewy in texture compared to the yellowwhite commercial quinoa Several WSU field trial
varieties (lsquoQQ74rsquo lsquoLinaresrsquo and CO407D) exhibited greater variation in adhesiveness The first
two PCA factors explained 817 of the variation among samples lsquoPeruvian Redrsquo was most
accurately described by firm and crunchy texture and a lack of pasty sticky and cohesive
texture In contrast lsquoLinaresrsquo lsquoCO407Daversquo and lsquoQQ74rsquo were mostly described as pasty sticky
and cohesive yet lacking in firmness and crunchiness Mixed color or red color samples
(lsquoPeruvian Redrsquo lsquoBlackrsquo lsquoCahuilrsquo and lsquoCalifornia Tricolorrsquo) tended to be both firmer and
crunchier compared to the samples with light color However some yellow samples such as
lsquoTiticacarsquo and lsquoKU-2rsquo also had hard texture The varieties lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Daversquo
had the softest texture and also exhibited the least crunchy but the most pasty sticky and moist
texture Additionally compared to field trial varieties commercial samples tended to be lower in
intensity for the attributes of cohesiveness pastiness adhesiveness and astringency Moreover
astringent is the dry and puckering mouth feeling which is caused by the combination of tannins
and salivary proteins The differences found in this study among quinoa varieties may be caused
by processing protocols (removal of tannins to various degrees) or diverse genetic backgrounds
Consumer acceptance
160
Consumers evaluated six selected quinoa samples including the field trial varieties of
lsquoBlackrsquo lsquoTiticacarsquo lsquoQQ74rsquo and the commercial samples of lsquoPeruvian Redrsquo lsquoBolivian Redrsquo and
lsquoBolivian Whitersquo The selected samples were diverse in color texture and included both WSU
field trial varieties and commercial quinoa Among the field trial varieties the lsquoBlackrsquo variety
exhibited more grassy aroma earthy flavor and chewy texture lsquoTiticacarsquo had more caramel
aroma and lsquoQQ74rsquo was more adhesive than the other samples
The quinoa varieties varied significantly in consumer acceptance of color appearance
taste flavor texture and overall acceptance (P lt 0001) (Table 5) Overall lsquoPeruvian Redrsquo was
more accepted by consumers compared to lsquoTiticacarsquo and lsquoQQ74rsquo lsquoBlackrsquo received a similar
level of acceptance with all the commercial samples and the acceptance of lsquoTiticacarsquo did not
differ from lsquoBolivian Redrsquo and lsquoBolivian Whitersquo In aroma acceptance no significant difference
was found among the varieties In color lsquoPeruvian Redrsquo and lsquoBolivian Redrsquo received
significantly higher scores In appearance lsquoPeruvian Redrsquo was rated higher than all other
varieties except lsquoBolivian Redrsquo while lsquoQQ74rsquo gained the lowest rate Additionally lsquoQQ74rsquo was
less accepted in tasteflavor than all commercial samples but did not differ from other field trial
varieties lsquoBlackrsquo and lsquoTiticacarsquo Furthermore the texture of lsquoQQ74rsquo was the least accepted and
other varieties did not show any significant differences
However low acceptance in adhesive texture of cooked quinoa does not indicate the
adhesive quinoa varieties will not have market potential Adhesiveness in cooked rice is
correlated with high amylopectin and low amylose (Mossman et al 1983 Sowbhagya et al
1987) Hence adhesive quinoa may also contain low amylose Additionally previous studies
found waxy cereal or starch (0 amylose and 100 amylopectin) exhibited excellent
161
performance in extrusion Kowalski et al (2014) found that waxy wheat extrudates exhibited
nearly twice the expansion ratio as that of normal wheat Koumlksel et al (2004) found hulless waxy
barley to be promising for extrusion using low shear screw configuration Van Soest et al (1996)
reported high elongation (500) in extruded maize starch Consequently the adhesive quinoa
varieties have great potential to apply in extruded or other puffed foods
Consumer preference of the sensory attributes was analyzed using Partial Least Square
Regression (PLS) (Figure 4) The attributes presented by lsquoPeruvian Redrsquo including lsquograssyrsquo
aroma lsquograinyrsquo flavors and lsquofirmrsquo and lsquocrunchyrsquo textures were preferred among consumers The
less preferred attributes included lsquopastyrsquo lsquowaterymoistrsquo lsquoadhesiversquo and lsquocohesiversquo all attributes
used to describe the lsquoQQ74rsquo variety Overall acceptance was driven by crunchy texture (r =
090) but negatively correlated with lsquocohesiversquo lsquopastyrsquo and lsquoadhesiversquo texture (r = -096 -087
and -089 respectively) Specifically aroma acceptance of cooked quinoa was negatively
correlated with lsquowoodyrsquo (r = -083) Texture acceptance was positively correlated with lsquofirmrsquo(r =
084) and lsquocrunchyrsquo (r = 094) but was negatively correlated with lsquocohesiversquo (r = -096) lsquopastyrsquo
(r = -095) lsquoadhesiversquo (r = -096) and lsquomoistrsquo (r = -085) Even though lsquoearthyrsquo is a common
attribute in foods such as mushroom and beets this study on quinoa indicated that earthy aroma
and flavor were not the attributes driving consumersrsquo liking of cooked quinoa Color and
appearance did not exhibit significant correlation with color intensity of cooked quinoa
however the varieties with red or dark colors (lsquoPeruvian Redrsquo lsquoBolivian Redrsquo and lsquoBlackrsquo)
were more highly accepted by consumers compared to samples with light color (lsquoTiticacarsquo
lsquoBolivian Whitersquo lsquoQQ74rsquo) In sum consumers preferred cooked quinoa with grassy aroma firm
and crunchy texture and lack of woody aroma and low cohesive pasty or adhesive texture
162
The variety lsquoBlackrsquo was accepted at a similar level as commercial samples in aroma
tasteflavor texture and overall evaluation With a closer examination of the consumer
demographic consumers who were more familiar with quinoa rated the lsquoBlackrsquo quinoa variety
with higher scores (average of 7) compared to those panelists less familiar with quinoa who
assigned lower average scores (59) (Figure 1S) This tricolor quinoa (browndark mixture) is not
as common as red and yellowwhite quinoa in the US market However the potential of tricolor
quinoa may be great due to the relative high consumer acceptance as well as high gain yield in
the field
Instrumental Texture Profile Analysis (TPA)
The physical properties of cooked quinoa were determined using the texture analyzer
(Table 6) Samples differed in all six texture parameters lsquoNL-6rsquo lsquoPeruvian Redrsquo lsquoBolivian Redrsquo
and lsquoCalifornia Tricolorrsquo exhibited the hardest texture while lsquoTemukorsquo lsquoQQ74rsquo lsquoIslugarsquo
lsquoLinaresrsquo and lsquoCO407Daversquo displayed the lowest hardness values Consistent with trained panel
evaluation lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Daversquo were more adhesive than all other varieties
lsquoTiticacarsquo was the springiest variety while lsquoKaslaearsquo and lsquoQuF9P1-20rsquo were the least springy
varieties The commercial samples with the exception of lsquoPeruvian Whitersquo exhibited a more
gummy texture lsquoTiticacarsquo and lsquoBolivian Whitersquo were the chewiest samples In contrast varieties
of lsquoTemukorsquo lsquoQQ74rsquo lsquoIslugarsquo lsquoLinaresrsquo lsquoQuF9P1-20rsquo and lsquoCO407Daversquo showed the least
gummy and chewy texture The result was comparable to an earlier study (Wu et al 2014)
Similarly quinoa varieties with darker color (orangeredbrowndark) tended to yield harder
texture compared to the varieties with light color (whiteyellow) which is caused by the thicker
seed coat in dark colored quinoa In this study adhesive quinoa varieties lsquoQQ74rsquo lsquoLinaresrsquo and
163
lsquoCO407Daversquo were found to have higher adhesiveness values (-17 kgs to -13 kgs) compared
to other varieties previously reported (-029 kgs to 0) (Wu et al 2014)
Correlations of instrumental tests and trained panel evaluations of texture were
significant for hardness and adhesiveness (r = 070 and -063 respectively) (Table 7) Since
adhesiveness was calculated from the first negative peak area of the TPA graph a negative
correlation coefficient was observed but still indicating a high level of agreement between
instrumental and panel tests Springiness tested by TPA was not correlated with texture
attributes
Cohesiveness from the instrumental test was negatively correlated with cohesiveness
from the trained panel texture evaluation (r = -066) Instrumental cohesiveness also exhibited
positive correlations with the trained panel evaluation of firmness and crunchiness (r = 080 and
076 respectively) and negative correlations with pastiness adhesiveness moistness (r = -072
-075 and -082 respectively) Upon a closer examination of the definitions in the instrumental
test cohesiveness was defined as lsquohow well the product withstands a second deformation relative
to its resistance under the first deformationrsquo and is calculated as the ratio of second peak area to
first peak area (Wiles et al 2004) In the sensory lexicon cohesiveness was defined as lsquodegree
to which a substance is compressed between the teeth before it breaksrsquo (Szczesniak 2002) These
differential definitions or explanations of these attributes may have caused the different results
Additionally the gumminess and chewiness from the instrumental evaluation were not
significantly correlated with their counterpart notes from the trained panel evaluations but
correlated with other sensory attributes evaluated by the trained panel Instrumental gumminess
164
was positively correlated with firm and crunchy textures(r = 079 and 078 respectively) but
negatively correlated with cohesive pasty adhesive and moist (r = -067 -068 -075 and -
078 respectively) Additionally a positive correlation was found between instrumental
chewiness and firmness from the panel evaluation (r = 057) whereas negative correlations were
found between instrumental chewiness and panel evaluated cohesiveness pastiness
adhesiveness and moistness (r = -043 -045 -055 and -052 respectively) In the instrumental
texture profile gumminess is calculated by hardness multiplied by cohesiveness and chewiness
is calculated by gumminess multiplied by springiness (Epstein et al 2002) Hence gumminess
was significantly correlated with hardness and cohesiveness and chewiness was significantly
correlated with gumminess In another study of Lyon et al (2000) pasty and adhesive were
expressed as lsquoinitial starchy coatingrsquo and lsquoself-adhesivenessrsquo respectively in cooked rice and
were both negatively correlated with instrumental hardness Generally the instrument test is
more accurate and stable but the parameter or sensory attributes were relatively limited Sensory
panels are able to use various vocabularies to describe the food however accuracy and precision
of panel evaluations were lower than for the instrument Consequently both tools can be
important in sensory evaluation depending on the objectives and resources availability
Future Studies
A lexicon of cooked quinoa was firstly developed in this paper Further discussion and
improvement of the lexicon are necessary and require cooperation with industry and chefs The
lexicon is not only useful in categorizing varieties but also can be used to evaluate post-harvest
practice cooking protocols and other quinoa foodsdishes Additionally quinoa seed quality
varies among years and locations and sensory properties also change over different
165
environments To validate the sensory profile of varieties especially adhesiveness evaluation
should be repeated on the samples from other years and locations Finally multiple dishes food
types should be included in future consumer evaluation studies to identify the best application of
different varieties
Conclusion
A lexicon of cooked quinoa was developed based on aroma tastefavor texture and
color Using the lexicon the trained panel conducted descriptive analysis evaluation on 16
quinoa varieties from field trials and 5 commercial samples Many sensory attributes exhibited
significant differences among quinoa samples especially texture attributes
Consumer evaluations (n = 102) were conducted on six selected samples with diverse
color texture and origin Commercial samples and the variety lsquoBlackrsquo were better accepted by
consumers The adhesive variety lsquoQQ74rsquo was the least accepted quinoa variety in the plain
cooked quinoa dish However because of its cohesive texture lsquoQQ74rsquo shows possible
application in other dishes and foods such as quinoa sushi and extruded snacks Furtherly Partial
Least Square Regression indicated the consumerrsquos preferred attributes were grassy aroma and
firm and crunchy texture while the attributes of pasty adhesive and cohesive were not liked by
consumers
Correlations of panel evaluation and instrumental test were observed in hardness and
adhesiveness However chewiness and gumminess were not significant correlated between panel
test and instrumental test Further training should be addressed to clarify the definitions of
sensory attributes With the assistance and calibration from instruments such as the texture
166
analyzer and electronic tongue panel training can be more efficient and panelists can be more
accurate at evaluation
Acknowledgements
The study was funded by the USDA Organic Research and Extension Initiative
(NIFAGRANT11083982) The authors acknowledge Washington State University Sensory
Facility and their technicians Beata Vixie and Karen Weller The authors also acknowledge
Sergio Nunez de Arco and Sarah Connolly to provide commercial samples Thanks to Raymond
Kinney Max Wood and Hanna Walters who managed the plants harvested the seeds and
collected the data of yield and 1000-seed weight on field trial quinoa varieties Thanks also go to
the USDA-ARS Western Wheat Quality Lab which provided equipment for protein and ash tests
and the texture analyzer
Author contributions
CF Ross and G Wu together designed the study G Wu conducted panel training
collected and processed data and drafted the manuscript KM Murphyrsquos research group provided
the quinoa samples and assisted cleaning process CF Ross CF Morris and KM Murphy edited
the manuscript
167
References
Abugoch LEJ 2009 Chapter 1 quinoa (Chenopodium quinoa Willd) Adv Food Nutr Res
581ndash31
Arco SND Quinoas Calling In Murphy KM Matanguihan J editors Quinoa improvement
and sustainable production Hoboken NJ John Wiley amp Sons Inc p 211
Casas Moreno MM Barreto-Palacios V Gonzalez-Carrascosa R Iborra-Bernad C Andres-Bello
A Martiacutenez-Monzoacute J Garciacutea-Segovia P 2015 Evaluation of textural and sensory properties
on typical spanish small cakes designed using alternative flours J Culinary Sci Technol 13
19-28
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(Waxy) genes J Cereal Sci 35 51-63
Foumlste M Nordlohne SD Elgeti D Linden MH Heinz V Jekle M Becker T Impact of quinoa
bran on gluten-free dough and bread characteristics Eur Food Res Technol 2014 239 767-
75
Furche C Salcedo S Krivonos E Rabczuk P Jara B Fernaacutendez D Correa F 2015 Chapter 41
International quinoa trade In Bazile D Bertero D Nieto C editors State of the art report
on quinoa in 2013 Rome FAO amp CIRAD p 317 ndash 20
Gerber NN1968 Geosmin from microorganisms is trans-1 10-dimethyl-trans-9-decalol
Tetrahedron Lett 9 2971-4
168
Koumlksel H Ryu GH Basman A Demiralp H Ng PK 2004 Effects of extrusion variables on the
properties of waxy hulless barley extrudates FoodNahrung 48 19-24
Kowalski RJ Morris CF Ganjyal GM 2015 Waxy soft white wheat extrusion characteristics
and thermal and rheological propertiesCereal Chem 92 145-53
Koziol MJ 1991 Afrosimetric estimation of threshold saponin concentration for bitterness in
quinoa (Chenopodium quinoa Willd) J Sci Food Agr 54 211-9
Limpawattana M Shewfelt R 2010 Flavor lexicon for sensory descriptive profiling of different
rice types J Food Sci 75 199-205
Lorenz K Coulter L Quinoa flour in baked products Plant Food Hum Nutr 1991 41 213-23
Lyon BG Champagne ET Vinyard BT Windham WR Barton FE Webb BD McKenzie KS
1999 Effects of degree of milling drying condition and final moisture content on sensory
texture of cooked rice Cereal Chem 76 56-62
Lyon BG Champagne ET Vinyard BT Windham WR 2000 Sensory and instrumental
relationships of texture of cooked rice from selected cultivars and postharvest handling
practices Cereal Chem 77 64-9
Meilgaad MC Civille GV Carr BT 2007 Chapter 11 The spectrum descriptive analysis
method In Meilgaad MC Civille GV Carr BT Sensory evaluation techniques Boca Raton
FL CRC Press p 225 ndash 32
169
Meullenet JF Marks BP Hankins JA Griffin VK Daniels MJ 2000 Sensory quality of cooked
long-grain rice as affected by rough rice moisture content storage temperature and storage
duration Cereal Chem 77 259 ndash 63
Mossman AP Fellers DA Suzuki H 1983 Rice stickiness I Determination of rice stickiness
with an Instron tester Cereal Chem 60 286ndash92
Muntildeoz AM 2003 Training time in descriptive analysis In Moskowitz HR Muntildeoz AM and
Gacula MC editors Viewpoints and controversies in sensory science and consumer product
testing Trumbull Food amp Nutrition Press Inc p 351 ndash 6
Peterson AJ Murphy KM 2015 Quinoa cultivation for temperate North America
considerations and areas for investigation In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 173-92
Palmer GH 1994 Chapter 5 Storage In Hoseney RC editor Cereal science and technology
2nd edition St Paul MN American Association of Cereal Chemisty Inc p 107
Pop A Muste S Man S Mureșan C 2014 Improvement of tagliatelle quality by addition of red
quinoa flour Bulletin UASVM Food Sci Tech 71 225-6
Pulvento C Riccardia M Biondib S Orsinic F Jacobsend SE Ragabe R DrsquoAndriaa R Lavinia
A 2015 Chapter 613 Quinoa in Italy research and perspectives In Bazile D Bertero D
Nieto C editors State of the art report on quinoa in 2013 Rome FAO amp CIRAD p 460
Quiroga C Escalera R Aroni G Bonifacio A Gonzaacutelez JA Villca M Saravia R Ruiz A 2015
Chapter 31 Traditional processes and technological innovations in quinoa harvesting
170
processing and industrialization In Bazile D Bertero D Nieto C editors State of the art
report of quinoa in the world in 2013 Rome FAO amp CIRAD p 231
Repo-Carrasco R Espinoza C Jacobsen SE 2003 Nutritional value and use of the Andean
crops quinoa (Chenopodium quinoa) and kantildeiwa (Chenopodium pallidicaule) Food Rev Int
19 179-89
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile
D Bertero D Nieto C editors State of the art report on quinoa in 2013 Rome FAO amp
CIRAD p 67
Sowbhagya CM Ramesh BS Bhattacharya KR 1987 The relationship between cooked-rice
texture and physicochemical characteristics of rice J Cereal Sci 5 287ndash97
Suwannaporn P Linnemann A and Chaveesuk R 2008 Consumer preference mapping for rice
product concepts Brit Food J 110 595-606
Stikic R Glamoclija D Demin M Vucelic-Radovic B Jovanovic Z Milojkovic-Opsenica D
Milovanovic M 2012 Agronomical and nutritional evaluation of quinoa seeds
(Chenopodium quinoa Willd) as an ingredient in bread formulations J Cereal Sci 55 132-8
Szczesniak AS 2002 Texture is a sensory property Food Qual Prefer 13 215-25
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Belton PS JRN Taylor editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science Business Media p 108 ndash 10
171
Tomlins KI Manful JT Larwer P and Hammond L 2005 Urban consumer preferences and
sensory evaluation of locally produced and imported rice in West Africa Food Qual Prefer
16 79-89
Van Soest JJG De Wit D Vliegenthart JFG 1996 Mechanical properties of thermoplastic waxy
maize starch J Appl Polym Sci 61 1927-37
Wang S Opassathavorn A Zhu F 2015 Influence of quinoa flour on quality characteristics of
cookie bread and Chinese steamed bread J Texture Stud 46 281-92
Wiles JL Green BW Bryant R 2004 Texture profile analysis and composition of a minced
catfish product J Texture Stud 35 325-37
Wu G Morris C F Murphy K M 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79 2337-45
172
Table 1-Quinoa samples
Varietya Color Source
Titicaca Yellowwhite Denmark
Black Blackbrown mixture White Mountain Farm Colorado USA
KU-2 Yellowwhite Washington USA
Cahuil Brownorange mixture White Mountain Farm Colorado USA
Red Head Yellowwhite Wild Garden Seed Oregon USA
Cherry Vanilla Yellowwhite Wild Garden Seed Oregon USA
Temuko Yellowwhite Washington USA
QuF9P39-51 Yellowwhite Washington USA
Kaslaea Yellowwhite MN USA
QQ74 Yellowwhite Chile
Isluga Yellowwhite Chile
Linares Yellowwhite Washington USA
Puno Yellowwhite Denmark
QuF9P1-20 Yellowwhite Washington USA
NL-6 Yellowwhite Washington USA
CO407Dave Yellowwhite White Mountain Farm Colorado USA
Bolivian White White Bolivia
Bolivian Red Red Bolivia
California Tricolor
Blackbrown mixture California USA
Peruvian Red Red Peru
Peruvian White White Peru aThe first 16 varieties (Tititcaca ndash CO407Dave) were grown in Chimacum WA
173
Table 2-Lexicon of cooked quinoa as developed by the trained panelists (n = 9)
Attribute Intensitya Reference Definition
Aroma
Caramel 10 1 piece of caramel candy (Kraft) (81 g) in 100 mL water
Aromatics associated with caramel tastes
Grain-like 10 Cooked brown rice (15 g) (Great Value)
Rice like wheaty sorghum like
Bean-like 8 Cooked red bean (10 g) (Great Value)
Aromatics associated with cooked beans or bean protein
Nutty 10 Dry roasted peanuts (10 g) (Planters)c
Aromatics associated with roasted nuts
Buttery 10 Unsalted butter (1cm1cm01cm) (Tillamook)c
Aromatics associated with natural fresh butter
Starchy 10 Wheat flour water (11 ww) (Great Value)c
Aromatics associated with the starch
Grassygreen 9 Fresh cut grass collected 1 h before usingc
Aromatics associated with grass
Earthymusty 8 Sliced raw button mushrooms (fresh cut)c
Aromatic reminiscent of decaying vegetative matters and damp black soil root like
Woody 7 Toothpicks (20)c Aromatics reminiscent of dry cut wood cardboard
TasteFlavor
Sweet 3 9 2 and 5 (ww) sucrose solution (CampH pure cane sugar)b
Basic taste sensation elicited by sugar
Bitter 5 8 mgL quinine sulfate acid (Sigma)
Basic taste sensation elicited by caffeine
174
Grain-like 10 Cooked brown rice (Great Value)
Tasted associated with cooked grain such as rice
Bean-like 10 Cooked red beans (Great Value)
Beans bean protein
Nutty 10 Dry roasted peanut (Planters)c Taste associated with roasted nuts
Earthy 7 Sliced raw button mushrooms (fresh)
Taste associated with decaying vegetative matters and damp black soil
Toasted 10 Toasted English muffin (at 6 of a toaster) (Franze Original English Muffin)
Taste associated with toast
Texturee
Soft - Firm 3
7
Firm tofu (Azumaya)b
Brown rice (Great Value)
Force required to compress a substance between molar teeth (in the case of solids) or between tongue and palate (in the case of semi-solids)d
Separate - Cohesive
15
7
Cracker (Premium unsalted cracker)
Cake (Sponge cake Walmart Bakery)
Degree to which a substance is compressed between the teeth before it breaks
Pasty
10 Mashed potato (Great Value Mashed Potatoes powder)
Smooth creamy pulpy slippery
Adhesiveness sticky
10
3
Sticky rice (Koda Farms Premium Sweet Rice)
Brown rice (Great Value)
Force required to remove the material that adheres to the mouth (the palate and teeth) during the normal eating process
Crunchy 13 Thick cut potato chip (Tostitos Restaurant Style
Force with which a sample crumbles cracks or shatters
175
Tortilla Chips)b
Chewygummy
15
7
Gummy Bear (Haribo Gold-Bears mixed flavor)
Brown rice (Great Value)
Length of time (in sec) required to masticate the sample at a constant rate of force application to reduce it to a consistency suitable for swallowing
Astringent 12
6
Tannic acid (2gL)
Tannic acid (1gL) (Sigma)
Puckering or tingling sensation elicited by grape juice
Waterymoist 10
3
Salad tomato (Natural Sweet Cherubs)
Brown rice (Great Value)
Degree of wet or dry
Color
Red 4 9
N-W8M Board Walke
N-W16N Ballet Barree
Yellow 3 10
15B-2U Sandy Toese 15B-7
N Summer Harveste
Black 3 10
N-C32N Strong Influencee N-C4M Trench Coate
aReference intensities were based on a 15-cm scale with 0 = extremely low and 15 = extremely high bMeilgaad et al (2007) cLimpawattana and Shewfelt (2010) dTexture definitions in Szczesniak (2002) were used eAce Hardware color chip
176
Table 3-Significance and F-value of the effects of panelist replicate and quinoa variety on aroma flavor and texture of cooked quinoa as determined using a trained panel (n = 9)
Attribute Panelist Replicate Quinoa Variety PanelistVariety
Aroma
Caramel 26548 093 317 174
Grain-like 7338 000 125 151
Bean-like 7525 029 129 135
Nutty 6274 011 322 118
Buttery 21346 003 301 104
Starchy 12094 1102 094 135
Grassy 17058 379dagger 282 162
Earthy 12946 239 330 198
Woody 13178 039 269 131
TasteFlavor
Sweet 6745 430 220 137
Bitter 9368 1290 2059 236
Grain-like 7681 392 222 206
Bean-like 7039 122 142 141
Nutty 7209 007 169 153
Earthy 9313 131 330 177
Toasted 10975 015 373 184
Texture
Firm 1803 022 1587 141
Cohesive 14750 011 656 208
Pasty 3919 2620 1832 205
Adhesive 2439 287dagger 5740 183
177
Crunchy 13649 001 1871 167
Chewy 3170 870 150dagger 167
Astringent 10183 544 791 252
Waterymoist 10281 369dagger 1809 164
daggerP lt 010 P lt 005 P lt 001 P lt 0001
178
Table 4-Mean separation of significant tasteflavor attributes of cooked quinoa determined by the trained panel Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Sweet Bitter Grain-like Nutty Earthy Toasty
Titicaca 40cdef1 39bcde 73abc 51abcdef 44bcdef 47abcd
Black 36f 42bcd 69bcde 49def 52a 46abcd
KU2 41bcdef 38cde 73abc 52abcdef 40fg 44bcdefg
Cahuil 41abcdef 44b 70bcde 50abcdef 48abc 51a
Red Head 42abcd 43bc 72abcd 51abcdef 42defg 44bcdefg
Cherry Vanilla 40def 52a 66e 48ef 44bcdef 40fghi
Temuko 36ef 56a 68cde 47f 43cdef 40ghi
QuF9P39-51 47a 34e 73abc 48def 40efg 46abcde
Kaslaea 47ab 39bcde 70bcde 55ab 44bcdef 45bcdefg
QQ74 40def 38cde 66e 50abcdef 45bcde 42defghi
Isluga 41bcdef 41bcd 69cde 55a 46bcd 47abcd
Linares 39def 40bcd 65e 49cdef 43def 38i
Puno 44abcd 39bcde 72abcd 51abcdef 45bcde 43cdefghi
QuF9P1-20 42abcdef 43bc 69bcde 53abcd 45bcde 38i
NL-6 38def 37de 72abcd 55a 45bcd 44bcdefgh
CO 407 Dave 41bcdef 40bcd 67de 51abcdef 41defg 39hi
Bolivian White 47ab 22f 69bcde 50bcdef 42def 41efghi
Bolivian Red 42abcde 24f 72abcd 53abcdef 43cdef 46bcde
California Tricolor 40def 27f 74ab 53abcde 48ab 48ab
Peruvian Red 43abcd 25f 75a 48ef 45bcde 47abc
Peruvian White 46abc 26f 70bcde 55abc 37g 45bcdef
179
Table 5-Mean separation of consumer preference Different letters within a column indicate consumer evaluation scores were different among quinoa samples at P lt 005
Samples Aroma Color Appearance TasteFlavor Texture Overall
Black 56a 63b 61bc 61abc 65a 63ab
QQ74 61a 56c 53d 56c 53b 53c
Titicaca 60a 57bc 56cd 58bc 63a 59bc
Peruvian Red 60a 72a 70a 65a 68a 67a
Bolivian Red 60a 69a 66ab 64ab 67a 64ab
Bolivian White 57a 59bc 58c 62ab 63a 62ab
180
Table 6-Hardness adhesiveness cohesiveness springiness gumminess and chewiness of the cooked quinoa samples as determined using Texture Profile Analysis (TPA)
Variety Hardness
(kg)
Adhesiveness
(kgs)
Cohesiveness Springiness Gumminess
(kg)
Chewiness
(kg)
Titicaca 505abc1 -02ab 08abc 15a 384bc 599a
Black 545ab -01a 07bcd 10abc 404abc 404ab
KU-2 490abcd -01a 07bcd 09abc 363bcd 332abc
Cahuil 464bcde -01a 07bcd 08abc 344cd 281bc
Red Head 412defg -03ab 06ef 09abc 246ef 225bc
Cherry Vanilla 391efgh -02ab 05fgh 08abc 208fg 178bc
Temuko 328gh -09c 04hi 08abc 147g 120c
QuF9P39-51 451cde -02ab 07de 10abc 297de 272bc
Kaslaea 493abcd -02ab 07bcd 06c 359cd 227bc
QQ74 312h -17e 04i 09abc 132g 119c
Isluga 362fgh -05b 05ghi 08abc 171fg 137bc
Linares 337gh -16de 05ghi 09abc 159g 146bc
Puno 504abc -01a 06ef 10abc 301de 301bc
QuF9P1-20 438cdef -02ab 06fg 05c 242ef 137bc
NL-6 555a -01a 07cde 09abc 376bcd 350abc
CO407Dave 357fgh -13d 04hi 09abc 160g 141bc
Bolivian White 441cdef -01ab 05fg 14ab 242ef 340abc
Bolivian Red 572a -01ab 08ab 14ab 440ab 593a
California Tricolor
572a -01a 08a 08bc 477a 361abc
Peruvian Red 568a 00a 08ab 08abc 439ab 342abc
Peruvian White 459bcde -01a 08abc 11abc 347cd 394abc
181
Table 7-Correlation of trained panel texture evaluation data and instrumental TPA over the 21 quinoa varieties
Variables Hardness Adhesiveness Cohesiveness Gumminess Chewiness Firm 070 059 080 079 057 Cohesive -060 -051 -066 -067 -043 Pasty -060 -070 -072 -068 -045 Adhesive -067 -063 -075 -075 -055 Crunchy 072 054 076 078 055 Moist -066 -066 -082 -078 -052
daggerP lt 01 P lt 005 P lt 001 P lt 0001
182
Figure 1-Principal component Analysis (PCA) biplot of aroma evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil Red Head
Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white Kaslaea
QQ74
Isluga
Linares
Puno
QuF9P1-20 NL-6
CO 407 Dave
Bolivia white
Bolivia red California Tricolor
Caramel Grain-like
Bean-like Nutty
Buttery Starchy
Grassy
Earthy
Woody
-25
-2
-15
-1
-05
0
05
1
15
2
-3 -25 -2 -15 -1 -05 0 05 1 15 2 25 3 35 4
F2 (2
455
)
F1 (4234 )
183
Figure 2-Principal component Analysis (PCA) biplot of tasteflavor evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil
Red Head Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white
Kaslaea
QQ74 Isluga
Linares
Puno
QuF9P1-20
NL-6
CO 407 Dave
Bolivia white
Bolivia red
California Tricolor
Sweet
Bitter Grain-like
Bean-like
Nutty
Earthy
Toasted
-3
-2
-1
0
1
2
3
-4 -3 -2 -1 0 1 2 3 4 5
F2 (3
073
)
F1 (3391 )
184
Figure 3-Principal component Analysis (PCA) biplot of texturemouthfeel evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil
Red Head Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white
Kaslaea
QQ74 Isluga
Linares
Puno
QuF9P1-20
NL-6
CO 407 Dave
Bolivia white
Bolivia red California Tricolor
Firm Cohesive
Pasty
Adhesive
Crunchy
Chewy Astringent
Moist
-2
-15
-1
-05
0
05
1
15
2
25
-3 -25 -2 -15 -1 -05 0 05 1 15 2 25 3 35
F2 (2
212
)
F1 (5959 )
185
Figure 4-Partial Least Squares (PLS) biplot correlating aroma color appearance tasteflavor texture and overall attributes evaluated by the trained panel (n = 9) to the consumer panel (n = 102) for 6 cooked quinoa samples (Consumer acceptances are in bold italics)
Grainy aroma
Beany aroma
Nutty aroma
Buttery
Starchy
Grassy
Earthy
Woody
Sweet
Bitter grainy flavor
Beany flavor
Earthy flavor Nutty flavor
Toasty
Firm Cohesive
Pasty
Adhesive
Crunchy
Chewy
Astringent
Waterymoist
Aroma
Color Appearance TasteFlavor
Texture Overall
Black
Bolivia red
QQ74
Bolivia white
Commercial Red
Titicaca
-1
-075
-05
-025
0
025
05
075
1
-1 -075 -05 -025 0 025 05 075 1
t2
t1
186
Supplementary tables
Table 1S-Mean separation of significant aroma attributes of cooked quinoa determined by the trained panel (n = 9) Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Caramel Nutty Buttery Green Earthy Woody
Titicaca 59a1 60a 45abc 39fg 42defgh 37cdef
Black 46g 50efg 38ef 47abc 54a 46a
KU2 50efg 51defg 41cdef 40efg 38h 35ef
Cahuil 56abc 53bcdefg 43abcd 49a 48b 39bcde
Red Head 55abcd 60a 45abc 44bcde 46bcd 41bc
Cherry Vanilla 52cdef 54bcdef 43abcde 43bcdef 46bcdef 37bcdef
Temuko 55abcd 56abcde 44abc 40defg 41efgh 37bcdef
QuF9P39-51 58ab 60a 46ab 42bcdefg 44bcdefg 36def
Kaslaea 53bcde 55abcde 42abcde 41defg 40gh 37bcdef
QQ74 50efg 48fg 39def 42defg 45bcdef 38bcdef
Isluga 52cdef 57abc 43abcd 43bcdefg 46bcde 39bcde
Linares 52cdef 54bcdef 42bcde 38g 44bcdefg 37cdef
Puno 56abc 56abcde 46ab 42cdefg 46bcdef 38bcdef
QuF9P1-20 53bcdef 58ab 44abcd 42cdefg 44bcdefg 40bcd
NL-6 57abc 53bcdefg 44abcd 39fg 44bcdefg 35def
CO 407 Dave 51def 54abcde 46ab 40efg 42defgh 34f
Bolivian White 53bcde 57abcd 46ab 43bcdef 43cdefgh 39bcd
Bolivian Red 52cdef 51defg 42bcde 43bcdefg 44bcdefg 37bcdef
California Tricolor 54abcde 51cdefg 38ef 44abcd 48bc 41ab
Peruvian Red 48fg 48g 36f 47ab 46bcdef 38bcdef
Peruvian White 54abcde 60a 48a 45abcd 41fgh 40bc
187
Table 2S-Mean separation of significant texture attributes of cooked quinoa determined by the trained panel Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Firm Cohesive Pasty Adhesive Crunchy Astringent Moist
Titicaca 70ab 63efgh 37ghi 37ghi 56bc 47d 38hij
Black 71ab 63efgh 32i 38ghi 58b 55abc 35jk
KU2 66bcd 64efg 38fghi 37ghi 49de 46de 38hij
Cahuil 68abc 61fghi 37ghi 36hi 56bc 55ab 37ij
Red Head 57fgh 68bcde 46cde 49d 45ef 55ab 48de
Cherry Vanilla 56gh 65cdef 49c 44def 43fg 55ab 49de
Temuko 49ij 70abcd 56b 57c 39gh 59a 51cd
QuF9P39-51 61defg 65def 47cd 40efgh 48def 48cd 42fgh
Kaslaea 60defg 62fghi 40defgh 40fgh 51cd 51bcd 42gh
QQ74 44j 70abc 60ab 81ab 37hi 46def 57ab
Isluga 52hi 66cdef 43cdef 55c 44efg 50bcd 48de
Linares 45j 75a 65a 86a 33i 47d 61a
Puno 58efgh 60fghij 41defg 43efg 52cd 47d 47def
QuF9P1-20 52hi 65def 43cdefg 46de 44fg 55ab 47defg
NL-6 64cde 61fghi 40efgh 41efgh 51cd 46de 46efg
CO 407 Dave 45j 72ab 59ab 80b 35hi 47d 55bc
Bolivian White 56gh 61fghi 38fghi 41efgh 50de 34g 48de
Bolivian Red 62cdef 59hij 34hi 36hi 56bc 38g 42fgh
California Tricolor 68abc 56j 32i 33i 60ab 39efg 39hij
Peruvian Red 74a 57ij 35hi 33i 64a 39fg 31k
Peruvian White 60defg 59ghij 38fghi 37hi 48def 34g 40hi
188
Figure-1S Demographic influence on preference of variety lsquoBlackrsquo
75a
66ab 61bc
54c
61bc
0
1
2
3
4
5
6
7
8
75 50 25 None Other
Liking score of lsquoBlackrsquo
Proportion of organic food consumption
52b
64a 65a 69a 70a
57ab 59ab
0
1
2
3
4
5
6
7
8
Everyday 4-5 timesper week
2-3 timesper week
Once aweek
A fewtimes per
month
Aboutevery 6months
Other
Liking score of lsquoBlackrsquo
Frequency of rice consumption
189
Chapter 7 Conclusions
Quinoa quality is a complex topic with seed composition influencing sensory and
physical properties This dissertation evaluated the seed characteristics composition flour
properties and cooking quality of 13 quinoa samples Differences in seed morphology and
composition contributed to the texture of cooked quinoa The seeds with higher raw seed
hardness lower bulk density or higher seed coat proportion yielded a firmer gummier and
chewier texture after cooking Higher protein content correlated with harder more adhesive
more cohesive gummier and chewier texture of cooked quinoa Additionally flour peak
viscosity breakdown final viscosity and setback exhibited influence on different texture
parameters Cooking time and water uptake ratio also significantly influence the texture whereas
cooking loss did not show any correlation with texture Starch characteristics also significantly
differed among quinoa varieties (Chapter 3) Amylose content ranged from 27 to 169
among 13 quinoa samples The quinoa samples with higher amylose proportion or higher starch
enthalpy tended to yield harder stickier more cohesive and chewier quinoa These studies on
seed quality seed characteristics compositions and cooking quality provided useful information
to food industry professionals to use in the development of quinoa products using appropriate
quinoa varieties Indices such protein content and flour viscosity (RVA) can be quickly
determined and exhibited strong correlations with cooked quinoa texture Furthur study should
develop a prediction model using protein content or RVA parameters to predict the texture of
cooked quinoa In this way food manufactures can quickly predict the texture or functionality of
quinoa varieties and then determine their specific application Moreover many of the test
methods were using the methods used in rice such as kernel hardness texture of cooked quinoa
190
thermal properties (DSC) and cooking qualities Such methods should be standardized in near
future as those defined by AACC (American Association of Cereal Chemists) The development
of standard methods allows for easier comparisons among different studies In Chapter 4 the
seed quality response to soil salinity and fertilization was studied Quinoa protein content
increased under high Na2SO4 concentration (32 dS m-1) The variety lsquoQQ065rsquo maintained similar
levels of hardness and density under salinity stress and is considered to be the best adapted
variety among four varieties The variety can be applied in salinity affected areas Future studies
can be applied on salinity drought influence on quinoa amino acids profile starch composition
fiber content and saponins content
Sensory evaluation of cooked quinoa was further examined in Chapter 5 Using a trained
panel the lexicon for cooked quinoa was developed Using this lexicon the sensory profiles of
16 field trial varieties and 5 commercial quinoa samples were generated Varietal differences
were observed in the aromas of caramel nutty buttery grassy earthy and woody tasteflavor of
sweet bitter grain-like nutty earthy and toasty and texture of firm cohesive pasty adhesive
crunchy chewy astringent and moist Subsequent consumer evaluation on 6 selected quinoa
samples indicated lsquoPeruvian Redrsquo was the most accepted overall whereas a sticky variety lsquoQQ74rsquo
was the least accepted Partial least square analysis using trained panel data and consumer
acceptance data indicated that overall consumer liking was driven by grassy aroma and firm and
crunchy texture The lexicon and the attributes driving consumer-liking can be utilized by
breeders and farmers to evaluate their quinoa varieties and products The information is also
useful to the food industry to evaluate ingredients from different locations and years improve
processing procedures and develop products
191
Overall the dissertation provided significant information of quinoa seed quality and
sensory characteristics among different varieties including both commercialized samples and
field trial samples not yet available in market Several quinoa varieties increasingly grown in
US were included in the studies The variety lsquoCherry Vanillarsquo and lsquoTiticacarsquo are among the
varieties gaining the best yields in US Their seed characteristics and sensory attributes
described in this dissertation should be helpful for industry professionals in their research and
product development Varieties include lsquoTiticacarsquo lsquoCherry Vanillarsquo and lsquoBlackrsquo Additionally
important tools were developed in quinoa evaluation including texture analysis using TPA and
the lexicon of cooked quinoa
As with any set of studies other research questions arise to be addressed in future
research First saponins the compounds introducing bitter taste in quinoa require further study
Sweet quinoa varieties (saponins content lt 011) should be bred and adapted to the US
Although many consumers may like the bitter taste and especially the potential health benefits of
saponins it is important to provide consumers choices of both bitter and non-bitter quinoa types
To assist the breeding of sweet quinoa genetic markers can be developed and associated with the
phenotype of saponin content As for the methods testing saponin content the foam method is
quick but not accurate whereas the GC method is accurate but requires long sample preparation
time and high capital investment An accurate more affordable and more efficient method such
as one using a spectrophotometer should be developed
Second one important nutritional value of quinoa is the balanced essential amino acids
The essential amino acids profiles change according to environment (drought and saline soil)
quinoa variety and processing (cleaning milling and cooking) and these changes should be
192
further studied It is important to prove quinoa seed maintains the rich essential amino acids even
growing under marginal conditions or being subjected to cleaning processes such as abrasion
and washing
Third betalains are the compounds contributing to the color of quinoa seed and providing
potential health benefits Betalain content type (relate to diverse colors) and their genetic loci in
quinoa can be further investigated Color diversity is one of the attractive properties in quinoa
seeds However the commercialized quinoa samples are in white or red color while more quinoa
varieties present orange purple brown and gray colors More choices of quinoa colorstypes
may attract more consumers
Finally sensory evaluation of quinoa varieties should be applied to the samples from
multiple years and locations since environment can significantly influence the sensory attributes
Also in addition to plain cooked quinoa more quinoa dishes can be involved in consumer
acceptance studies as different quinoa varieties may be suitable for various dishes
ii
To the Faculty of Washington State University
The members of the Committee appointed to examine the dissertation of GEYANG WU find it satisfactory and recommend that it be accepted
_________________________________ Carolyn F Ross PhD Co-Chair
_________________________________
Craig F Morris PhD Co-Chair
_________________________________ Barbara Rasco PhD
_________________________________
Kevin M Murphy PhD
iii
ACKNOWLEDGMENT
This dissertation is accomplished with a lot of collaborations of Food Science USDA-
ARS Western Wheat Quality Lab and Crop Science I gained significant advice and help from
my co-chairs and co-advisors Dr Craig Morris and Dr Carolyn Ross as well as my committee
members Dr Barbara Rasco and Dr Kevin Murphy Working with them on research proposals
experiments data processing and editing manuscripts I learned so much from scientific
philosophy critical thinking and efficient argument to scientific writing skills This dissertation
could never have been accomplished without their professional patient and persistent work
Additionally I owe thanks to many lab members who provided important help with the
experiments From the USDA-ARS Western Wheat Quality Lab Bozena Paszczynska who is no
longer with us trained me on most of the flour testing equipment Patrick Fuerst Alecia
Kiszonas Douglas Engle and Eric Wegner helped with experimental methods manuscript
preparation milling and equipment maintenance From the WSU Sensory Evaluation Lab Beata
Vixie Karen Weller Charles Diako and Ben Bernhard provided help in sensory study
preparation and serving From the WSU Sustainable Seed System Lab Max Wood Janet
Matanguihan Hannah Walters Adam Peterson Raymond Kinney Cedric Habiyaremye
Leonardo Hinojosa and Kristofor Ludvigson helped with quinoa field work (planting weeding
harvesting) post-harvest cleaning and greenhouse management I feel grateful to have met so
many brilliant and kind people and it is a pleasant journey to work with them and develop
friendships with them
Finally thanks to my family and friends Their understanding and support helped me
sincerely enjoy life and work during the past four years
iv
QUINOA SEED QUALITY AND SENSORY EVALUATION
Abstract
by Geyang Wu PhD Washington State University
May 2016
Co-Chairs Carolyn F Ross Craig F Morris
Quinoa is a grain that has garnered increasing interest in recent years from global
markets as well as in academic research The studies in this dissertation focused on quinoa seed
quality and sensory evaluation among diverse quinoa varieties with potential adaptation to
growing conditions in Washington State The objectives in the dissertation were to study quinoa
seed quality as well as the sensory attributes of cooked quinoa as defined by both trained and
consumer panelists Regarding quinoa seed quality we investigated seed characteristics
(diameter weight density hardness seed coat proportion) seed composition (protein and ash
content) flour viscosity and thermal properties quinoa cooking quality and texture of cooked
quinoa Additionally the functional characteristics of quinoa were studied including the
determination of amylose content starch swelling power and water solubility texture of starch
gel and starch thermal properties Results indicated texture of cooked quinoa was significantly
influenced by protein content flour viscosity quinoa cooking quality amylose content and
starch enthalpy In addition the influences of soil salinity and fertility on quinoa seed quality
were evaluated The variety lsquoQQ065rsquo exhibited increased protein content and maintained similar
levels of hardness and density under salinity stress and is considered to be the best adapted
v
variety among four varieties Finally sensory evaluation studies on cooked quinoa were
conducted A lexicon of cooked quinoa was developed including the sensory attributes of aroma
tasteflavor texture and color Results from the trained and consumer panel indicated that
consumer liking of quinoa was positively influenced by grassy aroma and firm and crunchy
texture These results represent valuable information to quinoa breeders in the determination of
seed quality of diverse quinoa varieties In the food industry the results of seed quality and
sensory studies (lexicon and consumer-liking) can be utilized to evaluate quinoa ingredients from
multiple locations or years determine the efficiency of post-harvest processing and develop
appropriate products according to the properties of the specific quinoa variety Overall this
dissertation contributed to the growing body of research describing the chemical physical and
sensory properties of quinoa
vi
TABLE OF CONTENTS
Page
ACKNOWLEDGMENTS iii
ABSTRACT iv-v
LIST OF TABLES ix-xi
LIST OF FIGURES xii-xiii
CHAPTERS
1 Introduction 1
References 6
2 Literature review 9
References 26
Tables 41
Figures44
3 Evaluation of texture differences among varieties of cooked quinoa 46
Abstract 46
Introduction 48
Materials and Methods 51
Results 54
Discussion 60
vii
Conclusion 63
References 65
Tables 71
Figures78
4 Quinoa starch characteristics and their correlation with
texture of cooked quinoa 80
Abstract 80
Introduction 81
Materials and Methods 82
Results 87
Discussion 95
Conclusion 102
References 103
Tables 109
5 Quinoa seed quality response to sodium chloride and
Sodium sulfate salinity 118
Abstract 118
Introduction 120
Materials and Methods 122
Results 125
Discussion 123
viii
Conclusion 132
References 134
Tables 139
Figure 145
6 Lexicon development and sensory attributes of cooked quinoa 146
Abstract 146
Introduction 148
Materials and Methods 150
Results and Discussion 155
Conclusion 165
References 167
Tables 172
Figures183
7 Conclusions 189
ix
LIST OF TABLES
Page
CHAPTER 2
Table 1 Essential amino acid of quinoa protein and FAOWHO suggested requirement (mgg
protein) 41
Table 2 Quinoa vitamin content (mg100g) 42
Table 3 Quinoa mineral content (mgmg ) 43
CHAPTER 3
Table 1 Varieties of quinoa used in the experimenthelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip71
Table 2 Seed characteristics and composition 72
Table 3 Texture profile analysis (TPA) of cooked quinoa 73
Table 4 Cooking quality of quinoa 74
Table 5 Pasting properties of quinoa flour by RVA 75
Table 6 Thermal properties of quinoa flour by Differential Scanning Calorimetry (DSC) 76
Table 7 Correlation coefficients between quinoa seed characteristics composition and
processing parameters and TPA texture of cooked quinoa 77
CHAPTER 4
Table 1 Quinoa varieties tested 109
Table 2 Starch content and composition 110
Table 3 Starch properties and α-amylase activity 111
Table 4 Texture of starch gel 112
Table 5 Thermal properties of starch 113
x
Table 6 Pasting properties of starch 114
Table 7 Correlation coefficients between starch properties and texture of cooked quinoa 115
Table 8 Correlations between starch properties and seed DSC RVA characteristics 116
CHAPTER 5
Table 1 Analysis of variance with F-values for protein content hardness and density of quinoa
seed 139
Table 2 Salinity variety and fertilization effects on quinoa seed protein content () 140
Table 3 Salinity variety and fertilization effects on quinoa seed hardness (kg) 141
Table 4 Salinity variety and fertilization effects on quinoa seed density (g cm3) 142
Table 5 Correlation coefficients of protein hardness and density of quinoa seed 143
Table 6 Correlation coefficients of quinoa seed quality and agronomic performance and seed
mineral content144
CHAPTER 6
Table 1 Quinoa samples 172
Table 2 Lexicon of cooked quinoa as developed by the trained panelists (n = 9) 173
Table 3 Significance and F-value of the effects of panelist replicate and quinoa variety on
aroma flavor and texture of cooked quinoa as determined using a trained panel (n = 9) 176
Table 4 Mean separation of significant tasteflavor attributes of cooked quinoa determined by
the trained panel Different letters within a column indicate attribute intensities were different
among quinoa samples at P lt 005 as determined using Fisherrsquos LSD 178
Table 5 Mean separation of consumer preference Different letters within a column indicate
consumer evaluation scores were different among quinoa samples at P lt 005 179
xi
Table 6 Hardness adhesiveness cohesiveness springiness gumminess and chewiness of the
cooked quinoa samples as determined using Texture Profile Analysis (TPA) Different letters
within a column indicate attribute intensities were different among quinoa samples at P lt 005
180
Table 7 Correlation of trained panel texture evaluation data and instrumental TPA over the 21
quinoa varieties 181
Table 1S Mean separation of significant aroma attributes of cooked quinoa determined by the
trained panel (n = 9) Different letters within a column indicate attribute intensities were different
among quinoa samples at P lt 005 as determined using Fisherrsquos LSD 186
Table 2S Mean separation of significant texture attributes of cooked quinoa determined by the
trained panel Different letters within a column indicate attribute intensities were different among
quinoa samples at P lt 005 as determined using Fisherrsquos LSD 187
xii
LIST OF FIGURES
Page
CHAPTER 2
Figure 1 Quinoa seed section and two-layered pericarp under perianth (Wu et al 2014) 44
Figure 2 Figure 2-Quinoa seed structure (Prego et al 1998) 45
CHAPTER 3
Figure 1 Rapid Visco Analyzer (RVA) graph of lsquoCherry Vanillarsquo and lsquoRed Commercialrsquo quinoa
flours 78
Figure 2 Seed coat image by SEM 79
CHAPTER 5
Figure 1 Protein content () of quinoa in response to combined fertility and
salinity treatments 145
CHAPTER 6
Figure 1 Principal component Analysis (PCA) biplot of aroma evaluations by the trained
sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 182
Figure 2 Principal component Analysis (PCA) biplot of tasteflavor evaluations by the trained
sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 183
xiii
Figure 3 Principal component Analysis (PCA) biplot of texturemouthfeel evaluations by the
trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 184
Figure 4 Partial Least Squares (PLS) biplot correlating aroma color appearance tasteflavor
texture and overall attributes evaluated by the trained panel (n = 9) to the consumer panel (n =
102) for 6 quinoa samples (Consumer acceptances are in bold italics) 185
Figure-1S Demographic influence on preference of variety lsquoBlackrsquo 188
xiv
Dedication
This dissertation is dedicated to those who are interested in quinoa
the beautiful small grain providing nutrition and fun
1
Chapter 1 Introduction
Quinoa is growing rapidly in the global market largely due to its high nutritional value
and potential application in a wide range of products Bolivia and Peru are the major producers
and exporters of quinoa In Peru production increased from 31824 MT (Metric Ton) in 2007 to
108000 MT in 2015 (USDA 2015) In 2013 organic quinoa from Bolivia and Peru were sold at
averages of $8000MT and $7000MT respectively (Nuntildeez de Acro 2015) Of all countries the
US and Canada import the most quinoa and comprise 53 and 15 of the global imports
respectively (Carimentrand et al 2015) Quinoa yield is on average 600 kgha with yield
varying greatly and among varieties and environments (Garcia et al 2004) The total production
cost is $720ha in the southern Altiplano region of Bolivia and the farm-gate price reached
$60kg in 2013 (Nuntildeez de Acro 2015) With 2600 kg annual quinoa yield in a small 3 ha farm
the revenue would be $15390 which could potentially raise a family out of poverty (Nuntildeez de
Acro 2015)
Quinoa possesses many sensory properties Food texture refers to those qualities of a
food that can be felt with the fingers tongue palate or teeth (Sahin and Sumnu 2006) Texture is
one of most significant properties of food products Quinoa has unique texture ndash creamy smooth
and a little crunchy (James 2009) The texture of cooked quinoa is not only influenced by seed
structure but also determined by compounds such as starch and protein However publications
describing the texture of cooked quinoa are limited
Seed characteristics and structure are important factors influencing the textual properties
of cooked quinoa seed Quinoa is a dicotyledonous plant species very different from
2
monocotyledonous cereal grains The majority of the seed is the middle perisperm of which cells
have very thin walls and angular-shaped starch grains (Prego et al 1998) The two-layer
endosperm of the quinoa seed consists of living thick-walled cells rich in proteins and lipids but
without starch The protein bodies found in the embryo and endosperm lack crystalloids and
contain one or more globoids of phytin (Prego 1998) Given the structure of quinoa the seed
properties such as seed size hardness and seed coat proportion may influence the texture of the
cooked quinoa Nevertheless correlations between seed characteristics seed structure and
texture of cooked quinoa have not been performed
Beside the physical properties of seed the seed composition will influence the texture as
well Protein and starch are the major components in quinoa while their correlation to texture
has not been studied Starch characteristics and structures significantly influence the texture of
the end product Starch granules of quinoa is very small (1-2μm) compared to that of rice and
barley (Tari et al 2003) Quinoa starch is lower in amylose content (11 of starch) (Ahamed
1996) which may yield the hard texture Chain length of amylopectin also influences hardness of
food product (Ong and Blanshard 1995) In sum the influence of quinoa seed composition and
characteristics on cooked product should be studied
In addition to seed quality and characteristics the sensory attributes of quinoa are also
significant as they influence consumer acceptance and the application of the quinoa variety
However there is a lack of lexicon to describe the sensory attributes of cooked quinoa Rice is
considered as a model when studying quinoa sensory attributes because they are cooked in
similar ways The lexicon of cooked rice were developed and defined in the study of Champagne
3
et al (2004) Sewer floral starchygrain hay-likemusty popcorn green beans sweet taste
sour and astringent were among those attributes
Consumer acceptance is of great interested to breeders farmers and the food industry
Acceptability of quinoa bread was studied by Rosell et al (2009) and Chlopicka et al (2012)
Gluten free quinoa spaghetti (Chillo et al 2008) and dark chocolate with 20 quinoa
(Schumacher et al 2010) were evaluated using a sensory panel However cooked quinoa the
most common way of consuming quinoa has not been studied for its sensory properties and
consumer preference Additionally consumer acceptance of quinoa may be influenced by the
panelistsrsquo demographic such as origin food culture familiarity with less common grains and
quinoa and opinion of a healthy diet Furthermore compared to instrumental tests sensory
evaluation tests are generally more expensive and time consuming hence correlations of sensory
panel and instrumental data are of interest If correlations exist instrumental analyses can be
used to substitute or complement sensory panel evaluation
Based on the above discussion this dissertation focused on the study of seed
characteristics quality and texture of cooked quinoa and starch characteristics among various
quinoa varieties Seed quality under saline soil conditions was also investigated To develop the
sensory profiles of cooked quinoa a trained panel developed and validated a lexicon for cooked
quinoa while a consumer panel evaluated their acceptance of different quinoa varieties From
these data the drivers of consumer liking were determined
The dissertation is divided into 7 chapters Chapter 1 is an introduction of the topic and
overall objectives of the studies Chapter 2 provides a literature review of recent progress in
4
quinoa studies including quinoa seed structure and compositions physical properties flour
properties health benefits and quinoa products Chapter 3 was published in Journal of Food
Science under the title of lsquoEvaluation of texture differences among varieties of cooked quinoarsquo
The objectives of Chapter 3 were to study the texture difference among varieties of cooked
quinoa and evaluate the correlation between the texture and the seed characters and
composition cooking process flour pasting properties and thermal properties
Chapter 4 includes the manuscript entitled lsquoQuinoa starch characteristics and their
correlation with texture of cooked quinoarsquo The objectives of Chapter 4 were to determine starch
characteristics of quinoa among different varieties and investigate the correlations between the
starch characteristics and cooking quality of quinoa
Chapter 5 has been submitted to Frontier in Plant Science under the title lsquoQuinoa seed
quality response to sodium chloride and sodium sulfate salinityrsquo In Chapter 5 quinoa seed
quality grown under salinity stress was assessed Four quinoa varieties were grown under six
salinity treatments and two levels of fertilization and then quinoa seed quality characteristics
such as protein content seed hardness and seed density were evaluated
Chapter 6 is the manuscript entitled lsquoLexicon development and sensory attributes of
cooked quinoarsquo In Chapter 6 a lexicon of cooked quinoa was developed using a trained panel
The lexicon provided descriptions of the sensory attributes of aroma tasteflavor texture and
color with references developed for each attribute The trained panel then applied this lexicon to
the evaluation of 16 field trial quinoa varieties from WSU and 5 commercial quinoa samples
from Bolivia and Peru A consumer panel also evaluated their acceptance of 6 selected quinoa
5
samples Using data from the trained panel and the consumer panel the key sensory attributes
driving consumer liking were determined Finally Chapter 7 presents the conclusions and
recommendations for future studies
6
References
Nuntildeez de Acro Chapter 12 Quinoarsquos calling In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 211 ndash 25
Ahamed NT Singhal RS Kulkarni PR Pal M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 31 99-103
Ando H Chen Y Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food Components in
Fractions of Quinoa Seed Food Sci Technol Res 8(1) 80-4
Carimentrand A Baudoin A Lacroix P Bazile D Chia E 2015 Chapter 41 International
quinoa trade In D Bazile D Bertero and C Nieto editors State of the Art Report of
Quinoa in the World in 2013 Rome FAO amp CIRAD p 316 ndash 29
Champagne ET Bett-Garber KL McClung AM Bergman C 2004 Sensory characteristics of
diverse rice cultivars as influenced by genetic and environmental factors Cereal Chem 81
237-43
Chillo S Civica V Iannetti M Mastromatteo M Suriano N Del Nobile M 2010 Influence of
repeated extrusions on some properties of non-conventional spaghetti J Food Eng 100 329-
35
Chlopicka J Pasko P Gorinstein S Jedryas A Zagrodzki P 2012 Total phenolic and total
flavonoid content antioxidant activity and sensory evaluation of pseudocereal breads LWT-
Food Sci Technol 46 548-55
7
Garcia M Raes D Allen R Herbas C 2004 Dynamics of reference evapotranspiration in the
Bolivian highlands (Altiplano) Agr Forest Meteorol 125(1) 67-82
James LEA 2009 Quinoa (Chenopodium quinoa Willd) composition chemistry nutritional
and functional properties Adv Food Nutr Res 58 1-31
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine structure of amylopectin J Cereal Sci 21 251-60
Perdon AA Siebenmorgen TJ Buescher RW Gbur EE 1999 Starch retrogradation and texture
of cooked milled rice during storage J Food Sci 64 828-32
Prego I Maldonado S Otegui M 1998 Seed structure and localization of reserves in
Chenopodium quinoa Ann Bot 82(4) 481-8
Ramesh M Ali SZ Bhattacharya KR1999 Structure of rice starch and its relation to cooked-
rice texture Carbohydr Polym 38 337-47
Rosell CM Cortez G Repo-Carrasco R 2009 Bread making use of Andean crops quinoa
kantildeiwa kiwicha and tarwi Cereal Chem 86 386-92
Sahin S Sumnu SG 2006 Physical properties of foods Springer Science amp Business Media
P39 ndash 109
Schumacher AB Brandelli A Macedo FC Pieta L Klug TV de Jong EV 2010 Chemical and
sensory evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J
Food Sci Technol 47 202-6
8
Tari TA Annapure US Singhal RS Kulkarni PR 2003 Starch-based spherical aggregates
screening of small granule sized starches for entrapment of a model flavouring compound
vanillin Carbohydr Polym 53 45-51
USDA US Department of Agriculture 2015a Peru Quinoa outlook Access from
httpwwwfasusdagovdataperu-quinoa-outlook
9
Chapter 2 Literature Review
Introduction
Quinoa (Chenopodium quinoa Willd) is a dicotyledonous pseudocereal from the Andean
region of South America The plant belongs to a complex of allotetraploid taxa (2n = 4x = 36)
which includes Chenopodium berlandieri subsp berlandieri Chenopodium berlandieri subsp
nuttalliae Chenopodium hircinum and Chenopodium quinoa (Gomez-Pando 2015 Matanguihan
et al 2015) Closely related species include the weed lambsquarter (Chenopodium album)
amaranth (Amaranth palmeri) sugar beet (Beta vulgaris L) and spinach (Spinacea oleracea L)
(Maughan et al 2004) Quinoa plant is C3 specie with 90 self-pollenating (Gonzalez et al
2011) Quinoa was domesticated approximately 5000 ndash 7000 years ago in the Lake Titicaca area
in Bolivia and Peru (Gonzalez et al 2015) Quinoa produces small oval-shaped seeds with a
diameter of 2 mm and a weight of 2 g ndash 46 g 1000-seed (Wu et al 2014) The seed color varies
and can be white yellow orange red purple brown or gray White and red quinoas are the most
common commercially available varietals in the US marketplace (Data from online resources
and local stores in Pullman WA) With such small seeds quinoa provides excellent nutritional
value such as high protein content balanced essential amino acids high proportion of
unsaturated fatty acids rich vitamin B complex vitamin E and minerals antioxidants such as
phenolics and betalains and rich dietary fibers (Wu 2015) For these reasons quinoa is
recognized as a ldquocompleterdquo food (Taverna et al 2012)
10
This chapter reviewed publications in quinoa varieties global development seed
structure and constituents quinoa health benefits physical properties and thermal properties
quinoa flour characteristics processing and quinoa products
Quinoa varieties
There are 16422 quinoa accessions or genetypes conserved worldwide 14502 of which
are conserved in genebanks from the Andean region (Rojas et al 2013) Bolivia and Peru
manage 13023 quinoa accessions (80 of world total accessions) in 140 genebanks (Rojas and
Pinto 2015)
Based on genetic diversity adaptation and morphological characteristics five ecotypes
of quinoa have been identified in the Andean region including valley quinoa Altiplano quinoa
salar quinoa sea level quinoa and subtropical quinoa (Tapia et al 1980) The sea-level ecotype
or Chilean lowland ecotype is the best adapted to temperate climate and high summer
temperature (Peterson and Murphy 2015a)
Adaptation
Quinoa has shown excellent adaptation to marginal or extreme environments and such
adaptation was summarized by Gonzalez et al (2015) Quinoa growing areas range from sea
level to 4200 masl (meters above sea level) with growing temperature rangeing from -4 to 38 ordmC
The plant has adapted to drought-stressed environments but can also grow in areas with
humidity ranging from 40 to 88 Quinoa can grow in marginal soil conditions such as dry
(Garcia et al 2003) infertile (Sanchez et al 2003) and with wide pH range from acidic to basic
(Jacobsen and Stolen 1993) Quinoa has also adapted to high salinity soil (equal to sea salt level
11
or 40 dSm) (Koyro and Eisa 2008 Hariadi et al 2011 Peterson and Murphy 2015b)
Furthermore quinoa has shown tolerance to frost at -8 to -4 ordmC (Jacobsen et al 2005)
Even though quinoa varieties are remarkably diverse and able to adapt to extreme
conditions time and resources are required to breed the high-yielding varieties that are adapted
to regional environments in North America Challenges to achieving strong performance include
yield waterlogging pre-harvest sprouting weed control and tolerance to disease insect pests
and animal stress (Peterson and Murphy 2015a) The breeding work not only needs the effort
from breeders and researchers but also demands the participation and collaboration of local
farmers
In addition to being widely grown in South America quinoa has also recently been
grown in North America Europe Australia Africa and Asia In US quinoa cultivation and
breeding started in the 1980s by the efforts from seed companies private individuals and
Colorado State University (Peterson and Murphy 2015a) Since 2010 Washington State
University has been breeding quinoa in the Pacific Northwest to suit the diverse environmental
conditions including rainfall and temperature Peterson and Murphy (2015a) found the major
challenges in North America included heat susceptibility downy mildew (Plasmopara viticola)
saponin removal weed stress and insect stress (such as aphids and Lygus sp)
With high nutritional value quinoa is recognized as significant in food security and
treating malnutrition issue in developing countries (Rojas 2011) Maliro and Guwela (2015)
reviewed quinoa breeding in Africa Initial experiments showed quinoa can grow well in Malawi
and Kenya in both warm and cool areas The quinoa grain yields in Malawi and Kenya are 3-4
12
tonha which are comparable to the yields in South America However the challenge remains to
adopt quinoa into the local diet and cultivate a quinoa consuming market
Physical Properties of Quinoa
Physical properties of seed refer to seed morphology size gravimetric properties
(weight density and porosity) aerodynamic properties and hardness which are critical to
technology and equipment designed for post-harvest process such as seed cleaning
classification aeration drying and storage (Vilche et al 2003)
The quinoa seed is oval-shaped with a diameter of approximately 18 to 22 mm (Bertero
et al 2004 Wu et al 2014) Mean 1000-seed weight of quinoa is around 27 g (Bhargava et al
2006) and a range of 15 g to 45 g has been observed among varieties (Wu et al 2014)
Commercial quinoa from Bolivia tends to have higher 1000-seed weight of 38 g to 45 g
Additionally bulk density ranges from 066 gmL to 075 gmL in most varieties (Wu et al
2014) Porosity refers to the fraction of space in bulk seed which is not occupied by the seed
(Thompson and Isaac 1976) The porosity of quinoa is 23 (Vilche et al 2003) while that of
rice is 50 to 60 (Kunze et al 2004)
Terminal velocity is the air velocity at which seeds remain in suspension This parameter
is important in cleaning quinoa to remove impurities such as dockage hollow and immature
kernels and mixed weed seeds Vilche et al (2003) reported the terminal velocity of 081 ms-1
while the value of rice was 6 ms-1 to 77 ms-1 (Razavi and Farahmandfar 2008)
Seed hardness or crushing strength is used as a rough estimation of moisture content in
rice (Kunze et al 2004) The hardness of quinoa seed can be tested using a texture analyzer (Wu
13
et al 2014) A stainless cylinder (10 mm in diameter) compressed one quinoa seed to 90 strain
at the rate of 5 mms Because of hardness variation among individual seeds at least six
measurements were required Among the thirteen quinoa samples that were tested hardness
ranged from 58 kg to 110 kg (Wu et al 2014)
Quinoa Seed Structure
Grain structure of quinoa was described in detail by Taylor and Parker (2002) On the
outside of grain is a perianth which can be easily removed during cleaning or rubbing
Sometimes betalain pigments concentrate on this perianth layer and the seed shows bright purple
or golden colors However this color will disappear with the removal of the perianth Inside the
perianth is two-layered pericarp with papillose surface (Figure 1) Beneath the pericarp a seed
coat or episperm is located The seed coat can be white yellow orange red brown or black
Red and white quinoa share the largest market share with consumers exhibiting increasing
interest in brownblack mixed products such as lsquoCalifornia Tricolorrsquo(data from Google
Shopping Amazon and local stores in Pullman WA)
The main seed is enveloped in outside layers and the structure was depicted by Prego et
al (1998) (Figure 2) The embryo (two cotyledons and radicle) coils around a center pericarp
which occupies ~40 of seed volume (Fleming and Galwey 1998) Protein and lipid bodies are
primarily present in the embryo whereas starch granules provide storage in the thin-walled
perisperm Minerals of phosphorus potassium and magnesium are concentrated in phytin
globoids located in the embryo and calcium is located in the pericarp (Konishi et al 2004)
Quinoa Seed Constituents
14
Quinoa is known as a lsquocomplete foodrsquo (James 2009) The seed composition was recently
reviewed by Wu (2015) and Maradini Filho et al (2015) In sum the high nutritional value of
quinoa arises from its high protein content complete and balanced essential amino acids high
proportion of unsaturated fatty acids high concentrations of vitamin B complex vitamin E and
minerals and high phenolic and betalain content
A protein range of 12 to 17 in quinoa has been reported by most studies (Rojas et al
2015) This protein content is higher than wheat (8 to 14 ww) (Halverson and Zeleny 1988)
and rice (4 - 105 ww) (Champagne et al 2004) Additionally quinoa contains all essential
amino acids at concentrations exceeding the suggested requirements from FAOWHO (Table 1)
Quinoa is also gluten-free because it is lacking in prolamins Prolamins are a group of
storage proteins that are rich in proline Prolamins can interact with water and form the gluten
structure which cannot be tolerated by those with celiac disease (Fasano et al 2003) Quinoa and
rice both contain low prolamins (72 and 89 of total protein respectively) and are
considered gluten-free crops Prolamins in wheat (called gliadin) comprise 285 of its total
protein and in maize this concentration of prolamin is 245 (Koziol 1992)
The protein quality of quinoa protein was reported by Ruales and Nair (1992) In raw
quinoa the net protein utilization (NPU) was 757 biological value (BV) was 826 and
digestibility (TD) was 917 all of which were slightly lower than those of casein The
digestibility of quinoa protein is comparable to that of other high quality food proteins such as
soy beans and skim milk (Taylor and Parker 2002) The Protein Efficiency Ratio (PER) in
quinoa ranges from 195 to 31 and is similar to that of casein (Gross et al 1989 Guzmaacuten-
15
Maldonado and Paredes-Lopez 2002) Regarding functional properties of quinoa protein isolates
Eugenia et al (2015) found Bolivian quinoa exhibited the highest thermal stability oil binding
capacity and water binding capacity at acidic pH The Peruvian samples showed the highest
water binding capacity at basic pH and the best foaming capacity at pH 5
Quinoa starch content ranges from 58 to 64 of the dry seed weight (Vega‐Gaacutelvez et
al 2010) Quinoa possesses a small granule size of 06 to 2 μm similar to that of amaranth (1 to
2 μm) and much smaller than those of other grains such as rice wheat oat barley and
buckwheat (2 to 36 μm) (Lindeboom et al 2004) The amylose content in quinoa starch tends to
be lower than found in common grains A range of 3 to 20 was reported by Lindeboom et al
(2005) whereas amylose content is around 25 in cereals As in most cereals quinoa starch is
type A in X-ray diffraction pattern (Ando et al 2002) Li et al (2016) found significant variation
among 26 commercial quinoa samples in the physicochemical properties of starch such as gel
texture thermal and pasting parameters which were strongly affected by apparent amylose
content
Quinoa lipids comprise 55 to 71 of dry seed weight in most reports (Maradini Filho
et al 2015) Ando et al (2002) found quinoa (cultivar Real TKW from Bolivia) perisperm and
embryo contained 50 and 102 total fatty acids respectively Among these fatty acids
unsaturated fatty acids such as oleic linoleic and linolenic comprised 875 Ogungbenle
(2003) reported the properties of quinoa lipids The values of acid iodine peroxide and
saponification were 05 54 24 and 192 respectively
16
Quinoa micronutrients of vitamins and minerals and the relative lsquoreference daily intakersquo
are summarized in Table 2 and 3 respectively Compared to Daily Intake References quinoa
provides a good source of Vitamin B1 B2 and B9 and Vitamin E as well as minerals such as
magnesium phosphorous iron and copper
Quinoa is one of the crops representing diversity in color including white vanilla
yellow orange red brown gray and dark Besides the anthocyannins in dark quinoa (Paśko et
al 2009) the major pigment in quinoa is betalain primarily presenting in seed coat and the
compounds can be subdivided into red-violet betacyannins and yellow-orange betaxanthins
(Tang et al 2015) Betalain is a water-soluble pigment which is permitted quantum satis as a
natural food colorant and applied in fruit yogurt ice cream jams chewing gum sauces and
soups (Esatbeyoglu et al 2015) Additionally betalain potentially offers health benefits such as
antioxidant activity anti-inflammation activity preventing low-density lipoprotein (LDL)
oxidation and DNA damage (Benavente-Garcia and Castillo 2008 Esatbeyoglu et al 2015)
Saponins
Saponins are compounds on the seed coat of quinoa that confer a bitter taste The
compounds are considered to be a defense system against herbivores and pathogens Regarding
chemical structure saponins are a group of glycosides consisting of a hydrophilic carbohydrate
chain (such as arabinose glucose galactose xylose and rhamnose) and a hydrophobic aglycone
(Kuljanabhagavad and Wink 2009) Chemical structures of aglycones were summarized by
Kuljanabhagavad and Wink (2009)
17
Saponins have been considered as anti-nutrient because of haemolytic activity which
refers to the breakdown of red blood cells (Khalil and El-Adawy 1994) However saponins
exhibited health benefit functions such as anti-inflammation (Yao et al 2009) antibacterial
antimicrobial activity (Killeen et al 1998) anti-tumor activity (Shao et al 1996) and
antioxidant activity (Guumllccedilin et al 2006) Furthermore saponins have medicinal use Sun et al
(2009) reported saponins can activate immune system and were used as vaccine adjuvants
Saponins also exhibited anti-cancer activity (Man et al 2010)
Even though saponins have potential health benefits their bitter taste is not pleasant to
consumers To address the bitterness found in bitter quinoa varieties (gt 011 saponin content)
sweet quinoa varieties were bred through conventional genetic selection to contain a lower
saponin content (lt 011 saponin content) For instance lsquoSajamarsquo lsquoKurmirsquo lsquoAynoqarsquo
lsquoKosunarsquo and lsquoBlanquitarsquo in Bolivia lsquoBlanca de Juninrsquo in Peru and lsquoTunkahuanrsquo in Ecuador are
considered sweet quinoa varieties (Quiroga et al 2015) Unfortunately varieties from Bolivia
Peru and Ecuador do not adapt to temperate climates such as those found in the Pacific
Northwest in US and Europe A sweet variety called lsquoJessiersquo exhibits acceptable yield in Pacific
Northwest and has a great market potential Further development of sweet quinoa varieties
adapted to local climate will happen in near future
To remove saponins both dry and wet processing methods have been developed The wet
method or moist method refers to washing quinoa while rubbing the grain with hands or by a
stone Repo-Carrasco et al (2003) suggested the best washing conditions of 20 min soaking 20
min stirring with a water temperature of 70 degC The wet method becomes costly due to the
required drying process Additionally quinoa grain may begin to germinate during wet cleaning
18
The dry method or abrasive dehulling uses mechanical abrasion to polish the grain and
remove the saponins A dehulling process was reported by Reichert et al (1986) using Tanential
Abrasive Dehulling Device (TADD) and removal of 6 - 15 of kernel was required to reduce
the saponins content to lower than 011 Additionally a TM-05 Taka-Yama testing mill was
used in the quinoa pearling process (to 20 - 30 pearling degree) (Goacutemez-Caravaca et al
2014) The dry method is relatively cheaper than wet method and does not generate saponin
waste water The saponin removal efficiency of the dry and washing methods were reported to be
87 and 72 respectively (Reichert et al 1986 Gee et al 1993) A combination of dry and wet
methods was recommended to obtain the efficient cleaning (Repo-Carrasco et al 2003)
Since quinoa is such an expensive crop a 25 to 30 weight lost during the cleaning
process represents a substantial loss on an industrial scale In addition mineral phenolic and
fiber content may dramatically decrease during processing resulting in a loss of nutritional
value Hence cleaning process should be further optimized to reach lower grain weight loss
while maintain an efficient saponins elimination
Removed saponins can be utilized as side products Since saponins also have excellent
foaming property they can be applied in cosmetics and foods as foam-stabilizing and
emulsifying agents (Yang et al 2010) detergents (Chen et al 2010) and preservatives
(Taormina et al 2006)
Saponin content is important to analyze since it highly influences the taste of quinoa
Traditionally the afrosimetric method or foam method was used to estimate saponins content In
this method saponon content is calculated from foam height after shaking quinoa and water
19
mixture for a specific time (Koziol 1991) This afrosimetric method is fast and affordable and
can be used by farmers as a quick estimation of saponin content however the method is not very
accurate The foam stability varies among samples A more accurate method was developed
using Gas Chromatography (GC) (Ridout et al 1991) Using this method quinoa flour was first
defatted using a Soxhlet extraction and then hydrolyzed in reflux for 3 h with a methanol
solution of HCl (2 N) The hydrolysis product sapogenins were extracted with ethyl acetate and
derivatized with bis-(trimethylsilyl) trifluoroacetamide (BSTFA) and dry pyridine and then
tested using GC Generally GC method is a more solid and accurate method compared to foam
method however GC also requires high capital investment as well as long and complex sample
preparation For quinoa farmers and food manufactures fast and affordable methods to test
saponins content in quinoa need to be developed
Saponins have been an important topic in quinoa research Future studies in this area can
include 1) breeding and commercialization of saponin-free or sweet quinoa varieties with high
yield and high agronomy performance (resistance to biotic and abiotic stresses) 2) development
of quick and low cost detection method of saponin content and 3) application of saponin in
medicine foods and cosmetics can be further explored
Health benefits
Simnadis et al (2015) performed a meta-analysis of 18 studies which used animal models
to assess the physiological effects associated with quinoa consumption From these studies
purported physiological effects of quinoa consumption included decreased weight gain
improved lipid profile (decrease LDL and cholesterol) and improved capacity to respond to
20
oxidative stress Simnadis et al (2015) pointed out that the presence of saponins protein and
20-hydroxyecdysone (affects energy homeostasis and intestinal fat absorption) contributed to
those benefit effects
Furthermore Ruales et al (2002) found increased plasma levels of IGF-1 (insulin-like
growth factor) in 50-65 month-old boys after consuming a quinoa infant food for 15 days This
result implicated the potential of quinoa to reduce childhood malnutrition In another study of 22
students (aged 18 to 45) the daily consumption of a quinoa cereal bar for 30 days significantly
decreased triglycerides cholesterol and LDL compared to those parameters prior to quinoa
consumption These results suggest that quinoa intake may reduce the risk of developing
cardiovascular disease (Farinazzi-Machado et al 2012) De Carvalho et al (2014) studied the
influence of quinoa on over-weight postmenopausal women Consumption of quinoa flakes (25
gd for 4 weeks) was found to reduce serum triglycerides and TBARS (thiobarbituric acid
reactive substances) and increase GSH (glutathione) and urinary excretion of enterolignans
compared to those indexes before consuming quinoa flakes
Quinoa flour properties
Functional properties of quinoa flour were determined by Ogungbenle (2003) Quinoa
flour has high water absorption capacity (147) and low foaming capacity (9) and stability
(2) Water absorption capacity was determined by the volume of water retained per gram of
quinoa flour during 30-min mixing at 24 ordmC (Beuchat 1977) The water absorption of quinoa was
higher than that of fluted pumpkin seed (85) soy flour (130) and pigeon pea flour (138)
which implies the potential use of quinoa flour in viscous foods such as soups doughs and
21
baked products Additionally foaming capacity was determined by the foam volumes before and
after whipping of 8 protein solution at pH 70 (Coffmann and Garciaj 1977) Then foam
samples were inverted and dripped though 2 mm wire screen in to beakers The foam stability
was determined by the weight of liquid released from foam after a specific time and the original
weight of foam (Coffmann and Garciaj 1977) Furthermore minimum protein solubility was
observed at pH 60 similar to that of pearl millet and higher than pigeon pea (pH 50) and fluted
pumpkin seed (pH 40) Relatively high solubility of quinoa protein in acidic condition implies
the potential application of quinoa protein in acidic food and carbonated beverages
Wu et al (2014) studied flour viscosity among 13 quinoa samples with large variations
reported among samples The ranges of peak viscosity final viscosity and setback were 59
RVU ndash 197 RVU 56 RVU ndash 203 RVU and -62 RVU ndash 73 RVU respectively which were
comparable to those of rice flour (Zhou et al 2003) Flour viscosity significantly influence
texture of quinoa and rice (Champagne et al 1998 Wu et al 2014)
Ruales et al (1993) studied processing influence on the physico-chemical characteristics
of quinoa flour The process included cooking and autoclaving of the seeds drum drying of
flour and extrusion of the grits Autoclaved quinoa samples exhibited the lowest degree of starch
gelatinization (325) whereas precookeddrum dried quinoa samples were 974 Higher
polymer degradation was found in the cooked samples compared to the autoclaved samples
Water solubility in cooked samples (54 to 156) and autoclaved samples (70 to 96) increased
with the processing time (30 to 60 min cooking and 10 to 30 min autoclaving)
Thermal Properties of quinoa
22
Thermal properties of quinoa flour (both starch and protein) have been determined using
Differential Scanning Calorimetry (DSC) (Abugoch et al 2009) A quinoa flour suspension was
prepared in 20 (ww) concentration The testing temperature was raised from 27 to 120 degC at a
rate of 10 degCmin Two peaks in the DSC graph referenced the starch gelatinization temperature
at 657 degC and protein denaturalization at 989 degC Enthalpy refers to the energy required to
complete starch gelatinization or protein denaturazition In the study of Abugoch et al (2009)
the enthalpy was 59 Jg for starch and 22 Jg for proteins in quinoa
Product development with quinoa
Quinoa has been used in different products such as spaghetti bread and cookies to
enhance nutritional value including a higher protein content and more balanced amino acid
profile Chillo et al (2008) evaluated the quality of spaghetti from amaranth and quinoa flour
Compared to durum semolina spaghetti the spaghetti with amaranth and quinoa flour exhibited
equal breakage susceptibility higher cooking loss and lower instrumental stickiness The
sensory acceptance scores were not different from the control The solid loss weight increase
volume increase adhesiveness and moisture of a corn and quinoa mixed spaghetti were 162thinspg
kgminus1 23 times 26 times 20907thinspg and 384thinspg kgminus1 respectively (Caperuto et al 2001)
Schoenlechner et al (2010) found the optimal combination of 60 buckwheat 20 amaranth
and 20 quinoa yielded an improved dough matrix compared to other flour combinations With
the addition of 6 egg white powder and 12 emulsifier (distilled monoglycerides) this gluten-
free pasta exhibited acceptable firmness and cooking quality compared to wheat pasta
23
Stikic et al (2012) added 20 quinoa seeds in bread formulations which resulted in the
similar dough development time and stability compared to those of wheat dough even though
the bread specific volume was lower (63 mLg) compared to wheat bread (67 mLg) The
protein content of bread increased by 2 (ww) and sensory characteristics were lsquoexcellentrsquo as
evaluated by five trained expert panelists Iglesias-Puig et al (2015) found 25g100 g quinoa
flour substitution in wheat bread showed small depreciation in bread quality in terms of loaf
volume crumb firmness and acceptability whereas the nutritional value increased in dietary
fiber minerals protein and healthy fats Rizzello et al (2016) selected strains (lactic acid
bacteria) to develop a quinoa sourdough A wheat bread with 20 (ww) quinoa sourdough
exhibited improved nutritional (such as protein digestibility and quality) textural and sensory
features Quinoa leaves were also applied to bread making (Świeca et al 2014) With the
replacement of wheat flour by 1 to 5 (ww) quinoa leaves the bread crumb exhibited increased
firmness cohesiveness and gumminess Antioxidant activity and phenolic contents both
significantly increased compared to wheat bread
Pagamunici et al (2014) developed three gluten-free cookies with rice and quinoa flour
with 15 26 and 36 (ww) quinoa flour proportions respectively The formulation with
36 quinoa flour had the highest alpha-linolenic acid and mineral content and the cookie
displayed excellent sensory characteristics as evaluated by 80 non-trained consumer panelists
Another study optimized a gluten-free quinoa formulation with 30 quinoa flour 25 quinoa
flakes and 45 corn starch (Brito et al 2015) The cookie was characterized as a product rich in
essential amino acids linolenic acid minerals and dietary fiber This cookie was among those
24
products using the highest quinoa flour content (55 ww) while still received acceptable
sensory scores
Repo-Carrasco-Valencia and Serna (2011) introduced an extrusion process in Peru
Quinoa flour was tempered to 12 moisture for extrusion During extrusion total and insoluble
dietary fiber decreased by 5 to 17 and 13 to 29 respectively whereas the soluble dietary
fiber significantly increased by 38 to 71 Additionally the radical scavenging activity was
also increased in extruded quinoa compared to raw quinoa
Schumacher et al (2010) developed a dark chocolate with addition of 20 quinoa An
improved nutritional value was observed in 9 (ww) increase in vitamin E 70 - 104
increases in amino acids of cysteine tyrosine and methionine This quinoa dark chocolate
received over 70 acceptance index from sensory panel
Gluten-free beer is of increasing interest in the market (Dezelak et al 2014) Ogungbenle
(2003) found quinoa has high D-xylose and maltose and low glucose and fructose content
suggesting its potential use in malted drink de Meo et al (2011) applied alkaline steeping to
pseudocereal and found its positive effects on pseudocereals malt production by increasing total
soluble nitrogen and free amino nitrogen Kamelgard (2012) patented a method to create a
quinoa-based beverage fermented by a yeast Saccharomyces cerevisiae The beverage can be
distilled and aged to form gluten-free liquor Dezelak et al (2014) processed a quinoa beer-like
beverage (fermented with Saccharomyces pastorianus TUM 3470) resulting in a product with a
nutty aroma low alcohol content and rich in minerals and amino acids However further
development of the brewing procedure was necessary since the beverage showed a less attractive
25
appearance (near to black color and greyish foam) and astringent mouthfeel Compared to barley
brewing attributes of quinoa exhibited lower malt extracts longer saccharification times higher
values in total protein fermentable amino nitrogen content and iodine test
Processing quinoa grain to dried edible product and sweet quinoa product were developed
by Scanlin and Burnett (2010) The edible quinoa product was processed through pre-
conditioning (abrasion and washing) moist heating (steam cooking and pressure cooking) dry
heating (baking toasting and dehydrating) and post-production treatment As for sweet quinoa
product germination and malting processing were applied Caceres et al (2014) patented a
process to extract peptides and maltodextrins from quinoa flour and the extracts were applied in
a gel-format food as a supplement during and after physical activity
26
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flour proteins (Chenopodium quinoa Willd) during storage Int J Food Sci Tech 44(10)
2013-20
Abugoch LE Romero N Tapia CA Silva J Rivera M 2008 Study of some physicochemical
and functional properties of quinoa (Chenopodium quinoa Willd) protein isolates J Agric
Food Chem 56(12) 4745-50
Ando H Chen Y Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food Components in
Fractions of Quinoa Seed Food Sci Technol Res 8(1) 80-4
Benavente-Garcia O Castillo J 2008 Update on uses and properties of citrus flavonoids new
findings in anticancer cardiovascular and anti-inflammatory activity J Agric Food Chem
56(15) 6185-205
Bertero HD de la Vega AJ Correa G Jacobsen SE Mujica A 2004 Genotype and genotype-
by-environment interaction effects for grain yield and grain size of quinoa (Chenopodium
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Crops Res 89(2ndash3) 299-318
Beuchat LR 1977 Functional and electrophoretic characteristics of succinylated peanut flour
protein J Agric Food Chem 25(2) 258-61
Bhargava A Shukla S Rajan S Ohri D 2006 Genetic diversity for morphological and quality
traits in quinoa (Chenopodium quinoa Willd) Germplasm Genet Resour Crop Evol 54(1)
167-73
27
Brito IL de Souza EL Felex SSS Madruga MS Yamashita F Magnani M 2015 Nutritional
and sensory characteristics of gluten-free quinoa (Chenopodium quinoa Willd)-based
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73
Caceres JIE Calderon PD Lira FO 2014 Method for the formulation of a gel-format foodstuff
for use as a nutritional foodstuff enriched with peptides and maltodextrins obtained from
quinoa flour Google Patents
Caperuto LC Amaya-Farfan J Camargo CRO 2001 Performance of quinoa (Chenopodium
quinoa Willd) flour in the manufacture of gluten-free spaghetti J Sci Food Agric 81(1) 95-
101
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5) 764-71
Champagne ET Wood DF Juliano BO Bechtel D 2004 Chapter 4 The rice grain and its gross
composition In Champagne ET editor Rice Chemistry and Technology 3rd edition St
Paul MN American Association of Cereal Chemists Inc p 88 ndash 9
Chen YF Yang CH Chang MS Ciou YP Huang YC 2010 Foam properties and detergent
abilities of the saponins from Camellia oleifera Int J Mol Sci11(11) 4417-25
28
Chillo S Laverse J Falcone PM Del Nobile MA 2008 Quality of spaghetti in base amaranthus
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101-7
Coffmann CW Garciaj VV 1977 Functional properties and amino acid content of a protein
isolate from mung bean flour Int J Food Sci Technol 12(5) 473-84
De Carvalho FG Oviacutedio PP Padovan GJ Jordao Junior AA Marchini JS Navarro AM 2014
Metabolic parameters of postmenopausal women after quinoa or corn flakes intakendasha
prospective and double-blind study Int J Food Sci Nutr 65(3) 380-5
Deželak M Zarnkow M Becker T Košir IJ 2014 Processing of bottom-fermented gluten-free
beer-like beverages based on buckwheat and quinoa malt with chemical and sensory
characterization J Inst Brew 120(4) 360-70
Farinazzi-Machado FMV Barbalho SM Oshiiwa M Goulart R Pessan Junior O 2012 Use of
cereal bars with quinoa (Chenopodium quinoa W) to reduce risk factors related to
cardiovascular diseases Food Sci Technol(Campinas) 32(2) 239-44
Fasano A Berti I Gerarduzzi T Not T Colletti RB Drago S Hill ID 2003 Prevalence of celiac
disease in at-risk and not-at-risk groups in the United States a large multicenter study Arch
Intern Med 163(3) 286-92
Fleming JE Galwey NW 1998 Quinoa (Chenopodium quinoa Willd) nutritional quality and
technological aspects as human food In Belton PS Taylor JRN editors Increasing the
29
utilisation of sorghum buckwheat grain amaranth and quinoa for improved nutrition
Norwich UK Institute of Food Research p 49-64
Friedman M Brandon DL 2001 Nutritional and health benefits of soy proteins J Agric Food
Chem 49(3)1069-86
Garcia M Raes D Jacobsen SE 2003 Evapotranspiration analysis and irrigation requirements
of quinoa (Chenopodium quinoa) in the Bolivian highlands Agr Water Manage 60(2) 119-
34
Gee JM Price KR Ridout CL Wortley GM Hurrell RF Johnson IT 1993 Saponins of quinoa
(Chenopodium quinoa) effects of processing on their abundance in quinoa products and their
biological effects on intestinal mucosal tissue J Sci Food Agric 63(2) 201-9
Goacutemez-Caravaca AM Iafelice G Verardo V Marconi E Caboni MF 2014 Influence of
pearling process on phenolic and saponin content in quinoa (Chenopodium quinoa Willd)
Food Chem 157 174-8
Gomez-Pando L 2015 Chapter 6 Quinoa breeding In Murphy KM Matanguihan J editors
Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p
87 ndash 97
Gonzaacutelez JA Bruno M Valoy M Prado FE 2011 Genotypic variation of gas exchange
parameters and leaf stable carbon and nitrogen isotopes in ten quinoa cultivars grown under
drought J Agron Crop Sci 197(2) 81-93
30
Gonzaacutelez JA Eisa SSS Hussin SAES and Prado FE 2015 Chapter 1 Quinoa An Incan Crop
to Face Global Changes in Agriculture In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 182-6
Graf BL Rojas-Silva P Rojo LE Delatorre-Herrera J Baldeoacuten ME Raskin I 2015 Innovations
in health value and functional food development of quinoa (Chenopodium quinoa Willd)
Comp Rev Food Sci Food Safety 14(4) 431-45
Gross R Koch F Malaga I de Miranda A Schoeneberger H Trugo L 1989 Chemical
composition and protein quality of some local Andean food sources Food Chem 34(1) 25-
34
Guumllccedilin İ Mshvildadze V Gepdiremen A Elias R 2006 The antioxidant activity of a
triterpenoid glycoside isolated from the berries of Hedera colchica 3-O-(β-d-
glucopyranosyl)-hederagenin Phytother Res 20(2) 130-4
Guzmaacuten-Maldonado S Paredes-Lopez O 2002 Functional products of plants indigenous to
Latin America amaranth quinoa common beans and botanicals In Shi J Mazza G
Maguer ML editors Functional foods Biochemical and processing aspects CRC Press p
293-328
Halverson J Zeleny L 1988 Chapter 2 Criteria of wheat quality In Pomeranz Y editor
Wheat Chemistry and Technology 3rd edition St Paul MN American Association of
Cereal Chemists Inc p 25 ndash 6
31
Hariadi Y Marandon K Tian Y Jacobsen SE Shabala S 2011 Ionic and osmotic relations in
quinoa (Chenopodium quinoa Willd) plants grown at various salinity levels J Exp Bot
62(1) 185-93
Iglesias-Puig E Monedero V Haros M 2015 Bread with whole quinoa flour and bifidobacterial
phytases increases dietary mineral intake and bioavailability LWT-Food Sci Technol 60(1)
71-7
Jacobsen SE Monteros C Christiansen J Bravo L Corcuera L Mujica A 2005 Plant responses
of quinoa (Chenopodium quinoa Willd) to frost at various phenological stages Eur J Agron
22(2) 131-9
Jacobsen SE Stoslashlen O 1993 Quinoa-morphology phenology and prospects for its production as
a new crop in Europe Eur J Agron 2(1) 19-29
James LEA 2009 Quinoa (Chenopodium quinoa Willd) composition chemistry nutritional
and functional properties Adv Food Nutr Res 58 1-31
Kamelgard JI 2012 Quinoa-based beverages and method of creating quinoa-based beverages
Google Patents
Khalil A El-Adawy T 1994 Isolation identification and toxicity of saponin from different
legumes Food Chem 50(2) 197-201
Killeen GF Madigan CA Connolly CR Walsh GA Clark C Hynes MJ Power RF 1998
Antimicrobial saponins of Yucca schidigera and the implications of their in vitro properties
for their in vivo impact J Agric Food Chem 46(8) 3178-86
32
Konishi Y Hirano S Tsuboi H Wada M 2004 Distribution of minerals in quinoa
(Chenopodium quinoa Willd) seeds Biotechnol Appl Biochem 68(1) 231-4
Koyro HW Eisa SS 2008 Effect of salinity on composition viability and germination of seeds
of Chenopodium quinoa Willd Plant Soil 302(1-2) 79-90
Kozioł M1992 Chemical composition and nutritional evaluation of quinoa (Chenopodium
quinoa Willd) J Food Compost Anal 5(1) 35-68
Kuljanabhagavad T Wink M 2009 Biological activities and chemistry of saponins from
Chenopodium quinoa Willd Phytochem Rev 8(2) 473-90
Kunze OR Lan Y and Wratten FT 2004 Chapter 8 Physical and mechanical properties of rice
In Champagne ET editor Rice Chemistry and Technology 3rd edition St Paul MN
American Association of Cereal Chemists Inc p 193 ndash 211
Li G Wang S Zhu F 2016 Physicochemical properties of quinoa starch Carbohydr Polym 137
328-38
Lindeboom N Chang PR Falk KC Tyler RT 2005 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2) 216-22
Lindeboom N Chang PR Tyler RT 2004 Analytical biochemical and physicochemical aspects
of starch granule size with emphasis on small granule starches a review Starch-Staumlrke 56(3-
4) 89-99
Man S Gao W Zhang Y Huang L Liu C 2010 Chemical study and medical application of
saponins as anti-cancer agents Fitoterapia 81(7) 703-14
33
Maradini Filho AM Pirozi MR Da Silva Borges JT Pinheiro SantAna HM Paes Chaves JB
Dos Reis Coimbra JS 2015 Quinoa nutritional functional and antinutritional aspects Crit
Rev Food Sci Nutr (just-accepted)
Matanguihan JB Jellen EN and Kolano A 2015 Chapter 7 Quinoa cytogenetics molecular
genetics and diversity In Murphy KM Matanguihan J editors Quinoa Improvement and
Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 109-24
Maughan PJ Bonifacio A Jellen EN Stevens MR Coleman CE Ricks M Mason SL Jarvis
DE Gardunia BW Fairbanks DJ 2004 A genetic linkage map of quinoa (Chenopodium
quinoa) based on AFLP RAPD and SSR markers Theor Appl Genet 109(6) 1188-95
de Meo B Freeman G Marconi O Booer C Perretti G Fantozzi P 2011 Behaviour of Malted
Cereals and Pseudo-Cereals for Gluten-Free Beer Production J Inst Brew 117(4) 541-6
Ogungbenle H 2003 Nutritional evaluation and functional properties of quinoa (Chenopodium
quinoa) flour Int J Food Sci Nutr 54(2) 153-8
Ogungbenle HN 2003 Nutritional evaluation and functional properties of quinoa (Chenopodium
quinoa) flour Int J Food Sci Nutr 54(2) 153-8
Quiroga C Escalera R Aroni G Bonifacio A Gonzaacutelez JA Villca M Saravia R Ruiz A 2015
Chapter 31 Traditional processes and Technological Innovations in Quinoa Harvesting
Processing and Industrialization In D Bazile D Bertero and C Nieto editors State of the
Art Report of Quinoa in the World in 2013 Rome FAO amp CIRAD p 213 - 4
34
Pagamunici LM Gohara AK Souza AHP Bittencourt PRS Torquato AS Batiston WP
Matsushita M 2014 Using chemometric techniques to characterize gluten-free cookies
containing the whole flour of a new quinoa cultivar J Brazil Chem Soc 25 219-28
Paśko P Bartoń H Zagrodzki P Gorinstein S Fołta M Zachwieja Z 2009 Anthocyanins total
polyphenols and antioxidant activity in amaranth and quinoa seeds and sprouts during their
growth Food Chem 115(3) 994-8
Peterson AJ Murphy KM 2015a Chapter 10 Quinoa Cultivation for Temperate North America
Considerations and Areas for Investigation In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 182-6
Peterson A Murphy K 2015b Tolerance of lowland quinoa cultivars to sodium chloride and
sodium sulfate salinity Crop Sci 55(1) 331-8
Prego I Maldonado S Otegui M 1998 Seed structure and localization of reserves in
Chenopodium quinoa Ann Bot 82(4) 481-8
Ranhotra GS Gelroth JA Glaser BK Lorenz KJ Johnson DL 1993 Composition and protein
nutritional quality of quinoa Cereal Chem 70(3)303-5
Razavi SMA Farahmandfar R 2008 Effect of hulling and milling on the physical properties of
rice grains Int Agrophys 22(4) 353-9
Reichert R Tatarynovich J Tyler R 1986 Abrasive dehulling of quinoa (Chenopodium quinoa)
effect on saponin content as determined by an adapted hemolytic assay Cereal Chem 63(6)
471-5
35
Repo-Carrasco-Valencia RAM Serna LA 2011 Quinoa (Chenopodium quinoa Willd) as a
source of dietary fiber and other functional components Food Sci Technol (Campinas) 31
225-30
Repo-Carrasco R Espinoza C Jacobsen SE 2003 Nutritional value and use of the Andean crops
quinoa (Chenopodium quinoa) and kantildeiwa (Chenopodium pallidicaule) Food Rev Int 19(1-
2) 179-89
Ridout CL Price KR Dupont MS Parker ML Fenwick GR 1991 Quinoa saponinsmdashanalysis
and preliminary investigations into the effects of reduction by processing J Sci Food Agric
54(2) 165-76
Rizzello CG Lorusso A Montemurro M Gobbetti M 2016 Use of sourdough made with
quinoa (Chenopodium quinoa) flour and autochthonous selected lactic acid bacteria for
enhancing the nutritional textural and sensory features of white bread Food Microbiol 56 1-
13
Rojas W 2011 Quinoa an ancient crop to contribute to world food security Santiago Chile
FAO Oficina Regional para America Latina y el Caribe
Rojas W Pinto M Alanoca C Goacutemez-Pando L Leoacuten-Lobos P Alercia A Diulgheroff S
Padulosi S Bazile D 2013 Estado de la conservacioacuten ex situ de los recursos geneacuteticos de
quinua In Didier B Daniel BH Carlos N editors Estado del arte de la quinua en el mundo
en Libro de resuacutemenes Santiago FAO p 20-21
36
Rojas W Pinto M 2015 Chapter 8 Ex situ conservation of quinoa the bolivian experience In
Murphy KM Matanguihan J editors Quinoa Improvement and Sustainable Production
Hoboken NJ John Wiley amp Sons Inc p 128-30
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile D
Bertero D Nieto C editors State of the Art Report of Quinoa in the World in 2013 Rome
FAO amp CIRAD p 67
Ruales J Nair BM 1992 Nutritional quality of the protein in quinoa (Chenopodium quinoa
Willd) seeds Plant Foods Hum Nutr 42(1) 1-11
Ruales J Nair BM 1993 Saponins phytic acid tannins and protease inhibitors in quinoa
(Chenopodium quinoa Willd) seeds Food Chem 48(2)137-43
Ruales J Valencia S Nair B 1993 Effect of processing on the physico-chemical characteristics
of quinoa flour (Chenopodium quinoa Willd) Starch - Staumlrke 45(1)13-9
Ruales J Grijalva YD Lopez-Jaramillo P Nair BM 2002 The nutritional quality of an infant
food from quinoa and its effect on the plasma level of insulin-like growth factor-1 (IGF-1) in
undernourished children Int J Food Sci Nutr 53(2) 143-54
Sanchez HB Lemeur R Damme PV Jacobsen SE 2003 Ecophysiological analysis of drought
and salinity stress of quinoa (Chenopodium quinoa Willd) Food Rev Int 19(1-2) 111-9
Scanlin LA Burnett C (2010) Quinoa grain processing and products Google Patents
37
Schoenlechner R Drausinger J Ottenschlaeger V Jurackova K Berghofer E 2010 Functional
Properties of Gluten-Free Pasta Produced from Amaranth Quinoa and Buckwheat Plant
Foods Hum Nutr 65(4) 339-49
Schumacher AB Brandelli A Macedo FC Pieta L Klug TV de Jong EV 2010 Chemical and
sensory evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J
Food Sci Technol 47(2) 202-6
Shao Y Chin CK Ho CT Ma W Garrison SA Huang MT 1996 Anti-tumor activity of the
crude saponins obtained from asparagus Cancer Lett 104(1) 31-6
Simnadis TG Tapsell LC Beck EJ 2015 Physiological Effects Associated with Quinoa
Consumption and Implications for Research Involving Humans a Review Plant Foods Hum
Nutr 70(3) 238-49
Steffolani ME Villacorta P Morales-Soriano E Repo-Carrasco R Leoacuten AE Perez GT 2015
Physico-chemical and functional characterization of protein isolated from different quinoa
varieties (Chenopodium quinoa Willd) Cereal Chem (Accepted for publication)
Stevens MR Coleman CE Parkinson SE Maughan PJ Zhang HB Balzotti MR Kooyman DL
Arumuganathan K Bonifacio A Fairbanks DJ Jellen EN Stevens JJ 2006 Construction of
a quinoa (Chenopodium quinoa Willd) BAC library and its use in identifying genes
encoding seed storage proteins Theor Appl Genet 112(8) 1593-600
Stikic R Glamoclija D Demin M Vucelic-Radovic B Jovanovic Z Milojkovic-Opsenica D
Jacobsen SE Milovanovic M 2012 Agronomical and nutritional evaluation of quinoa seeds
38
(Chenopodium quinoa Willd) as an ingredient in bread formulations J Cereal Sci 55(2)
132-8
Sun HX Xie Y Ye YP 2009 Advances in saponin-based adjuvants Vaccine 27(12) 1787-96
Świeca M Sęczyk Ł Gawlik-Dziki U Dziki D 2014 Bread enriched with quinoa leaves - The
influence of protein-phenolics interactions on the nutritional and antioxidant quality Food
Chem 162 54-62
Tang Y Li X Zhang B Chen PX Liu R Tsao R 2015 Characterisation of phenolics betanins
and antioxidant activities in seeds of three Chenopodium quinoa Willd genotypes Food
Chem 166 380-8
Taormina PJ Simpson PG Bertera EA Komitopoulou E 2006 Beverage preservatives Google
Patents
Tapia M Mujica A Canahua A 1980 Origen y distribucion geografica y sistemas de
produccion de la quinua (Chenopodium quinoa Wild) Publicacion Universidad Nacional
Tecnica del Altiplano
Taverna LG Leonel M Mischan MM 2012 Changes in physical properties of extruded sour
cassava starch and quinoa flour blend snacks Food Sci Technol (Campinas) 32 826-34
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Taylor JRN Parker ML editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science amp Business Media p 96-9
39
Thompson R Isaacs G 1967 Porosity determinations of grains and seeds with an air-
comparison pycnometer T ASAE 10(5) 693-6
Vega-Gaacutelvez A Miranda M Vergara J Uribe E Puente L Martiacutenez EA 2010 Nutrition facts
and functional potential of quinoa (Chenopodium quinoa willd) an ancient Andean grain a
review J Sci Food Agric 90(15) 2541-7
USDA US Department of Agriculture Agricultrual Research Service 2015 USDA national
nutrient database for standard reference Release 18 Nutrient Data Laboratory Home Page
Available from httpwwwarsusdagovServicesdocshtmdocid=8964
Vilche C Gely M Santalla E 2003 Physical Properties of Quinoa Seeds Biosyst Eng 86(1) 59-
65
Wu G Morris CF Murphy KM 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79(11) 2337-45
Wu G Chapter 11 Nutritional properties of quinoa In Murphy KM Matanguihan J editors
Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc
p193 ndash 205
Yang CH Huang YC Chen YF Chang MH 2010 Foam properties detergent abilities and long-
term preservative efficacy of the saponins from J Food Drug Anal 18(3) 4417-25
Yao Y Yang X Shi Z Ren G 2014 Anti-inflammatory activity of saponins from quinoa
(Chenopodium quinoa Willd) Seeds in lipopolysaccharide-stimulated raw 2647
Macrophages Cells J Food Sci 79(5) 1018-23
40
Zhou Z Robards K Helliwell S Blanchard C 2003 Effect of rice storage on pasting properties
of rice flour Food Res Int 36(6) 625-34
41
Table 1-Essential amino acid of quinoa protein and FAOWHO suggested requirement (mgg protein)
Essential amino acid Quinoa protein a FAOWHO suggested requirement b
Histidine 258 18
Isoleucine 433 25
Leucine 736 55
Lysine 525 51
Methionine amp Cysteine 273 25
Phenylalanine amp Tyrosine 803 47
Threonine 439 27
Tryptophan 385 7
Valine 506 32
a) Abugoch et al (2008) b) Friedman and Brandon (2001)
42
Table 2-Quinoa vitamins content (mg100g)
Quinoa a-d Reference Daily Intake
Thianmin (B1) 029-038 15
Riboflavin (B2) 030-039 17
Niacin (B3) 106-152 20
Pyridoxine (B6) 0487 20
Folate (B9) 0781 04
Ascorbic acid (C) 40 60
α-Tocopherol (VE) (IU) 537 30
Β-Carotene 039 NR
a (Koziol 1992) b (Ruales and Nair 1993) c (Ranhotra et al 1993) d (USDA 2015)
43
Table 3-Quinoa minerals content (mgmg )
Whole graina RDI b
K 8257 NR
Mg 4526 400
Ca 1213 1000
P 3595 1000
Fe 95 18
Mn 37 NR
Cu 07 2
Zn 08 15
Na 13 NR
(aAndo et al 2002 bUSDA 2015)
44
Figure 1-Quinoa seed section and two-layered pericarp under perianth (Wu et al 2014)
45
Figure 2-Quinoa seed structure (Prego et al 1998)
(PE pericarp SC seed coat C cotyledons SA shoot apex H hypocotylradicle axis R radicle F funicle EN endosperm P perisperm Bar = 500 μm)
46
Chapter 3 Evaluation of Texture Differences among Varieties of
Cooked Quinoa
Published manuscript
Wu G Morris C F amp Murphy K M (2014) Evaluation of texture differences among
varieties of cooked quinoa Journal of Food Science 79(11) S2337-S2345
ABSTRACT
Texture is one of the most significant factors for consumersrsquo experience of foods Texture
differences of cooked quinoa were studied among thirteen different varieties Correlations
between the texture parameters and seed composition seed characteristics cooking quality flour
pasting properties and flour thermal properties were determined The results showed that texture
of cooked quinoa was significantly differed among varieties lsquoBlackrsquo lsquoCahuilrsquo and lsquoRed
Commercialrsquo yielded harder texture while lsquo49ALCrsquo lsquo1ESPrsquo and lsquoCol6197rsquo showed softer
texture lsquo49ALCrsquo lsquo1ESPrsquo lsquoCol6197rsquo and lsquoQQ63rsquo were more adhesive while other varieties
were not sticky The texture profile correlated to physical-chemical properties in different ways
Protein content was positively correlated with all the texture profile analysis (TPA) parameters
Seed hardness was positively correlated with TPA hardness gumminess and chewiness at P le
009 Seed density was negatively correlated with TPA hardness cohesiveness gumminess and
chewiness whereas seed coat proportion was positively correlated with these TPA parameters
Increased cooking time of quinoa was correlated with increased hardness cohesiveness
gumminess and chewiness The water uptake ratio was inversely related to TPA hardness
47
gumminess and chewiness RVA peak viscosity was negatively correlated with the hardness
gumminess and chewiness (P lt 007) breakdown was also negatively correlated with those TPA
parameters (P lt 009) final viscosity and setback were negatively correlated with the hardness
cohesiveness gumminess and chewiness (P lt 005) setback was correlated with the
adhesiveness as well (r = -063 P = 002) Onset gelatinization temperature (To) was
significantly positively correlated with all the texture profile parameters and peak temperature
(Tp) was moderately correlated with cohesiveness whereas neither conclusion temperature (Tc)
nor enthalpy correlated with the texture of cooked quinoa This study provided information for
the breeders and food industry to select quinoa with specific properties for difference use
purposes
Keywords cooked quinoa variety texture profile analysis (TPA) RVA DSC
Practical Application The research described in this paper indicates that the texture of different
quinoa varieties varies significantly The results can be used by quinoa breeders and food
processors
48
Introduction
Quinoa (Chenopodium quinoa Willd) a pseudocereal (Lindeboom et al 2007) is known as
a complete food due to its high nutritional value (Jancurovaacute et al 2009) Protein content of dry
quinoa grain ranges from 8 to 22 (Jancurovaacute et al 2009) Quinoa protein is high in nutritive
quality with an excellent balance of essential amino acids (Abugoch et al 2008) Quinoa is also a
gluten-free crop (Alvarez-Jubete et al 2010) Quinoa consumption in the US and Europe has
increased dramatically over the past decade but these regions rely on imports primarily from
Bolivia and Peru (Food and Agriculture Organization of the United Nations FAO 2013) For
these reasons greater knowledge of quinoa grain quality is needed
Quinoa is traditionally cooked as a whole grain similar to rice or milled into flour and made
into pasta and breads (Food and Agriculture Organization of the United Nations FAO 2013)
Quinoa can also be processed by extrusion drum-drying and autoclaving (Ruales et al 1993)
Commercial quinoa products include pasta bread cookies muffins cereal snacks drinks
flakes baby food and diet supplements (Ruales et al 2002 Del Castillo et al 2009 Cortez et al
2009 Demirkesen et al 2010 Schumacher et al 2010)
Texture is one of most significant properties of food that affects the consuming experience
Food texture refers to those qualities of a food that can be felt with the fingers tongue palate or
teeth (Vaclavik and Christian 2003) Cooked quinoa has a unique texture described as creamy
smooth and slightly crunchy (Abugoch 2009) Texture can be influenced by the seed structure
composition cooking quality and thermal properties However we know of no report which
documents the texture of cooked quinoa and the factors that affect it
49
Quinoa has small seeds compared to most cereals and seed size may affect the texture of
cooked quinoa Seed characteristics and structure are the significant factors potentially affecting
the textural properties of processed food Rousset et al (1995) indicated that the length and
lengthwidth ratio of rice kernels was associated with a wide range of texture attributes including
crunchy brittle elastic juicy pasty sticky and mealy which were determined by a sensory
panel The correlation between quinoa seed characteristics and cooked quinoa texture has not
been studied
Quinoa is consumed as whole grain without removing the bran unlike most rice and wheat
The insoluble fiber and non-starch polysaccharides in the seed coat can affect mouth feel and
texture Hence seed coat proportion may contribute to the texture of cooked quinoa Mohapatra
and Bal (2006) reported that the milling degree of rice positively influenced cohesiveness and
adhesiveness of cooked rice but was negatively correlated to hardness
Quinoa seed qualities such as the size hardness weight density and seed coat proportion
may influence the water binding capacity of seed during thermal processing thereby affecting
the texture of the cooked cereal (Fitzgerald et al 2003) Nevertheless correlations between seed
characteristics and texture of cooked quinoa have not been previously described
Seed composition may influence texture as well Higher protein content was reported to
cause reduced stickiness and harder texture of cooked rice (Ramesh et al 2000) Quinoa seeds
contain approximately 60 starch (Ando et al 2002) Starch granules are particularly small (05
- 3μm) Amylose content of quinoa is as low as 11 (Ahamed et al 1996) while the amylose
proportion in most cereals such as wheat is around 25 (Zeng et al 1997 BeMiller and Huber
50
2008) Amylose content of starch correlated positively with the hardness of cooked rice and
cooked white salted noodles (Ong and Blanshard 1995 Epstein et al 2002 Baik and Lee 2003)
Flour pasting properties can greatly influence the texture of cooked products Their
correlation has not been illustrated in quinoa while some research have been conducted on
cooked rice A lower peak viscosity and positive setback are associated with a harder texture
while a higher peak viscosity breakdown and lower setback are associated with a sticky texture
in cooked rice (Limpisut and Jindal 2002) Champagne et al (1999) indicated that adhesiveness
had strong correlations with Rapid Visco Analyzer (RVA) measurements Ramesh et al (2000)
reported that harder cooked rice texture was associated with a lower peak viscosity and positive
setback while sticky rice had a higher peak viscosity higher breakdown and lower setback
The gelatinization temperature of quinoa starch ranges from 54ordmC to 71ordmC (Ando et al
2002) lower than that of rice barley and wheat starches (Marshall 1994 Tang 2004 Tang et al
2005) Gelatinization temperature likely plays an important role in waxy rice quality (Perdon and
Juliano 1975 Juliano et al 1987) but was not correlated to the eating quality of normal rice
(Ramesh et al 2000) Despite a considerable amount of work having been conducted on the
thermal properties of cereal starch little is known about the relationship between quinoa flour
thermal properties and cooked quinoa texture
The correlation of quinoa cooking quality and texture has not been previously reported In
rice cooking quality exhibited strong correlations to the texture profile analysis (TPA) Cooking
time has been reported to correlate positively with hardness and negatively with adhesiveness of
cooked rice (Mohapatra and Bal 2006) Higher water uptake ratio and volume expansion ratio
were associated with softer more adhesive and more cohesive texture of cooked rice
51
(Mohapatra and Bal 2006) Cooking loss has been reported to improve firmness but decrease
juiciness (Rousset et al 1995)
There is a need to further study the texture of cooked quinoa and its determining factors
The objective of this paper is to study the texture difference among varieties of cooked quinoa
and evaluate the correlation between the texture and the seed characters and composition
cooking process flour pasting properties and thermal properties
Materials and Methods
Seed characteristics
Eleven varieties and two commercial lots of quinoa are listed in Table 1 The two grain
lots were referred as lsquoYellow Commercialrsquo and lsquoRed Commercialrsquo according to the seed color
Seed size (diameter) was determined by lining up and measuring the length of 20 seeds Average
seed diameter was calculated from three repeated measurements Bulk density of seed was
measured by the weightvolume method Seed weight was determined gravimetrically Seed
hardness was determined using the texture analyzer TAndashXT2i (Texture Technology Corp
Scarsdale NY USA) A cylinder of 10 mm in diameter compressed one seed to 90 strain at
the rate of 5 mms The force (kg) was recorded as the seed hardness Seed coat proportions were
determined by a Scanning Electron Microscope (SEM) FEI Quanta 200F (FEI Corp Hillsboro
OR USA) The seed was cross-sectioned and the SEM image was captured under 800times
magnification The seed coat proportions were measured using the software ruler in micrometers
Chemical compositions
Whole quinoa flour was prepared using a cyclone sample mill (UDY Corporation Fort
Collins CO USA) equipped with a 05 mm screen and was used for compositional analysis
52
pasting viscosity and thermal properties Ash and moisture content of quinoa flour were tested
according to the Approved Method 08-0101 and 44-1502 respectively (AACCI 2012) Protein
content was determined by a nitrogen analyzer coupled with a thermo-conductivity detector
(LECO Corporation Joseph MI USA) The factor of 625 was used to calculate the protein
content from the nitrogen content (Approved Method 46-3001 AACCI 2012) Protein and ash
were calculated on a dry weight basis
Cooking protocol
The cooking protocol of quinoa was modified from a rice cooking method (Champagne
et al 1998) Five grams of quinoa seed were soaked for 20 min in 10 mL deionized water in a
flask Soaking is required to remove the bitter saponins (Pappier et al 2008) and enhance
cooking quality (Mohapatra and Bal 2006) The mixture was then boiled for 2 min and the flask
was set in boiling water for 18 min The flask was covered to prevent water loss
Cooking quality
Two grams of quinoa seed were cooked in 20 mL deionized water for 20 min and extra
water was removed Cooking time was determined when the middle white part of the seed
completely disappeared (Mohapatra and Bal 2006) The water uptake ratio was calculated from
the seed weight ratio before and after cooking Cooking volume was the seed volume after
cooking Cooking loss was the total of soluble and insoluble matter in the cooking water
(Rousset et al 1995) Three mL of cooking water of each sample was placed on an aluminum
pan and dried at 130 ordmC overnight The weight of dry solids in the pan was used to calculate the
cooking loss
Texture profile analysis (TPA)
53
Texture profile analysis (TPA) was used to determine the texture of cooked quinoa
according to a modified method for cooked rice texture (Champagne et al 1999) Two grams of
cooked quinoa were arranged on the texture analyzer platform as close to one layer as possible
A stainless steel plate (50 mm times 40 mm times 10 mm) compressed the cooked quinoa from 5 mm to
01 mm at 5 mmsec The compression was conducted twice The texture analyzer generated a
graph with time as the x-axis and force as the y-axis Six parameters were calculated from the
graph (Epstein et al 2002) Hardness is the height of the first peak adhesiveness is the area 3
cohesiveness is area 2 divided by area 1 springiness is distance 1 divided by distance 2
gumminess is hardness multiplied by cohesiveness chewiness is gumminess multiplied by
springiness In the present study no significant differences or correlations were obtained for
springiness As such this parameter will not be included except to describe the overall result (see
below)
Flour viscosity
Quinoa flour pasting viscosity was determined using the Rapid Visco Analyzer (RVA)
RVA-4 (Newport Scientific Pty Ltd Narrabeen Australia) Quinoa flour (43 g) was added to
25 mL deionized water in an aluminum cylinder container The contents were immediately
mixed and heated following the instrument program The temperature was increased from 50 ordmC
to 93 ordmC in 8 min at a constant rate was held at 95 ordmC from 8 to 24 min cooled to 50 ordmC from 24
to 28 min and held at 50 ordmC from 29 to 40 min The program generated a graph with time against
shear force (Figure 1) expressed in RVU (cP = RVU times 12)
Two peaks representing peak viscosity and final viscosity are normally included in the
RVA graph Peak time was the time to reach the first peak Holding strength or trough is the
54
minimum viscosity after the first peak Breakdown is the viscosity difference between peak and
minimum viscosity Setback is the viscosity difference between final and minimum viscosity
Pasting temperature and the time to reach the peak were also recorded
Thermal properties using Differential Scanning Calorimetry (DSC)
Thermal properties of quinoa flour were determined by Differential Scanning
Calorimetry (DSC) Tzero Q2000 (TA instruments New Castle DE USA) The protocol was a
modification of the method of Abugoch et al (2009) Quinoa flour (02 g) was added to 200 μL
deionized water and mixed on a vortex mixer for 10 s to form a slurry Ten to twelve milligrams
of slurry was added to an aluminum pan by pipette The pan was sealed and placed at the center
of DSC platform An empty pan was used as reference The temperature was increased from 25
ordmC to 120 ordmC at 10 ordmCmin then equilibrated to 25 ordmC Gelatinization temperature and enthalpy
were determined from the graph
Statistical analysis
All experiments were repeated three times The hypothesis tests of normality and equal
variance multiple comparisons (Fisherrsquos LSD) and correlation studies were conducted by SAS
92 (SAS Institute Cary NC) A P-value of 005 is considered as the level of statistical
significance unless otherwise specified
Results
Seed characteristics and flour composition
Quinoa seed characteristics and composition are shown in Table 2 Quinoa seeds were
small compared to cereals such as rice wheat and maize Diameters of quinoa seed mostly
ranged between 19 to 22 mm except for lsquoJapanese Strainrsquo which was significantly smaller (15
55
mm) Seed hardness was significantly different among varieties ranging from 583 k g in
lsquoCol6197rsquo to 1096 kg in lsquoOro de Vallersquo Bulk seed density of quinoa varied from 063 kgL in
lsquoBlancarsquo to 081 kgL in lsquoJapanese Strainrsquo Varieties from White Mountain farm and the WSU
Organic Farm were lower in bulk density most of which were below 07 kgL The commercial
and Port Townsend samples were higher in density most of which were around 075 kgL
Thousand-seed weights of quinoa were particularly low ranging from 18 g in lsquoJapanese Strainrsquo
to 41g in lsquoRed Commercialrsquo Seed coat proportion was also significantly different among
varieties Three layers are shown in the seed coat (Figure 2) The varieties lsquoBlackrsquo and lsquoBlancarsquo
had the thickest seed coat (38 and 97 μm respectively) with coat proportions of 40 and 45
respectively lsquoYellow Commercialrsquo and lsquo1ESPrsquo had the thinnest seed coats (15 and 16 μm
respectively) with the coat proportion of 07 and 05 respectively The difference was
almost ten-fold among the varieties
Protein and ash content of quinoa flour
Protein content varied from 113 in lsquo1ESPrsquo to 170 in lsquoCahuilrsquo lsquoCherry Vanillarsquo and
lsquoOro de Vallersquo also had high protein contents of 160 and 156 respectively Ash content
ranged from 12 in the Commercial Yellow seed to 40 in lsquoQQ63rsquo comparable to that in rice
flour (Champagne 2004)
Texture of cooked quinoa
The hardness of cooked quinoa ranged from 20 g for lsquo49ALCrsquo and lsquoCol6197rsquo to 347
kg for lsquoBlackrsquo (Table 3) lsquoOro de Vallersquo and lsquoBlancarsquo were relatively hard varieties with TPA
hardness of 285 kg and 306 kg respectively whereas lsquo1ESPrsquo lsquoJapanese Strainrsquo and lsquoQQ63rsquo
were softer with a hardness of 245 kg 293 kg and 297 kg respectively
56
Adhesiveness is the extent to which seeds stick to each other the probe and the stage
lsquo49ALCrsquo lsquo1ESPrsquo lsquoCol6197rsquo and lsquoQQ63rsquo were significantly stickier with adhesiveness value
of -029 kgs -027 kgs -023 kgs and -020 kgs respectively All other varieties exhibited
lower adhesiveness with values less than 010 kgs Visual examination of the cooked samples
showed that with the more adhesive varieties the seeds stuck together as with sticky rice while
for other varieties the grains were separated
Cohesiveness of cooked lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo was
significantly higher with values from 068 to 071 respectively while those of lsquo49ALCrsquo lsquo1ESPrsquo
and lsquoCol6197rsquo were lower at 054 056 and 053 respectively Springiness is the recovery
from crushing or the elastic recovery (Tsuji 1981 Seguchi et al 1998) Cooked quinoa of all
varieties exhibited excellent elastic recovery properties with springiness values approximating
10
Gumminess is the combination of hardness and cohesiveness Chewiness is gumminess
multiplied by springiness As springiness values were all close to 10 gumminess and chewiness
of cooked quinoa were very similar in value lsquoBlackrsquo lsquoBlancarsquo and lsquoCahuilrsquo were highest in
gumminess and chewiness 24 kg 22 kg and 23 kg respectively while lsquo1ESPrsquo lsquo49ALCrsquo and
lsquoCol6197rsquo were lowest at 14 kg 11 kg and 11 kg respectively The difference among varieties
was greater than three-fold
Cooking quality
Cooking quality of quinoa is shown in Table 4 Cooking time varied from 119 min in
lsquoCol6197rsquo to 192 min in lsquoBlackrsquo cultivar and was significantly correlated with all TPA texture
parameters Longer cooking time also correlated with higher protein content (r = 052 P = 007)
57
Water uptake ratio varied from 25 to 4 fold in lsquoQQ63rsquo and lsquoCol6197rsquo respectively Water
uptake ratio was negatively correlated to seed hardness (r = 052 P = 004) Harder seeds tended
to absorb less water during cooking Cooking volume ranged from 107 mL to 137 mL and did
not significantly correlate with other properties Cooking loss ranged from 035 to 176 and
differed among varieties but was not correlated with water uptake ratio cooking time or cooking
volume
Quinoa flour pasting properties by RVA
Pasting viscosity of quinoa whole seed flour was determined using the Rapid Visco
Analyzer (RVA) The results are shown in Table 5 Peak viscosity differed among varieties
Varieties could be categorized into three groups based on peak viscosity The peak viscosity of
lsquoQQ63rsquo lsquoCol6197rsquo lsquo1ESPrsquo lsquoJapanese Strainrsquo lsquoYellow Commercialrsquo lsquoCopacabanarsquo and lsquoRed
Commercialrsquo varied from 144 to 197 RVU The peak viscosity of lsquoBlancarsquo lsquoBlackrsquo lsquo49ALCrsquo
and lsquoCahuilrsquo ranged from 98 to 116 RVU while those of lsquoOro de Vallersquo and lsquoCherry Vanillarsquo
were 59 and 66 RVU respectively
Trough viscosity namely the minimum viscosity after the first peak showed more than a
three-fold difference among varieties As in the case of peak viscosity the trough of different
varieties can be categorized into the same three groups
Breakdown is the difference between the peak and minimum viscosity lsquoQQ63rsquo lsquo1ESPrsquo
and lsquoJapanese Strainrsquo showed large breakdowns of 51 51 and 62 RVU respectively
Breakdown of lsquoCherry Vanillarsquo lsquoOro de Vallersquo and the Commercial Yellow seed were lower at
12 10 and 11 RVU respectively Breakdown of the other varieties ranged from 18 to 36 RVU
58
The final viscosity of the Commercial Yellow seed was 203 RVU the highest among all
varieties Final viscosity of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo
ranged from 56 to 82 RVU and was lower than that of other varieties which ranged from 106 to
190 RVU
Setback is the difference between final and trough viscosity Setback of lsquoRed
Commercialrsquo lsquoCahuilrsquo and lsquoBlackrsquo were all negative -62 -11 and -6 RVU respectively which
indicated that the final viscosity of these cultivars was lower than their trough viscosity Setback
of lsquoBlancarsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo were slightly positive at 2 2 and 6 RVU
respectively while those of other cultivars were much greater between 42 and 73 RVU Peak
time which is the time to reach the first peak ranged from 93 to 115 min The pasting
temperature was 93 ordmC and not different among the varieties
Thermal properties of quinoa flour using DSC
Thermal properties of quinoa flour were determined using DSC Gelatinization
temperatures (To onset temperature Tp peak temperature Tc conclusion temperature) and
gelatinization enthalpies are shown in Table 6 To of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry
Vanillarsquo and lsquoJapanese Strainrsquo were not different from each other and ranged from 645 ordmC to
659 ordmC To of lsquoOro de Vallersquo lsquoCopacabanarsquo lsquoCol6197rsquo and lsquoQQ63rsquo ranged from 605 ordmC to
631 ordmC while other varieties were lower and ranged from 544 ordmC to 589 ordmC Tp ranged from
675 ordmC in the Commercial Yellow seed to 752 ordmC in lsquoCahuilrsquo Tc ranged from 780 ordmC in lsquoRed
Commercialrsquo to 850ordmC in the lsquoJapanese Strainrsquo Enthalpy of quinoa flour differed among
varieties The range was from 11 Jg in lsquoYellow Commercialrsquo to 18 Jg in lsquoBlancarsquo
Correlations between physical-chemical properties and cooked quinoa texture
59
A summary of correlation coefficients between quinoa physical-chemical properties and
TPA texture profile parameters of cooked quinoa are shown in Table 7 Seed hardness was found
to be positively related to the TPA hardness gumminess and chewiness of cooked quinoa (P lt
009) Seed bulk density was negatively correlated to hardness cohesiveness gumminess and
chewiness while seed coat proportion was positively correlated to those parameters Protein
content of quinoa exhibited a positive relationship with TPA hardness (P = 008) and
adhesiveness cohesiveness gumminess and chewiness No significant correlation was observed
between the seed size 1000 seed weight ash content and the texture properties of cooked
quinoa
Cooking time of quinoa was highly positively correlated with all of the TPA texture
profile parameters Water uptake ratio during cooking was found to be significantly associated
with hardness gumminess and chewiness of cooked quinoa while cooking volume also showed
a modest correlation to hardness (r = -047 P = 010) Cooking loss was not correlated with any
texture parameter
Flour pasting viscosity was significantly correlated with texture of cooked quinoa Peak
viscosity and breakdown exhibited negative correlations with the hardness gumminess and
chewiness of cooked quinoa (P lt 010) Breakdown was also negatively associated with the
cohesiveness (r = -051 P lt 010) Final viscosity and setback were found to be negatively
correlated to hardness cohesiveness gumminess and chewiness while setback also exhibited a
significant correlation to adhesiveness (r = -064 P = 002)
60
Considering thermal properties To exhibited strong positive correlations with all texture
parameters Tp was found to be moderately related to cohesiveness (r = 050 P = 008) Neither
Tc nor enthalpy was significantly correlated to the TPA parameters of cooked quinoa
Discussion
Seed characteristics
Harder seed yielded harder gummier and chewier TPA texture after cooking The
varieties with lower seed bulk density or thicker seed coat yielded a firmer more cohesive
gummier and chewier texture Likely the condensed cells and non-starch polysaccharides of the
seed coat are a barrier between starch granules in the middle perisperm and water molecules
outside the seed
Seed composition
Higher protein appeared to contribute to a firmer more adhesive gummier and chewier
texture of cooked quinoa as evidenced by the TPA parameters Protein has been reported to play
a significant role in the texture of cooked rice and noodles (Ramesh et al 2000 Martin and
Fitzgerald 2002 Saleh and Meullenet 2007 Xie et al 2008 Hou et al 2013) According to the
previous studies proteins affect the food texture through three major routes (1) binding of water
(Saleh and Meullenet 2007) (2) interacting reversibly with starch bodies (Chrastil 1993) and (3)
forming networks via disulphide bonds which restrict starch granule swelling and water
hydration (Saleh and Meullenet 2007)
Cooking quality
Cooking time was found to be a key factor for cooked quinoa texture as it was closely
associated with most texture attributes Other cooking qualities such as the water uptake ratio
61
cooking volume and cooking loss were not significantly correlated to texture In the study of
rice the cooking time of rice positively correlated with hardness negatively with cohesiveness
and not significantly with adhesiveness (Mohapatra and Bal 2006) The higher water uptake ratio
and volume expansion ratio were negatively associated with softer more adhesive and more
cohesive texture This result agrees with the study on cooked rice Rousset et al (1995) study
indicated that longer cooking time greater water uptake and cooking loss related to the softer
less crunchy and more pasty texture
Flour pasting properties
The varieties with a higher peak viscosity in flour had a softer less gummy and less
chewy texture after cooking The cultivars with higher final peak viscosity yielded a softer less
cohesive less gummy and chewy texture The varieties with a greater breakdown such as
lsquoQQ63rsquo lsquo1ESPrsquo and lsquoJapanese Strainrsquo were softer in TPA parameter Breakdown has been
reported to negatively correlate with the proportion of long chain amylopectin (Han and
Hamaker 2001) Long chain amylopectin may form intra- or inter-molecular interactions with
protein and lipids and result in a firmer or harder texture (Ong and Blanshard 1995)
Quinoa varieties with a lower setback were harder after cooking compared to those with a
higher setback In rice conversely setback was positively correlated with amylose content
(Varavinit et al 2003) which would positively influence the hardness of cooked rice (Ong and
Blanshard 1995 Champagne et al 1999) Unlike rice and many other cereals where the amylose
content is approximately 25-29 the amylose proportion in quinoa starch is lower on the order
of 11 (Ahamed et al 1996) Amylose may play a different role in cooked quinoa hardness
compared to other cereals
62
Starch viscosity has been reported to significantly affect the texture of cooked rice
Champagne et al (1999) used the RVA measurements to predict TPA of cooked rice and found
that adhesiveness strongly correlated to RVA parameters Harder rice was correlated with lower
peak viscosity and positive setback while stickier rice had a higher peak viscosity breakdown
and lower setback (Ramesh et al 2000) The difference between quinoa and rice seed structure
and starch composition and the difference of texture determining methods may contribute to the
different trends in correlation
Thermal properties
The gelatinization temperature of quinoa flour ranged from 55 ordmC to 85 ordmC lower than
that of whole rice flour which was 70 ordmC to 103 ordmC (Marshall 1994) This result agrees with the
previous study on quinoa flour (Ando et al 2002) The quinoa varieties with higher To exhibited
a firmer more adhesive more cohesive gummier and chewier texture Higher Tp was associated
with increased cohesiveness The enthalpy of quinoa flour ranged from 11 to 18 Jg about one-
tenth that of whole rice flour (141 ndash 151 Jg) (Marshall 1994) indicating that it takes less
energy to cook quinoa than cook rice
Thermal properties of quinoa flour were generally correlated with flour pasting
properties Higher To and Tp were correlated with lower flour peak viscosity and lower trough
The result is comparable to the previous study of Sandhu and Singh (2007) who found that
gelatinization temperature and enthalpy of corn starch strongly influenced the peak breakdown
final and setback viscosity The thermal properties of quinoa flour were not correlated with
breakdown and setback likely was due to other composition factors in the flour such as protein
and fiber
63
Conclusions
The texture of cooked quinoa varied markedly among the different varieties indicating
that genetics management or geographic origin may all be important considerations for quinoa
quality As such differences in seed morphology and chemical composition appear to contribute
to quinoa processing parameters and cooked texture Harder seed yielded a firmer gummier and
chewier texture both lower seed density and high seed coat proportion related to a firmer more
cohesive gummier and chewier texture Seed size and weight appeared to be largely unrelated to
the texture of the cooked quinoa Protein content was a key factor apparently influencing texture
Higher protein content was related to harder more adhesive and cohesive gummier and chewier
texture Cooking time and water uptake ratio significantly affected the texture of cooked quinoa
whereas cooking volume moderately affected the hardness cooking loss was not correlated with
texture RVA peak viscosity was negatively correlated with the hardness gumminess and
chewiness breakdown was also negatively correlated with those TPA parameters Final viscosity
and setback were negatively correlated with the hardness cohesiveness gumminess and
chewiness Setback was correlated with the adhesiveness as well Gelatinization temperature To
affected all the texture profile parameters positively Tp slightly related to the cohesiveness
while Tc and enthalpy were not correlated with the texture
Acknowledgements
This project was supported by funding from the USDA Organic Research and Extension
Initiative project number NIFA GRANT11083982 The authors acknowledge Stacey Sykes and
Alecia Kiszonas for editing support
Author Contributions
64
G Wu and CF Morris designed the study together G Wu collected test data and drafted the
manuscript CF Morris and KM Murphy edited the manuscript KM Murphy provided
samples and project oversight
65
References
AACC International 2012 Approved Methods of Analysis Method 08-0101 Ash - Basic
method Approved April 13 1961 Method 44-1502 Moisture ndash Air-Oven Methods (130ordmC)
Approved October 30 1975 Method 46-3001 Crude protein ndash Combustion method
Approved November 8 1995 Reapproved November 3 1999 Available online only
AACCI St Paul MN
Abugoch LE Romero N Tapia CA Silva J Rivera M 2008 Study of some physicochemical
and functional properties of quinoa (Chenopodium quinoa Willd) protein isolates J Agric
Food Chem 564745-50
Abugoch LEJ 2009 Chapter 1 Quinoa (Chenopodium quinoa Willd) Adv Food Nutr Res
581-31
Abugoch L Castro E Tapia C Antildeoacuten MC Gajardo P Villarroel A 2009 Stability of quinoa
flour proteins (Chenopodium quinoa Willd) during storage Int J Food Sci Tech 442013-20
Ahamed NT Singhal RS Kulkami PR Palb M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 3199-103
Alvarez-Jubete L Arendt EK Gallagher E 2010 Nutritive value of pseudocereals and their
increasing use as functional gluten-free ingredients Trends in Food Sci Tech 21(2)106-13
Ando H Chen YC Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food components in
fractions of quinoa seed Food Sci Technol Res 8(1)80-4
66
Baik BK Lee MR 2003 Effects of starch amylose content of wheat on textural properties of
white salted noodles Cereal Chem 80304-9
BeMiller JN Huber KC 2008 Carbohydrates In Damdaran S Parkin KL Fennema OR editors
Food chemistry Boca Raton CRC Press p 121
Champagne ET Lyon BG Min BK Vinyard BT Bett KL Barton IIFE Webb BD Kohlwey DE
1998 Effects of postharvest processing on texture profile analysis of cooked rice Cereal
Chem 75(2)181-6
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5)764-71
Champagne ET 2004 The rice grain and its gross composition In Champagne ET editor Rice
chemistry and technology St Paul Minn American Association of Cereal Chemists p 88
Chrastil J 1993 Enzyme activities in preharvest rice grains J Agric Food Chem 41(12)2245-8
Cortez G Repo-Carrasco R Rosell CM 2009 Breadmaking use of andean crops quinoa kantildeiwa
kiwicha and tarwi Cereal Chem 86(4)386-92
Del Castillo V Lescano G Armada M 2009 Foods formulation for people with celiac disease
based on quinoa (Chenopodium quinoa) cereal flours and starches mixtures Archivos
Latinoamericanos De Nutricion 59(3)332-36
67
Demirkesen I Mert B Sumnu G Sahin S 2010 Rheological properties of gluten-free bread
formulations J Food Eng 96(2)295-303
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(Waxy) genes J Cereal Sci 3551-63
Fitzgerald MA Martin M Ward RM Park WD Shead HJ 2003 Viscosity of rice flour a
rheological and biological study J Agric Food Chem 51(8) 2295-9
Food and Agriculture Organization of the United Nations (FAO) 2013 The international year of
quinoa Available from httpwwwfaoorgquinoa-2013en Accessed 2013 February 20
Han XZ Hamaker BR 2001 Amylopectin fine structure and rice starch paste breakdown J
Cereal Sci 34(3)279-84
Hou GG Saini R Ng PKW 2013 Relationship between physicochemical properties of wheat
flour wheat protein composition and textural properties of cooked chinese white salted
noodles Cereal Chem 90(5)419-29
Jancurovaacute M Minarovicova L Dandar A 2009 Quinoa ndash a review Czech J Food Sci 27(2)71-9
Juliano BO Villareal RM Bantildeos L 1987 Varietal differences in physicochemical properties of
waxy rice starch Starch - Staumlrke 39(9)298-301
68
Limpisut P Jindal VK 2002 Comparison of rice flour pasting properties using brabender
viscoamylograph and rapid visco analyser for evaluating cooked rice texture Starch - Staumlrke
54(8)350-7
Lindeboom N Chang PR Falk KC Tyler RT 2007 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2)216-22
Marshall WE 1994 Starch gelatinization in brown and milled rice a study using differential
scanning calorimetry In Marshall WE Wadsworth IJ editors Rice science and technology
New York NY Marcel Dekker Inc p 222
Martin M Fitzgerald MA 2002 Proteins in rice grains influence cooking properties J Cereal Sci
36(3)285-94
Mohapatra D Bal S 2006 Cooking quality and instrumental textural attributes of cooked rice
for different milling fractions J Food Eng 73(3)253-9
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine stucture of amylopectin J Cereal Sci 21(3)251-60
Pappier U Fernandez Pinto V Larumbe G Vaamonde G 2008 Effect of processing for saponin
removal on fungal contamination of quinoa seeds (Chenopodium quinoa Willd) Int J Food
Microbiol 125(2)153-7
Perdon AA Juliano BO 1975 Gel and molecular properties of waxy rice starch Starch - Staumlrke
27(3)69-71
69
Ramesh M Bhattacharya KR Mitchell JR 2000 Developments in understanding the basis of
cooked-rice texture Crit Rev Food Sci Nutr 40(6)449-60
Rousset S Pons B Pilandon C 1995 Sensory texture profile grain physico-chemical
characteristics and instrumental measurements of cooked rice J Texture Stud 26(2)119-35
Ruales J Valencia S Nair B 1993 Effect of processing on the physico-chemical characteristics
of quinoa flour (Chenopodium quinoa Willd) Starch - Staumlrke 45(1)13-9
Ruales J de Grijalva Y Lopez-Jaramillo P Nair BM 2002 The nutritional quality of an infant
food from quinoa and its effect on the plasma level of insulin-like growth factor-1 (IGF-1) in
undernourished children Int J Food Sci Nutr 53(2)143-54
Saleh MI Meullenet JF 2007 Effect of protein disruption using proteolytic treatment on cooked
rice texture properties J Texture Stud 38(4)423-37
Sandhu KS Singh N 2007 Some properties of corn starches II Physicochemical gelatinization
retrogradation pasting and gel textural properties Food Chem 101(4)1499-507
Schumacher A Brandelli A Macedo F Pieta L Klug T Jong E 2010 Chemical and sensory
evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J Food
Sci Tech 47(2)202-6
Seguchi M Hayashi M Kanenaga K Ishihara C Noguchi S1998 Springiness of pancake and
its relation to binding of prime starch to tailings in stored wheat flour Cereal Chem
75(1)37-42
70
Tang H 2004 Relationship between functionality and structure in barley starches Carbohydr
Polym 57(2)145-52
Tang H Mitsunaga T Kawamura Y 2005 Functionality of starch granules in milling fractions
of normal wheat grain Carbohyd Polym 59(1)11-7
Tsuji S 1981 Texture measurement of cooked rice kernels using the multiple-point mensuration
method 1 J Texture Stud 12(2)93-105
Vaclavik VA Christian EW 2003 Evaluation of food quality In Vaclavik V Christian EW
editors Essentials of food science New York NY Kluwer AcademicPlnum Publishers p 4
Varavinit S Shobsngob S Varanyanond W Chinachoti P Naivikul O 2003 Effect of amylose
content on gelatinization retrogradation and pasting properties of flours from different
cultivars of thai rice Starch - Staumlrke 55(9)410-5
Xie L Chen N Duan B Zhu Z Liao X 2008 Impact of proteins on pasting and cooking
properties of waxy and non-waxy rice J Cereal Sci 47(2)372-9
Zeng M Morris CF Batey IL Wrigley CW 1997 Sources of variation for starch gelatinization
pasting and gelation properties in wheat Cereal Chem 7463-71
71
Table 1-Varieties of quinoa used in the experiment
Variety Original Seed Source Location
Black White Mountain Farm White Mountain Farm Colorado US
Blanca White Mountain Farm White Mountain Farm Colorado US
Cahuil White Mountain Farm White Mountain Farm Colorado US
Cherry Vanilla Wild Garden Seeds Philomath Oregon WSUa Organic Farm Pullman Washington US
Oro de Valle Wild Garden Seeds Philomath Oregon WSUa Organic Farm Pullman Washington US
49ALC USDA Port Townsend Washington US
1ESP USDA Port Townsend Washington US
Copacabana USDA Port Townsend Washington US
Col6197 USDA Port Townsend Washington US
Japanese Strain USDA Port Townsend Washington US
QQ63 USDA Port Townsend Washington US
Yellow Commercial Multi Organics company Bolivia
Red Commercial Multi Organics company Bolivia a WSU - Washington State University
72
Table 2-Seed characteristics and compositiona
Variety Diameter (mm)
Hardness (kg)
Bulk Density (gmL)
Seed Coat Proportion ()
Protein ()
Ash ()
Black 21bc 994b 0584d 37bc 143d 215hi
Blanca 22ab 608l 0672c 89a 135e 284ef
Cahuil 21abc 772e 0757a 49b 170a 260fg
Cherry Vanilla 19e 850d 0717b 41b 160b 239gh
Oro de Valle 19e 1096a 0715b 43b 156b 305de
49ALC 19de 935c 0669c 26cd 127g 348bc
1ESP 19e 664h 0672c 10f 113i 248gh
Copacabana 20cd 643i 0671c 44b 129g 361b
Col6197 19e 583m 0657c 24de 118h 291ef
Japanese Strain 15f 618k 0610d 21def 148cd 324cd
QQ63 19e 672g 0661c 45b 135f 401a
Yellow Commercial
21abc 622j 0663c 14ef 146c 198i
Red Commercial 22a 706f 0730ab 26cd 145cd 226hi a Mean values with different letters within a column are significantly different (P lt 005)
73
Table 3-Texture profile analysis (TPA)a of cooked quinoa
Variety Hardness (kg)
Adhesiveness (kgs)
Cohesiveness Gumminess (kg)
Chewiness (kg)
Black 347a -004a 069ab 24a 24a
Blanca 306bcd -003a 071a 22abc 22abc
Cahuil 327abc -003a 071a 23ab 23ab
Cherry Vanilla 278de -002a 071a 20cd 20cd
Oro de Valle 285d -001a 068ab 19cd 19cd
49ALC 209f -029c 054d 11ef 11ef
1ESP 245e -027bc 056d 14e 14e
Copacabana 305bcd -010a 068ab 21bcd 21bcd
Col6197 202f -023bc 053d 11ef 11ef
Japanese Strain 293d -008a 066bc 19cd 19cd
QQ63 297cd -020b 062c 19d 19d
Yellow Commercial 306bcd -003a 069ab 21abc 21bc
Red Commercial 338ab -005a 068ab 23ab 23ab a Mean values with different letters within a column are significantly different (P lt 005)
74
Table 4-Cooking qualitya of quinoa
Variety Optimal Cooking Time (min)
Water uptake ()
Cooking Volume (mL)
Cooking Loss ()
Black 192a 297c 109c 065f
Blanca 183abc 344b 130ab 067f
Cahuil 169de 357ab 137a 102c
Cherry Vanilla 165ef 291c 107c 102c
Oro de Valle 173cde 238d 109c 102c
49ALC 136h 359ab 126b 043g
1ESP 153g 373ab 132ab 035h
Copacabana 157fg 379ab 127b 175a
Col6197 119i 397a 126b 176a
Japanese Strain 166def 371ab 116c 106b
QQ63 177bc 244d 126b 067f
Yellow Commercial 187ab 372ab 129ab 076d
Red Commercial 155fg 276cd 132ab 071e a Mean values with different letters within a column are significantly different (P lt 005)
75
Table 5-Pasting properties of quinoa flour by RVAa
Variety Peak Viscosity (RVU)
Trough
(RVU)
Breakdown
(RVU)
Final Viscosity (RVU)
Setback (RVU)
Peak Time (min)
Black 102g 81e 21e 75g -6f 102e
Blanca 98g 80e 18e 82g 2e 99f
Cahuil 116f 85e 31d 74g -11f 104de
Cherry Vanilla
66h 54g 12f 57h 2e 97fg
Oro de Valle
59h 50g 10f 56h 6e 93h
49ALC 107fg 71f 36c 132e 62b 97fg
1ESP 161cd 110c 51b 174c 64b 98fg
Copacabana 175b 141b 34cd 190b 49c 106cd
Col6197 155de 133b 22e 177bc 44cd 108bc
Japanese Strain
172bc 109c 62a 159d 50c 96gh
QQ63 144e 94d 51b 167cd 73a 97fg
Yellow Commercial
172bc 162a 11f 203a 41d 109b
Red Commercial
197a 168a 29d 106f -62g 115a
a Mean values with different letters within a column are significantly different (P lt 005)
76
Table 6-Thermal properties of quinoa flour by Differential Scanning Calorimetry (DSC)a
Gelatinization Temperature (ordmC)
Variety To Tp Tc Enthalpy (Jg)
Black 656a 725c 818abcd 15abc
Blanca 658a 743ab 819abcd 18a
Cahuil 659a 752a 839ab 16ab
Cherry Vanilla 649ab 741ab 823abc 12c
Oro de Valle 631bc 719cd 809abcde 12bc
49ALC 579e 714d 810bcde 15abc
1ESP 544f 690f 785de 15abc
Copacabana 630c 715cd 802cde 14abc
Col6197 605d 689f 785de 15abc
Japanese Strain 645abc 740b 850a 12c
QQ63 630c 702e 784de 13bc
Yellow Commercial 570e 676g 790cde 11c
Red Commercial 589de 693ef 780e 12c a Mean values with different letters within a column are significantly different (P lt 005)
77
Table 7-Correlation coefficients between quinoa seed characteristics composition and processing parameters and TPA texture of cooked quinoaa
Hardness Adhesiveness Cohesiveness Gumminess Chewiness
Seed Hardness 051 002ns 028ns 049 049
Bulk Density -055 -044ns -063 -060 -060
Seed Coat Proportion 074 038ns 055 072 072
Protein 050 077 075 057 057
Cooking Time 077 062 074 076 076
Water Uptake Ratio -058 -025ns -046ns -056 -056
Cooking Volume -048 -014ns -032ns -046ns -046ns
Peak Viscosity -051 -014ns -041ns -053 -054
Breakdown -048 -047ns -051 -053 -053
Final Viscosity -069 -043ns -060 -070 -070
Setback -058 -064 -059 -060 -060
To 059 054 061 061 061
Tp 042ns 041ns 050 045ns 046ns a ns non-significant difference P lt 010 P lt 005 P lt 001
78
Figure 1-Rapid Visco Analyzer (RVA) graph of lsquoCherry Vanillarsquo and lsquoRed Commercialrsquo
quinoa flours ( lsquoCherry Vanillarsquo lsquoRed Commercialrsquo Temperature)
Time (min)
0 10 20 30 40
Vis
cosi
ty (R
VU
)
0
50
100
150
200
250
Tem
pera
ture
(degC
)
50
100
150
200
79
Figure 2-Seed coat image by SEM
(1 whole seed section P-perisperm C-cotyledon 2 three layers of quinoa seed coat
3 seed coat of lsquoCherry Vanillarsquo 382 microm 4 seed coat of lsquo1ESPrsquo 95microm)
4 3
2 1
P
C C
80
Chapter 4 Quinoa Starch Characteristics and Their Correlation with
Texture of Cooked Quinoa
ABSTRACT
Starch composition and physical properties strongly influence the functionality and end-
quality of cereals Here correlations between starch characteristics and seed quality cooking
properties and texture were investigated Starch characteristics differed among the eleven
experimental varieties and two commercial quinoa tested The total starch content of seed ranged
from 532 to 751 g 100 g Total starch amylose content ranged from 27 to 169 and the
degree of amylose-lipid complex ranged from 34 to 433 The quinoa samples with higher
amylose tended to yield harder stickier more cohesive more gummy and more chewy texture
after cooking With higher degree of amylose-lipid complex or amylose leaching the cooked
quinoa tended to be softer and less chewy Higher starch enthalpy correlated with firmer more
adhesive more cohesive and more chewy texture Indicating that varieties with different starch
properties should be utilized in different end-products
Keywords quinoa starch texture cooked quinoa
Practical Application The research provided the starch characteristics of different quinoa
varieties showing correlations between starch and cooked quinoa texture These results can help
breeders and food manufacturers to better understand quinoa starch properties and the use of
cultivars for different food product applications
81
Introduction
Quinoa (Chenopodium quinoa Willd) is a pseudocereal from the Andean mountains in
South America Quinoa is garnering greater attention worldwide because of its high protein
content and balanced essential amino acids As in other crops starch is one of the major
components of quinoa seed Starch content structure molecular composition pasting thermal
properties and other characteristics may influence the cooking quality and texture of cooked
quinoa
The total starch content of quinoa seed has been reported to range from 32 to 69
(Abugoch 2009) Starch granules are small (1-2μm) compared to those of rice and barley (Tari et
al 2003) Amylose content of quinoa starch was reported to range from 35 to 225 (Abugoch
2009) generally lower than that of other crops Amylose content exhibited significant influence
on the texture of cooked quinoa (Ong and Blanshard 1995) Similarly cooked rice texture was
correlated to starch amylose and chain length (Ong and Blanshard 1995 Ramesh et al 1999)
and leaching of amylose and amylopectin during cooking (Patindol et al 2010) However
amylose-lipid complex and amylose leaching properties have not been studied in quinoa cultivars
with diverse genetic backgrounds Perdon et al (1999) indicated that starch retrogradation was
positively correlated with firmness and stickiness of cooked milled rice during storage and
similar correlations would be anticipated for quinoa
Starch swelling power and water solubility influenced wheat and rice noodle quality and
texture (Crosbie 1991 McCormick et al 1991 Konik et al 1993 Ross et al 1997 Bhattacharya
et al 1999) whereas the role of starch swelling powerwater solubility in the texture of cooked
quinoa has not been reported
82
The texture of rice starch gels has been studied Gel texture was influenced by treatment
temperature incorporation of glucomannan and sugar concentration (Charoenrein et al 2011
Jiang et al 2011 Sun et al 2014) The texture of quinoa starch gel however has not been
reported
Gelatinization temperature enthalpy and pasting properties of starch were correlated
with the texture of cooked rice (Ong and Blanshard 1995 Champagne et al 1999 Limpisut and
Jindal 2002) The correlations between starch thermal properties pasting properties and cooked
quinoa texture however have also not been reported
Starch is an important component of grains and exhibits significant influence on the
texture of cooked rice noodles and other foods The texture of cooked quinoa has been studied
previously (Wu et al 2014) however the correlation of starch and cooked quinoa texture
nevertheless remained unclear The objectives of the present study were to understand 1) the
starch characteristics of different quinoa varieties and 2) the correlations between the starch
characteristics and the texture of cooked quinoa
Materials and Methods
Starch isolation
Eleven varieties and two commercial quinoa samples were included in this study (Table
1) Quinoa starch was isolated using a method modified from Lindeboom et al (2005) and Qian
et al (1999) Two hundred grams of seed were steeped in 1000 mL NaOH (03 wv) overnight
at 4 degC and rinsed with distilled water three times to remove the saponins The rinsed quinoa
was ground in a Waring blender (Conair Corp Stamford CT USA) for 15 min The slurry
was screened through a series of sieves US No 40 100 and 200 mesh sieves with openings of
83
425 150 and 74 μm respectively Distilled water was added and stirred to speed up the
filtration Filter residue was discarded whereas the filtrate was centrifuged under 2000 times g for 20
min The supernatant was decanted and the top brown layer of sediment (protein and lipids) was
gently scraped loose and discarded The remaining pellet was resuspended in distilled water and
centrifuged again This resuspension-centrifuge process was repeated three times or until the
brown topmost layer was all removed The white starch pellet was then dispersed in 95 ethanol
and centrifuged under 2000 times g for 10 min The supernatant was discarded and the starch pellet
was air-dried and gently ground using a mortar and pestle
α-amylase activity
The activity of α-amylase was determined using a Megazyme Kit (Megazyme
International Ireland Co Wicklow Ireland)
Apparent total amylose content degree of amylose-lipid complex
Apparent amylose content was determined using a cold NaOH method (Mahmood et al
2007) with modification Sample of 10 mg was weighed into a 20 mL microcentrifuge tube To
the sample was added 150 μL of 95 ethanol and 900 μL of 1M NaOH mixed vigorously and
kept on a shaker overnight at room temperature The starch solution of 200 μL was removed and
combined with 1 mL of 005 M citric acid 800 μL iodine solution (02 g I2 2 g KI in 250 mL
distilled water) and 10 mL distilled water reaching a final volume of 12 mL The solution was
chilled in a refrigerator for 20 min The absorbance at 620nm was determined using a
spectrophotometer (Shimadzu Biospec-1601 DNAProteinEnzyme Analyzer Shimadzu corp
Kyoto Japan) A standard curve was created using a dilution series of amylose amylopectin
84
proportions of 010 19 28 37 46 and 55 respectively (Sigma-Aldrich Co LLC St Louis
MO USA)
Total amylose content was determined using the same method for apparent amylose
except that lipids in the starch samples were removed in advance The starch was defatted using
hexane and ultrasonic treatment as follows One gram of starch was dissolved in 15 mL hexane
and set in an ultrasonic water bath for 2 hours The suspension was then centrifuged at 1000 times g
for 1 min The supernatant was discarded and the procedure was repeated a second time The
sample was then dried in a fume hood overnight
Degree of amylose-lipid complex = [total amylose ndash apparent amylose] total amylose times 100
Amylose leaching properties
Amylose leaching was determined using the modified method of Hoover and Ratnayake
(2002) Starch (025 g) was mixed with 5 mL distilled water and heated at 60 degC for 30 min
then cooled in ice water and centrifuged at 2000 times g for 10 min Supernatant of 1 mL was added
to 800 μL iodine solution and 102 mL distilled water to achieve the same volume of 12 mL as
in the apparent amylose test The solution was chilled in a refrigerator for 20 min and the
absorbance at 620 nm was determined The amylose leaching was expressed as mg of amylose
leached from 100 g of starch
Starch pasting properties
Starch pasting properties were determined using the Rapid Visco Analyzer RVA-4
(Newport Scientific Pty Ltd Narrabeen Australia) Starch (3 g) was added to 25 mL distilled
water mixed and heated in the RVA using the following procedure The initial temperature was
50 ordmC and increased to 93 ordmC within 8 min at a constant rate held at 95 ordmC from 8 min to 24 min
85
cooled to 50 ordmC from 24 min to 28 min and held at 50 ordmC from 29 min to 40 min The result was
expressed in RVU units (RVU = cP12)
Starch gel texture
Starch gel texture was determined using a TA-XT2i Texture Analyzer (Texture
Technologies Corp Hamilton MA USA) The starch gels were prepared in the RVA using the
same procedure as for pasting properties Then the starch gels were stored at 4 degC for 24 hours
The testing procedure followed the method of Jiang et al (2011) with modification The gel
cylinder (3 cm high and 35 cm diameter) was compressed using a TA-25 cylinder probe at the
speed of pre-test 20 mms test 05 mms and post-test 05 mms to 10 mm deformation Two
compressions were conducted with an interval time of 20 s Hardness springiness and
cohesiveness were obtained from the TPA (Texture Profile Analysis) graph (x-axis distance and
y-axis force) Hardness (g) was expressed by the maximum force of the first peak springiness
was the ratio of distance (time) to peak 2 to distance to peak 1 cohesiveness was the ratio of the
second positive area under the compression curve to that of the first positive area
Freeze-thaw stability
Freeze-thaw stability was determined using the modified method from Lindeboom et al
(2005) and Charoenrein et al (2005) Starch slurry was cooked using the RVA with 125 g
starch and 25 mL distilled water The starch suspensions were heated at 60 degC from 0 ndash 2 min
the temperature was increased to 105 degC from 3 ndash 8 min with a constant rate and held at 105 degC
from 9 - 11 min The cooked samples were stored at -18 degC for 20 hours and then kept at room
temperature for 4 hours Water was decanted and the weight difference was determined The
86
freeze-thaw cycle was repeated five times The freeze-thaw stability was expressed as water loss
after each freeze-thaw cycle
Starch thermal properties
Thermal properties of starch were determined using Differential Scanning Calorimetry
(DSC) (Lindeboom et al 2005) Starch samples of 10 mg were weighed into aluminum pans
(Perkin-Elmer Kit No 219-0062) with 20 μL distilled water The pans were sealed and the
suspensions were incubated at room temperature (25 degC) for 2 hours to achieve equilibrium The
pans were then scanned at 10 degCmin from 25 degC to 120 degC The onset temperature (To) peak
temperature (Tp) and completion temperature (Tc) were the temperature to start the peak reach
the peak and complete the peak respectively Additionally enthalpy of gelatinization was
determined by the area under the peak
Swelling power and solubility
Swelling power and water solubility of starch were obtained at 93 degC (Vandeputte et al
2003) Starch samples of 05 g were added to 12 mL distilled water and mixed vigorously The
suspensions were immediately set in a water bath with a rotating rack at 93 degC for 30 min The
suspensions were then cooled in ice water for 2 min and centrifuged at 3000 g for 15 min The
supernatant was carefully removed with a pipette and the weight of wet sediment was recorded
The removed supernatants were dried in a 105 degC oven over night The weight of dry sediment
was recorded The swelling power and water solubility were expressed using the following
equations
Swelling power = wet sediment weight [dry sample weight times (1 ndash water solubility))
Water solubility = dry sediment weight dry sample weight times 100
87
Swelling power is expressed as a unitless ratio
Statistical analysis
All experiments were repeated three times Multiple comparisons were conducted using
Fisherrsquos LSD in SAS 92 (SAS Inst Cary NC USA) Correlations were calculated using
PROC CORR code in SAS 92 A P value of 005 was considered as the level of significance
unless otherwise specified
Results
Starch content and composition
Total starch content of quinoa seeds on a dry basis ranged from 532 g 100 g in the
variety lsquoBlackrsquo to 751 g 100 g in a commercial sample named lsquoYellow Commercialrsquo (Table 2)
Varieties lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo were lower in total
starch content all below 60 g100 g The Port Townsend seeds and commercial seeds contained
higher levels of starch mostly over 70 g100 g
Apparent amylose contents ranged from 27 in lsquo49ALCrsquo to 169 in lsquoCahuilrsquo all
lower than the corn starch standard which was 264 Varieties lsquoCahuilrsquo lsquoBlackrsquo and lsquoYellow
Commercialrsquo contained higher apparent amylose 147 to 169 It is worth noting that
lsquo49ALCrsquo contained the lowest apparent and total amylose contents 27 and 47 respectively
Total amylose of the other varieties ranged from 111 in lsquoQQ63rsquo to 173 in lsquoCahuilrsquo
The degree of amylose-lipid complex differed among the samples ranging from 34 in
lsquoCahuilrsquo to 43 in lsquo49ALCrsquo and lsquoCol6197rsquo Statistically however only lsquo49ALCrsquo and
lsquoCol6197rsquo were significantly higher than lsquoCahuilrsquo in degree of amylose-lipid complex
Starch properties
88
Amylose leaching property exhibited great differences among samples (Table 3)
lsquo49ALCrsquo and lsquo1ESPrsquo showed the highest amylose leaching at 862 and 716 mg 100 g starch
respectively lsquoCahuilrsquo lsquoJapanese Stainrsquo and lsquoRed Commercialrsquo were the lowest with amylose
leaching less than 100 mg 100 g starch lsquoBlackrsquo and lsquoBlancarsquo were relatively low as well with
210 and 171 mg amylose leaching 100 g starch The other varieties were intermediate and
ranged from 349 to 552 mg 100 g starch
Water solubility of quinoa starch ranged from 07 to 45 all lower than that of corn
starch which was 79 lsquoJapanese Strainrsquo lsquoQQ63rsquo lsquoCommercial Yellowrsquo and lsquoPeruvian Redrsquo
were the highest in water solubility 26 to 45 The starch water solubility in the other varieties
was between 10 and 19
Swelling power of quinoa starch ranged from 170 to 282 all higher than that of corn
starch (89) lsquo49ALCrsquo and lsquo1ESPrsquo showed the highest swelling powers 282 and 276
respectively lsquoYellow Commercialrsquo and lsquoRed Commercialrsquo showed relatively lower swelling
power 188 and 196 respectively The remaining varieties did not exhibit differences in
swelling power with values between 253 and 263
α-Amylase activity
Activity of α-amylase in quinoa flour separated the samples to three groups (Table 3)
lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo showed high α-amylase activity from
086 CU to 116 CU (Ceralpha Unit) lsquoBlackrsquo lsquo49ALCrsquo and lsquoCopacabanarsquo were lower in α-
amylase activity 043 031 and 020 CU respectively The other varieties and commercial
samples exhibited particularly low α-amylase activities with the values lower than 01 CU
Starch gel texture
89
Texture of starch gels included hardness springiness and cohesiveness (Table 4)
Hardness of starch gel of lsquoCahuilrsquo and lsquoJapanese Strainrsquo represented the highest and the lowest
values 900 and 201 g respectively Hardness of the other varieties ranged from 333 g in
lsquo49ALCrsquo to 725 g in lsquoBlackrsquo
lsquoJapanese Strainrsquo and lsquoYellow Commercialrsquo exhibited the highest and lowest springiness
values of the starch gels 092 and 071 respectively Springiness of other starch samples ranged
from 075 to 085 and were not significantly different from each other
Cohesiveness of starch gels ranged from 053 to 089 The starch gels of lsquoJapanese
Strainrsquo lsquoCol6197rsquo and lsquoCopacabanarsquo were more cohesive at 089 083 and 078 respectively
The starch gels of lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquo1ESPrsquo were moderately cohesive
with the cohesiveness of 072 ndash 073 Other varieties exhibited less cohesive starch gels lsquoQQ63rsquo
and commercial samples showed the least cohesive starch gels 053 ndash 057 For comparison the
hardness springiness and cohesiveness of the corn starch gel was 721 084 and 073
respectively These values were among the upper-to-middle range of those counterpart values of
the texture of quinoa starch gels
Starch thermal properties
Thermal properties of quinoa starch include gelatinization temperature and enthalpy
(Table 5) Onset temperature To of quinoa starch ranged from 515 ordmC in lsquoYellow Commercialrsquo to
586 ordmC in lsquoBlancarsquo Peak temperature Tp ranged from 595 ordmC in lsquoRed Commercialrsquo to 654 ordmC
in lsquoJapanese Strainrsquo Conclusion temperature ranged from 697 ordmC in lsquoCol6197rsquo to 788 ordmC in
lsquoJapanese Strainrsquo The commercial samples exhibited lower gelatinization temperatures To Tp
90
and Tc of the corn starch were 560 626 and 743 ordmC respectively They were within the ranges
of those values of the quinoa starches
Enthalpy refers to the energy required during starch gelatinization The enthalpy of
quinoa starch ranged from 99 to 116 Jg Starch from lsquoCahuilrsquo exhibited the highest enthalpy
116 Jg higher than that of lsquo49ALCrsquo and lsquoQQ63rsquo However enthalpies of other samples were
not significantly different Corn starch enthalpy was 105 Jg comparable to those of quinoa
starches
Starch pasting properties
Starch viscosity was investigated using the RVA (Table 6) Peak viscosity of quinoa
starches ranged from 193 to 344 RVU Varieties lsquoBlancarsquo and lsquoCahuilrsquo showed the highest peak
viscosities 344 and 342 RVU respectively lsquoJapanese Strainrsquo and lsquoQQ63rsquo were lowest in starch
peak viscosity 193 and 213 RVU respectively The peak viscosity of corn starch was 255 RVU
falling within the middle range of quinoa peak viscosities
The tough is the minimum viscosity after the first peak The trrough of quinoa starch
ranged from 137 to 301 RVU The starches of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and
lsquoOro de Vallersquo showed highest trough values from 252 to 301 RVU lsquo49ALCrsquo lsquo1ESPrsquo
lsquoCopacabanarsquo lsquoJapanese Strainrsquo and lsquoQQ63rsquo were lowest in trough ranging from 137 to 186
RVU The trough of corn starch was 131 RVU lower than that of all quinoa starches
Starch breakdown of lsquo49ALCrsquo was 119 RVU higher than that of other samples except
corn starch which was 124 RVU lsquoJapanese Strainrsquo and lsquoOro de Vallersquo showed the lowest
breakdowns 12 and 17 RVU respectively Breakdown of the other samples ranged from 39 to
97 RVU
91
Final viscosity of lsquoCahuilrsquo starch was 405 RVU significantly higher than that of other
varieties At the other extreme final viscosity of lsquo49ALCrsquo starch was 225 RVU significantly
lower than that of the other varieties The final viscosity of corn starch was 283 RVU close to
that of lsquoJapanese Strainrsquo and lsquoQQ63rsquo but lower than that of the other quinoa samples
The highest setback was observed with lsquo1ESPrsquo starch (140 RVU) At the other extreme
the setback of lsquoOro de Vallersquo was 53 RVU which was lower than the other quinoa samples
Additionally setbacks of lsquoBlancarsquo lsquo49ALCrsquo and lsquoJapanese stainrsquo starches were also among the
lower range varying from 82 RVU to 88 RVU The remaining varieties exhibited higher setback
from 101 RVA to 127 RVU Setback of corn starch was 152 RVU significantly higher than all
the other quinoa starches
RVA peak times of quinoa starches varied significantly among the samples lsquoJapanese
Strainrsquo lsquoBlancarsquo lsquoCahuilrsquo and lsquoOro de Vallersquo required longer time to reach the peak viscosity
with peak times of 105 to 113 min Other varieties showed shorter peak times between 79 to
99 min The starch of lsquo49ALCrsquo however only needed 64 min to reach peak viscosity shorter
than those of other quinoa samples The peak time of corn starch was 73 min shorter than those
of quinoa starches except lsquo49ALCrsquo
Freeze-thaw stability of starch
Freeze-thaw stability of starches was expressed as the water loss () of each freeze-thaw
cycle Quinoa starch samples and corn starch showed similar trends in freeze-thaw stability
Most water loss occurred after cycles 1 and 2 Starch gels on average (excluding lsquo49ALCrsquo) lost a
cumulative total of 522 ndash 689 of water after cycle 2 and a total of 745 ndash 823 after cycle 5
Furthermore the starch gels of lsquoQQ63rsquo and lsquo1ESPrsquo lost the least water indicating higher freeze-
92
thaw stability Conversely the starch gel of lsquoJapanese Strainrsquo lost the most water in every cycle
indicating the lowest degree of freeze-thaw stability
lsquo49ALCrsquo and lsquo1ESPrsquo starches exhibited freeze-thaw behavior that was different
compared to the other samples After freezing the samples of lsquo49ALCrsquo and lsquo1ESPrsquo produced
gels that were less rigid more viscous than the other samples Further they did not lose as much
water after the first cycle The sample of lsquo1ESPrsquo however turned into a solid gel from cycle 2 to
5 And the water loss of the lsquo1ESPrsquo gel was close to that of other samples during cycles 2 and 5
Correlations between starch properties and the texture of cooked quinoa
Correlations between starch properties and texture of cooked quinoa were examined
(Table 7) using texture profile analysis (TPA) of cooked quinoa of Wu et al (2014) Total starch
content was moderately correlated with adhesiveness of cooked quinoa (r = -048 P = 009) but
was not significantly correlated with any of the other texture parameters Conversely apparent
amylose content was highly correlated with all texture parameters (067 le r le 072) Total
amylose content also exhibited significant correlations with all texture parameters (056 le r le
061) Furthermore the degree of amylose-lipid complex was negatively correlated with all
texture parameters (-070 le r le -060) and amylose leaching proportion was highly correlated
with the texture of cooked quinoa (-084 le r le -074)
Water solubility and swelling power of starch were not observed to correlate well with
any of the texture parameters Higher α-amylase activity tended to yield more adhesive (r = 055)
and more cohesive (r = 051 P = 007) texture However α-amylase activity was not correlated
with the hardness gumminess or chewiness of cooked quinoa
93
Some texture parameters of starch gels were associated with the texture parameters of
cooked quinoa The hardness of starch gels was not correlated with the hardness of cooked
quinoa but was weakly correlated with adhesiveness (r = 059) Weakly positive correlations
were found between starch gel hardness and cooked quinoa cohesiveness gumminess and
chewiness (049 le r le 051 P le 010) Springiness and cohesiveness of starch gels were not
correlated with the measured textural properties of cooked quinoa
Onset gelatinization temperature (To) of starch exhibited weak correlations with
adhesiveness (r = 049 P = 009) and cohesiveness (r = 051 P = 007) but was not correlated
with the other texture parameters Peak gelatinization temperature (Tp) of starch was correlated
with cohesiveness (r = 056) and hardness adhesiveness gumminess and chewiness (047 le r le
056 P le 010) No correlation was found with conclusion temperature (Tc) and texture Starch
enthalpy did correlate with the texture parameters (r = 064 in hardness 069 le r le 072 in other
texture parameters)
Starch viscosity measurements were variably correlated with the texture of cooked
quinoa Peak viscosity correlated adhesiveness (r = 054 P = 006) and cohesiveness (r = 047 P
= 010) but not with the other texture parameters Trough was more highly correlated with
adhesiveness cohesiveness gumminess and chewiness (r = 077 in adhesiveness 055 le r le
063 in other texture parameters)
It is interesting to note that starch breakdown only correlated with adhesiveness of
cooked quinoa (r = -060) and not with any other texture parameter Setback was not correlated
with any texture parameter These two RVA parameters breakdown and setback are usually
considered to be important indexes of end-use quality In quinoa however breakdown and
94
setback of starch apparently are not predictive of cooked quinoa texture In addition final
viscosity was also correlated with adhesiveness (r = 068) and cohesiveness (r = 058) and
correlated moderately with gumminess and chewiness (r = 053 P = 006) Peak time was
correlated with adhesiveness (r = 077) cohesiveness (r = 068) gumminess (r = 060) and
chewiness (r = 060) and to a lesser extent with hardness (r = 053 P = 006)
Correlations between starch properties and seed DSC RVA characteristics
Total starch content correlated with seed hardness (r = -073) seed coat proportion (r = -
071) and starch viscosities (peak viscosity trough and final viscosity) (-068 lt r lt -060) and
also to a lesser extent with seed density (r = 054 P = 006) and starch thermal properties (To
Tp and enthalpy) (-051 lt r lt -049 008 lt P lt009) (Table 8)
Water solubility of starch was correlated with starch viscosity such as peak viscosity (r =
-049 P = 009) and breakdown (r = -048 P = 010) Swelling power was only correlated with
peak time (r = -054 P = 006) (data not shown)
Apparent amylose content was correlated with protein content (r = 058) and optimal
cooking time (r = 056) but total amylose content did not show either of these correlations Both
apparent and total amylose contents were correlated with starch gel hardness starch enthalpy
and starch viscosity such as trough breakdown final viscosity and peak time
The degree of amylose-lipid complex exhibited negative correlations with seed protein
content (r = -07) and optimal cooking time of quinoa seed (r = -067) Moreover amylose
leaching was negatively correlated with protein content (r = -062) starch gel hardness (r = --
064) starch Tp (r = -058) and enthalpy (r = -064) optimal cooking time (r = -055) and starch
viscosities such as breakdown (r = 062) and peak time (r = -081) Additionally α-amylase
95
activity was correlated with protein content (r = 066) seed density (r = -072) seed coat
proportion (r = 055) starch To (r = 061) and starch viscosities such as peak viscosity (r =
070) trough (r = 072) and final viscosity (r = 061)
Discussion
Starch content and composition
Total starch content does influence the functional and processing properties of cereals
The total starch content of quinoa was reported to be between 32 and 69 (Abugoch 2009)
Among our varieties most of the Port Townsend varieties and commercial quinoa contained
more than 69 starch It is interesting to note that the Port Townsend samples lsquo49ALCrsquo lsquo1ESPrsquo
lsquoCol6197rsquo and lsquoQQ63rsquo were also more sticky or more adhesive after cooking than other
varieties These varieties may exhibit better performance in extrusion products or in beverages
which require high viscosity
Amylose content affects texture and gelation properties The proportion of amylose and
amylopectin impacts the functionality of cereals in this study both apparent and total amylose
contents were determined Total amylose includes those amylose molecules that are complexed
with lipids
Amylose content of quinoa was reported to range from 35 to 225 dry basis
(Abugoch 2009) generally lower than that of common cereals which is around 25 Overall
both apparent and total amylose contents of the quinoa in the present study fell within the range
which has been reported lsquo49ALCrsquo was an exception showing significantly lower apparent and
total amylose contents of 27 and 47 respectively Thus this variety is close to be being a
lsquowaxyrsquo which refers to the cereal starches that are comprised of mostly amylopectin (99) and
96
little amylose (~1) As the waxy wheat showed an excellent expansion during extrusion
(Kowalski et al 2014) lsquo49ALCrsquo is a promising variety to produce breakfast cereal or extruded
snacks
The degree of amylose-lipid complex showed great variability among the samples 34 ndash
433 whereas the value in wheat flour was reported to be 32 (Bhatnagar and Hanna 1994) or
13 to 23 (Zeng et al 1997) Degree of amylose-lipid complex showed significant and
negative correlations with all texture parameters such as hardness adhesiveness cohesiveness
gumminess and chewiness
The effect of amylose-lipid complex on product texture has been reported in previous
studies The degree of amylose-lipid complex correlated with the texture (hardness and
crispness) and quality (radial expansion) of corn-based snack (Thachil et al 2014) Wokadala et
al (2012) indicated that amylose-lipid complexes played a significant role in starch biphasic
pasting
Starch properties
Amylose leaching was also highly variable among the quinoa varieties 35 ndash 862 mg
100g starch Vandeputte et al (2003) studied amylose leaching of waxy and normal rice
starches The amylose leaching values at 65 ordmC were below 1 of starch comparable with those
in quinoa starch Pronounced increase of amylose leaching was observed at the temperatures
higher than 95 ordmC Patindol et al (2010) found that both amylose and amylopectin leached out
during cooking rice The proportion of the leached amylose and amylopectin influenced the
texture of cooked rice We found similar results indicating correlations between amylose
leaching and texture of cooked quinoa
97
Water solubility of quinoa starch was significantly lower than that of corn starch whereas
swelling power of quinoa starch was higher than that of corn starch Both water solubility and
swelling power were determined at 95 ordmC Lindeboom et al (2005) determined swelling power
and solubility of quinoa starch among eight varieties at 65 75 85 and 95 ordmC The water
solubility at 95 ordmC ranged from 01 to 47 which was lower than the corn starch standard of
100 The swelling power at 95 ordmC ranged from 164 to 526 lower than the corn starch
standard of 549 The quinoa starch in this study showed a narrower range of swelling power
170 to 282
α-Amylase activity
The quinoa in this study had significantly different α-amylase activity (003 ndash 116 CU)
Previous studies reported low α-amylase activity in quinoa compared to oat (Maumlkinen et al
2013) and traditional malting cereals (Hager et al 2014) Moreover the activity of α-amylase
indicates the degree of seed germination and the availability of sugars for fermentation In the
study of Hager et al (2014) α-amylase activity increased from 0 to 35 CU during 72 h
germination
Texture of starch gel
Starch gel texture has been previously studied on corn and rice starches but not on
quinoa starch Hardness of rice starch gel was reported to be 339 g by Charoenrein et al (2011)
and 116 g by Jiang et al (2011) Hardness of corn starch was reported to be around 100 g in the
study of Sun et al (2014) much lower than the standard corn starch hardness in this study 721
g Compared to those of rice and corn starch quinoa starch gel exhibited harder texture which
may be caused by either genetic variation or different processing procedures to form the gel
98
Additionally springiness and cohesiveness of rice starch gel were reported as 085 and 055
respectively (Jiang et al 2011) Quinoa starch gel exhibited comparable springiness and higher
cohesiveness than those of rice starch gel
Thermal properties of quinoa starch
The thermal properties of quinoa starch in this study were comparable to those of rice
starch (Cai et al 2014) The study of Lindeboom et al (2005) however found lower
gelatinization temperatures and higher enthalpies compared to the present study which may be
due to varietal difference
Furthermore correlation between thermal properties of quinoa starch and flour (Wu et al
2014) was investigated Gelatinization temperatures To Tp and Tc of starch and whole seed
flour were highly correlated especially To and Tp exhibited high r of 088 The enthalpy of
starch and flour however was not significantly correlated In this case quinoa flour can be used
to estimate quinoa starch gelatinization temperatures but not the enthalpy Additionally since
flour is easier to prepare compared to starch further studies can be conducted with a larger
number of quinoa samples to model the prediction of starch thermal properties using flour
thermal properties
Starch pasting properties
Viscosity and pasting properties of starch play a significant role in the functionality of
cereals Jane et al (1999) studied the pasting properties of starch from cereals such as maize
rice wheat barley amaranth and millet The peak viscosities ranged from 58 RVU in barley to
219 RVU in sweet rice lower than those of most quinoa starches except lsquoJapanese Strainrsquo and
lsquoQQ63rsquo Final viscosities ranged from 54 RVU in barley to 208 RVU in cattail millet all lower
99
than those of the quinoa starches in the present study Setback of cereal starches mostly ranged
from 6 RVU in waxy amaranth to 74 RVU in non-waxy maize lower than those of most quinoa
starches except lsquoOre de Vallersquo Cattail millet starch exhibited the setback of 208 RVU higher
than those of quinoa starches
The relationships between RVA pasting parameters of quinoa starch and flour were
studied by Wu et al (2014) Final viscosity of starch and flour was correlated negatively (r = -
063 P = 002) The other RVA parameters did not exhibit significant correlation between starch
and flour RVA In other words RVA of quinoa flour cannot be used to predict RVA of quinoa
starch In addition to starch the fiber and protein in whole quinoa flour may influence the
viscosity As quinoa is normally utilized as whole grain or whole grain flour instead of refined
flour the flour RVA should be a better indication on the end-use functionality
Freeze-thaw stability of starch
Quinoa starches in the present study did not show high stability during freeze and thaw
cycles Praznik et al (1999) studied freeze-thaw stability of various cereal starches Similar to
the present study Praznik et al concluded quinoa starches exhibited low freeze-thaw stability
Conversely Ahamed et al (1996) found quinoa starch exhibited excellent freeze-thaw stability
Unfortunately the variety was not indicated Overall it is reasonable to assert that for some
quinoa cultivars the starch may have better freeze-thaw stability than in other cultivars
However most quinoa varieties in published studies did not show good freeze-thaw stability
Correlations between starch characteristics and texture of cooked quinoa
The quinoa starch characteristics correlated with the texture of cooked quinoa in some
aspects Total starch content however did not show any strong correlations with TPA
100
parameters as was initially expected Since quinoa is consumed as whole grain or whole flour
fiber and bran may exhibit more influence on the texture than anticipated from the impact of
starch alone
The quinoa varieties with higher apparent and total amylose contents tended to yield a
harder stickier more cohesive more gummy and chewy texture Similar correlations are found
with cooked rice noodle and corn-based extrusion snacks The hardness of cooked rice was
positively correlated with amylose content and negatively correlated with adhesiveness (Yu et al
2009) Epstein et al (2002) reported that full waxy noodles were softer thicker less adhesive
and chewy and more cohesive and springy compared to normal noodles and partial waxy
noodles Increased amylose content in a corn-based extrusion snack resulted in higher amylose-
lipid formation and softer texture (Thachil et al 2014)
Higher levels of amylose-lipid complex in starch were associated with softer less
adhesive less cohesive and less gummy and less chewy cooked quinoa The correlation between
the degree of amylose-lipid complex and texture of cooked rice or quinoa has not been
previously reported Kaur and Singh (2000) however found that amylose-lipid complex
increased with longer cooking time of rice flour Additionally cooking time is a key factor to
determine texture ndash the longer a cereal is cooked the softer less sticky less cohesive and less
gummy and chewy the texture
Correlations were found between amylose leaching and cooked quinoa TPA parameters
especially hardness gumminess and chewiness with r of -082 Increased amylose leaching
yielded a softer gel made from potato starch (Hoover et al 1994) However the correlations of
101
amylose leaching and α-amylase activity with texture of end product for quinoa have not been
reported previously
Swelling power and water solubility were reported to influence the texture of wheat and
rice noodle (Crosbie 1991 McCormick et al 1991 Konik et al 1993 Ross et al 1997
Bhattacharya et al 1999) However in the present report no correlation was found between
swelling power water solubility and the texture of cooked quinoa Additionally the study of
Ong and Blanshard (1995) indicated a positive correlation between enthalpy and the texture of
cooked rice Similar results were found in this study
RVA is a fast and reliable way to predict flour functionality and end-use properties
Pasting properties of rice flour have been used to predict texture of cooked rice (Champagne et
al 1999 Limpisut and Jindal 2002) In our previous study cooked quinoa texture correlated
negatively with the final viscosity and setback of quinoa flour (Wu et al 2014) In this study
texture correlated with trough breakdown final viscosity and peak time of quinoa starch
However RVA of quinoa flour and starch did not correlate with each other Flour RVA might be
a convenient way to predict cooked quinoa texture
Correlations between starch properties and seed DSC RVA characteristics
Quinoa with higher total starch tended to have a thinner seed coat This makes sense
because starch protein lipids and fiber are the major components of seed An increase in one
component will result in a proportional decrease in the other component contents
Additionally the starch RVA parameters (except peak viscosity) can be used to estimate
apparent or total amylose content based on their correlations Further studies should be
conducted with a larger sample size of quinoa and a more accurate prediction model can be built
102
The samples with lower protein or those requiring shorter cooking time tended to contain
higher levels of amylose-lipid complex Additionally amylose-lipid complex was reported to
influence the texture of extrusion products (Bhatnagar and Hanna 1994 Thachil et al 2014) For
this reason protein and optimal cooking time are promising indicators of the behavior of quinoa
during extrusion
Conclusions
In summary starch content composition and characteristics were significantly different
among quinoa varieties Amylose content degree of amylose-lipid complex and amylose
leaching property of quinoa starch exhibited great variances and strong correlations with texture
of cooked quinoa Additionally starch gel texture pasting properties and thermal properties
were different among varieties and different from those of rice and corn starches Enthalpy
RVA trough final viscosity and peak time exhibited significant correlations with cooked quinoa
texture Overall starch characteristics greatly influenced the texture of cooked quinoa
Acknowledgments
This project was supported by the USDA Organic Research and Extension Initiative
(NIFAGRANT11083982) The authors acknowledge Girish Ganjyal and Shyam Sablani for
using the Differential Scanning Calorimetry (DSC) thanks to Stacey Sykes for editing support
Author Contributions
G Wu and CF Morris designed the study together and established the starch isolation
protocol G Wu collected test data and drafted the manuscript CF Morris and KM Murphy
edited the manuscript KM Murphy provided quinoa samples
103
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Chem 71(4)511-7
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92(2)145-53
Limpisut P Jindal VK 2002 Comparison of rice flour pasting properties using Brabender
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Patindol J Gu X Wang YJ 2010 Chemometric analysis of cooked rice texture in relation to
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of cooked milled rice during storage J Food Sci 64(5)828-32
107
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starch Starch‐Staumlrke 51(4)116-20
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cooked-rice texture Carbohydr Polym 38(4)337-47
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glucose fructose and maltose syrup PloS one 9(4)e95862
Thachil MT Chouksey MK Gudipati V 2014 Amylose-lipid complex formation during
extrusion cooking effect of added lipid type and amylose level on corn-based puffed snacks
Int J Food Sci Tech 49(2)309-16
Vandeputte GE Derycke V Geeroms J Delcour JA 2003 Rice starches II Structural aspects
provide insight into swelling and pasting properties J Cereal Sci 38(1)53-9
Wokadala OC Ray SS Emmambux MN 2012 Occurrence of amylosendashlipid complexes in teff
and maize starch biphasic pastes Carbohydr Polym 90(1)616-22
108
Wu G Morris C F Murphy K M 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79(11)2337-45
Yu S Ma Y Sun DW 2009 Impact of amylose content on starch retrogradation and texture of
cooked milled rice during storage J Cereal Sci 50(2)139-44
Zeng M Morris CF Batey IL Wrigley CW 1997 Sources of variation for starch gelatinization
pasting and gelation properties in wheat Cereal Chem 74(1)63-71
109
Table 1-Quinoa varieties tested
Variety Original Seed Source Location
Black White Mountain Farm White Mountain Farm Colo USA
Blanca White Mountain Farm White Mountain Farm Colo USA
Cahuil White Mountain Farm White Mountain Farm Colo USA
Cherry Vanilla Wild Garden Seeds Philomath Oregon
WSUa Organic Farm Pullman Wash USA
Oro de Valle Wild Garden Seeds Philomath Oregon
WSUa Organic Farm Pullman Wash USA
49ALC USDA Port Townsend Wash USA
1ESP USDA Port Townsend Wash USA
Copacabana USDA Port Townsend Wash USA
Col6197 USDA Port Townsend Wash USA
Japanese Strain USDA Port Townsend Wash USA
QQ63 USDA Port Townsend Wash USA
Yellow Commercial Multi Organics company Bolivia
Red Commercial Multi Organics company Bolivia a WSU Washington State Univ
110
Table 2-Starch content and composition
Variety Total starch
(g 100 g)
Apparent amylose
()
Total
amylose ()
Degree of amylose
lipid complex ()
Black 532f 153a 159ab 96bc
Blanca 595de 102cd 163a 361ab
Cahuil 622d 169a 173a 34c
Cherry Vanilla
590de 105cd 116bc 164abc
Oro de Valle 573ef 114bcd 166a 300abc
49ALC 674c 27e 47d 426a
1ESP 705bc 86d 152abc 389ab
Copacabana 734ab 120bc 153abc 222abc
Col6197 725ab 102cd 140abc 433a
Japanese Strain
723ab 116bcd 165ab 305abc
QQ63 713abc 84d 111c 241abc
Yellow Commercial
751a 147ab 150abc 118abc
Red Commercial
691bc 100cd 164a 375ab
Corn starch - 264 - -
111
Table 3-Starch properties and α-amylase activity
Variety Amylose leaching (mg 100 g starch)
Water solubility ()
Swelling power
α-Amylase activity (CU)
Black 210ef 16de 260bcd 043d
Blanca 171efg 10de 260bcd 086c
Cahuil 97fg 16cde 253cd 106b
Cherry Vanilla 394d 15de 253cd 116a
Oro de Valle 420d 16de 245d 103b
49ALC 862a 07e 282a 031e
1ESP 716b 13de 276ab 003g
Copacabana 438cd 14de 263bc 020f
Col6197 552c 19cd 257cd 009g
Japanese Strain 31fg 45a 170f 005g
QQ63 315de 26bc 262bc 008g
Yellow Commercial
349d 32b 188e 005g
Red Commercial 35g 26bc 196e 003g
Corn starch - 79 89 -
112
Table 4-Texture of starch gel
Variety Hardness (g) Springiness Cohesiveness
Black 725ab 082ab 064cd
Blanca 649abc 083ab 072bc
Cahuil 900a 085ab 072bc
Cherry Vanilla 607abc 078bc 072bc
Oro de Valle 448abc 078bc 064cd
49ALC 333bc 081bc 061cd
1ESP 341bc 081bc 073bc
Copacabana 402bc 084ab 078ab
Col6197 534abc 083ab 083ab
Japanese Strain 765ab 092a 089a
QQ63 201c 078bc 053d
Yellow Commercial 436bc 071c 057d
Red Commercial 519abc 075bc 055d
Corn starch 721 084 073
113
Table 5-Thermal properties of starch
Variety Gelatinization temperature Enthalpy (Jg)
To (ordmC) Tp (ordmC) Tc (ordmC)
Black 560b 639bc 761bc 112abc
Blanca 586a 652ab 754bcd 113abc
Cahuil 582a 648ab 755bcd 116a
Cherry Vanilla 563b 627cd 747bcd 111abc
Oro de Valle 562b 623d 739cd 106abc
49ALC 524ef 598f 747bcd 101bc
1ESP 530de 608ef 738cd 103abc
Copacabana 565b 622d 731de 106abc
Col6197 540cd 598f 697f 105abc
Japanese Strain 579a 654a 788a 104abc
QQ63 545c 616de 766ab 99c
Yellow Commercial 515f 599f 708ef 107abc
Red Commercial 520ef 595f 700 f 116ab
Corn starch 560 626 743 105
114
Table 6-Pasting properties of starch
Variety Peak viscosity
(RVU)a
Trough
(RVU)
Breakdown
(RVU)
Final viscosity
(RVU)
Setback
(RVU)
Peak time
(min)
Black 293abc 252abc 41efg 363ab 111abcd 92e
Blanca 344a 301a 42defg 384ab 82de 111ab
Cahuil 342ab 297a 45def 405a 108abcd 106bc
Cherry Vanilla 313abc 263abc 50de 369ab 106abcd 99d
Oro de Valle 294abc 277ab 17fg 330abc 53e 105c
49ALC 256cde 137f 119a 225d 88cde 64i
1ESP 269bcd 172ef 97ab 313bc 140a 79h
Copacabana 258cde 186def 72bcd 308bc 122abc 81gh
Col6197 270bcd 231bcd 39efg 347ab 116abcd 86fg
Japanese Strain 193e 181def 12g 264cd 83de 113a
QQ63 213de 152f 60cde 254cd 101bcd 88ef
Yellow Commercial
290abc 223cde 67bcde 350ab 127ab 93de
Red Commercial 327abc 242bc 85bc 366ab 125ab 92ef
Corn 255 131 124 283 152 73 aRVU = cP12
115
Table 7-Correlation coefficients between starch properties and texture of cooked quinoaa
Hardness Adhesiveness Cohesiveness Gumminess Chewiness
Total starch content
-032ns -048 -043ns -039ns -039ns
Apparent amylose content
069 072 069 072 072
Actual amylose content
061 062 056 061 061
Degree of amylose-lipid complex
-065 -060 -070 -070 -070
Amylose leaching
-082 -075 -074 -082 -082
α-Amylase activity
018ns 055 051 032ns 032ns
Starch gel hardness
042ns 059 051 049 049
DSC
To 034ns 049 051 041ns 041ns
Tp 047 052 056 052 052
ΔH 064 072 069 070 070
RVA
Peak viscosity 031ns 054 047 041ns 041ns
Trough 044ns 077 063 055 055
Breakdown -034ns -060 -044ns -038ns -038ns
Final viscosity 045ns 068 058 053 053
Peak time 053 077 068 060 060
ns non-significant difference P lt 010 P lt 005 P lt 001 aTPA is the Texture Profile Analysis of cooked quinoa data were presented in Wu et al (2014)
116
Table 8-Correlations between starch properties and seed DSC RVA characteristicsa
Total
starch content
Water solubility
Apparent amylose content
Total amylose content
Degree of amylose-lipid complex
Amylose leaching
α-Amylase activity
Protein -047ns 023ns 058 031ns -069 -062 066
Seed hardness
-073 -041ns -003ns -021ns -020ns 019ns 053
Bulk density
054 049 -020ns -015ns 031ns 019ns -072
Seed coat proportion
-071 -041ns 027ns 021ns -028ns -038ns 055
Starch gel hardness
-045ns 017 ns 065 053 -044ns -064 046ns
Starch DSC
To -049 -004ns 041ns 043ns -033ns -049 061
Tp -050 010ns 047ns 045ns -042ns -058 052
Enthalpy -051 -011ns 059 055 -041ns -064 049
Starch viscosity
Peak viscosity
-066 -049 028ns 027ns -020ns -023ns 070
Trough -068 -017ns 056 057 -031ns -052 072
Breakdown
022ns -048 -061 -067 027ns 062 -025ns
Final viscosity
-060 -022ns 063 060 -037ns -046ns 061
Peak time -032ns 045ns 058 072 -029ns -081 043ns
117
Cooking quality
Optimal cooking time
-043ns 019ns 056 040ns -067 -055 029ns
ns non-significant difference P lt 010 P lt 005 P lt 001 aSeed characteristics data were presented in Wu et al (2014)
118
Chapter 5 Quinoa Seed Quality Response to Sodium Chloride and
Sodium Sulfate Salinity
Submitted to the Frontiers in Plant Science
Research Topic Protein crops Food and feed for the future
Abstract
Quinoa (Chenopodium quinoa Willd) is an Andean grain with an edible seed that both contains
high protein content and provides high quality protein with a balanced amino acid profile
Quinoa is a halophyte adapted to harsh environments with highly saline soil In this study four
quinoa varieties were grown under six salinity treatments and two levels of fertilization and then
evaluated for quinoa seed quality characteristics including protein content seed hardness and
seed density Concentrations of 8 16 and 32 dS m-1 of NaCl and Na2SO4 as well as a no-salt
control were applied to the soil medium across low (1 g N 029 g P 029 g K per pot) and high
(3 g N 085 g P 086 g K per pot) fertilizer treatments Seed protein content differed across soil
salinity treatments varieties and fertilization levels Protein content of quinoa grown under
salinized soil ranged from 130 to 167 comparable to that from normal conditions NaCl
and Na2SO4 exhibited different impacts on protein content Whereas the different concentrations
of NaCl did not show differential effects on protein content the seed from 32 dS m-1 Na2SO4
contained the highest protein content Seed hardness differed among varieties and was
moderately influenced by salinity level (P = 009) Seed density was affected significantly by
119
variety and Na2SO4 concentration but was unaffected by NaCl concentration The plants from 8
dS m-1 Na2SO4 soil had lower density (066 gcm3) than those from 16 dS m-1 and 32 dS m-1
Na2SO4 074 and 072gcm3 respectively This paper identifies changes in critical seed quality
traits of quinoa as influenced by soil salinity and fertility and offers insights into variety
response and choice across different abiotic stresses in the field environment
Key words quinoa soil salinity protein content hardness density
120
Introduction
Quinoa (Chenopodium quinoa Willd) has garnered much attention in recent years
because it is an excellent source of plant-based protein and is highly tolerance of soil salinity
Because soil salinity affects between 20 to 50 of irrigated arable land worldwide (Pitman and
Lauchli 2002) the question of how salinity affects seed quality in a halophytic crop like quinoa
needs to be addressed Protein content in most quinoa accessions has been reported to range from
12 to 17 depending on variety environment and inputs (Rojas et al 2015) This range
tends to be higher than the protein content of wheat barley and rice which were reported to be
105- 14 8-14 and 6-7 respectively (Shih 2006 Orth and Shellenberger1988 Cai et
al 2013) Additionally quinoa has a well-balanced complement of essential amino acids
Specifically quinoa is rich in lysine which is considered the first limiting essential amino acid in
cereals (Taylor and Parker 2002) Protein quality such as Protein Efficiency Ratio is similar to
that of casein (Ranhotra et al 1993) Furthermore with a lack of gluten protein quinoa can be
safely consumed by gluten sensitiveintolerant population (Zevallos et al 2014)
Quinoa shows exceptional adaption to harsh environments such as drought and salinity
(Gonzaacutelez et al 2015) Soil salinity reduces crop yields and is a worldwide problem In the
United States approximately 54 million acres of cropland in forty-eight States were occupied by
saline soils while another 762 million acres are at risk of becoming saline (USDA 2011) The
salinity issue leads producers to grow more salt-tolerant crops such as quinoa
Many studies have focused on quinoarsquos tolerance to soil salinity with a particular
emphasis on plant physiology (Ruiz-Carrasco et al 2011 Adolf et al 2012 Cocozza et al
121
2013 Shabala et al 2013) and agronomic characteristics such as germination rate plant height
and yield (Prado et al 2000 Chilo et al 2009 Peterson and Murphy 2015 Razzaghi et al
2012) For instance Razzaghi et al (2012) showed that the seed number per m2 and seed yield
did not decrease as salinity increased from 20 to 40 dS m-1 in the variety Titicaca Ruiz-Carrasco
et al (2011) reported that under 300 mM NaCl germination and shoot length were significantly
reduced whereas root length was inhibited in variety BO78 variety PRJ biomass was less
affected and exhibited the greatest increase in proline concentration Jacobsen et al (2000)
suggested that stomatal conductance leaf area and plant height were the characters in quinoa
most sensitive to salinity Wilson et al (2002) examined salinity stress of salt mixtures of
MgSO4 Na2SO4 NaCl and CaCl2 (3 ndash 19 dS m-1) No significant reduction in plant height and
fresh weight were observed In a comparison of the effects of NaCl and Na2SO4 on seed yield
quinoa exhibited greater tolerance to Na2SO4 than to NaCl (Peterson and Murphy 2015)
Few studies have focused on the influence of salinity on seed quality in quinoa Karyotis
et al (2003) conducted a field experiment in Greece (80 m above sea level latitude 397degN)
With the exception of Chilean variety lsquoNo 407rsquo seven other varieties exhibited significant
increases in protein (13 to 33) under saline-sodic soil with electrical conductivity (EC) of
65 dS m-1 Mineral contents of phosphorous iron copper and boron did not decrease under
saline conditions Koyro and Eisa (2008) found a significant increase in protein and a decrease in
total carbohydrates under high salinity (500 mM) Pulvento et al (2012) indicated that fiber and
saponin contents increased under saline conditions with well watersea water ratio of 11
compared to those under normal soil
122
Protein is one of the most important nutritional components of quinoa seed The content
and quality of protein contribute to the nutritional value of quinoa Additionally seed hardness is
an important trait in crops such as wheat and soybeans For instance kernel hardness highly
influences wheat end-use quality (Morris 2002) and correlates with other seed quality
parameters such as ash content semolina yield and flour protein content (Hruškovaacute and Švec
2009) Hardness of soybean influenced water absorption seed coat permeability cookability
and overall texture (Zhang et al 2008) Quinoa seed hardness was correlated with the texture of
cooked quinoa influencing hardness chewiness and gumminess and potentially consumer
experience (Wu et al 2014) Furthermore seed density is also a quality index and is negatively
correlated with the texture of cooked quinoa such as hardness cohesiveness chewiness and
gumminess (Wu et al 2014)
Chilean lowland varieties have been shown to be the most well-adapted to temperate
latitudes (Bertero 2003) and therefore they have been extensively utilized in quinoa breeding
programs in both Colorado State University and Washington State University (Peterson and
Murphy 2015) For these reasons Chilean lowland varieties were evaluated in the present study
The objectives of this study were to 1) examine the effect of soil salinity on the protein content
seed hardness and density of quinoa varieties 2) determine the effect of different levels of two
agronomically important soil salts NaCl and Na2SO4 on seed quality and 3) test the influence
of fertilization levels on salinity tolerance of quinoa The present study illustrates the different
influence of NaCl and Na2SO4 on quinoa seed quality and provides better guidance for variety
selection and agronomic planning in highly saline environments
Materials and Methods
123
Genetic material
Quinoa germplasms were obtained from Dr David Brenner at the USDA-ARS North
Central Regional Plant Introduction Station in Ames Iowa The four quinoa varieties CO407D
(PI 596293) UDEC-1 (PI 634923) Baer (PI 634918) and QQ065 (PI 614880) were originally
sourced from lowland Chile CO407D was released by Colorado State University in 1987
UDEC-1 Baer and QQ065 were varieties from northern central and southern locations in Chile
with latitudes of 3463deg S 3870deg S and 4250deg S respectively
Experimental design
A controlled environment greenhouse study was conducted using a split-split-plot
randomized complete block design with three replicates per treatment Factors included four
quinoa varieties two fertility levels and seven salinity treatments (three concentration levels
each of NaCl and Na2SO4) Three subsamples each representing a single plant were evaluated
for each treatment combination Quinoa variety was treated as the main plot salinity level as the
sub-plot and fertilization as the sub-sub-plot Salinity levels included 8 16 and 32 dS m-1 of
NaCl and Na2SO4 The details of controlling salinity levels were described by Peterson and
Murphy (2015) In brief fertilization was provided by a mixture of alfalfa meal
monoammonium phosphate and feather meal Low fertilization level referred to 1 g of N 029 g
of P and 029 g of K in each pot and high fertilization level referred to 3 g of N 086 g of P and
086 g of K in each pot Each pot contained about 1 L of Sunshine Mix 1 (Sun Gro Horticulture
Bellevue WA) (dry density of 100 gL water holding capacity of ca 480 gL potting mix) The
124
entire experiment was conducted twice with the planting dates of September 10th 2011 and
October 7th 2011
Seed quality tests
Protein content of quinoa was determined using the Dumas combustion nitrogen method
(LECO Corp Joseph Mich USA) (AACCI Method 46-3001) A factor of 625 was used to
convert nitrogen to protein Seed hardness was determined using the Texture Analyzer (TA-
XT2i) (Texture Technologies Corp Scarsdale NY) and a modified rice kernel hardness method
(Krishnamurthy and Giroux 2001) A single quinoa kernel was compressed until the point of
fracture using a 1 cm2 cylinder probe traveling at 5 mms Repeat measurements were taken on 9
random kernels The seed hardness was recorded as the average peak force (Kg) of the repeated
measures
Seed density was determined using a pycnometer (Pentapyc 5200e Quantachrome
Instruments Boynton Beach FL) Quinoa seed was placed in a closed micro container and
compressed nitrogen was suffused in the container Pressure in the container was recorded both
with and without nitrogen The volume of the quinoa sample was calculated by comparing the
standard pressure obtained with a stainless steel ball Density was the seed weight divided by the
displaced volume Seed density was collected on only the second greenhouse experiment
Statistical analysis
Data were analyzed using the PROC GLM procedure in SAS (SAS Institute Cary NC)
Greenhouse experiment repetition was treated as a random factor in protein content and seed
hardness analysis Variety salinity and fertilization were treated as fixed factors Fisherrsquos LSD
125
Test was used to access multiple comparisons Pearson correlation coefficients between protein
hardness and density were obtained via PROC CORR procedure in SAS using the treatment
means
Results
Protein
Variety salinity and fertilization all exhibited highly significant effects on protein
content (P lt 0001) (Table 1) The greatest contribution to variation in seed protein was due to
fertilization (F = 40247) In contrast salinity alone had a relatively minor effect and the
varieties responded similarly to salinity as evidenced by a non-significant interaction The
interactions however were found in variety x fertilization as well as in salinity x fertilization
both of which were addressed in later paragraphs It is worth noting that the two experiments
produced different seed protein contents (F = 4809 P lt0001) experiment x variety interaction
was observed (F = 1494 P lt0001) (data not shown) Upon closer examination this interaction
was caused by variety QQ065 which produced an overall mean protein content of 129 in
experiment 1 and 149 in experiment 2 Protein contents of the other three varieties were
essentially consistent across the two experiments
Across all salinity and fertilization treatments the variety protein means ranged from
130 to 167 (data not shown) As expected high fertilization resulted in an increase in
protein content across all varieties The mean protein contents under high and low fertilization
were 158 and 136 respectively (Table 2) The means of Baer and CO407D were the
126
highest 151 and 149 respectively QQ065 contained 141 protein significantly lower
than the other varieties
Even though salinity effects were relatively smaller than fertilization and variety effects
salinity still had a significant effect on protein content (Table 1) The two types of salt exhibited
different impacts on protein (Table 2) Protein content did not differ according to different
concentrations of NaCl with means (across varieties and fertilization levels) from 147 to
149 Seed from 32 dS m-1 Na2SO4 however contained higher protein (152) than that from
8 dS m-1 and 16 dS m-1 Na2SO4 (144 and 142 respectively)
A significant interaction of salinity x fertilization was detected indicating that salinity
differentially impacted seed protein content under high and low fertilization level (Figure 1)
Within the high fertilizer treatment protein content in the seed from 32dS m-1 Na2SO4 was
significantly higher (167) than all other samples which did not differ from each other (~13)
Within the low fertilizer treatment protein content of seeds from 8 dS m-1 and 16 dS m-1
Na2SO4 were significantly lower than those from the NaCl treatments and 32dS m-1 Na2SO4
The significant interaction between variety and fertilization (Table 1) was due to the
different response of QQ065 Protein mean of QQ065 from high fertilization was 144 lower
than the other varieties CO407D UDEC-1 and Baer exhibited a decline of 16 - 18 in
protein under low fertilization while QQ065 dropped only 5
Hardness
Variety exhibited the greatest influence on seed hardness (F = 21059 P lt0001)
whereas fertilization did not show any significant effect (Table 1) Salinity exhibited a moderate
127
effect (F = 200 P = 009) Varieties responded consistently to salinity under various fertilization
levels since neither variety x salinity nor salinity x fertilization interaction was significant
However a variety x fertilization interaction was observed which will be discussed in a later
paragraph Similar to the situation in protein content experiment repetition exhibited a
significant influence on seed hardness Whereas the hardness of CO407D was consistent across
the two greenhouse experiments the hardness of other three varieties all decreased by 8 to 9
Mean hardness was significantly different among varieties CO407D had the hardest
seeds with hardness mean of 100 kg (Table 3) UDEC-1 was softer at 94 kg whereas Baer and
QQ065 were the softest and with similar hardness means of 77 kg and 74 kg respectively
Salinity exhibited a moderate impact on seed hardness (P = 009) The highest hardness
mean was observed under 16 dS m-1 Na2SO4 whereas the lowest was under 8 dS m-1 NaCl with
means of 89 and 83 kg respectively
A significant fertilization x variety interaction was found for seed hardness The hardness
of UDEC-1 and Baer did not differ across fertilization level whereas CO407D was harder under
low fertilization and QQ065 was harder under high fertilization
Seed density
Variety and salinity both significantly affected seed density whereas fertilization did not
show a significant influence (Table 1) The greatest contribution to variation in seed density was
due to variety (F = 2282) Salinity exhibited a relatively smaller effect yet still significant (F =
282 P lt005) Neither variety x salinity interaction nor salinity x fertilization interaction was
observed which indicated that varieties similarly responded to salinity under high and low
128
fertilization levels An interaction of variety x fertilization was found and the details were
presented later
Across all salinity and fertilization treatments CO407D had the highest mean density
080 gcm3 followed by Baer with 069 gcm3 (Table 4) UDEC-1 and QQ065 had the lowest and
similar densities (~065 gcm3)
With regard to salinity effect the Na2SO4 treatments exhibited differential influence on
seed density Density means did not significantly change due to the increased concentration of
NaCl ranging from 068 to 071 gcm3 (Table 4) The samples from 8 dS m-1 Na2SO4 soil had
lower density (066 gcm3) than those from 16 dS m-1 and 32 dS m-1 Na2SO4 074 and
072gcm3 respectively
A significant variety x fertilization interaction was found With closer examination
UDEC-1 and Baer yielded higher density seeds under high fertilization whereas CO407D and
QQ065 did not differ in density between fertilization treatments
Correlations of protein hardness and density
Correlation coefficients among seed protein content hardness and density are shown in
Table 5 No significant correlation was detected between protein content and seed hardness
However both protein content and hardness were correlated with seed density The overall
correlation coefficient was low (r = 019 P = 003) between density and protein A marginally
significant correlation was found between density and protein content of the seeds from NaCl
salinized soil under low fertilization No correlation was found between density and protein
content of the seeds from NaCl salinized soil under high fertilization or Na2SO4 salinized soil
129
The overall correlation coefficient was 038 (P lt 00001) between density and hardness
The low fertilization samples from both NaCl and Na2SO4 soil showed significant correlations
between density and hardness with coefficients of 051 and 047 (both P lt 0005) The high
fertility quinoa did not exhibit any correlation between density and hardness
Correlation with yield leaf greenness index plant height and seed minerals contents
Correlation between seed quality and yield leaf greenness index plant height and seed
mineral concentration were obtained using data from Peterson and Murphy (2015) (Table 6)
Seed hardness significantly correlated with yield and plant height (r = 035 and 031
respectively) Protein content and density however did not correlate with yield leaf greenness
or plant height Correlations were found between quality indices and the concentration of
different minerals Protein was negatively correlated with Cu and Mg (r = -052 and -050
respectively) Hardness was negatively correlated with Cu P and Zn (r = -037 -056 -029
respectively) but was positively correlated with Mn (r = 057) Density was negatively
correlated with Cu (r = -035)
Discussion
Protein
Although salinity exhibited a significant effect on seed protein content the impact was
relatively minor compared to fertilization and variety effects In another words over a wide
range of saline soil quinoa can grow and yield seeds with stable protein content
130
Protein content of quinoa growing under salinized soil ranged from 127 to 167 (data
not shown) within the general range of protein content under non-saline conditions which was
12 to 17 (Rojas et al 2015) Saline soil did not cause a significant decrease in seed protein
It is interesting to notice that the samples from 32 dS m-1 Na2SO4 tended to contain the highest
protein especially in variety QQ065 The studies of Koyro and Eisa (2008) and Karyotis et al
(2003) also indicated that protein content significantly increased under high salinity (NaCl)
whereas total carbohydrates decreased In contrast Ruffino et al (2009) found that quinoa
protein decreased under 250 mM NaCl salinity in a growth chamber experiment It is reasonable
to conclude that salinity exhibits contrasting effects on different quinoa genotypes QQ065 and
CO407D both significantly increased in protein under 32 dS m-1 Na2SO4 however the yield
decline was 519 and 245 respectively (Peterson and Murphy 2015) This result indicted
that CO407D was the variety most optimally adapted to severe sodic saline soil tested in this
study
Na2SO4 level exhibited a significant influence on protein content whereas NaCl level did
not In the study of Koyro and Eisa (2008) however seed protein of the quinoa variety Hualhuas
(origin from Peru) increased under the highest salinity level of 500 mM NaCl compared to lower
NaCl levels (0 ndash 400 mM) This disagreement of NaCl influence may be due to diversity of
genotypes It is worth noting that quinoa protein contents in this paper were primarily above 13
based on wet weight (as-is-moisture of approximately ~8 -10) even under saline soil and low
fertilization level This protein content is generally equal to or higher than that of other crops
such as barley and rice (Wu 2015) In conclusion quinoa maintained high and stable protein
content under salinity stress
131
Hardness
Quinoa seed hardness was only moderately affected by salinity (P = 009) indicating that
quinoa primarily maintained seed texture when growing under a wide range of saline soil
CO407D exhibited the hardest seed (100 kg) whereas Baer and QQ065 were relatively soft (74
ndash 77 kg) A previous study indicated a hardness range of 58 ndash 109 kg among 11 quinoa
varieties and 2 commercial samples (Wu et al 2014) The commercial samples had hardness
values of 62 kg and 71 kg Since commercial samples generally maintain stable quality and
indicate an acceptable level for consumers seed hardness around 7 kg as in Baer and QQ065
should be considered as acceptable quality The hardness of CO407D was close to that of the
colored variety lsquoBlackrsquo (100 kg) which had a thicker seed coat than that of the yellow seeded
varieties It was reported that a thicker seed coat is related to harder texture (Fraczek et al 2005)
Even though the greenhouse is a highly controlled environment and the two experiments
were conducted in similar seasons (planted in September and October respectively) seed protein
and hardness were still different across the two experiments However ANOVA indicated
modest-to-no significant interactions with salinity and fertilization such that responses to salinity
and fertilization were consistent with little or no change in rank order Even though experiment x
variety was significant the F-values were relatively low compared to the major effects such as
variety and fertilization and neither of them was crossing interaction This is a particularly
noteworthy result for breeders farmers and processors
Density
132
The range of seed density under salinity 055 ndash 089 gcm3 was comparable to the
density range of 13 quinoa samples (058 ndash 076 gcm3 ) (Wu et al 2014) Generally CO407D
had higher seed density (071 ndash 089 gcm3) which indicated that seed density in this variety was
affected by salinity stress In contrast the density of QQ065 did not change according to salinity
type or concentration which indicated a stable quality under saline soil
Correlations
The correlation between seed hardness and density was only significant under low fertilization
but not under high fertilization The high fertilization level in the greenhouse experiment
exceeded the amount of fertilizer that would normally be applied in field environments whereas
the low fertilization level is closer to the field situation Therefore correlation between hardness
and density may still exist in field trials
Conclusions
Under saline soil conditions quinoa did not show any marked decrease in seed quality
such as protein content hardness and density Protein content even increased under high Na2SO4
concentration (32 dS m-1) Varieties exhibited great differential reactions to fertilization and
salinity levels QQ065 maintained a similar level of hardness and density whereas seed of
CO407D was both harder and higher density under salinity stress If only seed quality is
considered then QQ065 is the most well-adapted variety in this study
The influences of NaCl and Na2SO4 were different The higher concentration of Na2SO4
tended to increase protein content and seed density whereas NaCl concentration did not exhibit
any significant difference on those quality indexes
133
Acknowledgement
The research was funded by USDA Organic Research and Extension Initiative project
number NIFAGRANT11083982 The authors acknowledge Alecia Kiszonas for assisting in the
data analysis
Author contributions
Peterson AJ set up the experiment design in the greenhouse and grew harvested and
processed quinoa samples Wu G collected seed quality data such as protein content seed
hardness and density Peterson AJ and Wu G together processed the data Wu G also drafted the
manuscript Murphy KM and Morris CF edited the manuscript
Conflict of interest statement
The authors declared to have no conflict of interest
134
References
AACC International Approved Methods of Analysis Method 46-3001 Crude protein ndash
Combustion method Approved November 8 1995 Reapproved November 3 1999
Availablenline only AACCI St Paul MN
Adolf VI Shabala S Andersen MN Razzaghi F Jacobsen SE 2012 Varietal differences of
quinoas tolerance to saline conditions Plant Soil 357 117ndash29
Bertero HD 2003 Response of developmental processes to temperature and photoperiod in
quinoa (Chenopodium quinoa Willd) Food Rev Int 19 87ndash97
Cai S Yu G Chen X Huang Y Jiang X Zhang G Jin X 2013 Grain protein content variation
and its association analysis in barley BMC Plant Boil 13 35
Chilo G Molina MV Carabajal R Ochoa M 2009 Temperature and salinity effects on
germination and seedling growth on two varieties of Chenopodium quinoa Agri-Scientia 26
15ndash22
Cocozza C Pulvento C Lavini A Riccardi M dAndria R Tognetti R 2013 Effects of
increasing salinity stress and decreasing water availability on ecophysiological traits of
quinoa (Chenopodium quinoa Willd) grown in a mediterranean-type agroecosystem J Agron
Crop Sci 199 229ndash40
Fraczek J Hebda T Slipek Z Kurpaska S 2005 Effect of seed coat thickness on seed hardness
Can Biosyst Eng 47 41ndash5
135
Gonzaacutelez JA Eisa SSS Hussin SAES Prado FE 2015 Quinoa an Incan crop to face global
changes in agriculture In Murphy KM Matanguihan J editors Quinoa Improvement and
Sustainable Production Hoboken NJ John Wiley Sons p 7ndash11
Hruškovaacute M Švec I 2009 Wheat hardness in relation to other quality factors Czech J Food Sci
27 240ndash8
Jacobsen S Quispe H Mujica A 2000 Quinoa an alternative crop for saline soils in the Andes
in Scientist and Farmer Partners in Research for the 21st Century (Program Report 1999-
2000) ed International Potato Center (Peru) 403ndash8
Jancurovaacute M Minarovicovaacute L Dandar A 2009 Quinoandasha review Czech J Food Sci 27 71ndash9
Karyotis T Iliadis C Noulas C Mitsibonas T 2003 Preliminary research on seed production
and nutrient content for certain quinoa varieties in a salinendashsodic soil J Agron Crop Sci 189
402ndash8
Koyro HW Eisa S 2008 Effect of salinity on composition viability and germination of seeds of
Chenopodium quinoa Willd Plant Soil 302 79-90
Krishnamurthy K Giroux MJ 2001 Expression of wheat puroindoline genes in transgenic rice
enhances grain softness Nat Biotechnol 19 162ndash6
Morris CF 2002 Puroindolines the molecular genetic basis of wheat grain hardness Plant mol
Biol 48 633ndash47
136
Orth RA Shellenberger JA 1988 Chapter 1 Origin production and utilization of wheat In
Pomeranz Y editor Wheat Chemistry and Technology 3th edition St Paul MN American
Association of Cereal Chemists Inc p 11ndash2
Peterson A Murphy K 2015 Tolerance of lowland quinoa cultivars to sodium chloride and
sodium sulfate salinity Crop Sci 55 331ndash8
Pitman MG Laumluchli A 2002 Global impact of salinity and agricultural ecosystems In Laumluchli
A Luumlttge U editors Netherlands Springer p 3ndash20
Prado FE Boero C Gallardo M Gonzaacutelez JA 2000 Effect of NaCl on germination growth and
soluble sugar content in Chenopodium quinoa Willd seeds Bot Bull Acad Sinica 41 27ndash34
Pulvento C Riccardi M Lavini A Iafelice G Marconi E dAndria R 2012 Yield and quality
characteristics of quinoa grown in open field under different saline and non-saline irrigation
regimes J Agron Crop Sci 198 254ndash63
Ranhotra G Gelroth J Glaser B Lorenz K Johnson D 1993 Composition and protein
nutritional quality of quinoa Cereal Chem 70 303ndash5
Razzaghi F Ahmadi SH Jacobsen SE Jensen CR Andersen MN 2012 Effects of salinity and
soilndashdrying on radiation use efficiency water productivity and yield of quinoa (Chenopodium
quinoa Willd) J Agron Crop Sci 198 173ndash84
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile D
137
Bertero D Nieto C editors State of the Art Report of Quinoa in the World in 2013 Rome
FAO amp CIRAD p 67-8
Ruffino A Rosa M Hilal M Gonzaacutelez J Prado F 2010 The role of cotyledon metabolism in the
establishment of quinoa (Chenopodium quinoa)seedlings growing under salinity Plant Soil
326 213ndash24
Ruiz-Carrasco K Antognoni F Coulibaly A K Lizardi S Covarrubias A Martiacutenez E A
Shabala S Hariadi Y Jacobsen SE 2013 Genotypic difference in salinity tolerance in quinoa is
determined by differential control of xylem Na+ loading and stomatal density J Plant Physiol
170 906ndash14
Shih FF 2006 Chapter 6 Rice protein In Champagne ET editor Rice Chemistry and
Technology 3rd edition St Paul MN American Association of Cereal Chemists Inc p
143-4
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Taylor JRN Parker ML editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science amp Business Media p 96-101
USDA (United States Department of Agriculture) 2011 Soil and water resources conservation
act (RCA) P 31 Access from
httpwwwnrcsusdagovInternetFSE_DOCUMENTSstelprdb1044939pdf
Wilson C Read J Abo-Kassem E 2002 Effect of mixed-salt salinity on growth and ion
relations of a quinoa and a wheat variety J Plant Nutri 25 2689ndash704
138
Wu G Morris CF Murphy KM 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79 2337ndash45
Wu G 2015 Chapter 11 Nutritional properties of quinoa In Murphy KM Matanguihan J
editors Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp
Sons Inc p 193-205
Zhang B Chen P Chen CY Wang D Shi A Hou A Ishibashi T 2008 Quantitative trait loci
mapping of seed hardness in soybean Crop Sci 48 1341ndash9
Zevallos VF Herencia LI Chang F Donnelly S Ellis HJ Ciclitira PJ 2014 Gastrointestinal
effects of eating quinoa (Chenopodium quinoa Willd) in celiac patients Am J Gastroenterol
109 270ndash8
Zurita-Silva A 2011 Variation in salinity tolerance of four lowland genotypes of quinoa
(Chenopodium quinoa Willd) as assessed by growth physiological traits and sodium
transporter gene expression Plant Physiol Bioch 49 1333ndash41
139
Table 1-Analysis of variance with F-values for protein content hardness and density of quinoa seed
Effect F-values
Protein Hardness Density
Model 524 360 245
Variety 2463 21059 2282
Salinity 975 200dagger 282
Fertilization 40247 107 260
Variety x Salinity 096 098 036
Variety x Fertilization 2062 1094 460
Salinity x Fertilization 339 139 071
Variety x Salinity x Fertilization 083 161dagger 155
dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the 001 probability level Significant at the lt0001 probability level
140
Table 2-Salinity variety and fertilization effects on quinoa seed protein content ()
Salinity Protein content ()
Variety Protein content ()
Fertilization Protein content ()
8 dS m-1 NaCl 147bc1 CO407D 149ab High 158a
16 dS m-1 NaCl 148ab UDEC-1 147b Low 136b
32 dS m-1 NaCl 149ab Baer 151a
8 dS m-1 Na2SO4 144cd QQ065 141c
16 dS m-1 Na2SO4 142d
32 dS m-1 Na2SO4 152a 1Different letters in a given column indicate significant differences (P lt 005)
141
Table 3-Salinity variety and fertilization effects on quinoa seed hardness (kg)
Salinity Hardness (kg)1 Variety Hardness (kg)
8 dS m-1 NaCl 83 CO407D 100a2
16 dS m-1 NaCl 87 UDEC-1 94b
32 dS m-1 NaCl 85 Baer 77c
8 dS m-1 Na2SO4 87 QQ065 74c
16 dS m-1 Na2SO4 89
32 dS m-1 Na2SO4 88 1Hardness was significant at the 009 probability level 2Different letters in a given column indicate significant differences (P lt 005)
142
Table 4-Salinity variety and fertilization effects on quinoa seed density (g cm3)
Salinity density (g cm3) Variety density (g cm3)
8 dS m-1 NaCl 069bc1 CO407D 080a
16 dS m-1 NaCl 068bc UDEC-1 066bc
32 dS m-1 NaCl 071abc Baer 069b
8 dS m-1 Na2SO4 066c QQ065 065c
16 dS m-1 Na2SO4 074a
32 dS m-1 Na2SO4 072ab 1Different letters in a given column indicate significant differences (P lt 005)
143
Table 5-Correlation coefficients of protein hardness and density of quinoa seed
Correlation All NaCl Na2SO4
High fertilization
Low fertilization
High fertilization
Low fertilization
Protein -Density 019 013ns 029dagger 026ns 019ns
Hardness - Density 038 027ns 051 022ns 047
ns Not significant dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the lt0001 probability level
144
Table 6-Correlation coefficients of quinoa seed quality and agronomic performance and seed mineral content
Protein Hardness Density
Yield 004 035 006
Plant Height -004 031 011
Cu -052 -037 -035
Mg -050 004 0
Mn -006 057 025dagger
P -001 -056 -015
Zn -004 -029 -028dagger
dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the 001 probability level Significant at the lt0001 probability level
145
Figure 1-Protein content () of quinoa in response to combined fertility and salinity treatments
146
Chapter 6 Lexicon development and consumer acceptance
of cooked quinoa
ABSTRACT
Quinoa is becoming increasingly popular with an expanding number of varieties being
commercially available In order to compare the sensory properties of these quinoa varieties a
common sensory lexicon needs to be developed Thus the objective of this study was to develop
a lexicon of cooked quinoa and examine consumer acceptance of various varieties A trained
panel (n = 9) developed appropriate aroma tasteflavor texture and color descriptors to describe
cooked quinoa and evaluated 21 quinoa varieties Additionally texture of the cooked quinoa was
determined using a texture analyzer Results indicated panelists using this developed lexicon
could distinguish among these quinoa varieties showing significant differences in aromas
tasteflavors and textures Specifically quinoa variety effects were observed for the aromas of
caramel nutty buttery grassy earthy and woody tasteflavor of sweet bitter grain-like nutty
earthy and toasty and texture of firm cohesive pasty adhesive crunchy chewy astringent and
moist The varieties lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Drsquo exhibited adhesive texture that has not
been seen in any commercialized quinoa Subsequent consumer evaluation (n = 102) on 6
selected samples found that the lsquoPeruvian Redrsquo was the most accepted overall while the least
accepted was lsquoQQ74rsquo Partial least squares analysis on the consumer and trained panel data
indicated that overall consumer liking was driven by higher intensities of grassy aroma and firm
and crunchy texture The attributes of pasty moist and adhesive were less accepted by
consumers This overall liking was highly correlated with consumer liking of texture (r = 096)
147
tasteflavor (r = 095) and appearance (r = 091) of cooked quinoa From the present study the
quinoa lexicon and key drivers of consumer acceptance can be utilized in the industry to evaluate
quinoa product quality and processing procedures
Keywords quinoa lexicon sensory evaluation
Practical application The lexicon of cooked quinoa can be used by breeders to screen quinoa
varieties Furthermore the lexicon will useful in the food industry to evaluate quinoa ingredients
from multiple farms harvest years processing procedures and product development
148
Introduction
Quinoa is classified as a pseudocereal like amaranth and buckwheat With its high
protein content and balanced essential amino acid profile quinoa is becoming popular
worldwide From 1992 to 2012 quinoa exports increased dramatically from 600 tons to 37000
tons (Furche et al 2015) Quinoa price in retail stores increased from $9kg in 2013 to $13kg -
$20kg in 2015 (Arco 2015) Quinoa has been incorporated into numerous products including
bread cookies pasta cakes and chocolates (Pop et al 2014 Alencar et al 2015 Casas Moreno
et al 2015 Wang et al 2015) Some of these products are gluten-free foods thus targeting the
gluten-sensitive market segment (Wang et al 2015)
Popularity of quinoa inspired US researchers to breed varieties that are compatible with
local weather and soil conditions which greatly differ from quinoarsquos original land the Andean
mountain region Since 2010 Washington State University has been breeding quinoa in the
Pacific Northwest region of United States Of the quinoa varieties evaluated in the breeding
program agronomic attributes of interest include high yield consistent performance over years
and tolerance to drought salinity heat and diseases (Peterson and Murphy 2013 Peterson
2013) However beyond agronomic attributes the grain sensory profiles of these quinoa
varieties are also important to assist in breeding decisions as well as screening
genotypescultivars for various food applications
In order to provide a complete descriptive profile of the cooked quinoa a trained sensory
evaluation should be used along with a complete lexicon of the sensory attributes of importance
Currently no quinoa lexicon is available and descriptions of quinoa sensory properties are
149
limited From currently published research papers attributes describing quinoa taste have been
limited to bitter sweet earthy and nutty (Koziol 1991 Lorenz and Coulter 1991 Repo-Carrasco
et al 2003 Stikic et al 2012 Foumlste M et al 2014) and texture of cooked quinoa has been
described as creamy smooth and crunchy (Abugoch 2009) Thus to address the lack of quinoa
lexicon one objective of this study is to develop a lexicon describing the sensory properties of
quinoa
Beyond developing a lexicon to describe quinoa consumer preference of the different
quinoa varieties is also of great interest Most previous sensory studies in quinoa focused on
acceptance of quinoa-containing products while consumer acceptance on plain grain of quinoa
varieties has not been studied Because of the lack of cooked quinoa studies with consumers rice
may be considered as a model to study quinoa because of their similar cooking process Tomlins
et al (2005) found consumer preference of rice was driven by the attributes of uniform clean
bright translucent and cream with consumers not liking the brown color of cooked rice and
unshelled paddy in raw rice In another study Suwannaporn et al (2008) found consumer
acceptance of rice products was significantly influenced by convenience grain variety and
traditionnaturalness
This study presenting a quinoa lexicon along with consumer acceptance of quinoa
varieties provides critical information for both the breeding programs and food industry
researchers Given the predicted importance of texture in consumer acceptance of quinoa texture
analysis was conducted to evaluate the parameters of hardness adhesiveness cohesiveness
chewiness and gumminess in quinoa samples
150
This lexicon describing the sensory attributes of cooked quinoa will be a useful tool to
evaluate quinoa varieties compare samples from different farms harvest years seed quality and
cleaning processing procedures Finally the sensory attributes driving consumersrsquo liking can be
utilized to evaluate optimal quinoa quality and target different consumers based on preference
Materials and methods
Quinoa samples
The present study included twenty-one quinoa samples harvested in 2014 which included
sixteen varieties from Finnriver Organic Farm (Finnriver WA) and five commercial samples
from Bolivia and Peru (Table 1)
Quinoa preparation
Following harvest the samples from Finnriver Farm were cleaned in a Clipper Office
Tester (Seedburo Des Plainies IL USA) to separate mixed weed seeds and threshed materials
Furthermore the samples were soaked for 30 min rubbed manually under running water and
dried at 43 ordmC until the moisture reached lt 11 Generally a moisture of 12 - 14 is
considered safe for grain storage (Hoseney 1989)
To prepare quinoa samples for sensory evaluation samples were soaked for 30 min and
mixed with water at a 12 ratio These mixtures were brought to a boil and simmered for 20 min
Following cooking the quinoa was cooled to room temperature Samples of cooked quinoa (10
g) were served in 30 mL plastic containers with lids (SOLO Lakeforest IL USA) Quinoa
151
samples were cooked and placed in covered cups within 2 h before evaluation Unsalted
crackers plastic cups used as cuspidors and napkins were provided to each panelist
Trained sensory evaluation panel
This project was approved by the Institutional Review Board of Washington State
University Sensory panelists (n = 9) were recruited via email announcements Panelists were
selected based on their interest in quinoa and availability All participants signed the Informed
Consent Form They received non-monetary incentives for each training session and a large non-
monetary reward at the completion of the formal evaluation
Demographic information was collected using a questionnaire Panelists included 4
females and 5 males ranging in age from 21 to 60 (mean age of 35) Regarding quinoa
consumption frequency four panelists frequently consumed quinoa (few times per month to
everyday) whereas five panelists rarely consumed quinoa As quinoa is a novel crop to most of
the world this was expected Since rice is a comparable model of quinoa frequency of rice
consumption was also considered with all panelists being frequent rice consumers
Sensory training and lexicon development
The training consisted of 12 sessions of 15 hours totaling 18 hours In the early stages
of the panel training attribute terms and references were discussed Panelists were first presented
with samples in covered plastic containers The samples widely varied in their sensory attributes
and included the varieties of lsquoBlackrsquo lsquoBolivian Redrsquo and lsquoBolivian Whitersquo The panelists
developed terms to describe the appearance aroma flavor taste and texture of the samples
Additionally the same samples were evaluated by an experienced sensory evaluation panel with
152
terms collected from this set of evaluators Terms were collected from panelists professionals
and literature describing rice (Meilgaard et al 2007 Limpawattana and Shewfelt 2010) The
term list was presented and discussed with panelist consensus being used to determine which
sensory terms appeared in the final lexicon
The final lexicon and associated definitions are presented in Table 2 This lexicon
included the sensory attributes of color (black red yellow) aroma (caramel grain-like bean-
like nutty buttery starchy grassygreen earthymusty woody) tasteflavor (sweet bitter grain-
like bean-like nutty earthy and toasted) and texture (soft-firm separate-cohesive pasty
adhesivenesssticky crunchycrumblycrisp chewygummy astringent and waterymoist)
References standards for each attribute were introduced The references were discussed and
modified until the panelists were in agreement Panelists reviewed the reference standards at the
beginning of each training session Since aroma varies over time all aroma references were
prepared 1-2 h before training During training three to four quinoa samples were evaluated and
discussed in each session The ability to detect attribute differences and the reproducibility of
panelists were both monitored and visualized using spider graphs and line graphs Using this
feedback panelists were calibrated paying extra attention to those attributes that were outside of
the panel standard deviation Practice sessions were continued until the panelists accurately and
consistently assessed varietal differences of quinoa
The protocols applied to evaluate samples and references were consistent among
panelists At the start of the evaluation the sample cup was shaken to allow the aroma to
accumulate in the headspace Panelists then lifted the cover and immediately took three short
sharp sniffs to evaluate the aroma Panelists then determined the color and its intensity Finally
153
panelists used the spoon to place the sample in-mouth and evaluate the tasteflavor and texture
Between each sample panelists rinsed their palate using water and unsalted crackers A 15-cm
line scale with 15-cm indentations on each end was used to determine the intensity of attributes
The values of 15 and 135 represented the extremely low and high intensity respectively Using
the lexicon panelists were trained to sense and quantify the attributes of cooked quinoa on
aroma color tasteflavor and texture
Following the development of the lexicon formal evaluations were conducted in the
sensory booths under white lights Compusensereg Five (Guelph Ontario Canada) provided scales
and programs for evaluation and collected results Panelists followed the protocol and used the
lexicon and 15-cm scales to evaluate the sensory attributes of the cooked quinoa samples
Twenty-one quinoa samples were tested in duplicate Panelists attended one session per day and
four sessions in total During each session panelists evaluated 10 or 11 samples with a 30 s
break after each sample and a 10 min break after the fifth sample Each variety was assigned
with a random three-digit code and the serving order was randomized
Consumer acceptance panel
From the 21 samples evaluated by the trained panelists six were selected for consumer
evaluation These six samples selected were diverse in color tasteflavor and texture as defined
by the trained panel results Consumers (n = 102) were recruited from Pullman WA Of the
consumers 49 were male and 52 were female with age ranging from 19 to 64 (mean age of 33)
The consumers showed different familiarity with quinoa with 29 indicating that they were
154
familiar with quinoa 40 having tried quinoa a few times and 32 having never tried quinoa
before All consumers had consumed rice before
The project was approved by the Institutional Review Board of Washington State
University Each consumer signed an Informed Consent Form and received a non-monetary
incentive at the end of evaluation The evaluation was conducted in the sensory booths under
white light Six quinoa samples were assigned with three-digit code and randomly presented to
each consumer using monadic presentation Quinoa samples were cooked and distributed in
evaluation cups and lidded (~10 gcup) the day before stored at 4 degC overnight and placed at
room temperature (25 degC) for 1 h prior to evaluation
During evaluation consumers followed the protocol instructions and indicated the degree
of acceptance of aroma color appearance tasteflavor texture and overall liking using a 7-point
hedonic scale (1 = dislike extremely 7 = like extremely) provided by Compusensereg Five
(Guelph Ontario Canada) A comments section was provided at the end of each sample
evaluation to gather additional opinions and information Between samples panelists took a 30 s
break and cleansed their palates using unsalted crackers and water
Texture Profile Analysis by instrument (TPA)
The texture of 21 cooked quinoa samples were conducted using a TA-XT2i Texture
Analyzer (Texture Technologies Corp Hamilton MA USA) (Wu et al 2014) Samples were
cooked using the same procedure as in the trained panel evaluation and cooled to room
temperature prior to evaluation
Statistical analysis
155
Sample characteristics and trained panel results were analyzed using three-way ANOVA
and mean separation (Fisherrsquos LSD) PCA was performed on the trained panel data Using
trained panel data and consumer evaluation data partial least square regression analysis was
performed Additionally correlations between instrument tests and panel evaluation on texture
and tasteflavor were determined XLSTAT 2013 (Addinsoft Paris France) was used for all data
analysis
Results and Discussion
Lexicon Development
A lexicon was created to describe the sensory attributes of cooked quinoa (Table 2) A
total of 27 attributes were included in the lexicon based on color (black red yellow) aroma
(caramel grain-like bean-like nutty buttery starchy grassygreen earthymusty and woody)
tasteflavor (sweet bitter grain-like bean-like nutty earthy and toasted) and texture (firm
cohesive pasty adhesivenesssticky crunchy chewygummy astringent and waterymoist)
Rice is considered as a good model of quinoa lexicon developments since both products
have common preparation methods The lexicon for cooked rice has been developed for the
aroma tasteflavor and texture properties of rice (Lyon et al 1999 Meullenet et al 2000
Limpawattana and Shewfelt 2010) Many attributes from these previously developed rice
lexicons can be applied to cooked quinoa For instance rice aroma and flavor notes such as
starchy woody grain nutty buttery earthy sweet bitter and astringent are also present in
quinoa Hence those notes were also included in the lexicon of cooked quinoa in present study
with quinoa varieties showing differences in these attributes
156
This present lexicon presents some sensory attributes not found to be significantly
different among the quinoa varieties These attributes include grain-like bean-like and starchy
aroma bean-like flavor and chewy texture Even though the trained panel did not detect
differences in this study future studies may find differences among other quinoa varieties for
these attributes so they were kept in the lexicon For instance the flavoraroma notes of
lsquorancidoxidizedrsquo lsquosourrsquo lsquometallicrsquo may also be present in other quinoa varieties or have these
attributes develop during storage as has been shown in rice (Meullenet et al 2000)
The lexicon also expanded the vocabularies to describe quinoa This lexicon is a
valuable tool with multiple practical applications such as describing and screening quinoa
varieties in breeding and evaluating post-harvest process and cooking methods
Lexicon Application Evaluation of the 21 quinoa samples
The effects of panelist replicate and quinoa variety on aroma tasteflavor and texture of
cooked quinoa were evaluated (n = 9) (Table 3) The quinoa variety exhibited significant
influences on most attributes listed in the lexicon (P lt 005) except for grain-like bean-like and
starchy aroma and bean-like flavor Generally quinoa variety effects were greater in the
perceived texture of cooked quinoa than in the aroma and flavor attributes however bitterness
was also highly significant among varieties Although panelists were trained over 18 h and
references were used for calibration significant panelist effects were still observed Based on the
inherent variation of human subjects such panelist effects commonly occur in sensory evaluation
of a complex product (Muntildeoz 2003) In future studies increased training and practice to further
clarify attribute definitions may reduce panelist effects (Muntildeoz 2003)
157
Examining the details of aroma attributes quinoa variety effect significantly influenced
the aroma attributes of caramel nutty buttery grassy earthy and woody (Figure 1) Principal
Components Analysis (PCA) was performed in order to visualize differences among the
varieties For aroma the first two components described 669 of the variation among quinoa
samples PC1 was primarily defined by the grassy and woody aromas while PC2 was primarily
described by more starchy and grain-like aromas The proximity of the attributes to a specific
quinoa sample reflected its degree of association For instance lsquoCalifornia Tricolorrsquo was most
commonly described by earthy woody grassy bean-like and nutty aroma lsquoTemukorsquo exhibited
sweet and grain-like aroma Yellowwhite quinoa such as lsquoTiticacarsquo lsquoRed Headrsquo lsquoQuF9P39-51rsquo
and lsquoPeruvian Whitersquo showed significantly more nutty (6) aroma compared to brown and red
quinoa varieties (48 ndash 51) (Table 1S) lsquoBlackrsquo lsquoCahuilrsquo and lsquoPeruvian Redrsquo exhibited more
grassy aroma (47 ndash 49) compared to lsquoTiticacarsquo lsquoLinaresrsquo and lsquoNL-6rsquo (38 ndash 39) lsquoBlackrsquo
showed the most earthy aroma (54) among all varieties
PCA was also performed to show how the varieties differed in their flavortaste
properties (Figure 2) The first two components described 646 of the varietal differences The
lsquoBlackrsquo variety was found to have more bitter and earthy flavors lsquoPeruvian Whitersquo was most
commonly described by sweet and nutty flavor and lack of earthy flavors lsquoTemukorsquo was mostly
defined by its bitter taste and lack of sweetness nutty grain-like and toasty flavors Overall
sweet and bitter taste and grain-like nutty earthy and toasty flavor exhibited significant
difference among quinoa varieties (plt005) The lsquoQuF9P39-51rsquo lsquoKaslaearsquo lsquoBolivian Whitersquo
and lsquoPeruvian Whitersquo were assigned the highest values in sweet taste (46 ndash 47) significantly
sweeter than lsquoBlackrsquo lsquoCherry Vanillarsquo lsquoTemukorsquo lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCalifornia Tricolorrsquo
158
(36 ndash 40)(Table 4) lsquoTemukorsquo and lsquoCherry Vanillarsquo were the most bitter samples (56 and 52
respectively) It is worth noting that the commercial samples were assigned the lowest bitterness
scores ranging from 22 ndash 27 significantly lower than the field trial varieties (34 ndash 56) Similar
to earthy aroma lsquoBlackrsquo also exhibited the earthiest flavor (52) Additionally lsquoCahuilrsquo and
lsquoCalifornia Tricolorrsquo showed high scores in earthy flavor (both 48) Toasty flavor varied from
38 in lsquoLinaresrsquo and lsquoQuF9P1-20rsquo to 51 in lsquoCahuilrsquo
Quinoa bitterness is caused by saponin compounds present on the seed coat It has been
reported that saponin can be removed by abrasion pearling and rinsing (Taylor and Parker
2002) However in the present study despite two cleaning process steps (airscreen and rinsing)
there was still bitter flavor remained Besides processing genetic background can also affect
saponin content Some sweet quinoa varieties (lsquoSajamarsquo lsquoKurmirsquo lsquoAynoqrsquoarsquo lsquoKrsquoosuntildearsquo and
lsquoBlanquitarsquo in Bolivia and lsquoBlancade Juninrsquo in Peru) have been developed with total seed
saponin content lower than 110 mg100 g (Quiroga et al 2015) However these varieties are not
adapted to the growing conditions in the Pacific Northwest (Peterson and Murphy 2015) The
quinoa varieties in WSU breeding program are primarily from Chilean lowland and those
varieties are more highly adapted to temperate areas In this case sweet quinoa varieties from
Bolivia and Peru were not included in this study However in 2015 a saponin-free quinoa
variety lsquoJessiersquo was grown in different locations of Washington State with a comparable yield
to bitter varieties The sensory evaluation of this new variety lsquoJessiersquo would be meaningful
Earthy which may be referred to as moldy and musty is caused by geosmin (a bicyclic
alcohol with formula C12H22O) which produced by actinobacteria (Gerber 1968) Samples with a
dark color (lsquoBlackrsquo lsquoCalifornia Tricolorrsquo and lsquoCahuilrsquo) tended to exhibit more earthy aroma and
159
flavor Possibly the pericarpseed coat composition of dark quinoa favors the actinobacteria-
producing geosmin
Overall texture attributes of cooked quinoa exhibited greater differences in values
(Figure 3) Among commercial quinoa varieties the red quinoa was firmer more gummy and
more chewy in texture compared to the yellowwhite commercial quinoa Several WSU field trial
varieties (lsquoQQ74rsquo lsquoLinaresrsquo and CO407D) exhibited greater variation in adhesiveness The first
two PCA factors explained 817 of the variation among samples lsquoPeruvian Redrsquo was most
accurately described by firm and crunchy texture and a lack of pasty sticky and cohesive
texture In contrast lsquoLinaresrsquo lsquoCO407Daversquo and lsquoQQ74rsquo were mostly described as pasty sticky
and cohesive yet lacking in firmness and crunchiness Mixed color or red color samples
(lsquoPeruvian Redrsquo lsquoBlackrsquo lsquoCahuilrsquo and lsquoCalifornia Tricolorrsquo) tended to be both firmer and
crunchier compared to the samples with light color However some yellow samples such as
lsquoTiticacarsquo and lsquoKU-2rsquo also had hard texture The varieties lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Daversquo
had the softest texture and also exhibited the least crunchy but the most pasty sticky and moist
texture Additionally compared to field trial varieties commercial samples tended to be lower in
intensity for the attributes of cohesiveness pastiness adhesiveness and astringency Moreover
astringent is the dry and puckering mouth feeling which is caused by the combination of tannins
and salivary proteins The differences found in this study among quinoa varieties may be caused
by processing protocols (removal of tannins to various degrees) or diverse genetic backgrounds
Consumer acceptance
160
Consumers evaluated six selected quinoa samples including the field trial varieties of
lsquoBlackrsquo lsquoTiticacarsquo lsquoQQ74rsquo and the commercial samples of lsquoPeruvian Redrsquo lsquoBolivian Redrsquo and
lsquoBolivian Whitersquo The selected samples were diverse in color texture and included both WSU
field trial varieties and commercial quinoa Among the field trial varieties the lsquoBlackrsquo variety
exhibited more grassy aroma earthy flavor and chewy texture lsquoTiticacarsquo had more caramel
aroma and lsquoQQ74rsquo was more adhesive than the other samples
The quinoa varieties varied significantly in consumer acceptance of color appearance
taste flavor texture and overall acceptance (P lt 0001) (Table 5) Overall lsquoPeruvian Redrsquo was
more accepted by consumers compared to lsquoTiticacarsquo and lsquoQQ74rsquo lsquoBlackrsquo received a similar
level of acceptance with all the commercial samples and the acceptance of lsquoTiticacarsquo did not
differ from lsquoBolivian Redrsquo and lsquoBolivian Whitersquo In aroma acceptance no significant difference
was found among the varieties In color lsquoPeruvian Redrsquo and lsquoBolivian Redrsquo received
significantly higher scores In appearance lsquoPeruvian Redrsquo was rated higher than all other
varieties except lsquoBolivian Redrsquo while lsquoQQ74rsquo gained the lowest rate Additionally lsquoQQ74rsquo was
less accepted in tasteflavor than all commercial samples but did not differ from other field trial
varieties lsquoBlackrsquo and lsquoTiticacarsquo Furthermore the texture of lsquoQQ74rsquo was the least accepted and
other varieties did not show any significant differences
However low acceptance in adhesive texture of cooked quinoa does not indicate the
adhesive quinoa varieties will not have market potential Adhesiveness in cooked rice is
correlated with high amylopectin and low amylose (Mossman et al 1983 Sowbhagya et al
1987) Hence adhesive quinoa may also contain low amylose Additionally previous studies
found waxy cereal or starch (0 amylose and 100 amylopectin) exhibited excellent
161
performance in extrusion Kowalski et al (2014) found that waxy wheat extrudates exhibited
nearly twice the expansion ratio as that of normal wheat Koumlksel et al (2004) found hulless waxy
barley to be promising for extrusion using low shear screw configuration Van Soest et al (1996)
reported high elongation (500) in extruded maize starch Consequently the adhesive quinoa
varieties have great potential to apply in extruded or other puffed foods
Consumer preference of the sensory attributes was analyzed using Partial Least Square
Regression (PLS) (Figure 4) The attributes presented by lsquoPeruvian Redrsquo including lsquograssyrsquo
aroma lsquograinyrsquo flavors and lsquofirmrsquo and lsquocrunchyrsquo textures were preferred among consumers The
less preferred attributes included lsquopastyrsquo lsquowaterymoistrsquo lsquoadhesiversquo and lsquocohesiversquo all attributes
used to describe the lsquoQQ74rsquo variety Overall acceptance was driven by crunchy texture (r =
090) but negatively correlated with lsquocohesiversquo lsquopastyrsquo and lsquoadhesiversquo texture (r = -096 -087
and -089 respectively) Specifically aroma acceptance of cooked quinoa was negatively
correlated with lsquowoodyrsquo (r = -083) Texture acceptance was positively correlated with lsquofirmrsquo(r =
084) and lsquocrunchyrsquo (r = 094) but was negatively correlated with lsquocohesiversquo (r = -096) lsquopastyrsquo
(r = -095) lsquoadhesiversquo (r = -096) and lsquomoistrsquo (r = -085) Even though lsquoearthyrsquo is a common
attribute in foods such as mushroom and beets this study on quinoa indicated that earthy aroma
and flavor were not the attributes driving consumersrsquo liking of cooked quinoa Color and
appearance did not exhibit significant correlation with color intensity of cooked quinoa
however the varieties with red or dark colors (lsquoPeruvian Redrsquo lsquoBolivian Redrsquo and lsquoBlackrsquo)
were more highly accepted by consumers compared to samples with light color (lsquoTiticacarsquo
lsquoBolivian Whitersquo lsquoQQ74rsquo) In sum consumers preferred cooked quinoa with grassy aroma firm
and crunchy texture and lack of woody aroma and low cohesive pasty or adhesive texture
162
The variety lsquoBlackrsquo was accepted at a similar level as commercial samples in aroma
tasteflavor texture and overall evaluation With a closer examination of the consumer
demographic consumers who were more familiar with quinoa rated the lsquoBlackrsquo quinoa variety
with higher scores (average of 7) compared to those panelists less familiar with quinoa who
assigned lower average scores (59) (Figure 1S) This tricolor quinoa (browndark mixture) is not
as common as red and yellowwhite quinoa in the US market However the potential of tricolor
quinoa may be great due to the relative high consumer acceptance as well as high gain yield in
the field
Instrumental Texture Profile Analysis (TPA)
The physical properties of cooked quinoa were determined using the texture analyzer
(Table 6) Samples differed in all six texture parameters lsquoNL-6rsquo lsquoPeruvian Redrsquo lsquoBolivian Redrsquo
and lsquoCalifornia Tricolorrsquo exhibited the hardest texture while lsquoTemukorsquo lsquoQQ74rsquo lsquoIslugarsquo
lsquoLinaresrsquo and lsquoCO407Daversquo displayed the lowest hardness values Consistent with trained panel
evaluation lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Daversquo were more adhesive than all other varieties
lsquoTiticacarsquo was the springiest variety while lsquoKaslaearsquo and lsquoQuF9P1-20rsquo were the least springy
varieties The commercial samples with the exception of lsquoPeruvian Whitersquo exhibited a more
gummy texture lsquoTiticacarsquo and lsquoBolivian Whitersquo were the chewiest samples In contrast varieties
of lsquoTemukorsquo lsquoQQ74rsquo lsquoIslugarsquo lsquoLinaresrsquo lsquoQuF9P1-20rsquo and lsquoCO407Daversquo showed the least
gummy and chewy texture The result was comparable to an earlier study (Wu et al 2014)
Similarly quinoa varieties with darker color (orangeredbrowndark) tended to yield harder
texture compared to the varieties with light color (whiteyellow) which is caused by the thicker
seed coat in dark colored quinoa In this study adhesive quinoa varieties lsquoQQ74rsquo lsquoLinaresrsquo and
163
lsquoCO407Daversquo were found to have higher adhesiveness values (-17 kgs to -13 kgs) compared
to other varieties previously reported (-029 kgs to 0) (Wu et al 2014)
Correlations of instrumental tests and trained panel evaluations of texture were
significant for hardness and adhesiveness (r = 070 and -063 respectively) (Table 7) Since
adhesiveness was calculated from the first negative peak area of the TPA graph a negative
correlation coefficient was observed but still indicating a high level of agreement between
instrumental and panel tests Springiness tested by TPA was not correlated with texture
attributes
Cohesiveness from the instrumental test was negatively correlated with cohesiveness
from the trained panel texture evaluation (r = -066) Instrumental cohesiveness also exhibited
positive correlations with the trained panel evaluation of firmness and crunchiness (r = 080 and
076 respectively) and negative correlations with pastiness adhesiveness moistness (r = -072
-075 and -082 respectively) Upon a closer examination of the definitions in the instrumental
test cohesiveness was defined as lsquohow well the product withstands a second deformation relative
to its resistance under the first deformationrsquo and is calculated as the ratio of second peak area to
first peak area (Wiles et al 2004) In the sensory lexicon cohesiveness was defined as lsquodegree
to which a substance is compressed between the teeth before it breaksrsquo (Szczesniak 2002) These
differential definitions or explanations of these attributes may have caused the different results
Additionally the gumminess and chewiness from the instrumental evaluation were not
significantly correlated with their counterpart notes from the trained panel evaluations but
correlated with other sensory attributes evaluated by the trained panel Instrumental gumminess
164
was positively correlated with firm and crunchy textures(r = 079 and 078 respectively) but
negatively correlated with cohesive pasty adhesive and moist (r = -067 -068 -075 and -
078 respectively) Additionally a positive correlation was found between instrumental
chewiness and firmness from the panel evaluation (r = 057) whereas negative correlations were
found between instrumental chewiness and panel evaluated cohesiveness pastiness
adhesiveness and moistness (r = -043 -045 -055 and -052 respectively) In the instrumental
texture profile gumminess is calculated by hardness multiplied by cohesiveness and chewiness
is calculated by gumminess multiplied by springiness (Epstein et al 2002) Hence gumminess
was significantly correlated with hardness and cohesiveness and chewiness was significantly
correlated with gumminess In another study of Lyon et al (2000) pasty and adhesive were
expressed as lsquoinitial starchy coatingrsquo and lsquoself-adhesivenessrsquo respectively in cooked rice and
were both negatively correlated with instrumental hardness Generally the instrument test is
more accurate and stable but the parameter or sensory attributes were relatively limited Sensory
panels are able to use various vocabularies to describe the food however accuracy and precision
of panel evaluations were lower than for the instrument Consequently both tools can be
important in sensory evaluation depending on the objectives and resources availability
Future Studies
A lexicon of cooked quinoa was firstly developed in this paper Further discussion and
improvement of the lexicon are necessary and require cooperation with industry and chefs The
lexicon is not only useful in categorizing varieties but also can be used to evaluate post-harvest
practice cooking protocols and other quinoa foodsdishes Additionally quinoa seed quality
varies among years and locations and sensory properties also change over different
165
environments To validate the sensory profile of varieties especially adhesiveness evaluation
should be repeated on the samples from other years and locations Finally multiple dishes food
types should be included in future consumer evaluation studies to identify the best application of
different varieties
Conclusion
A lexicon of cooked quinoa was developed based on aroma tastefavor texture and
color Using the lexicon the trained panel conducted descriptive analysis evaluation on 16
quinoa varieties from field trials and 5 commercial samples Many sensory attributes exhibited
significant differences among quinoa samples especially texture attributes
Consumer evaluations (n = 102) were conducted on six selected samples with diverse
color texture and origin Commercial samples and the variety lsquoBlackrsquo were better accepted by
consumers The adhesive variety lsquoQQ74rsquo was the least accepted quinoa variety in the plain
cooked quinoa dish However because of its cohesive texture lsquoQQ74rsquo shows possible
application in other dishes and foods such as quinoa sushi and extruded snacks Furtherly Partial
Least Square Regression indicated the consumerrsquos preferred attributes were grassy aroma and
firm and crunchy texture while the attributes of pasty adhesive and cohesive were not liked by
consumers
Correlations of panel evaluation and instrumental test were observed in hardness and
adhesiveness However chewiness and gumminess were not significant correlated between panel
test and instrumental test Further training should be addressed to clarify the definitions of
sensory attributes With the assistance and calibration from instruments such as the texture
166
analyzer and electronic tongue panel training can be more efficient and panelists can be more
accurate at evaluation
Acknowledgements
The study was funded by the USDA Organic Research and Extension Initiative
(NIFAGRANT11083982) The authors acknowledge Washington State University Sensory
Facility and their technicians Beata Vixie and Karen Weller The authors also acknowledge
Sergio Nunez de Arco and Sarah Connolly to provide commercial samples Thanks to Raymond
Kinney Max Wood and Hanna Walters who managed the plants harvested the seeds and
collected the data of yield and 1000-seed weight on field trial quinoa varieties Thanks also go to
the USDA-ARS Western Wheat Quality Lab which provided equipment for protein and ash tests
and the texture analyzer
Author contributions
CF Ross and G Wu together designed the study G Wu conducted panel training
collected and processed data and drafted the manuscript KM Murphyrsquos research group provided
the quinoa samples and assisted cleaning process CF Ross CF Morris and KM Murphy edited
the manuscript
167
References
Abugoch LEJ 2009 Chapter 1 quinoa (Chenopodium quinoa Willd) Adv Food Nutr Res
581ndash31
Arco SND Quinoas Calling In Murphy KM Matanguihan J editors Quinoa improvement
and sustainable production Hoboken NJ John Wiley amp Sons Inc p 211
Casas Moreno MM Barreto-Palacios V Gonzalez-Carrascosa R Iborra-Bernad C Andres-Bello
A Martiacutenez-Monzoacute J Garciacutea-Segovia P 2015 Evaluation of textural and sensory properties
on typical spanish small cakes designed using alternative flours J Culinary Sci Technol 13
19-28
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(Waxy) genes J Cereal Sci 35 51-63
Foumlste M Nordlohne SD Elgeti D Linden MH Heinz V Jekle M Becker T Impact of quinoa
bran on gluten-free dough and bread characteristics Eur Food Res Technol 2014 239 767-
75
Furche C Salcedo S Krivonos E Rabczuk P Jara B Fernaacutendez D Correa F 2015 Chapter 41
International quinoa trade In Bazile D Bertero D Nieto C editors State of the art report
on quinoa in 2013 Rome FAO amp CIRAD p 317 ndash 20
Gerber NN1968 Geosmin from microorganisms is trans-1 10-dimethyl-trans-9-decalol
Tetrahedron Lett 9 2971-4
168
Koumlksel H Ryu GH Basman A Demiralp H Ng PK 2004 Effects of extrusion variables on the
properties of waxy hulless barley extrudates FoodNahrung 48 19-24
Kowalski RJ Morris CF Ganjyal GM 2015 Waxy soft white wheat extrusion characteristics
and thermal and rheological propertiesCereal Chem 92 145-53
Koziol MJ 1991 Afrosimetric estimation of threshold saponin concentration for bitterness in
quinoa (Chenopodium quinoa Willd) J Sci Food Agr 54 211-9
Limpawattana M Shewfelt R 2010 Flavor lexicon for sensory descriptive profiling of different
rice types J Food Sci 75 199-205
Lorenz K Coulter L Quinoa flour in baked products Plant Food Hum Nutr 1991 41 213-23
Lyon BG Champagne ET Vinyard BT Windham WR Barton FE Webb BD McKenzie KS
1999 Effects of degree of milling drying condition and final moisture content on sensory
texture of cooked rice Cereal Chem 76 56-62
Lyon BG Champagne ET Vinyard BT Windham WR 2000 Sensory and instrumental
relationships of texture of cooked rice from selected cultivars and postharvest handling
practices Cereal Chem 77 64-9
Meilgaad MC Civille GV Carr BT 2007 Chapter 11 The spectrum descriptive analysis
method In Meilgaad MC Civille GV Carr BT Sensory evaluation techniques Boca Raton
FL CRC Press p 225 ndash 32
169
Meullenet JF Marks BP Hankins JA Griffin VK Daniels MJ 2000 Sensory quality of cooked
long-grain rice as affected by rough rice moisture content storage temperature and storage
duration Cereal Chem 77 259 ndash 63
Mossman AP Fellers DA Suzuki H 1983 Rice stickiness I Determination of rice stickiness
with an Instron tester Cereal Chem 60 286ndash92
Muntildeoz AM 2003 Training time in descriptive analysis In Moskowitz HR Muntildeoz AM and
Gacula MC editors Viewpoints and controversies in sensory science and consumer product
testing Trumbull Food amp Nutrition Press Inc p 351 ndash 6
Peterson AJ Murphy KM 2015 Quinoa cultivation for temperate North America
considerations and areas for investigation In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 173-92
Palmer GH 1994 Chapter 5 Storage In Hoseney RC editor Cereal science and technology
2nd edition St Paul MN American Association of Cereal Chemisty Inc p 107
Pop A Muste S Man S Mureșan C 2014 Improvement of tagliatelle quality by addition of red
quinoa flour Bulletin UASVM Food Sci Tech 71 225-6
Pulvento C Riccardia M Biondib S Orsinic F Jacobsend SE Ragabe R DrsquoAndriaa R Lavinia
A 2015 Chapter 613 Quinoa in Italy research and perspectives In Bazile D Bertero D
Nieto C editors State of the art report on quinoa in 2013 Rome FAO amp CIRAD p 460
Quiroga C Escalera R Aroni G Bonifacio A Gonzaacutelez JA Villca M Saravia R Ruiz A 2015
Chapter 31 Traditional processes and technological innovations in quinoa harvesting
170
processing and industrialization In Bazile D Bertero D Nieto C editors State of the art
report of quinoa in the world in 2013 Rome FAO amp CIRAD p 231
Repo-Carrasco R Espinoza C Jacobsen SE 2003 Nutritional value and use of the Andean
crops quinoa (Chenopodium quinoa) and kantildeiwa (Chenopodium pallidicaule) Food Rev Int
19 179-89
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile
D Bertero D Nieto C editors State of the art report on quinoa in 2013 Rome FAO amp
CIRAD p 67
Sowbhagya CM Ramesh BS Bhattacharya KR 1987 The relationship between cooked-rice
texture and physicochemical characteristics of rice J Cereal Sci 5 287ndash97
Suwannaporn P Linnemann A and Chaveesuk R 2008 Consumer preference mapping for rice
product concepts Brit Food J 110 595-606
Stikic R Glamoclija D Demin M Vucelic-Radovic B Jovanovic Z Milojkovic-Opsenica D
Milovanovic M 2012 Agronomical and nutritional evaluation of quinoa seeds
(Chenopodium quinoa Willd) as an ingredient in bread formulations J Cereal Sci 55 132-8
Szczesniak AS 2002 Texture is a sensory property Food Qual Prefer 13 215-25
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Belton PS JRN Taylor editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science Business Media p 108 ndash 10
171
Tomlins KI Manful JT Larwer P and Hammond L 2005 Urban consumer preferences and
sensory evaluation of locally produced and imported rice in West Africa Food Qual Prefer
16 79-89
Van Soest JJG De Wit D Vliegenthart JFG 1996 Mechanical properties of thermoplastic waxy
maize starch J Appl Polym Sci 61 1927-37
Wang S Opassathavorn A Zhu F 2015 Influence of quinoa flour on quality characteristics of
cookie bread and Chinese steamed bread J Texture Stud 46 281-92
Wiles JL Green BW Bryant R 2004 Texture profile analysis and composition of a minced
catfish product J Texture Stud 35 325-37
Wu G Morris C F Murphy K M 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79 2337-45
172
Table 1-Quinoa samples
Varietya Color Source
Titicaca Yellowwhite Denmark
Black Blackbrown mixture White Mountain Farm Colorado USA
KU-2 Yellowwhite Washington USA
Cahuil Brownorange mixture White Mountain Farm Colorado USA
Red Head Yellowwhite Wild Garden Seed Oregon USA
Cherry Vanilla Yellowwhite Wild Garden Seed Oregon USA
Temuko Yellowwhite Washington USA
QuF9P39-51 Yellowwhite Washington USA
Kaslaea Yellowwhite MN USA
QQ74 Yellowwhite Chile
Isluga Yellowwhite Chile
Linares Yellowwhite Washington USA
Puno Yellowwhite Denmark
QuF9P1-20 Yellowwhite Washington USA
NL-6 Yellowwhite Washington USA
CO407Dave Yellowwhite White Mountain Farm Colorado USA
Bolivian White White Bolivia
Bolivian Red Red Bolivia
California Tricolor
Blackbrown mixture California USA
Peruvian Red Red Peru
Peruvian White White Peru aThe first 16 varieties (Tititcaca ndash CO407Dave) were grown in Chimacum WA
173
Table 2-Lexicon of cooked quinoa as developed by the trained panelists (n = 9)
Attribute Intensitya Reference Definition
Aroma
Caramel 10 1 piece of caramel candy (Kraft) (81 g) in 100 mL water
Aromatics associated with caramel tastes
Grain-like 10 Cooked brown rice (15 g) (Great Value)
Rice like wheaty sorghum like
Bean-like 8 Cooked red bean (10 g) (Great Value)
Aromatics associated with cooked beans or bean protein
Nutty 10 Dry roasted peanuts (10 g) (Planters)c
Aromatics associated with roasted nuts
Buttery 10 Unsalted butter (1cm1cm01cm) (Tillamook)c
Aromatics associated with natural fresh butter
Starchy 10 Wheat flour water (11 ww) (Great Value)c
Aromatics associated with the starch
Grassygreen 9 Fresh cut grass collected 1 h before usingc
Aromatics associated with grass
Earthymusty 8 Sliced raw button mushrooms (fresh cut)c
Aromatic reminiscent of decaying vegetative matters and damp black soil root like
Woody 7 Toothpicks (20)c Aromatics reminiscent of dry cut wood cardboard
TasteFlavor
Sweet 3 9 2 and 5 (ww) sucrose solution (CampH pure cane sugar)b
Basic taste sensation elicited by sugar
Bitter 5 8 mgL quinine sulfate acid (Sigma)
Basic taste sensation elicited by caffeine
174
Grain-like 10 Cooked brown rice (Great Value)
Tasted associated with cooked grain such as rice
Bean-like 10 Cooked red beans (Great Value)
Beans bean protein
Nutty 10 Dry roasted peanut (Planters)c Taste associated with roasted nuts
Earthy 7 Sliced raw button mushrooms (fresh)
Taste associated with decaying vegetative matters and damp black soil
Toasted 10 Toasted English muffin (at 6 of a toaster) (Franze Original English Muffin)
Taste associated with toast
Texturee
Soft - Firm 3
7
Firm tofu (Azumaya)b
Brown rice (Great Value)
Force required to compress a substance between molar teeth (in the case of solids) or between tongue and palate (in the case of semi-solids)d
Separate - Cohesive
15
7
Cracker (Premium unsalted cracker)
Cake (Sponge cake Walmart Bakery)
Degree to which a substance is compressed between the teeth before it breaks
Pasty
10 Mashed potato (Great Value Mashed Potatoes powder)
Smooth creamy pulpy slippery
Adhesiveness sticky
10
3
Sticky rice (Koda Farms Premium Sweet Rice)
Brown rice (Great Value)
Force required to remove the material that adheres to the mouth (the palate and teeth) during the normal eating process
Crunchy 13 Thick cut potato chip (Tostitos Restaurant Style
Force with which a sample crumbles cracks or shatters
175
Tortilla Chips)b
Chewygummy
15
7
Gummy Bear (Haribo Gold-Bears mixed flavor)
Brown rice (Great Value)
Length of time (in sec) required to masticate the sample at a constant rate of force application to reduce it to a consistency suitable for swallowing
Astringent 12
6
Tannic acid (2gL)
Tannic acid (1gL) (Sigma)
Puckering or tingling sensation elicited by grape juice
Waterymoist 10
3
Salad tomato (Natural Sweet Cherubs)
Brown rice (Great Value)
Degree of wet or dry
Color
Red 4 9
N-W8M Board Walke
N-W16N Ballet Barree
Yellow 3 10
15B-2U Sandy Toese 15B-7
N Summer Harveste
Black 3 10
N-C32N Strong Influencee N-C4M Trench Coate
aReference intensities were based on a 15-cm scale with 0 = extremely low and 15 = extremely high bMeilgaad et al (2007) cLimpawattana and Shewfelt (2010) dTexture definitions in Szczesniak (2002) were used eAce Hardware color chip
176
Table 3-Significance and F-value of the effects of panelist replicate and quinoa variety on aroma flavor and texture of cooked quinoa as determined using a trained panel (n = 9)
Attribute Panelist Replicate Quinoa Variety PanelistVariety
Aroma
Caramel 26548 093 317 174
Grain-like 7338 000 125 151
Bean-like 7525 029 129 135
Nutty 6274 011 322 118
Buttery 21346 003 301 104
Starchy 12094 1102 094 135
Grassy 17058 379dagger 282 162
Earthy 12946 239 330 198
Woody 13178 039 269 131
TasteFlavor
Sweet 6745 430 220 137
Bitter 9368 1290 2059 236
Grain-like 7681 392 222 206
Bean-like 7039 122 142 141
Nutty 7209 007 169 153
Earthy 9313 131 330 177
Toasted 10975 015 373 184
Texture
Firm 1803 022 1587 141
Cohesive 14750 011 656 208
Pasty 3919 2620 1832 205
Adhesive 2439 287dagger 5740 183
177
Crunchy 13649 001 1871 167
Chewy 3170 870 150dagger 167
Astringent 10183 544 791 252
Waterymoist 10281 369dagger 1809 164
daggerP lt 010 P lt 005 P lt 001 P lt 0001
178
Table 4-Mean separation of significant tasteflavor attributes of cooked quinoa determined by the trained panel Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Sweet Bitter Grain-like Nutty Earthy Toasty
Titicaca 40cdef1 39bcde 73abc 51abcdef 44bcdef 47abcd
Black 36f 42bcd 69bcde 49def 52a 46abcd
KU2 41bcdef 38cde 73abc 52abcdef 40fg 44bcdefg
Cahuil 41abcdef 44b 70bcde 50abcdef 48abc 51a
Red Head 42abcd 43bc 72abcd 51abcdef 42defg 44bcdefg
Cherry Vanilla 40def 52a 66e 48ef 44bcdef 40fghi
Temuko 36ef 56a 68cde 47f 43cdef 40ghi
QuF9P39-51 47a 34e 73abc 48def 40efg 46abcde
Kaslaea 47ab 39bcde 70bcde 55ab 44bcdef 45bcdefg
QQ74 40def 38cde 66e 50abcdef 45bcde 42defghi
Isluga 41bcdef 41bcd 69cde 55a 46bcd 47abcd
Linares 39def 40bcd 65e 49cdef 43def 38i
Puno 44abcd 39bcde 72abcd 51abcdef 45bcde 43cdefghi
QuF9P1-20 42abcdef 43bc 69bcde 53abcd 45bcde 38i
NL-6 38def 37de 72abcd 55a 45bcd 44bcdefgh
CO 407 Dave 41bcdef 40bcd 67de 51abcdef 41defg 39hi
Bolivian White 47ab 22f 69bcde 50bcdef 42def 41efghi
Bolivian Red 42abcde 24f 72abcd 53abcdef 43cdef 46bcde
California Tricolor 40def 27f 74ab 53abcde 48ab 48ab
Peruvian Red 43abcd 25f 75a 48ef 45bcde 47abc
Peruvian White 46abc 26f 70bcde 55abc 37g 45bcdef
179
Table 5-Mean separation of consumer preference Different letters within a column indicate consumer evaluation scores were different among quinoa samples at P lt 005
Samples Aroma Color Appearance TasteFlavor Texture Overall
Black 56a 63b 61bc 61abc 65a 63ab
QQ74 61a 56c 53d 56c 53b 53c
Titicaca 60a 57bc 56cd 58bc 63a 59bc
Peruvian Red 60a 72a 70a 65a 68a 67a
Bolivian Red 60a 69a 66ab 64ab 67a 64ab
Bolivian White 57a 59bc 58c 62ab 63a 62ab
180
Table 6-Hardness adhesiveness cohesiveness springiness gumminess and chewiness of the cooked quinoa samples as determined using Texture Profile Analysis (TPA)
Variety Hardness
(kg)
Adhesiveness
(kgs)
Cohesiveness Springiness Gumminess
(kg)
Chewiness
(kg)
Titicaca 505abc1 -02ab 08abc 15a 384bc 599a
Black 545ab -01a 07bcd 10abc 404abc 404ab
KU-2 490abcd -01a 07bcd 09abc 363bcd 332abc
Cahuil 464bcde -01a 07bcd 08abc 344cd 281bc
Red Head 412defg -03ab 06ef 09abc 246ef 225bc
Cherry Vanilla 391efgh -02ab 05fgh 08abc 208fg 178bc
Temuko 328gh -09c 04hi 08abc 147g 120c
QuF9P39-51 451cde -02ab 07de 10abc 297de 272bc
Kaslaea 493abcd -02ab 07bcd 06c 359cd 227bc
QQ74 312h -17e 04i 09abc 132g 119c
Isluga 362fgh -05b 05ghi 08abc 171fg 137bc
Linares 337gh -16de 05ghi 09abc 159g 146bc
Puno 504abc -01a 06ef 10abc 301de 301bc
QuF9P1-20 438cdef -02ab 06fg 05c 242ef 137bc
NL-6 555a -01a 07cde 09abc 376bcd 350abc
CO407Dave 357fgh -13d 04hi 09abc 160g 141bc
Bolivian White 441cdef -01ab 05fg 14ab 242ef 340abc
Bolivian Red 572a -01ab 08ab 14ab 440ab 593a
California Tricolor
572a -01a 08a 08bc 477a 361abc
Peruvian Red 568a 00a 08ab 08abc 439ab 342abc
Peruvian White 459bcde -01a 08abc 11abc 347cd 394abc
181
Table 7-Correlation of trained panel texture evaluation data and instrumental TPA over the 21 quinoa varieties
Variables Hardness Adhesiveness Cohesiveness Gumminess Chewiness Firm 070 059 080 079 057 Cohesive -060 -051 -066 -067 -043 Pasty -060 -070 -072 -068 -045 Adhesive -067 -063 -075 -075 -055 Crunchy 072 054 076 078 055 Moist -066 -066 -082 -078 -052
daggerP lt 01 P lt 005 P lt 001 P lt 0001
182
Figure 1-Principal component Analysis (PCA) biplot of aroma evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil Red Head
Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white Kaslaea
QQ74
Isluga
Linares
Puno
QuF9P1-20 NL-6
CO 407 Dave
Bolivia white
Bolivia red California Tricolor
Caramel Grain-like
Bean-like Nutty
Buttery Starchy
Grassy
Earthy
Woody
-25
-2
-15
-1
-05
0
05
1
15
2
-3 -25 -2 -15 -1 -05 0 05 1 15 2 25 3 35 4
F2 (2
455
)
F1 (4234 )
183
Figure 2-Principal component Analysis (PCA) biplot of tasteflavor evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil
Red Head Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white
Kaslaea
QQ74 Isluga
Linares
Puno
QuF9P1-20
NL-6
CO 407 Dave
Bolivia white
Bolivia red
California Tricolor
Sweet
Bitter Grain-like
Bean-like
Nutty
Earthy
Toasted
-3
-2
-1
0
1
2
3
-4 -3 -2 -1 0 1 2 3 4 5
F2 (3
073
)
F1 (3391 )
184
Figure 3-Principal component Analysis (PCA) biplot of texturemouthfeel evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil
Red Head Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white
Kaslaea
QQ74 Isluga
Linares
Puno
QuF9P1-20
NL-6
CO 407 Dave
Bolivia white
Bolivia red California Tricolor
Firm Cohesive
Pasty
Adhesive
Crunchy
Chewy Astringent
Moist
-2
-15
-1
-05
0
05
1
15
2
25
-3 -25 -2 -15 -1 -05 0 05 1 15 2 25 3 35
F2 (2
212
)
F1 (5959 )
185
Figure 4-Partial Least Squares (PLS) biplot correlating aroma color appearance tasteflavor texture and overall attributes evaluated by the trained panel (n = 9) to the consumer panel (n = 102) for 6 cooked quinoa samples (Consumer acceptances are in bold italics)
Grainy aroma
Beany aroma
Nutty aroma
Buttery
Starchy
Grassy
Earthy
Woody
Sweet
Bitter grainy flavor
Beany flavor
Earthy flavor Nutty flavor
Toasty
Firm Cohesive
Pasty
Adhesive
Crunchy
Chewy
Astringent
Waterymoist
Aroma
Color Appearance TasteFlavor
Texture Overall
Black
Bolivia red
QQ74
Bolivia white
Commercial Red
Titicaca
-1
-075
-05
-025
0
025
05
075
1
-1 -075 -05 -025 0 025 05 075 1
t2
t1
186
Supplementary tables
Table 1S-Mean separation of significant aroma attributes of cooked quinoa determined by the trained panel (n = 9) Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Caramel Nutty Buttery Green Earthy Woody
Titicaca 59a1 60a 45abc 39fg 42defgh 37cdef
Black 46g 50efg 38ef 47abc 54a 46a
KU2 50efg 51defg 41cdef 40efg 38h 35ef
Cahuil 56abc 53bcdefg 43abcd 49a 48b 39bcde
Red Head 55abcd 60a 45abc 44bcde 46bcd 41bc
Cherry Vanilla 52cdef 54bcdef 43abcde 43bcdef 46bcdef 37bcdef
Temuko 55abcd 56abcde 44abc 40defg 41efgh 37bcdef
QuF9P39-51 58ab 60a 46ab 42bcdefg 44bcdefg 36def
Kaslaea 53bcde 55abcde 42abcde 41defg 40gh 37bcdef
QQ74 50efg 48fg 39def 42defg 45bcdef 38bcdef
Isluga 52cdef 57abc 43abcd 43bcdefg 46bcde 39bcde
Linares 52cdef 54bcdef 42bcde 38g 44bcdefg 37cdef
Puno 56abc 56abcde 46ab 42cdefg 46bcdef 38bcdef
QuF9P1-20 53bcdef 58ab 44abcd 42cdefg 44bcdefg 40bcd
NL-6 57abc 53bcdefg 44abcd 39fg 44bcdefg 35def
CO 407 Dave 51def 54abcde 46ab 40efg 42defgh 34f
Bolivian White 53bcde 57abcd 46ab 43bcdef 43cdefgh 39bcd
Bolivian Red 52cdef 51defg 42bcde 43bcdefg 44bcdefg 37bcdef
California Tricolor 54abcde 51cdefg 38ef 44abcd 48bc 41ab
Peruvian Red 48fg 48g 36f 47ab 46bcdef 38bcdef
Peruvian White 54abcde 60a 48a 45abcd 41fgh 40bc
187
Table 2S-Mean separation of significant texture attributes of cooked quinoa determined by the trained panel Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Firm Cohesive Pasty Adhesive Crunchy Astringent Moist
Titicaca 70ab 63efgh 37ghi 37ghi 56bc 47d 38hij
Black 71ab 63efgh 32i 38ghi 58b 55abc 35jk
KU2 66bcd 64efg 38fghi 37ghi 49de 46de 38hij
Cahuil 68abc 61fghi 37ghi 36hi 56bc 55ab 37ij
Red Head 57fgh 68bcde 46cde 49d 45ef 55ab 48de
Cherry Vanilla 56gh 65cdef 49c 44def 43fg 55ab 49de
Temuko 49ij 70abcd 56b 57c 39gh 59a 51cd
QuF9P39-51 61defg 65def 47cd 40efgh 48def 48cd 42fgh
Kaslaea 60defg 62fghi 40defgh 40fgh 51cd 51bcd 42gh
QQ74 44j 70abc 60ab 81ab 37hi 46def 57ab
Isluga 52hi 66cdef 43cdef 55c 44efg 50bcd 48de
Linares 45j 75a 65a 86a 33i 47d 61a
Puno 58efgh 60fghij 41defg 43efg 52cd 47d 47def
QuF9P1-20 52hi 65def 43cdefg 46de 44fg 55ab 47defg
NL-6 64cde 61fghi 40efgh 41efgh 51cd 46de 46efg
CO 407 Dave 45j 72ab 59ab 80b 35hi 47d 55bc
Bolivian White 56gh 61fghi 38fghi 41efgh 50de 34g 48de
Bolivian Red 62cdef 59hij 34hi 36hi 56bc 38g 42fgh
California Tricolor 68abc 56j 32i 33i 60ab 39efg 39hij
Peruvian Red 74a 57ij 35hi 33i 64a 39fg 31k
Peruvian White 60defg 59ghij 38fghi 37hi 48def 34g 40hi
188
Figure-1S Demographic influence on preference of variety lsquoBlackrsquo
75a
66ab 61bc
54c
61bc
0
1
2
3
4
5
6
7
8
75 50 25 None Other
Liking score of lsquoBlackrsquo
Proportion of organic food consumption
52b
64a 65a 69a 70a
57ab 59ab
0
1
2
3
4
5
6
7
8
Everyday 4-5 timesper week
2-3 timesper week
Once aweek
A fewtimes per
month
Aboutevery 6months
Other
Liking score of lsquoBlackrsquo
Frequency of rice consumption
189
Chapter 7 Conclusions
Quinoa quality is a complex topic with seed composition influencing sensory and
physical properties This dissertation evaluated the seed characteristics composition flour
properties and cooking quality of 13 quinoa samples Differences in seed morphology and
composition contributed to the texture of cooked quinoa The seeds with higher raw seed
hardness lower bulk density or higher seed coat proportion yielded a firmer gummier and
chewier texture after cooking Higher protein content correlated with harder more adhesive
more cohesive gummier and chewier texture of cooked quinoa Additionally flour peak
viscosity breakdown final viscosity and setback exhibited influence on different texture
parameters Cooking time and water uptake ratio also significantly influence the texture whereas
cooking loss did not show any correlation with texture Starch characteristics also significantly
differed among quinoa varieties (Chapter 3) Amylose content ranged from 27 to 169
among 13 quinoa samples The quinoa samples with higher amylose proportion or higher starch
enthalpy tended to yield harder stickier more cohesive and chewier quinoa These studies on
seed quality seed characteristics compositions and cooking quality provided useful information
to food industry professionals to use in the development of quinoa products using appropriate
quinoa varieties Indices such protein content and flour viscosity (RVA) can be quickly
determined and exhibited strong correlations with cooked quinoa texture Furthur study should
develop a prediction model using protein content or RVA parameters to predict the texture of
cooked quinoa In this way food manufactures can quickly predict the texture or functionality of
quinoa varieties and then determine their specific application Moreover many of the test
methods were using the methods used in rice such as kernel hardness texture of cooked quinoa
190
thermal properties (DSC) and cooking qualities Such methods should be standardized in near
future as those defined by AACC (American Association of Cereal Chemists) The development
of standard methods allows for easier comparisons among different studies In Chapter 4 the
seed quality response to soil salinity and fertilization was studied Quinoa protein content
increased under high Na2SO4 concentration (32 dS m-1) The variety lsquoQQ065rsquo maintained similar
levels of hardness and density under salinity stress and is considered to be the best adapted
variety among four varieties The variety can be applied in salinity affected areas Future studies
can be applied on salinity drought influence on quinoa amino acids profile starch composition
fiber content and saponins content
Sensory evaluation of cooked quinoa was further examined in Chapter 5 Using a trained
panel the lexicon for cooked quinoa was developed Using this lexicon the sensory profiles of
16 field trial varieties and 5 commercial quinoa samples were generated Varietal differences
were observed in the aromas of caramel nutty buttery grassy earthy and woody tasteflavor of
sweet bitter grain-like nutty earthy and toasty and texture of firm cohesive pasty adhesive
crunchy chewy astringent and moist Subsequent consumer evaluation on 6 selected quinoa
samples indicated lsquoPeruvian Redrsquo was the most accepted overall whereas a sticky variety lsquoQQ74rsquo
was the least accepted Partial least square analysis using trained panel data and consumer
acceptance data indicated that overall consumer liking was driven by grassy aroma and firm and
crunchy texture The lexicon and the attributes driving consumer-liking can be utilized by
breeders and farmers to evaluate their quinoa varieties and products The information is also
useful to the food industry to evaluate ingredients from different locations and years improve
processing procedures and develop products
191
Overall the dissertation provided significant information of quinoa seed quality and
sensory characteristics among different varieties including both commercialized samples and
field trial samples not yet available in market Several quinoa varieties increasingly grown in
US were included in the studies The variety lsquoCherry Vanillarsquo and lsquoTiticacarsquo are among the
varieties gaining the best yields in US Their seed characteristics and sensory attributes
described in this dissertation should be helpful for industry professionals in their research and
product development Varieties include lsquoTiticacarsquo lsquoCherry Vanillarsquo and lsquoBlackrsquo Additionally
important tools were developed in quinoa evaluation including texture analysis using TPA and
the lexicon of cooked quinoa
As with any set of studies other research questions arise to be addressed in future
research First saponins the compounds introducing bitter taste in quinoa require further study
Sweet quinoa varieties (saponins content lt 011) should be bred and adapted to the US
Although many consumers may like the bitter taste and especially the potential health benefits of
saponins it is important to provide consumers choices of both bitter and non-bitter quinoa types
To assist the breeding of sweet quinoa genetic markers can be developed and associated with the
phenotype of saponin content As for the methods testing saponin content the foam method is
quick but not accurate whereas the GC method is accurate but requires long sample preparation
time and high capital investment An accurate more affordable and more efficient method such
as one using a spectrophotometer should be developed
Second one important nutritional value of quinoa is the balanced essential amino acids
The essential amino acids profiles change according to environment (drought and saline soil)
quinoa variety and processing (cleaning milling and cooking) and these changes should be
192
further studied It is important to prove quinoa seed maintains the rich essential amino acids even
growing under marginal conditions or being subjected to cleaning processes such as abrasion
and washing
Third betalains are the compounds contributing to the color of quinoa seed and providing
potential health benefits Betalain content type (relate to diverse colors) and their genetic loci in
quinoa can be further investigated Color diversity is one of the attractive properties in quinoa
seeds However the commercialized quinoa samples are in white or red color while more quinoa
varieties present orange purple brown and gray colors More choices of quinoa colorstypes
may attract more consumers
Finally sensory evaluation of quinoa varieties should be applied to the samples from
multiple years and locations since environment can significantly influence the sensory attributes
Also in addition to plain cooked quinoa more quinoa dishes can be involved in consumer
acceptance studies as different quinoa varieties may be suitable for various dishes
iii
ACKNOWLEDGMENT
This dissertation is accomplished with a lot of collaborations of Food Science USDA-
ARS Western Wheat Quality Lab and Crop Science I gained significant advice and help from
my co-chairs and co-advisors Dr Craig Morris and Dr Carolyn Ross as well as my committee
members Dr Barbara Rasco and Dr Kevin Murphy Working with them on research proposals
experiments data processing and editing manuscripts I learned so much from scientific
philosophy critical thinking and efficient argument to scientific writing skills This dissertation
could never have been accomplished without their professional patient and persistent work
Additionally I owe thanks to many lab members who provided important help with the
experiments From the USDA-ARS Western Wheat Quality Lab Bozena Paszczynska who is no
longer with us trained me on most of the flour testing equipment Patrick Fuerst Alecia
Kiszonas Douglas Engle and Eric Wegner helped with experimental methods manuscript
preparation milling and equipment maintenance From the WSU Sensory Evaluation Lab Beata
Vixie Karen Weller Charles Diako and Ben Bernhard provided help in sensory study
preparation and serving From the WSU Sustainable Seed System Lab Max Wood Janet
Matanguihan Hannah Walters Adam Peterson Raymond Kinney Cedric Habiyaremye
Leonardo Hinojosa and Kristofor Ludvigson helped with quinoa field work (planting weeding
harvesting) post-harvest cleaning and greenhouse management I feel grateful to have met so
many brilliant and kind people and it is a pleasant journey to work with them and develop
friendships with them
Finally thanks to my family and friends Their understanding and support helped me
sincerely enjoy life and work during the past four years
iv
QUINOA SEED QUALITY AND SENSORY EVALUATION
Abstract
by Geyang Wu PhD Washington State University
May 2016
Co-Chairs Carolyn F Ross Craig F Morris
Quinoa is a grain that has garnered increasing interest in recent years from global
markets as well as in academic research The studies in this dissertation focused on quinoa seed
quality and sensory evaluation among diverse quinoa varieties with potential adaptation to
growing conditions in Washington State The objectives in the dissertation were to study quinoa
seed quality as well as the sensory attributes of cooked quinoa as defined by both trained and
consumer panelists Regarding quinoa seed quality we investigated seed characteristics
(diameter weight density hardness seed coat proportion) seed composition (protein and ash
content) flour viscosity and thermal properties quinoa cooking quality and texture of cooked
quinoa Additionally the functional characteristics of quinoa were studied including the
determination of amylose content starch swelling power and water solubility texture of starch
gel and starch thermal properties Results indicated texture of cooked quinoa was significantly
influenced by protein content flour viscosity quinoa cooking quality amylose content and
starch enthalpy In addition the influences of soil salinity and fertility on quinoa seed quality
were evaluated The variety lsquoQQ065rsquo exhibited increased protein content and maintained similar
levels of hardness and density under salinity stress and is considered to be the best adapted
v
variety among four varieties Finally sensory evaluation studies on cooked quinoa were
conducted A lexicon of cooked quinoa was developed including the sensory attributes of aroma
tasteflavor texture and color Results from the trained and consumer panel indicated that
consumer liking of quinoa was positively influenced by grassy aroma and firm and crunchy
texture These results represent valuable information to quinoa breeders in the determination of
seed quality of diverse quinoa varieties In the food industry the results of seed quality and
sensory studies (lexicon and consumer-liking) can be utilized to evaluate quinoa ingredients from
multiple locations or years determine the efficiency of post-harvest processing and develop
appropriate products according to the properties of the specific quinoa variety Overall this
dissertation contributed to the growing body of research describing the chemical physical and
sensory properties of quinoa
vi
TABLE OF CONTENTS
Page
ACKNOWLEDGMENTS iii
ABSTRACT iv-v
LIST OF TABLES ix-xi
LIST OF FIGURES xii-xiii
CHAPTERS
1 Introduction 1
References 6
2 Literature review 9
References 26
Tables 41
Figures44
3 Evaluation of texture differences among varieties of cooked quinoa 46
Abstract 46
Introduction 48
Materials and Methods 51
Results 54
Discussion 60
vii
Conclusion 63
References 65
Tables 71
Figures78
4 Quinoa starch characteristics and their correlation with
texture of cooked quinoa 80
Abstract 80
Introduction 81
Materials and Methods 82
Results 87
Discussion 95
Conclusion 102
References 103
Tables 109
5 Quinoa seed quality response to sodium chloride and
Sodium sulfate salinity 118
Abstract 118
Introduction 120
Materials and Methods 122
Results 125
Discussion 123
viii
Conclusion 132
References 134
Tables 139
Figure 145
6 Lexicon development and sensory attributes of cooked quinoa 146
Abstract 146
Introduction 148
Materials and Methods 150
Results and Discussion 155
Conclusion 165
References 167
Tables 172
Figures183
7 Conclusions 189
ix
LIST OF TABLES
Page
CHAPTER 2
Table 1 Essential amino acid of quinoa protein and FAOWHO suggested requirement (mgg
protein) 41
Table 2 Quinoa vitamin content (mg100g) 42
Table 3 Quinoa mineral content (mgmg ) 43
CHAPTER 3
Table 1 Varieties of quinoa used in the experimenthelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip71
Table 2 Seed characteristics and composition 72
Table 3 Texture profile analysis (TPA) of cooked quinoa 73
Table 4 Cooking quality of quinoa 74
Table 5 Pasting properties of quinoa flour by RVA 75
Table 6 Thermal properties of quinoa flour by Differential Scanning Calorimetry (DSC) 76
Table 7 Correlation coefficients between quinoa seed characteristics composition and
processing parameters and TPA texture of cooked quinoa 77
CHAPTER 4
Table 1 Quinoa varieties tested 109
Table 2 Starch content and composition 110
Table 3 Starch properties and α-amylase activity 111
Table 4 Texture of starch gel 112
Table 5 Thermal properties of starch 113
x
Table 6 Pasting properties of starch 114
Table 7 Correlation coefficients between starch properties and texture of cooked quinoa 115
Table 8 Correlations between starch properties and seed DSC RVA characteristics 116
CHAPTER 5
Table 1 Analysis of variance with F-values for protein content hardness and density of quinoa
seed 139
Table 2 Salinity variety and fertilization effects on quinoa seed protein content () 140
Table 3 Salinity variety and fertilization effects on quinoa seed hardness (kg) 141
Table 4 Salinity variety and fertilization effects on quinoa seed density (g cm3) 142
Table 5 Correlation coefficients of protein hardness and density of quinoa seed 143
Table 6 Correlation coefficients of quinoa seed quality and agronomic performance and seed
mineral content144
CHAPTER 6
Table 1 Quinoa samples 172
Table 2 Lexicon of cooked quinoa as developed by the trained panelists (n = 9) 173
Table 3 Significance and F-value of the effects of panelist replicate and quinoa variety on
aroma flavor and texture of cooked quinoa as determined using a trained panel (n = 9) 176
Table 4 Mean separation of significant tasteflavor attributes of cooked quinoa determined by
the trained panel Different letters within a column indicate attribute intensities were different
among quinoa samples at P lt 005 as determined using Fisherrsquos LSD 178
Table 5 Mean separation of consumer preference Different letters within a column indicate
consumer evaluation scores were different among quinoa samples at P lt 005 179
xi
Table 6 Hardness adhesiveness cohesiveness springiness gumminess and chewiness of the
cooked quinoa samples as determined using Texture Profile Analysis (TPA) Different letters
within a column indicate attribute intensities were different among quinoa samples at P lt 005
180
Table 7 Correlation of trained panel texture evaluation data and instrumental TPA over the 21
quinoa varieties 181
Table 1S Mean separation of significant aroma attributes of cooked quinoa determined by the
trained panel (n = 9) Different letters within a column indicate attribute intensities were different
among quinoa samples at P lt 005 as determined using Fisherrsquos LSD 186
Table 2S Mean separation of significant texture attributes of cooked quinoa determined by the
trained panel Different letters within a column indicate attribute intensities were different among
quinoa samples at P lt 005 as determined using Fisherrsquos LSD 187
xii
LIST OF FIGURES
Page
CHAPTER 2
Figure 1 Quinoa seed section and two-layered pericarp under perianth (Wu et al 2014) 44
Figure 2 Figure 2-Quinoa seed structure (Prego et al 1998) 45
CHAPTER 3
Figure 1 Rapid Visco Analyzer (RVA) graph of lsquoCherry Vanillarsquo and lsquoRed Commercialrsquo quinoa
flours 78
Figure 2 Seed coat image by SEM 79
CHAPTER 5
Figure 1 Protein content () of quinoa in response to combined fertility and
salinity treatments 145
CHAPTER 6
Figure 1 Principal component Analysis (PCA) biplot of aroma evaluations by the trained
sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 182
Figure 2 Principal component Analysis (PCA) biplot of tasteflavor evaluations by the trained
sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 183
xiii
Figure 3 Principal component Analysis (PCA) biplot of texturemouthfeel evaluations by the
trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 184
Figure 4 Partial Least Squares (PLS) biplot correlating aroma color appearance tasteflavor
texture and overall attributes evaluated by the trained panel (n = 9) to the consumer panel (n =
102) for 6 quinoa samples (Consumer acceptances are in bold italics) 185
Figure-1S Demographic influence on preference of variety lsquoBlackrsquo 188
xiv
Dedication
This dissertation is dedicated to those who are interested in quinoa
the beautiful small grain providing nutrition and fun
1
Chapter 1 Introduction
Quinoa is growing rapidly in the global market largely due to its high nutritional value
and potential application in a wide range of products Bolivia and Peru are the major producers
and exporters of quinoa In Peru production increased from 31824 MT (Metric Ton) in 2007 to
108000 MT in 2015 (USDA 2015) In 2013 organic quinoa from Bolivia and Peru were sold at
averages of $8000MT and $7000MT respectively (Nuntildeez de Acro 2015) Of all countries the
US and Canada import the most quinoa and comprise 53 and 15 of the global imports
respectively (Carimentrand et al 2015) Quinoa yield is on average 600 kgha with yield
varying greatly and among varieties and environments (Garcia et al 2004) The total production
cost is $720ha in the southern Altiplano region of Bolivia and the farm-gate price reached
$60kg in 2013 (Nuntildeez de Acro 2015) With 2600 kg annual quinoa yield in a small 3 ha farm
the revenue would be $15390 which could potentially raise a family out of poverty (Nuntildeez de
Acro 2015)
Quinoa possesses many sensory properties Food texture refers to those qualities of a
food that can be felt with the fingers tongue palate or teeth (Sahin and Sumnu 2006) Texture is
one of most significant properties of food products Quinoa has unique texture ndash creamy smooth
and a little crunchy (James 2009) The texture of cooked quinoa is not only influenced by seed
structure but also determined by compounds such as starch and protein However publications
describing the texture of cooked quinoa are limited
Seed characteristics and structure are important factors influencing the textual properties
of cooked quinoa seed Quinoa is a dicotyledonous plant species very different from
2
monocotyledonous cereal grains The majority of the seed is the middle perisperm of which cells
have very thin walls and angular-shaped starch grains (Prego et al 1998) The two-layer
endosperm of the quinoa seed consists of living thick-walled cells rich in proteins and lipids but
without starch The protein bodies found in the embryo and endosperm lack crystalloids and
contain one or more globoids of phytin (Prego 1998) Given the structure of quinoa the seed
properties such as seed size hardness and seed coat proportion may influence the texture of the
cooked quinoa Nevertheless correlations between seed characteristics seed structure and
texture of cooked quinoa have not been performed
Beside the physical properties of seed the seed composition will influence the texture as
well Protein and starch are the major components in quinoa while their correlation to texture
has not been studied Starch characteristics and structures significantly influence the texture of
the end product Starch granules of quinoa is very small (1-2μm) compared to that of rice and
barley (Tari et al 2003) Quinoa starch is lower in amylose content (11 of starch) (Ahamed
1996) which may yield the hard texture Chain length of amylopectin also influences hardness of
food product (Ong and Blanshard 1995) In sum the influence of quinoa seed composition and
characteristics on cooked product should be studied
In addition to seed quality and characteristics the sensory attributes of quinoa are also
significant as they influence consumer acceptance and the application of the quinoa variety
However there is a lack of lexicon to describe the sensory attributes of cooked quinoa Rice is
considered as a model when studying quinoa sensory attributes because they are cooked in
similar ways The lexicon of cooked rice were developed and defined in the study of Champagne
3
et al (2004) Sewer floral starchygrain hay-likemusty popcorn green beans sweet taste
sour and astringent were among those attributes
Consumer acceptance is of great interested to breeders farmers and the food industry
Acceptability of quinoa bread was studied by Rosell et al (2009) and Chlopicka et al (2012)
Gluten free quinoa spaghetti (Chillo et al 2008) and dark chocolate with 20 quinoa
(Schumacher et al 2010) were evaluated using a sensory panel However cooked quinoa the
most common way of consuming quinoa has not been studied for its sensory properties and
consumer preference Additionally consumer acceptance of quinoa may be influenced by the
panelistsrsquo demographic such as origin food culture familiarity with less common grains and
quinoa and opinion of a healthy diet Furthermore compared to instrumental tests sensory
evaluation tests are generally more expensive and time consuming hence correlations of sensory
panel and instrumental data are of interest If correlations exist instrumental analyses can be
used to substitute or complement sensory panel evaluation
Based on the above discussion this dissertation focused on the study of seed
characteristics quality and texture of cooked quinoa and starch characteristics among various
quinoa varieties Seed quality under saline soil conditions was also investigated To develop the
sensory profiles of cooked quinoa a trained panel developed and validated a lexicon for cooked
quinoa while a consumer panel evaluated their acceptance of different quinoa varieties From
these data the drivers of consumer liking were determined
The dissertation is divided into 7 chapters Chapter 1 is an introduction of the topic and
overall objectives of the studies Chapter 2 provides a literature review of recent progress in
4
quinoa studies including quinoa seed structure and compositions physical properties flour
properties health benefits and quinoa products Chapter 3 was published in Journal of Food
Science under the title of lsquoEvaluation of texture differences among varieties of cooked quinoarsquo
The objectives of Chapter 3 were to study the texture difference among varieties of cooked
quinoa and evaluate the correlation between the texture and the seed characters and
composition cooking process flour pasting properties and thermal properties
Chapter 4 includes the manuscript entitled lsquoQuinoa starch characteristics and their
correlation with texture of cooked quinoarsquo The objectives of Chapter 4 were to determine starch
characteristics of quinoa among different varieties and investigate the correlations between the
starch characteristics and cooking quality of quinoa
Chapter 5 has been submitted to Frontier in Plant Science under the title lsquoQuinoa seed
quality response to sodium chloride and sodium sulfate salinityrsquo In Chapter 5 quinoa seed
quality grown under salinity stress was assessed Four quinoa varieties were grown under six
salinity treatments and two levels of fertilization and then quinoa seed quality characteristics
such as protein content seed hardness and seed density were evaluated
Chapter 6 is the manuscript entitled lsquoLexicon development and sensory attributes of
cooked quinoarsquo In Chapter 6 a lexicon of cooked quinoa was developed using a trained panel
The lexicon provided descriptions of the sensory attributes of aroma tasteflavor texture and
color with references developed for each attribute The trained panel then applied this lexicon to
the evaluation of 16 field trial quinoa varieties from WSU and 5 commercial quinoa samples
from Bolivia and Peru A consumer panel also evaluated their acceptance of 6 selected quinoa
5
samples Using data from the trained panel and the consumer panel the key sensory attributes
driving consumer liking were determined Finally Chapter 7 presents the conclusions and
recommendations for future studies
6
References
Nuntildeez de Acro Chapter 12 Quinoarsquos calling In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 211 ndash 25
Ahamed NT Singhal RS Kulkarni PR Pal M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 31 99-103
Ando H Chen Y Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food Components in
Fractions of Quinoa Seed Food Sci Technol Res 8(1) 80-4
Carimentrand A Baudoin A Lacroix P Bazile D Chia E 2015 Chapter 41 International
quinoa trade In D Bazile D Bertero and C Nieto editors State of the Art Report of
Quinoa in the World in 2013 Rome FAO amp CIRAD p 316 ndash 29
Champagne ET Bett-Garber KL McClung AM Bergman C 2004 Sensory characteristics of
diverse rice cultivars as influenced by genetic and environmental factors Cereal Chem 81
237-43
Chillo S Civica V Iannetti M Mastromatteo M Suriano N Del Nobile M 2010 Influence of
repeated extrusions on some properties of non-conventional spaghetti J Food Eng 100 329-
35
Chlopicka J Pasko P Gorinstein S Jedryas A Zagrodzki P 2012 Total phenolic and total
flavonoid content antioxidant activity and sensory evaluation of pseudocereal breads LWT-
Food Sci Technol 46 548-55
7
Garcia M Raes D Allen R Herbas C 2004 Dynamics of reference evapotranspiration in the
Bolivian highlands (Altiplano) Agr Forest Meteorol 125(1) 67-82
James LEA 2009 Quinoa (Chenopodium quinoa Willd) composition chemistry nutritional
and functional properties Adv Food Nutr Res 58 1-31
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine structure of amylopectin J Cereal Sci 21 251-60
Perdon AA Siebenmorgen TJ Buescher RW Gbur EE 1999 Starch retrogradation and texture
of cooked milled rice during storage J Food Sci 64 828-32
Prego I Maldonado S Otegui M 1998 Seed structure and localization of reserves in
Chenopodium quinoa Ann Bot 82(4) 481-8
Ramesh M Ali SZ Bhattacharya KR1999 Structure of rice starch and its relation to cooked-
rice texture Carbohydr Polym 38 337-47
Rosell CM Cortez G Repo-Carrasco R 2009 Bread making use of Andean crops quinoa
kantildeiwa kiwicha and tarwi Cereal Chem 86 386-92
Sahin S Sumnu SG 2006 Physical properties of foods Springer Science amp Business Media
P39 ndash 109
Schumacher AB Brandelli A Macedo FC Pieta L Klug TV de Jong EV 2010 Chemical and
sensory evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J
Food Sci Technol 47 202-6
8
Tari TA Annapure US Singhal RS Kulkarni PR 2003 Starch-based spherical aggregates
screening of small granule sized starches for entrapment of a model flavouring compound
vanillin Carbohydr Polym 53 45-51
USDA US Department of Agriculture 2015a Peru Quinoa outlook Access from
httpwwwfasusdagovdataperu-quinoa-outlook
9
Chapter 2 Literature Review
Introduction
Quinoa (Chenopodium quinoa Willd) is a dicotyledonous pseudocereal from the Andean
region of South America The plant belongs to a complex of allotetraploid taxa (2n = 4x = 36)
which includes Chenopodium berlandieri subsp berlandieri Chenopodium berlandieri subsp
nuttalliae Chenopodium hircinum and Chenopodium quinoa (Gomez-Pando 2015 Matanguihan
et al 2015) Closely related species include the weed lambsquarter (Chenopodium album)
amaranth (Amaranth palmeri) sugar beet (Beta vulgaris L) and spinach (Spinacea oleracea L)
(Maughan et al 2004) Quinoa plant is C3 specie with 90 self-pollenating (Gonzalez et al
2011) Quinoa was domesticated approximately 5000 ndash 7000 years ago in the Lake Titicaca area
in Bolivia and Peru (Gonzalez et al 2015) Quinoa produces small oval-shaped seeds with a
diameter of 2 mm and a weight of 2 g ndash 46 g 1000-seed (Wu et al 2014) The seed color varies
and can be white yellow orange red purple brown or gray White and red quinoas are the most
common commercially available varietals in the US marketplace (Data from online resources
and local stores in Pullman WA) With such small seeds quinoa provides excellent nutritional
value such as high protein content balanced essential amino acids high proportion of
unsaturated fatty acids rich vitamin B complex vitamin E and minerals antioxidants such as
phenolics and betalains and rich dietary fibers (Wu 2015) For these reasons quinoa is
recognized as a ldquocompleterdquo food (Taverna et al 2012)
10
This chapter reviewed publications in quinoa varieties global development seed
structure and constituents quinoa health benefits physical properties and thermal properties
quinoa flour characteristics processing and quinoa products
Quinoa varieties
There are 16422 quinoa accessions or genetypes conserved worldwide 14502 of which
are conserved in genebanks from the Andean region (Rojas et al 2013) Bolivia and Peru
manage 13023 quinoa accessions (80 of world total accessions) in 140 genebanks (Rojas and
Pinto 2015)
Based on genetic diversity adaptation and morphological characteristics five ecotypes
of quinoa have been identified in the Andean region including valley quinoa Altiplano quinoa
salar quinoa sea level quinoa and subtropical quinoa (Tapia et al 1980) The sea-level ecotype
or Chilean lowland ecotype is the best adapted to temperate climate and high summer
temperature (Peterson and Murphy 2015a)
Adaptation
Quinoa has shown excellent adaptation to marginal or extreme environments and such
adaptation was summarized by Gonzalez et al (2015) Quinoa growing areas range from sea
level to 4200 masl (meters above sea level) with growing temperature rangeing from -4 to 38 ordmC
The plant has adapted to drought-stressed environments but can also grow in areas with
humidity ranging from 40 to 88 Quinoa can grow in marginal soil conditions such as dry
(Garcia et al 2003) infertile (Sanchez et al 2003) and with wide pH range from acidic to basic
(Jacobsen and Stolen 1993) Quinoa has also adapted to high salinity soil (equal to sea salt level
11
or 40 dSm) (Koyro and Eisa 2008 Hariadi et al 2011 Peterson and Murphy 2015b)
Furthermore quinoa has shown tolerance to frost at -8 to -4 ordmC (Jacobsen et al 2005)
Even though quinoa varieties are remarkably diverse and able to adapt to extreme
conditions time and resources are required to breed the high-yielding varieties that are adapted
to regional environments in North America Challenges to achieving strong performance include
yield waterlogging pre-harvest sprouting weed control and tolerance to disease insect pests
and animal stress (Peterson and Murphy 2015a) The breeding work not only needs the effort
from breeders and researchers but also demands the participation and collaboration of local
farmers
In addition to being widely grown in South America quinoa has also recently been
grown in North America Europe Australia Africa and Asia In US quinoa cultivation and
breeding started in the 1980s by the efforts from seed companies private individuals and
Colorado State University (Peterson and Murphy 2015a) Since 2010 Washington State
University has been breeding quinoa in the Pacific Northwest to suit the diverse environmental
conditions including rainfall and temperature Peterson and Murphy (2015a) found the major
challenges in North America included heat susceptibility downy mildew (Plasmopara viticola)
saponin removal weed stress and insect stress (such as aphids and Lygus sp)
With high nutritional value quinoa is recognized as significant in food security and
treating malnutrition issue in developing countries (Rojas 2011) Maliro and Guwela (2015)
reviewed quinoa breeding in Africa Initial experiments showed quinoa can grow well in Malawi
and Kenya in both warm and cool areas The quinoa grain yields in Malawi and Kenya are 3-4
12
tonha which are comparable to the yields in South America However the challenge remains to
adopt quinoa into the local diet and cultivate a quinoa consuming market
Physical Properties of Quinoa
Physical properties of seed refer to seed morphology size gravimetric properties
(weight density and porosity) aerodynamic properties and hardness which are critical to
technology and equipment designed for post-harvest process such as seed cleaning
classification aeration drying and storage (Vilche et al 2003)
The quinoa seed is oval-shaped with a diameter of approximately 18 to 22 mm (Bertero
et al 2004 Wu et al 2014) Mean 1000-seed weight of quinoa is around 27 g (Bhargava et al
2006) and a range of 15 g to 45 g has been observed among varieties (Wu et al 2014)
Commercial quinoa from Bolivia tends to have higher 1000-seed weight of 38 g to 45 g
Additionally bulk density ranges from 066 gmL to 075 gmL in most varieties (Wu et al
2014) Porosity refers to the fraction of space in bulk seed which is not occupied by the seed
(Thompson and Isaac 1976) The porosity of quinoa is 23 (Vilche et al 2003) while that of
rice is 50 to 60 (Kunze et al 2004)
Terminal velocity is the air velocity at which seeds remain in suspension This parameter
is important in cleaning quinoa to remove impurities such as dockage hollow and immature
kernels and mixed weed seeds Vilche et al (2003) reported the terminal velocity of 081 ms-1
while the value of rice was 6 ms-1 to 77 ms-1 (Razavi and Farahmandfar 2008)
Seed hardness or crushing strength is used as a rough estimation of moisture content in
rice (Kunze et al 2004) The hardness of quinoa seed can be tested using a texture analyzer (Wu
13
et al 2014) A stainless cylinder (10 mm in diameter) compressed one quinoa seed to 90 strain
at the rate of 5 mms Because of hardness variation among individual seeds at least six
measurements were required Among the thirteen quinoa samples that were tested hardness
ranged from 58 kg to 110 kg (Wu et al 2014)
Quinoa Seed Structure
Grain structure of quinoa was described in detail by Taylor and Parker (2002) On the
outside of grain is a perianth which can be easily removed during cleaning or rubbing
Sometimes betalain pigments concentrate on this perianth layer and the seed shows bright purple
or golden colors However this color will disappear with the removal of the perianth Inside the
perianth is two-layered pericarp with papillose surface (Figure 1) Beneath the pericarp a seed
coat or episperm is located The seed coat can be white yellow orange red brown or black
Red and white quinoa share the largest market share with consumers exhibiting increasing
interest in brownblack mixed products such as lsquoCalifornia Tricolorrsquo(data from Google
Shopping Amazon and local stores in Pullman WA)
The main seed is enveloped in outside layers and the structure was depicted by Prego et
al (1998) (Figure 2) The embryo (two cotyledons and radicle) coils around a center pericarp
which occupies ~40 of seed volume (Fleming and Galwey 1998) Protein and lipid bodies are
primarily present in the embryo whereas starch granules provide storage in the thin-walled
perisperm Minerals of phosphorus potassium and magnesium are concentrated in phytin
globoids located in the embryo and calcium is located in the pericarp (Konishi et al 2004)
Quinoa Seed Constituents
14
Quinoa is known as a lsquocomplete foodrsquo (James 2009) The seed composition was recently
reviewed by Wu (2015) and Maradini Filho et al (2015) In sum the high nutritional value of
quinoa arises from its high protein content complete and balanced essential amino acids high
proportion of unsaturated fatty acids high concentrations of vitamin B complex vitamin E and
minerals and high phenolic and betalain content
A protein range of 12 to 17 in quinoa has been reported by most studies (Rojas et al
2015) This protein content is higher than wheat (8 to 14 ww) (Halverson and Zeleny 1988)
and rice (4 - 105 ww) (Champagne et al 2004) Additionally quinoa contains all essential
amino acids at concentrations exceeding the suggested requirements from FAOWHO (Table 1)
Quinoa is also gluten-free because it is lacking in prolamins Prolamins are a group of
storage proteins that are rich in proline Prolamins can interact with water and form the gluten
structure which cannot be tolerated by those with celiac disease (Fasano et al 2003) Quinoa and
rice both contain low prolamins (72 and 89 of total protein respectively) and are
considered gluten-free crops Prolamins in wheat (called gliadin) comprise 285 of its total
protein and in maize this concentration of prolamin is 245 (Koziol 1992)
The protein quality of quinoa protein was reported by Ruales and Nair (1992) In raw
quinoa the net protein utilization (NPU) was 757 biological value (BV) was 826 and
digestibility (TD) was 917 all of which were slightly lower than those of casein The
digestibility of quinoa protein is comparable to that of other high quality food proteins such as
soy beans and skim milk (Taylor and Parker 2002) The Protein Efficiency Ratio (PER) in
quinoa ranges from 195 to 31 and is similar to that of casein (Gross et al 1989 Guzmaacuten-
15
Maldonado and Paredes-Lopez 2002) Regarding functional properties of quinoa protein isolates
Eugenia et al (2015) found Bolivian quinoa exhibited the highest thermal stability oil binding
capacity and water binding capacity at acidic pH The Peruvian samples showed the highest
water binding capacity at basic pH and the best foaming capacity at pH 5
Quinoa starch content ranges from 58 to 64 of the dry seed weight (Vega‐Gaacutelvez et
al 2010) Quinoa possesses a small granule size of 06 to 2 μm similar to that of amaranth (1 to
2 μm) and much smaller than those of other grains such as rice wheat oat barley and
buckwheat (2 to 36 μm) (Lindeboom et al 2004) The amylose content in quinoa starch tends to
be lower than found in common grains A range of 3 to 20 was reported by Lindeboom et al
(2005) whereas amylose content is around 25 in cereals As in most cereals quinoa starch is
type A in X-ray diffraction pattern (Ando et al 2002) Li et al (2016) found significant variation
among 26 commercial quinoa samples in the physicochemical properties of starch such as gel
texture thermal and pasting parameters which were strongly affected by apparent amylose
content
Quinoa lipids comprise 55 to 71 of dry seed weight in most reports (Maradini Filho
et al 2015) Ando et al (2002) found quinoa (cultivar Real TKW from Bolivia) perisperm and
embryo contained 50 and 102 total fatty acids respectively Among these fatty acids
unsaturated fatty acids such as oleic linoleic and linolenic comprised 875 Ogungbenle
(2003) reported the properties of quinoa lipids The values of acid iodine peroxide and
saponification were 05 54 24 and 192 respectively
16
Quinoa micronutrients of vitamins and minerals and the relative lsquoreference daily intakersquo
are summarized in Table 2 and 3 respectively Compared to Daily Intake References quinoa
provides a good source of Vitamin B1 B2 and B9 and Vitamin E as well as minerals such as
magnesium phosphorous iron and copper
Quinoa is one of the crops representing diversity in color including white vanilla
yellow orange red brown gray and dark Besides the anthocyannins in dark quinoa (Paśko et
al 2009) the major pigment in quinoa is betalain primarily presenting in seed coat and the
compounds can be subdivided into red-violet betacyannins and yellow-orange betaxanthins
(Tang et al 2015) Betalain is a water-soluble pigment which is permitted quantum satis as a
natural food colorant and applied in fruit yogurt ice cream jams chewing gum sauces and
soups (Esatbeyoglu et al 2015) Additionally betalain potentially offers health benefits such as
antioxidant activity anti-inflammation activity preventing low-density lipoprotein (LDL)
oxidation and DNA damage (Benavente-Garcia and Castillo 2008 Esatbeyoglu et al 2015)
Saponins
Saponins are compounds on the seed coat of quinoa that confer a bitter taste The
compounds are considered to be a defense system against herbivores and pathogens Regarding
chemical structure saponins are a group of glycosides consisting of a hydrophilic carbohydrate
chain (such as arabinose glucose galactose xylose and rhamnose) and a hydrophobic aglycone
(Kuljanabhagavad and Wink 2009) Chemical structures of aglycones were summarized by
Kuljanabhagavad and Wink (2009)
17
Saponins have been considered as anti-nutrient because of haemolytic activity which
refers to the breakdown of red blood cells (Khalil and El-Adawy 1994) However saponins
exhibited health benefit functions such as anti-inflammation (Yao et al 2009) antibacterial
antimicrobial activity (Killeen et al 1998) anti-tumor activity (Shao et al 1996) and
antioxidant activity (Guumllccedilin et al 2006) Furthermore saponins have medicinal use Sun et al
(2009) reported saponins can activate immune system and were used as vaccine adjuvants
Saponins also exhibited anti-cancer activity (Man et al 2010)
Even though saponins have potential health benefits their bitter taste is not pleasant to
consumers To address the bitterness found in bitter quinoa varieties (gt 011 saponin content)
sweet quinoa varieties were bred through conventional genetic selection to contain a lower
saponin content (lt 011 saponin content) For instance lsquoSajamarsquo lsquoKurmirsquo lsquoAynoqarsquo
lsquoKosunarsquo and lsquoBlanquitarsquo in Bolivia lsquoBlanca de Juninrsquo in Peru and lsquoTunkahuanrsquo in Ecuador are
considered sweet quinoa varieties (Quiroga et al 2015) Unfortunately varieties from Bolivia
Peru and Ecuador do not adapt to temperate climates such as those found in the Pacific
Northwest in US and Europe A sweet variety called lsquoJessiersquo exhibits acceptable yield in Pacific
Northwest and has a great market potential Further development of sweet quinoa varieties
adapted to local climate will happen in near future
To remove saponins both dry and wet processing methods have been developed The wet
method or moist method refers to washing quinoa while rubbing the grain with hands or by a
stone Repo-Carrasco et al (2003) suggested the best washing conditions of 20 min soaking 20
min stirring with a water temperature of 70 degC The wet method becomes costly due to the
required drying process Additionally quinoa grain may begin to germinate during wet cleaning
18
The dry method or abrasive dehulling uses mechanical abrasion to polish the grain and
remove the saponins A dehulling process was reported by Reichert et al (1986) using Tanential
Abrasive Dehulling Device (TADD) and removal of 6 - 15 of kernel was required to reduce
the saponins content to lower than 011 Additionally a TM-05 Taka-Yama testing mill was
used in the quinoa pearling process (to 20 - 30 pearling degree) (Goacutemez-Caravaca et al
2014) The dry method is relatively cheaper than wet method and does not generate saponin
waste water The saponin removal efficiency of the dry and washing methods were reported to be
87 and 72 respectively (Reichert et al 1986 Gee et al 1993) A combination of dry and wet
methods was recommended to obtain the efficient cleaning (Repo-Carrasco et al 2003)
Since quinoa is such an expensive crop a 25 to 30 weight lost during the cleaning
process represents a substantial loss on an industrial scale In addition mineral phenolic and
fiber content may dramatically decrease during processing resulting in a loss of nutritional
value Hence cleaning process should be further optimized to reach lower grain weight loss
while maintain an efficient saponins elimination
Removed saponins can be utilized as side products Since saponins also have excellent
foaming property they can be applied in cosmetics and foods as foam-stabilizing and
emulsifying agents (Yang et al 2010) detergents (Chen et al 2010) and preservatives
(Taormina et al 2006)
Saponin content is important to analyze since it highly influences the taste of quinoa
Traditionally the afrosimetric method or foam method was used to estimate saponins content In
this method saponon content is calculated from foam height after shaking quinoa and water
19
mixture for a specific time (Koziol 1991) This afrosimetric method is fast and affordable and
can be used by farmers as a quick estimation of saponin content however the method is not very
accurate The foam stability varies among samples A more accurate method was developed
using Gas Chromatography (GC) (Ridout et al 1991) Using this method quinoa flour was first
defatted using a Soxhlet extraction and then hydrolyzed in reflux for 3 h with a methanol
solution of HCl (2 N) The hydrolysis product sapogenins were extracted with ethyl acetate and
derivatized with bis-(trimethylsilyl) trifluoroacetamide (BSTFA) and dry pyridine and then
tested using GC Generally GC method is a more solid and accurate method compared to foam
method however GC also requires high capital investment as well as long and complex sample
preparation For quinoa farmers and food manufactures fast and affordable methods to test
saponins content in quinoa need to be developed
Saponins have been an important topic in quinoa research Future studies in this area can
include 1) breeding and commercialization of saponin-free or sweet quinoa varieties with high
yield and high agronomy performance (resistance to biotic and abiotic stresses) 2) development
of quick and low cost detection method of saponin content and 3) application of saponin in
medicine foods and cosmetics can be further explored
Health benefits
Simnadis et al (2015) performed a meta-analysis of 18 studies which used animal models
to assess the physiological effects associated with quinoa consumption From these studies
purported physiological effects of quinoa consumption included decreased weight gain
improved lipid profile (decrease LDL and cholesterol) and improved capacity to respond to
20
oxidative stress Simnadis et al (2015) pointed out that the presence of saponins protein and
20-hydroxyecdysone (affects energy homeostasis and intestinal fat absorption) contributed to
those benefit effects
Furthermore Ruales et al (2002) found increased plasma levels of IGF-1 (insulin-like
growth factor) in 50-65 month-old boys after consuming a quinoa infant food for 15 days This
result implicated the potential of quinoa to reduce childhood malnutrition In another study of 22
students (aged 18 to 45) the daily consumption of a quinoa cereal bar for 30 days significantly
decreased triglycerides cholesterol and LDL compared to those parameters prior to quinoa
consumption These results suggest that quinoa intake may reduce the risk of developing
cardiovascular disease (Farinazzi-Machado et al 2012) De Carvalho et al (2014) studied the
influence of quinoa on over-weight postmenopausal women Consumption of quinoa flakes (25
gd for 4 weeks) was found to reduce serum triglycerides and TBARS (thiobarbituric acid
reactive substances) and increase GSH (glutathione) and urinary excretion of enterolignans
compared to those indexes before consuming quinoa flakes
Quinoa flour properties
Functional properties of quinoa flour were determined by Ogungbenle (2003) Quinoa
flour has high water absorption capacity (147) and low foaming capacity (9) and stability
(2) Water absorption capacity was determined by the volume of water retained per gram of
quinoa flour during 30-min mixing at 24 ordmC (Beuchat 1977) The water absorption of quinoa was
higher than that of fluted pumpkin seed (85) soy flour (130) and pigeon pea flour (138)
which implies the potential use of quinoa flour in viscous foods such as soups doughs and
21
baked products Additionally foaming capacity was determined by the foam volumes before and
after whipping of 8 protein solution at pH 70 (Coffmann and Garciaj 1977) Then foam
samples were inverted and dripped though 2 mm wire screen in to beakers The foam stability
was determined by the weight of liquid released from foam after a specific time and the original
weight of foam (Coffmann and Garciaj 1977) Furthermore minimum protein solubility was
observed at pH 60 similar to that of pearl millet and higher than pigeon pea (pH 50) and fluted
pumpkin seed (pH 40) Relatively high solubility of quinoa protein in acidic condition implies
the potential application of quinoa protein in acidic food and carbonated beverages
Wu et al (2014) studied flour viscosity among 13 quinoa samples with large variations
reported among samples The ranges of peak viscosity final viscosity and setback were 59
RVU ndash 197 RVU 56 RVU ndash 203 RVU and -62 RVU ndash 73 RVU respectively which were
comparable to those of rice flour (Zhou et al 2003) Flour viscosity significantly influence
texture of quinoa and rice (Champagne et al 1998 Wu et al 2014)
Ruales et al (1993) studied processing influence on the physico-chemical characteristics
of quinoa flour The process included cooking and autoclaving of the seeds drum drying of
flour and extrusion of the grits Autoclaved quinoa samples exhibited the lowest degree of starch
gelatinization (325) whereas precookeddrum dried quinoa samples were 974 Higher
polymer degradation was found in the cooked samples compared to the autoclaved samples
Water solubility in cooked samples (54 to 156) and autoclaved samples (70 to 96) increased
with the processing time (30 to 60 min cooking and 10 to 30 min autoclaving)
Thermal Properties of quinoa
22
Thermal properties of quinoa flour (both starch and protein) have been determined using
Differential Scanning Calorimetry (DSC) (Abugoch et al 2009) A quinoa flour suspension was
prepared in 20 (ww) concentration The testing temperature was raised from 27 to 120 degC at a
rate of 10 degCmin Two peaks in the DSC graph referenced the starch gelatinization temperature
at 657 degC and protein denaturalization at 989 degC Enthalpy refers to the energy required to
complete starch gelatinization or protein denaturazition In the study of Abugoch et al (2009)
the enthalpy was 59 Jg for starch and 22 Jg for proteins in quinoa
Product development with quinoa
Quinoa has been used in different products such as spaghetti bread and cookies to
enhance nutritional value including a higher protein content and more balanced amino acid
profile Chillo et al (2008) evaluated the quality of spaghetti from amaranth and quinoa flour
Compared to durum semolina spaghetti the spaghetti with amaranth and quinoa flour exhibited
equal breakage susceptibility higher cooking loss and lower instrumental stickiness The
sensory acceptance scores were not different from the control The solid loss weight increase
volume increase adhesiveness and moisture of a corn and quinoa mixed spaghetti were 162thinspg
kgminus1 23 times 26 times 20907thinspg and 384thinspg kgminus1 respectively (Caperuto et al 2001)
Schoenlechner et al (2010) found the optimal combination of 60 buckwheat 20 amaranth
and 20 quinoa yielded an improved dough matrix compared to other flour combinations With
the addition of 6 egg white powder and 12 emulsifier (distilled monoglycerides) this gluten-
free pasta exhibited acceptable firmness and cooking quality compared to wheat pasta
23
Stikic et al (2012) added 20 quinoa seeds in bread formulations which resulted in the
similar dough development time and stability compared to those of wheat dough even though
the bread specific volume was lower (63 mLg) compared to wheat bread (67 mLg) The
protein content of bread increased by 2 (ww) and sensory characteristics were lsquoexcellentrsquo as
evaluated by five trained expert panelists Iglesias-Puig et al (2015) found 25g100 g quinoa
flour substitution in wheat bread showed small depreciation in bread quality in terms of loaf
volume crumb firmness and acceptability whereas the nutritional value increased in dietary
fiber minerals protein and healthy fats Rizzello et al (2016) selected strains (lactic acid
bacteria) to develop a quinoa sourdough A wheat bread with 20 (ww) quinoa sourdough
exhibited improved nutritional (such as protein digestibility and quality) textural and sensory
features Quinoa leaves were also applied to bread making (Świeca et al 2014) With the
replacement of wheat flour by 1 to 5 (ww) quinoa leaves the bread crumb exhibited increased
firmness cohesiveness and gumminess Antioxidant activity and phenolic contents both
significantly increased compared to wheat bread
Pagamunici et al (2014) developed three gluten-free cookies with rice and quinoa flour
with 15 26 and 36 (ww) quinoa flour proportions respectively The formulation with
36 quinoa flour had the highest alpha-linolenic acid and mineral content and the cookie
displayed excellent sensory characteristics as evaluated by 80 non-trained consumer panelists
Another study optimized a gluten-free quinoa formulation with 30 quinoa flour 25 quinoa
flakes and 45 corn starch (Brito et al 2015) The cookie was characterized as a product rich in
essential amino acids linolenic acid minerals and dietary fiber This cookie was among those
24
products using the highest quinoa flour content (55 ww) while still received acceptable
sensory scores
Repo-Carrasco-Valencia and Serna (2011) introduced an extrusion process in Peru
Quinoa flour was tempered to 12 moisture for extrusion During extrusion total and insoluble
dietary fiber decreased by 5 to 17 and 13 to 29 respectively whereas the soluble dietary
fiber significantly increased by 38 to 71 Additionally the radical scavenging activity was
also increased in extruded quinoa compared to raw quinoa
Schumacher et al (2010) developed a dark chocolate with addition of 20 quinoa An
improved nutritional value was observed in 9 (ww) increase in vitamin E 70 - 104
increases in amino acids of cysteine tyrosine and methionine This quinoa dark chocolate
received over 70 acceptance index from sensory panel
Gluten-free beer is of increasing interest in the market (Dezelak et al 2014) Ogungbenle
(2003) found quinoa has high D-xylose and maltose and low glucose and fructose content
suggesting its potential use in malted drink de Meo et al (2011) applied alkaline steeping to
pseudocereal and found its positive effects on pseudocereals malt production by increasing total
soluble nitrogen and free amino nitrogen Kamelgard (2012) patented a method to create a
quinoa-based beverage fermented by a yeast Saccharomyces cerevisiae The beverage can be
distilled and aged to form gluten-free liquor Dezelak et al (2014) processed a quinoa beer-like
beverage (fermented with Saccharomyces pastorianus TUM 3470) resulting in a product with a
nutty aroma low alcohol content and rich in minerals and amino acids However further
development of the brewing procedure was necessary since the beverage showed a less attractive
25
appearance (near to black color and greyish foam) and astringent mouthfeel Compared to barley
brewing attributes of quinoa exhibited lower malt extracts longer saccharification times higher
values in total protein fermentable amino nitrogen content and iodine test
Processing quinoa grain to dried edible product and sweet quinoa product were developed
by Scanlin and Burnett (2010) The edible quinoa product was processed through pre-
conditioning (abrasion and washing) moist heating (steam cooking and pressure cooking) dry
heating (baking toasting and dehydrating) and post-production treatment As for sweet quinoa
product germination and malting processing were applied Caceres et al (2014) patented a
process to extract peptides and maltodextrins from quinoa flour and the extracts were applied in
a gel-format food as a supplement during and after physical activity
26
References
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2013-20
Abugoch LE Romero N Tapia CA Silva J Rivera M 2008 Study of some physicochemical
and functional properties of quinoa (Chenopodium quinoa Willd) protein isolates J Agric
Food Chem 56(12) 4745-50
Ando H Chen Y Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food Components in
Fractions of Quinoa Seed Food Sci Technol Res 8(1) 80-4
Benavente-Garcia O Castillo J 2008 Update on uses and properties of citrus flavonoids new
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56(15) 6185-205
Bertero HD de la Vega AJ Correa G Jacobsen SE Mujica A 2004 Genotype and genotype-
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Crops Res 89(2ndash3) 299-318
Beuchat LR 1977 Functional and electrophoretic characteristics of succinylated peanut flour
protein J Agric Food Chem 25(2) 258-61
Bhargava A Shukla S Rajan S Ohri D 2006 Genetic diversity for morphological and quality
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167-73
27
Brito IL de Souza EL Felex SSS Madruga MS Yamashita F Magnani M 2015 Nutritional
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73
Caceres JIE Calderon PD Lira FO 2014 Method for the formulation of a gel-format foodstuff
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101
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
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Paul MN American Association of Cereal Chemists Inc p 88 ndash 9
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28
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101-7
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Deželak M Zarnkow M Becker T Košir IJ 2014 Processing of bottom-fermented gluten-free
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Farinazzi-Machado FMV Barbalho SM Oshiiwa M Goulart R Pessan Junior O 2012 Use of
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cardiovascular diseases Food Sci Technol(Campinas) 32(2) 239-44
Fasano A Berti I Gerarduzzi T Not T Colletti RB Drago S Hill ID 2003 Prevalence of celiac
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Fleming JE Galwey NW 1998 Quinoa (Chenopodium quinoa Willd) nutritional quality and
technological aspects as human food In Belton PS Taylor JRN editors Increasing the
29
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Friedman M Brandon DL 2001 Nutritional and health benefits of soy proteins J Agric Food
Chem 49(3)1069-86
Garcia M Raes D Jacobsen SE 2003 Evapotranspiration analysis and irrigation requirements
of quinoa (Chenopodium quinoa) in the Bolivian highlands Agr Water Manage 60(2) 119-
34
Gee JM Price KR Ridout CL Wortley GM Hurrell RF Johnson IT 1993 Saponins of quinoa
(Chenopodium quinoa) effects of processing on their abundance in quinoa products and their
biological effects on intestinal mucosal tissue J Sci Food Agric 63(2) 201-9
Goacutemez-Caravaca AM Iafelice G Verardo V Marconi E Caboni MF 2014 Influence of
pearling process on phenolic and saponin content in quinoa (Chenopodium quinoa Willd)
Food Chem 157 174-8
Gomez-Pando L 2015 Chapter 6 Quinoa breeding In Murphy KM Matanguihan J editors
Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p
87 ndash 97
Gonzaacutelez JA Bruno M Valoy M Prado FE 2011 Genotypic variation of gas exchange
parameters and leaf stable carbon and nitrogen isotopes in ten quinoa cultivars grown under
drought J Agron Crop Sci 197(2) 81-93
30
Gonzaacutelez JA Eisa SSS Hussin SAES and Prado FE 2015 Chapter 1 Quinoa An Incan Crop
to Face Global Changes in Agriculture In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 182-6
Graf BL Rojas-Silva P Rojo LE Delatorre-Herrera J Baldeoacuten ME Raskin I 2015 Innovations
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Comp Rev Food Sci Food Safety 14(4) 431-45
Gross R Koch F Malaga I de Miranda A Schoeneberger H Trugo L 1989 Chemical
composition and protein quality of some local Andean food sources Food Chem 34(1) 25-
34
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Guzmaacuten-Maldonado S Paredes-Lopez O 2002 Functional products of plants indigenous to
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Maguer ML editors Functional foods Biochemical and processing aspects CRC Press p
293-328
Halverson J Zeleny L 1988 Chapter 2 Criteria of wheat quality In Pomeranz Y editor
Wheat Chemistry and Technology 3rd edition St Paul MN American Association of
Cereal Chemists Inc p 25 ndash 6
31
Hariadi Y Marandon K Tian Y Jacobsen SE Shabala S 2011 Ionic and osmotic relations in
quinoa (Chenopodium quinoa Willd) plants grown at various salinity levels J Exp Bot
62(1) 185-93
Iglesias-Puig E Monedero V Haros M 2015 Bread with whole quinoa flour and bifidobacterial
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71-7
Jacobsen SE Monteros C Christiansen J Bravo L Corcuera L Mujica A 2005 Plant responses
of quinoa (Chenopodium quinoa Willd) to frost at various phenological stages Eur J Agron
22(2) 131-9
Jacobsen SE Stoslashlen O 1993 Quinoa-morphology phenology and prospects for its production as
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and functional properties Adv Food Nutr Res 58 1-31
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Google Patents
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for their in vivo impact J Agric Food Chem 46(8) 3178-86
32
Konishi Y Hirano S Tsuboi H Wada M 2004 Distribution of minerals in quinoa
(Chenopodium quinoa Willd) seeds Biotechnol Appl Biochem 68(1) 231-4
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of Chenopodium quinoa Willd Plant Soil 302(1-2) 79-90
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Chenopodium quinoa Willd Phytochem Rev 8(2) 473-90
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In Champagne ET editor Rice Chemistry and Technology 3rd edition St Paul MN
American Association of Cereal Chemists Inc p 193 ndash 211
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328-38
Lindeboom N Chang PR Falk KC Tyler RT 2005 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2) 216-22
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4) 89-99
Man S Gao W Zhang Y Huang L Liu C 2010 Chemical study and medical application of
saponins as anti-cancer agents Fitoterapia 81(7) 703-14
33
Maradini Filho AM Pirozi MR Da Silva Borges JT Pinheiro SantAna HM Paes Chaves JB
Dos Reis Coimbra JS 2015 Quinoa nutritional functional and antinutritional aspects Crit
Rev Food Sci Nutr (just-accepted)
Matanguihan JB Jellen EN and Kolano A 2015 Chapter 7 Quinoa cytogenetics molecular
genetics and diversity In Murphy KM Matanguihan J editors Quinoa Improvement and
Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 109-24
Maughan PJ Bonifacio A Jellen EN Stevens MR Coleman CE Ricks M Mason SL Jarvis
DE Gardunia BW Fairbanks DJ 2004 A genetic linkage map of quinoa (Chenopodium
quinoa) based on AFLP RAPD and SSR markers Theor Appl Genet 109(6) 1188-95
de Meo B Freeman G Marconi O Booer C Perretti G Fantozzi P 2011 Behaviour of Malted
Cereals and Pseudo-Cereals for Gluten-Free Beer Production J Inst Brew 117(4) 541-6
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quinoa) flour Int J Food Sci Nutr 54(2) 153-8
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quinoa) flour Int J Food Sci Nutr 54(2) 153-8
Quiroga C Escalera R Aroni G Bonifacio A Gonzaacutelez JA Villca M Saravia R Ruiz A 2015
Chapter 31 Traditional processes and Technological Innovations in Quinoa Harvesting
Processing and Industrialization In D Bazile D Bertero and C Nieto editors State of the
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34
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containing the whole flour of a new quinoa cultivar J Brazil Chem Soc 25 219-28
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Peterson AJ Murphy KM 2015a Chapter 10 Quinoa Cultivation for Temperate North America
Considerations and Areas for Investigation In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 182-6
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sodium sulfate salinity Crop Sci 55(1) 331-8
Prego I Maldonado S Otegui M 1998 Seed structure and localization of reserves in
Chenopodium quinoa Ann Bot 82(4) 481-8
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nutritional quality of quinoa Cereal Chem 70(3)303-5
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rice grains Int Agrophys 22(4) 353-9
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471-5
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Repo-Carrasco-Valencia RAM Serna LA 2011 Quinoa (Chenopodium quinoa Willd) as a
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225-30
Repo-Carrasco R Espinoza C Jacobsen SE 2003 Nutritional value and use of the Andean crops
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2) 179-89
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and preliminary investigations into the effects of reduction by processing J Sci Food Agric
54(2) 165-76
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enhancing the nutritional textural and sensory features of white bread Food Microbiol 56 1-
13
Rojas W 2011 Quinoa an ancient crop to contribute to world food security Santiago Chile
FAO Oficina Regional para America Latina y el Caribe
Rojas W Pinto M Alanoca C Goacutemez-Pando L Leoacuten-Lobos P Alercia A Diulgheroff S
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Murphy KM Matanguihan J editors Quinoa Improvement and Sustainable Production
Hoboken NJ John Wiley amp Sons Inc p 128-30
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
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of quinoa flour (Chenopodium quinoa Willd) Starch - Staumlrke 45(1)13-9
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37
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crude saponins obtained from asparagus Cancer Lett 104(1) 31-6
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Stikic R Glamoclija D Demin M Vucelic-Radovic B Jovanovic Z Milojkovic-Opsenica D
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(Chenopodium quinoa Willd) as an ingredient in bread formulations J Cereal Sci 55(2)
132-8
Sun HX Xie Y Ye YP 2009 Advances in saponin-based adjuvants Vaccine 27(12) 1787-96
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Pseudocereals and less common cereals grain properties and utilization potential Springer
Science amp Business Media p 96-9
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comparison pycnometer T ASAE 10(5) 693-6
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cooked quinoa J Food Sci 79(11) 2337-45
Wu G Chapter 11 Nutritional properties of quinoa In Murphy KM Matanguihan J editors
Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc
p193 ndash 205
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term preservative efficacy of the saponins from J Food Drug Anal 18(3) 4417-25
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(Chenopodium quinoa Willd) Seeds in lipopolysaccharide-stimulated raw 2647
Macrophages Cells J Food Sci 79(5) 1018-23
40
Zhou Z Robards K Helliwell S Blanchard C 2003 Effect of rice storage on pasting properties
of rice flour Food Res Int 36(6) 625-34
41
Table 1-Essential amino acid of quinoa protein and FAOWHO suggested requirement (mgg protein)
Essential amino acid Quinoa protein a FAOWHO suggested requirement b
Histidine 258 18
Isoleucine 433 25
Leucine 736 55
Lysine 525 51
Methionine amp Cysteine 273 25
Phenylalanine amp Tyrosine 803 47
Threonine 439 27
Tryptophan 385 7
Valine 506 32
a) Abugoch et al (2008) b) Friedman and Brandon (2001)
42
Table 2-Quinoa vitamins content (mg100g)
Quinoa a-d Reference Daily Intake
Thianmin (B1) 029-038 15
Riboflavin (B2) 030-039 17
Niacin (B3) 106-152 20
Pyridoxine (B6) 0487 20
Folate (B9) 0781 04
Ascorbic acid (C) 40 60
α-Tocopherol (VE) (IU) 537 30
Β-Carotene 039 NR
a (Koziol 1992) b (Ruales and Nair 1993) c (Ranhotra et al 1993) d (USDA 2015)
43
Table 3-Quinoa minerals content (mgmg )
Whole graina RDI b
K 8257 NR
Mg 4526 400
Ca 1213 1000
P 3595 1000
Fe 95 18
Mn 37 NR
Cu 07 2
Zn 08 15
Na 13 NR
(aAndo et al 2002 bUSDA 2015)
44
Figure 1-Quinoa seed section and two-layered pericarp under perianth (Wu et al 2014)
45
Figure 2-Quinoa seed structure (Prego et al 1998)
(PE pericarp SC seed coat C cotyledons SA shoot apex H hypocotylradicle axis R radicle F funicle EN endosperm P perisperm Bar = 500 μm)
46
Chapter 3 Evaluation of Texture Differences among Varieties of
Cooked Quinoa
Published manuscript
Wu G Morris C F amp Murphy K M (2014) Evaluation of texture differences among
varieties of cooked quinoa Journal of Food Science 79(11) S2337-S2345
ABSTRACT
Texture is one of the most significant factors for consumersrsquo experience of foods Texture
differences of cooked quinoa were studied among thirteen different varieties Correlations
between the texture parameters and seed composition seed characteristics cooking quality flour
pasting properties and flour thermal properties were determined The results showed that texture
of cooked quinoa was significantly differed among varieties lsquoBlackrsquo lsquoCahuilrsquo and lsquoRed
Commercialrsquo yielded harder texture while lsquo49ALCrsquo lsquo1ESPrsquo and lsquoCol6197rsquo showed softer
texture lsquo49ALCrsquo lsquo1ESPrsquo lsquoCol6197rsquo and lsquoQQ63rsquo were more adhesive while other varieties
were not sticky The texture profile correlated to physical-chemical properties in different ways
Protein content was positively correlated with all the texture profile analysis (TPA) parameters
Seed hardness was positively correlated with TPA hardness gumminess and chewiness at P le
009 Seed density was negatively correlated with TPA hardness cohesiveness gumminess and
chewiness whereas seed coat proportion was positively correlated with these TPA parameters
Increased cooking time of quinoa was correlated with increased hardness cohesiveness
gumminess and chewiness The water uptake ratio was inversely related to TPA hardness
47
gumminess and chewiness RVA peak viscosity was negatively correlated with the hardness
gumminess and chewiness (P lt 007) breakdown was also negatively correlated with those TPA
parameters (P lt 009) final viscosity and setback were negatively correlated with the hardness
cohesiveness gumminess and chewiness (P lt 005) setback was correlated with the
adhesiveness as well (r = -063 P = 002) Onset gelatinization temperature (To) was
significantly positively correlated with all the texture profile parameters and peak temperature
(Tp) was moderately correlated with cohesiveness whereas neither conclusion temperature (Tc)
nor enthalpy correlated with the texture of cooked quinoa This study provided information for
the breeders and food industry to select quinoa with specific properties for difference use
purposes
Keywords cooked quinoa variety texture profile analysis (TPA) RVA DSC
Practical Application The research described in this paper indicates that the texture of different
quinoa varieties varies significantly The results can be used by quinoa breeders and food
processors
48
Introduction
Quinoa (Chenopodium quinoa Willd) a pseudocereal (Lindeboom et al 2007) is known as
a complete food due to its high nutritional value (Jancurovaacute et al 2009) Protein content of dry
quinoa grain ranges from 8 to 22 (Jancurovaacute et al 2009) Quinoa protein is high in nutritive
quality with an excellent balance of essential amino acids (Abugoch et al 2008) Quinoa is also a
gluten-free crop (Alvarez-Jubete et al 2010) Quinoa consumption in the US and Europe has
increased dramatically over the past decade but these regions rely on imports primarily from
Bolivia and Peru (Food and Agriculture Organization of the United Nations FAO 2013) For
these reasons greater knowledge of quinoa grain quality is needed
Quinoa is traditionally cooked as a whole grain similar to rice or milled into flour and made
into pasta and breads (Food and Agriculture Organization of the United Nations FAO 2013)
Quinoa can also be processed by extrusion drum-drying and autoclaving (Ruales et al 1993)
Commercial quinoa products include pasta bread cookies muffins cereal snacks drinks
flakes baby food and diet supplements (Ruales et al 2002 Del Castillo et al 2009 Cortez et al
2009 Demirkesen et al 2010 Schumacher et al 2010)
Texture is one of most significant properties of food that affects the consuming experience
Food texture refers to those qualities of a food that can be felt with the fingers tongue palate or
teeth (Vaclavik and Christian 2003) Cooked quinoa has a unique texture described as creamy
smooth and slightly crunchy (Abugoch 2009) Texture can be influenced by the seed structure
composition cooking quality and thermal properties However we know of no report which
documents the texture of cooked quinoa and the factors that affect it
49
Quinoa has small seeds compared to most cereals and seed size may affect the texture of
cooked quinoa Seed characteristics and structure are the significant factors potentially affecting
the textural properties of processed food Rousset et al (1995) indicated that the length and
lengthwidth ratio of rice kernels was associated with a wide range of texture attributes including
crunchy brittle elastic juicy pasty sticky and mealy which were determined by a sensory
panel The correlation between quinoa seed characteristics and cooked quinoa texture has not
been studied
Quinoa is consumed as whole grain without removing the bran unlike most rice and wheat
The insoluble fiber and non-starch polysaccharides in the seed coat can affect mouth feel and
texture Hence seed coat proportion may contribute to the texture of cooked quinoa Mohapatra
and Bal (2006) reported that the milling degree of rice positively influenced cohesiveness and
adhesiveness of cooked rice but was negatively correlated to hardness
Quinoa seed qualities such as the size hardness weight density and seed coat proportion
may influence the water binding capacity of seed during thermal processing thereby affecting
the texture of the cooked cereal (Fitzgerald et al 2003) Nevertheless correlations between seed
characteristics and texture of cooked quinoa have not been previously described
Seed composition may influence texture as well Higher protein content was reported to
cause reduced stickiness and harder texture of cooked rice (Ramesh et al 2000) Quinoa seeds
contain approximately 60 starch (Ando et al 2002) Starch granules are particularly small (05
- 3μm) Amylose content of quinoa is as low as 11 (Ahamed et al 1996) while the amylose
proportion in most cereals such as wheat is around 25 (Zeng et al 1997 BeMiller and Huber
50
2008) Amylose content of starch correlated positively with the hardness of cooked rice and
cooked white salted noodles (Ong and Blanshard 1995 Epstein et al 2002 Baik and Lee 2003)
Flour pasting properties can greatly influence the texture of cooked products Their
correlation has not been illustrated in quinoa while some research have been conducted on
cooked rice A lower peak viscosity and positive setback are associated with a harder texture
while a higher peak viscosity breakdown and lower setback are associated with a sticky texture
in cooked rice (Limpisut and Jindal 2002) Champagne et al (1999) indicated that adhesiveness
had strong correlations with Rapid Visco Analyzer (RVA) measurements Ramesh et al (2000)
reported that harder cooked rice texture was associated with a lower peak viscosity and positive
setback while sticky rice had a higher peak viscosity higher breakdown and lower setback
The gelatinization temperature of quinoa starch ranges from 54ordmC to 71ordmC (Ando et al
2002) lower than that of rice barley and wheat starches (Marshall 1994 Tang 2004 Tang et al
2005) Gelatinization temperature likely plays an important role in waxy rice quality (Perdon and
Juliano 1975 Juliano et al 1987) but was not correlated to the eating quality of normal rice
(Ramesh et al 2000) Despite a considerable amount of work having been conducted on the
thermal properties of cereal starch little is known about the relationship between quinoa flour
thermal properties and cooked quinoa texture
The correlation of quinoa cooking quality and texture has not been previously reported In
rice cooking quality exhibited strong correlations to the texture profile analysis (TPA) Cooking
time has been reported to correlate positively with hardness and negatively with adhesiveness of
cooked rice (Mohapatra and Bal 2006) Higher water uptake ratio and volume expansion ratio
were associated with softer more adhesive and more cohesive texture of cooked rice
51
(Mohapatra and Bal 2006) Cooking loss has been reported to improve firmness but decrease
juiciness (Rousset et al 1995)
There is a need to further study the texture of cooked quinoa and its determining factors
The objective of this paper is to study the texture difference among varieties of cooked quinoa
and evaluate the correlation between the texture and the seed characters and composition
cooking process flour pasting properties and thermal properties
Materials and Methods
Seed characteristics
Eleven varieties and two commercial lots of quinoa are listed in Table 1 The two grain
lots were referred as lsquoYellow Commercialrsquo and lsquoRed Commercialrsquo according to the seed color
Seed size (diameter) was determined by lining up and measuring the length of 20 seeds Average
seed diameter was calculated from three repeated measurements Bulk density of seed was
measured by the weightvolume method Seed weight was determined gravimetrically Seed
hardness was determined using the texture analyzer TAndashXT2i (Texture Technology Corp
Scarsdale NY USA) A cylinder of 10 mm in diameter compressed one seed to 90 strain at
the rate of 5 mms The force (kg) was recorded as the seed hardness Seed coat proportions were
determined by a Scanning Electron Microscope (SEM) FEI Quanta 200F (FEI Corp Hillsboro
OR USA) The seed was cross-sectioned and the SEM image was captured under 800times
magnification The seed coat proportions were measured using the software ruler in micrometers
Chemical compositions
Whole quinoa flour was prepared using a cyclone sample mill (UDY Corporation Fort
Collins CO USA) equipped with a 05 mm screen and was used for compositional analysis
52
pasting viscosity and thermal properties Ash and moisture content of quinoa flour were tested
according to the Approved Method 08-0101 and 44-1502 respectively (AACCI 2012) Protein
content was determined by a nitrogen analyzer coupled with a thermo-conductivity detector
(LECO Corporation Joseph MI USA) The factor of 625 was used to calculate the protein
content from the nitrogen content (Approved Method 46-3001 AACCI 2012) Protein and ash
were calculated on a dry weight basis
Cooking protocol
The cooking protocol of quinoa was modified from a rice cooking method (Champagne
et al 1998) Five grams of quinoa seed were soaked for 20 min in 10 mL deionized water in a
flask Soaking is required to remove the bitter saponins (Pappier et al 2008) and enhance
cooking quality (Mohapatra and Bal 2006) The mixture was then boiled for 2 min and the flask
was set in boiling water for 18 min The flask was covered to prevent water loss
Cooking quality
Two grams of quinoa seed were cooked in 20 mL deionized water for 20 min and extra
water was removed Cooking time was determined when the middle white part of the seed
completely disappeared (Mohapatra and Bal 2006) The water uptake ratio was calculated from
the seed weight ratio before and after cooking Cooking volume was the seed volume after
cooking Cooking loss was the total of soluble and insoluble matter in the cooking water
(Rousset et al 1995) Three mL of cooking water of each sample was placed on an aluminum
pan and dried at 130 ordmC overnight The weight of dry solids in the pan was used to calculate the
cooking loss
Texture profile analysis (TPA)
53
Texture profile analysis (TPA) was used to determine the texture of cooked quinoa
according to a modified method for cooked rice texture (Champagne et al 1999) Two grams of
cooked quinoa were arranged on the texture analyzer platform as close to one layer as possible
A stainless steel plate (50 mm times 40 mm times 10 mm) compressed the cooked quinoa from 5 mm to
01 mm at 5 mmsec The compression was conducted twice The texture analyzer generated a
graph with time as the x-axis and force as the y-axis Six parameters were calculated from the
graph (Epstein et al 2002) Hardness is the height of the first peak adhesiveness is the area 3
cohesiveness is area 2 divided by area 1 springiness is distance 1 divided by distance 2
gumminess is hardness multiplied by cohesiveness chewiness is gumminess multiplied by
springiness In the present study no significant differences or correlations were obtained for
springiness As such this parameter will not be included except to describe the overall result (see
below)
Flour viscosity
Quinoa flour pasting viscosity was determined using the Rapid Visco Analyzer (RVA)
RVA-4 (Newport Scientific Pty Ltd Narrabeen Australia) Quinoa flour (43 g) was added to
25 mL deionized water in an aluminum cylinder container The contents were immediately
mixed and heated following the instrument program The temperature was increased from 50 ordmC
to 93 ordmC in 8 min at a constant rate was held at 95 ordmC from 8 to 24 min cooled to 50 ordmC from 24
to 28 min and held at 50 ordmC from 29 to 40 min The program generated a graph with time against
shear force (Figure 1) expressed in RVU (cP = RVU times 12)
Two peaks representing peak viscosity and final viscosity are normally included in the
RVA graph Peak time was the time to reach the first peak Holding strength or trough is the
54
minimum viscosity after the first peak Breakdown is the viscosity difference between peak and
minimum viscosity Setback is the viscosity difference between final and minimum viscosity
Pasting temperature and the time to reach the peak were also recorded
Thermal properties using Differential Scanning Calorimetry (DSC)
Thermal properties of quinoa flour were determined by Differential Scanning
Calorimetry (DSC) Tzero Q2000 (TA instruments New Castle DE USA) The protocol was a
modification of the method of Abugoch et al (2009) Quinoa flour (02 g) was added to 200 μL
deionized water and mixed on a vortex mixer for 10 s to form a slurry Ten to twelve milligrams
of slurry was added to an aluminum pan by pipette The pan was sealed and placed at the center
of DSC platform An empty pan was used as reference The temperature was increased from 25
ordmC to 120 ordmC at 10 ordmCmin then equilibrated to 25 ordmC Gelatinization temperature and enthalpy
were determined from the graph
Statistical analysis
All experiments were repeated three times The hypothesis tests of normality and equal
variance multiple comparisons (Fisherrsquos LSD) and correlation studies were conducted by SAS
92 (SAS Institute Cary NC) A P-value of 005 is considered as the level of statistical
significance unless otherwise specified
Results
Seed characteristics and flour composition
Quinoa seed characteristics and composition are shown in Table 2 Quinoa seeds were
small compared to cereals such as rice wheat and maize Diameters of quinoa seed mostly
ranged between 19 to 22 mm except for lsquoJapanese Strainrsquo which was significantly smaller (15
55
mm) Seed hardness was significantly different among varieties ranging from 583 k g in
lsquoCol6197rsquo to 1096 kg in lsquoOro de Vallersquo Bulk seed density of quinoa varied from 063 kgL in
lsquoBlancarsquo to 081 kgL in lsquoJapanese Strainrsquo Varieties from White Mountain farm and the WSU
Organic Farm were lower in bulk density most of which were below 07 kgL The commercial
and Port Townsend samples were higher in density most of which were around 075 kgL
Thousand-seed weights of quinoa were particularly low ranging from 18 g in lsquoJapanese Strainrsquo
to 41g in lsquoRed Commercialrsquo Seed coat proportion was also significantly different among
varieties Three layers are shown in the seed coat (Figure 2) The varieties lsquoBlackrsquo and lsquoBlancarsquo
had the thickest seed coat (38 and 97 μm respectively) with coat proportions of 40 and 45
respectively lsquoYellow Commercialrsquo and lsquo1ESPrsquo had the thinnest seed coats (15 and 16 μm
respectively) with the coat proportion of 07 and 05 respectively The difference was
almost ten-fold among the varieties
Protein and ash content of quinoa flour
Protein content varied from 113 in lsquo1ESPrsquo to 170 in lsquoCahuilrsquo lsquoCherry Vanillarsquo and
lsquoOro de Vallersquo also had high protein contents of 160 and 156 respectively Ash content
ranged from 12 in the Commercial Yellow seed to 40 in lsquoQQ63rsquo comparable to that in rice
flour (Champagne 2004)
Texture of cooked quinoa
The hardness of cooked quinoa ranged from 20 g for lsquo49ALCrsquo and lsquoCol6197rsquo to 347
kg for lsquoBlackrsquo (Table 3) lsquoOro de Vallersquo and lsquoBlancarsquo were relatively hard varieties with TPA
hardness of 285 kg and 306 kg respectively whereas lsquo1ESPrsquo lsquoJapanese Strainrsquo and lsquoQQ63rsquo
were softer with a hardness of 245 kg 293 kg and 297 kg respectively
56
Adhesiveness is the extent to which seeds stick to each other the probe and the stage
lsquo49ALCrsquo lsquo1ESPrsquo lsquoCol6197rsquo and lsquoQQ63rsquo were significantly stickier with adhesiveness value
of -029 kgs -027 kgs -023 kgs and -020 kgs respectively All other varieties exhibited
lower adhesiveness with values less than 010 kgs Visual examination of the cooked samples
showed that with the more adhesive varieties the seeds stuck together as with sticky rice while
for other varieties the grains were separated
Cohesiveness of cooked lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo was
significantly higher with values from 068 to 071 respectively while those of lsquo49ALCrsquo lsquo1ESPrsquo
and lsquoCol6197rsquo were lower at 054 056 and 053 respectively Springiness is the recovery
from crushing or the elastic recovery (Tsuji 1981 Seguchi et al 1998) Cooked quinoa of all
varieties exhibited excellent elastic recovery properties with springiness values approximating
10
Gumminess is the combination of hardness and cohesiveness Chewiness is gumminess
multiplied by springiness As springiness values were all close to 10 gumminess and chewiness
of cooked quinoa were very similar in value lsquoBlackrsquo lsquoBlancarsquo and lsquoCahuilrsquo were highest in
gumminess and chewiness 24 kg 22 kg and 23 kg respectively while lsquo1ESPrsquo lsquo49ALCrsquo and
lsquoCol6197rsquo were lowest at 14 kg 11 kg and 11 kg respectively The difference among varieties
was greater than three-fold
Cooking quality
Cooking quality of quinoa is shown in Table 4 Cooking time varied from 119 min in
lsquoCol6197rsquo to 192 min in lsquoBlackrsquo cultivar and was significantly correlated with all TPA texture
parameters Longer cooking time also correlated with higher protein content (r = 052 P = 007)
57
Water uptake ratio varied from 25 to 4 fold in lsquoQQ63rsquo and lsquoCol6197rsquo respectively Water
uptake ratio was negatively correlated to seed hardness (r = 052 P = 004) Harder seeds tended
to absorb less water during cooking Cooking volume ranged from 107 mL to 137 mL and did
not significantly correlate with other properties Cooking loss ranged from 035 to 176 and
differed among varieties but was not correlated with water uptake ratio cooking time or cooking
volume
Quinoa flour pasting properties by RVA
Pasting viscosity of quinoa whole seed flour was determined using the Rapid Visco
Analyzer (RVA) The results are shown in Table 5 Peak viscosity differed among varieties
Varieties could be categorized into three groups based on peak viscosity The peak viscosity of
lsquoQQ63rsquo lsquoCol6197rsquo lsquo1ESPrsquo lsquoJapanese Strainrsquo lsquoYellow Commercialrsquo lsquoCopacabanarsquo and lsquoRed
Commercialrsquo varied from 144 to 197 RVU The peak viscosity of lsquoBlancarsquo lsquoBlackrsquo lsquo49ALCrsquo
and lsquoCahuilrsquo ranged from 98 to 116 RVU while those of lsquoOro de Vallersquo and lsquoCherry Vanillarsquo
were 59 and 66 RVU respectively
Trough viscosity namely the minimum viscosity after the first peak showed more than a
three-fold difference among varieties As in the case of peak viscosity the trough of different
varieties can be categorized into the same three groups
Breakdown is the difference between the peak and minimum viscosity lsquoQQ63rsquo lsquo1ESPrsquo
and lsquoJapanese Strainrsquo showed large breakdowns of 51 51 and 62 RVU respectively
Breakdown of lsquoCherry Vanillarsquo lsquoOro de Vallersquo and the Commercial Yellow seed were lower at
12 10 and 11 RVU respectively Breakdown of the other varieties ranged from 18 to 36 RVU
58
The final viscosity of the Commercial Yellow seed was 203 RVU the highest among all
varieties Final viscosity of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo
ranged from 56 to 82 RVU and was lower than that of other varieties which ranged from 106 to
190 RVU
Setback is the difference between final and trough viscosity Setback of lsquoRed
Commercialrsquo lsquoCahuilrsquo and lsquoBlackrsquo were all negative -62 -11 and -6 RVU respectively which
indicated that the final viscosity of these cultivars was lower than their trough viscosity Setback
of lsquoBlancarsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo were slightly positive at 2 2 and 6 RVU
respectively while those of other cultivars were much greater between 42 and 73 RVU Peak
time which is the time to reach the first peak ranged from 93 to 115 min The pasting
temperature was 93 ordmC and not different among the varieties
Thermal properties of quinoa flour using DSC
Thermal properties of quinoa flour were determined using DSC Gelatinization
temperatures (To onset temperature Tp peak temperature Tc conclusion temperature) and
gelatinization enthalpies are shown in Table 6 To of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry
Vanillarsquo and lsquoJapanese Strainrsquo were not different from each other and ranged from 645 ordmC to
659 ordmC To of lsquoOro de Vallersquo lsquoCopacabanarsquo lsquoCol6197rsquo and lsquoQQ63rsquo ranged from 605 ordmC to
631 ordmC while other varieties were lower and ranged from 544 ordmC to 589 ordmC Tp ranged from
675 ordmC in the Commercial Yellow seed to 752 ordmC in lsquoCahuilrsquo Tc ranged from 780 ordmC in lsquoRed
Commercialrsquo to 850ordmC in the lsquoJapanese Strainrsquo Enthalpy of quinoa flour differed among
varieties The range was from 11 Jg in lsquoYellow Commercialrsquo to 18 Jg in lsquoBlancarsquo
Correlations between physical-chemical properties and cooked quinoa texture
59
A summary of correlation coefficients between quinoa physical-chemical properties and
TPA texture profile parameters of cooked quinoa are shown in Table 7 Seed hardness was found
to be positively related to the TPA hardness gumminess and chewiness of cooked quinoa (P lt
009) Seed bulk density was negatively correlated to hardness cohesiveness gumminess and
chewiness while seed coat proportion was positively correlated to those parameters Protein
content of quinoa exhibited a positive relationship with TPA hardness (P = 008) and
adhesiveness cohesiveness gumminess and chewiness No significant correlation was observed
between the seed size 1000 seed weight ash content and the texture properties of cooked
quinoa
Cooking time of quinoa was highly positively correlated with all of the TPA texture
profile parameters Water uptake ratio during cooking was found to be significantly associated
with hardness gumminess and chewiness of cooked quinoa while cooking volume also showed
a modest correlation to hardness (r = -047 P = 010) Cooking loss was not correlated with any
texture parameter
Flour pasting viscosity was significantly correlated with texture of cooked quinoa Peak
viscosity and breakdown exhibited negative correlations with the hardness gumminess and
chewiness of cooked quinoa (P lt 010) Breakdown was also negatively associated with the
cohesiveness (r = -051 P lt 010) Final viscosity and setback were found to be negatively
correlated to hardness cohesiveness gumminess and chewiness while setback also exhibited a
significant correlation to adhesiveness (r = -064 P = 002)
60
Considering thermal properties To exhibited strong positive correlations with all texture
parameters Tp was found to be moderately related to cohesiveness (r = 050 P = 008) Neither
Tc nor enthalpy was significantly correlated to the TPA parameters of cooked quinoa
Discussion
Seed characteristics
Harder seed yielded harder gummier and chewier TPA texture after cooking The
varieties with lower seed bulk density or thicker seed coat yielded a firmer more cohesive
gummier and chewier texture Likely the condensed cells and non-starch polysaccharides of the
seed coat are a barrier between starch granules in the middle perisperm and water molecules
outside the seed
Seed composition
Higher protein appeared to contribute to a firmer more adhesive gummier and chewier
texture of cooked quinoa as evidenced by the TPA parameters Protein has been reported to play
a significant role in the texture of cooked rice and noodles (Ramesh et al 2000 Martin and
Fitzgerald 2002 Saleh and Meullenet 2007 Xie et al 2008 Hou et al 2013) According to the
previous studies proteins affect the food texture through three major routes (1) binding of water
(Saleh and Meullenet 2007) (2) interacting reversibly with starch bodies (Chrastil 1993) and (3)
forming networks via disulphide bonds which restrict starch granule swelling and water
hydration (Saleh and Meullenet 2007)
Cooking quality
Cooking time was found to be a key factor for cooked quinoa texture as it was closely
associated with most texture attributes Other cooking qualities such as the water uptake ratio
61
cooking volume and cooking loss were not significantly correlated to texture In the study of
rice the cooking time of rice positively correlated with hardness negatively with cohesiveness
and not significantly with adhesiveness (Mohapatra and Bal 2006) The higher water uptake ratio
and volume expansion ratio were negatively associated with softer more adhesive and more
cohesive texture This result agrees with the study on cooked rice Rousset et al (1995) study
indicated that longer cooking time greater water uptake and cooking loss related to the softer
less crunchy and more pasty texture
Flour pasting properties
The varieties with a higher peak viscosity in flour had a softer less gummy and less
chewy texture after cooking The cultivars with higher final peak viscosity yielded a softer less
cohesive less gummy and chewy texture The varieties with a greater breakdown such as
lsquoQQ63rsquo lsquo1ESPrsquo and lsquoJapanese Strainrsquo were softer in TPA parameter Breakdown has been
reported to negatively correlate with the proportion of long chain amylopectin (Han and
Hamaker 2001) Long chain amylopectin may form intra- or inter-molecular interactions with
protein and lipids and result in a firmer or harder texture (Ong and Blanshard 1995)
Quinoa varieties with a lower setback were harder after cooking compared to those with a
higher setback In rice conversely setback was positively correlated with amylose content
(Varavinit et al 2003) which would positively influence the hardness of cooked rice (Ong and
Blanshard 1995 Champagne et al 1999) Unlike rice and many other cereals where the amylose
content is approximately 25-29 the amylose proportion in quinoa starch is lower on the order
of 11 (Ahamed et al 1996) Amylose may play a different role in cooked quinoa hardness
compared to other cereals
62
Starch viscosity has been reported to significantly affect the texture of cooked rice
Champagne et al (1999) used the RVA measurements to predict TPA of cooked rice and found
that adhesiveness strongly correlated to RVA parameters Harder rice was correlated with lower
peak viscosity and positive setback while stickier rice had a higher peak viscosity breakdown
and lower setback (Ramesh et al 2000) The difference between quinoa and rice seed structure
and starch composition and the difference of texture determining methods may contribute to the
different trends in correlation
Thermal properties
The gelatinization temperature of quinoa flour ranged from 55 ordmC to 85 ordmC lower than
that of whole rice flour which was 70 ordmC to 103 ordmC (Marshall 1994) This result agrees with the
previous study on quinoa flour (Ando et al 2002) The quinoa varieties with higher To exhibited
a firmer more adhesive more cohesive gummier and chewier texture Higher Tp was associated
with increased cohesiveness The enthalpy of quinoa flour ranged from 11 to 18 Jg about one-
tenth that of whole rice flour (141 ndash 151 Jg) (Marshall 1994) indicating that it takes less
energy to cook quinoa than cook rice
Thermal properties of quinoa flour were generally correlated with flour pasting
properties Higher To and Tp were correlated with lower flour peak viscosity and lower trough
The result is comparable to the previous study of Sandhu and Singh (2007) who found that
gelatinization temperature and enthalpy of corn starch strongly influenced the peak breakdown
final and setback viscosity The thermal properties of quinoa flour were not correlated with
breakdown and setback likely was due to other composition factors in the flour such as protein
and fiber
63
Conclusions
The texture of cooked quinoa varied markedly among the different varieties indicating
that genetics management or geographic origin may all be important considerations for quinoa
quality As such differences in seed morphology and chemical composition appear to contribute
to quinoa processing parameters and cooked texture Harder seed yielded a firmer gummier and
chewier texture both lower seed density and high seed coat proportion related to a firmer more
cohesive gummier and chewier texture Seed size and weight appeared to be largely unrelated to
the texture of the cooked quinoa Protein content was a key factor apparently influencing texture
Higher protein content was related to harder more adhesive and cohesive gummier and chewier
texture Cooking time and water uptake ratio significantly affected the texture of cooked quinoa
whereas cooking volume moderately affected the hardness cooking loss was not correlated with
texture RVA peak viscosity was negatively correlated with the hardness gumminess and
chewiness breakdown was also negatively correlated with those TPA parameters Final viscosity
and setback were negatively correlated with the hardness cohesiveness gumminess and
chewiness Setback was correlated with the adhesiveness as well Gelatinization temperature To
affected all the texture profile parameters positively Tp slightly related to the cohesiveness
while Tc and enthalpy were not correlated with the texture
Acknowledgements
This project was supported by funding from the USDA Organic Research and Extension
Initiative project number NIFA GRANT11083982 The authors acknowledge Stacey Sykes and
Alecia Kiszonas for editing support
Author Contributions
64
G Wu and CF Morris designed the study together G Wu collected test data and drafted the
manuscript CF Morris and KM Murphy edited the manuscript KM Murphy provided
samples and project oversight
65
References
AACC International 2012 Approved Methods of Analysis Method 08-0101 Ash - Basic
method Approved April 13 1961 Method 44-1502 Moisture ndash Air-Oven Methods (130ordmC)
Approved October 30 1975 Method 46-3001 Crude protein ndash Combustion method
Approved November 8 1995 Reapproved November 3 1999 Available online only
AACCI St Paul MN
Abugoch LE Romero N Tapia CA Silva J Rivera M 2008 Study of some physicochemical
and functional properties of quinoa (Chenopodium quinoa Willd) protein isolates J Agric
Food Chem 564745-50
Abugoch LEJ 2009 Chapter 1 Quinoa (Chenopodium quinoa Willd) Adv Food Nutr Res
581-31
Abugoch L Castro E Tapia C Antildeoacuten MC Gajardo P Villarroel A 2009 Stability of quinoa
flour proteins (Chenopodium quinoa Willd) during storage Int J Food Sci Tech 442013-20
Ahamed NT Singhal RS Kulkami PR Palb M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 3199-103
Alvarez-Jubete L Arendt EK Gallagher E 2010 Nutritive value of pseudocereals and their
increasing use as functional gluten-free ingredients Trends in Food Sci Tech 21(2)106-13
Ando H Chen YC Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food components in
fractions of quinoa seed Food Sci Technol Res 8(1)80-4
66
Baik BK Lee MR 2003 Effects of starch amylose content of wheat on textural properties of
white salted noodles Cereal Chem 80304-9
BeMiller JN Huber KC 2008 Carbohydrates In Damdaran S Parkin KL Fennema OR editors
Food chemistry Boca Raton CRC Press p 121
Champagne ET Lyon BG Min BK Vinyard BT Bett KL Barton IIFE Webb BD Kohlwey DE
1998 Effects of postharvest processing on texture profile analysis of cooked rice Cereal
Chem 75(2)181-6
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5)764-71
Champagne ET 2004 The rice grain and its gross composition In Champagne ET editor Rice
chemistry and technology St Paul Minn American Association of Cereal Chemists p 88
Chrastil J 1993 Enzyme activities in preharvest rice grains J Agric Food Chem 41(12)2245-8
Cortez G Repo-Carrasco R Rosell CM 2009 Breadmaking use of andean crops quinoa kantildeiwa
kiwicha and tarwi Cereal Chem 86(4)386-92
Del Castillo V Lescano G Armada M 2009 Foods formulation for people with celiac disease
based on quinoa (Chenopodium quinoa) cereal flours and starches mixtures Archivos
Latinoamericanos De Nutricion 59(3)332-36
67
Demirkesen I Mert B Sumnu G Sahin S 2010 Rheological properties of gluten-free bread
formulations J Food Eng 96(2)295-303
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(Waxy) genes J Cereal Sci 3551-63
Fitzgerald MA Martin M Ward RM Park WD Shead HJ 2003 Viscosity of rice flour a
rheological and biological study J Agric Food Chem 51(8) 2295-9
Food and Agriculture Organization of the United Nations (FAO) 2013 The international year of
quinoa Available from httpwwwfaoorgquinoa-2013en Accessed 2013 February 20
Han XZ Hamaker BR 2001 Amylopectin fine structure and rice starch paste breakdown J
Cereal Sci 34(3)279-84
Hou GG Saini R Ng PKW 2013 Relationship between physicochemical properties of wheat
flour wheat protein composition and textural properties of cooked chinese white salted
noodles Cereal Chem 90(5)419-29
Jancurovaacute M Minarovicova L Dandar A 2009 Quinoa ndash a review Czech J Food Sci 27(2)71-9
Juliano BO Villareal RM Bantildeos L 1987 Varietal differences in physicochemical properties of
waxy rice starch Starch - Staumlrke 39(9)298-301
68
Limpisut P Jindal VK 2002 Comparison of rice flour pasting properties using brabender
viscoamylograph and rapid visco analyser for evaluating cooked rice texture Starch - Staumlrke
54(8)350-7
Lindeboom N Chang PR Falk KC Tyler RT 2007 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2)216-22
Marshall WE 1994 Starch gelatinization in brown and milled rice a study using differential
scanning calorimetry In Marshall WE Wadsworth IJ editors Rice science and technology
New York NY Marcel Dekker Inc p 222
Martin M Fitzgerald MA 2002 Proteins in rice grains influence cooking properties J Cereal Sci
36(3)285-94
Mohapatra D Bal S 2006 Cooking quality and instrumental textural attributes of cooked rice
for different milling fractions J Food Eng 73(3)253-9
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine stucture of amylopectin J Cereal Sci 21(3)251-60
Pappier U Fernandez Pinto V Larumbe G Vaamonde G 2008 Effect of processing for saponin
removal on fungal contamination of quinoa seeds (Chenopodium quinoa Willd) Int J Food
Microbiol 125(2)153-7
Perdon AA Juliano BO 1975 Gel and molecular properties of waxy rice starch Starch - Staumlrke
27(3)69-71
69
Ramesh M Bhattacharya KR Mitchell JR 2000 Developments in understanding the basis of
cooked-rice texture Crit Rev Food Sci Nutr 40(6)449-60
Rousset S Pons B Pilandon C 1995 Sensory texture profile grain physico-chemical
characteristics and instrumental measurements of cooked rice J Texture Stud 26(2)119-35
Ruales J Valencia S Nair B 1993 Effect of processing on the physico-chemical characteristics
of quinoa flour (Chenopodium quinoa Willd) Starch - Staumlrke 45(1)13-9
Ruales J de Grijalva Y Lopez-Jaramillo P Nair BM 2002 The nutritional quality of an infant
food from quinoa and its effect on the plasma level of insulin-like growth factor-1 (IGF-1) in
undernourished children Int J Food Sci Nutr 53(2)143-54
Saleh MI Meullenet JF 2007 Effect of protein disruption using proteolytic treatment on cooked
rice texture properties J Texture Stud 38(4)423-37
Sandhu KS Singh N 2007 Some properties of corn starches II Physicochemical gelatinization
retrogradation pasting and gel textural properties Food Chem 101(4)1499-507
Schumacher A Brandelli A Macedo F Pieta L Klug T Jong E 2010 Chemical and sensory
evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J Food
Sci Tech 47(2)202-6
Seguchi M Hayashi M Kanenaga K Ishihara C Noguchi S1998 Springiness of pancake and
its relation to binding of prime starch to tailings in stored wheat flour Cereal Chem
75(1)37-42
70
Tang H 2004 Relationship between functionality and structure in barley starches Carbohydr
Polym 57(2)145-52
Tang H Mitsunaga T Kawamura Y 2005 Functionality of starch granules in milling fractions
of normal wheat grain Carbohyd Polym 59(1)11-7
Tsuji S 1981 Texture measurement of cooked rice kernels using the multiple-point mensuration
method 1 J Texture Stud 12(2)93-105
Vaclavik VA Christian EW 2003 Evaluation of food quality In Vaclavik V Christian EW
editors Essentials of food science New York NY Kluwer AcademicPlnum Publishers p 4
Varavinit S Shobsngob S Varanyanond W Chinachoti P Naivikul O 2003 Effect of amylose
content on gelatinization retrogradation and pasting properties of flours from different
cultivars of thai rice Starch - Staumlrke 55(9)410-5
Xie L Chen N Duan B Zhu Z Liao X 2008 Impact of proteins on pasting and cooking
properties of waxy and non-waxy rice J Cereal Sci 47(2)372-9
Zeng M Morris CF Batey IL Wrigley CW 1997 Sources of variation for starch gelatinization
pasting and gelation properties in wheat Cereal Chem 7463-71
71
Table 1-Varieties of quinoa used in the experiment
Variety Original Seed Source Location
Black White Mountain Farm White Mountain Farm Colorado US
Blanca White Mountain Farm White Mountain Farm Colorado US
Cahuil White Mountain Farm White Mountain Farm Colorado US
Cherry Vanilla Wild Garden Seeds Philomath Oregon WSUa Organic Farm Pullman Washington US
Oro de Valle Wild Garden Seeds Philomath Oregon WSUa Organic Farm Pullman Washington US
49ALC USDA Port Townsend Washington US
1ESP USDA Port Townsend Washington US
Copacabana USDA Port Townsend Washington US
Col6197 USDA Port Townsend Washington US
Japanese Strain USDA Port Townsend Washington US
QQ63 USDA Port Townsend Washington US
Yellow Commercial Multi Organics company Bolivia
Red Commercial Multi Organics company Bolivia a WSU - Washington State University
72
Table 2-Seed characteristics and compositiona
Variety Diameter (mm)
Hardness (kg)
Bulk Density (gmL)
Seed Coat Proportion ()
Protein ()
Ash ()
Black 21bc 994b 0584d 37bc 143d 215hi
Blanca 22ab 608l 0672c 89a 135e 284ef
Cahuil 21abc 772e 0757a 49b 170a 260fg
Cherry Vanilla 19e 850d 0717b 41b 160b 239gh
Oro de Valle 19e 1096a 0715b 43b 156b 305de
49ALC 19de 935c 0669c 26cd 127g 348bc
1ESP 19e 664h 0672c 10f 113i 248gh
Copacabana 20cd 643i 0671c 44b 129g 361b
Col6197 19e 583m 0657c 24de 118h 291ef
Japanese Strain 15f 618k 0610d 21def 148cd 324cd
QQ63 19e 672g 0661c 45b 135f 401a
Yellow Commercial
21abc 622j 0663c 14ef 146c 198i
Red Commercial 22a 706f 0730ab 26cd 145cd 226hi a Mean values with different letters within a column are significantly different (P lt 005)
73
Table 3-Texture profile analysis (TPA)a of cooked quinoa
Variety Hardness (kg)
Adhesiveness (kgs)
Cohesiveness Gumminess (kg)
Chewiness (kg)
Black 347a -004a 069ab 24a 24a
Blanca 306bcd -003a 071a 22abc 22abc
Cahuil 327abc -003a 071a 23ab 23ab
Cherry Vanilla 278de -002a 071a 20cd 20cd
Oro de Valle 285d -001a 068ab 19cd 19cd
49ALC 209f -029c 054d 11ef 11ef
1ESP 245e -027bc 056d 14e 14e
Copacabana 305bcd -010a 068ab 21bcd 21bcd
Col6197 202f -023bc 053d 11ef 11ef
Japanese Strain 293d -008a 066bc 19cd 19cd
QQ63 297cd -020b 062c 19d 19d
Yellow Commercial 306bcd -003a 069ab 21abc 21bc
Red Commercial 338ab -005a 068ab 23ab 23ab a Mean values with different letters within a column are significantly different (P lt 005)
74
Table 4-Cooking qualitya of quinoa
Variety Optimal Cooking Time (min)
Water uptake ()
Cooking Volume (mL)
Cooking Loss ()
Black 192a 297c 109c 065f
Blanca 183abc 344b 130ab 067f
Cahuil 169de 357ab 137a 102c
Cherry Vanilla 165ef 291c 107c 102c
Oro de Valle 173cde 238d 109c 102c
49ALC 136h 359ab 126b 043g
1ESP 153g 373ab 132ab 035h
Copacabana 157fg 379ab 127b 175a
Col6197 119i 397a 126b 176a
Japanese Strain 166def 371ab 116c 106b
QQ63 177bc 244d 126b 067f
Yellow Commercial 187ab 372ab 129ab 076d
Red Commercial 155fg 276cd 132ab 071e a Mean values with different letters within a column are significantly different (P lt 005)
75
Table 5-Pasting properties of quinoa flour by RVAa
Variety Peak Viscosity (RVU)
Trough
(RVU)
Breakdown
(RVU)
Final Viscosity (RVU)
Setback (RVU)
Peak Time (min)
Black 102g 81e 21e 75g -6f 102e
Blanca 98g 80e 18e 82g 2e 99f
Cahuil 116f 85e 31d 74g -11f 104de
Cherry Vanilla
66h 54g 12f 57h 2e 97fg
Oro de Valle
59h 50g 10f 56h 6e 93h
49ALC 107fg 71f 36c 132e 62b 97fg
1ESP 161cd 110c 51b 174c 64b 98fg
Copacabana 175b 141b 34cd 190b 49c 106cd
Col6197 155de 133b 22e 177bc 44cd 108bc
Japanese Strain
172bc 109c 62a 159d 50c 96gh
QQ63 144e 94d 51b 167cd 73a 97fg
Yellow Commercial
172bc 162a 11f 203a 41d 109b
Red Commercial
197a 168a 29d 106f -62g 115a
a Mean values with different letters within a column are significantly different (P lt 005)
76
Table 6-Thermal properties of quinoa flour by Differential Scanning Calorimetry (DSC)a
Gelatinization Temperature (ordmC)
Variety To Tp Tc Enthalpy (Jg)
Black 656a 725c 818abcd 15abc
Blanca 658a 743ab 819abcd 18a
Cahuil 659a 752a 839ab 16ab
Cherry Vanilla 649ab 741ab 823abc 12c
Oro de Valle 631bc 719cd 809abcde 12bc
49ALC 579e 714d 810bcde 15abc
1ESP 544f 690f 785de 15abc
Copacabana 630c 715cd 802cde 14abc
Col6197 605d 689f 785de 15abc
Japanese Strain 645abc 740b 850a 12c
QQ63 630c 702e 784de 13bc
Yellow Commercial 570e 676g 790cde 11c
Red Commercial 589de 693ef 780e 12c a Mean values with different letters within a column are significantly different (P lt 005)
77
Table 7-Correlation coefficients between quinoa seed characteristics composition and processing parameters and TPA texture of cooked quinoaa
Hardness Adhesiveness Cohesiveness Gumminess Chewiness
Seed Hardness 051 002ns 028ns 049 049
Bulk Density -055 -044ns -063 -060 -060
Seed Coat Proportion 074 038ns 055 072 072
Protein 050 077 075 057 057
Cooking Time 077 062 074 076 076
Water Uptake Ratio -058 -025ns -046ns -056 -056
Cooking Volume -048 -014ns -032ns -046ns -046ns
Peak Viscosity -051 -014ns -041ns -053 -054
Breakdown -048 -047ns -051 -053 -053
Final Viscosity -069 -043ns -060 -070 -070
Setback -058 -064 -059 -060 -060
To 059 054 061 061 061
Tp 042ns 041ns 050 045ns 046ns a ns non-significant difference P lt 010 P lt 005 P lt 001
78
Figure 1-Rapid Visco Analyzer (RVA) graph of lsquoCherry Vanillarsquo and lsquoRed Commercialrsquo
quinoa flours ( lsquoCherry Vanillarsquo lsquoRed Commercialrsquo Temperature)
Time (min)
0 10 20 30 40
Vis
cosi
ty (R
VU
)
0
50
100
150
200
250
Tem
pera
ture
(degC
)
50
100
150
200
79
Figure 2-Seed coat image by SEM
(1 whole seed section P-perisperm C-cotyledon 2 three layers of quinoa seed coat
3 seed coat of lsquoCherry Vanillarsquo 382 microm 4 seed coat of lsquo1ESPrsquo 95microm)
4 3
2 1
P
C C
80
Chapter 4 Quinoa Starch Characteristics and Their Correlation with
Texture of Cooked Quinoa
ABSTRACT
Starch composition and physical properties strongly influence the functionality and end-
quality of cereals Here correlations between starch characteristics and seed quality cooking
properties and texture were investigated Starch characteristics differed among the eleven
experimental varieties and two commercial quinoa tested The total starch content of seed ranged
from 532 to 751 g 100 g Total starch amylose content ranged from 27 to 169 and the
degree of amylose-lipid complex ranged from 34 to 433 The quinoa samples with higher
amylose tended to yield harder stickier more cohesive more gummy and more chewy texture
after cooking With higher degree of amylose-lipid complex or amylose leaching the cooked
quinoa tended to be softer and less chewy Higher starch enthalpy correlated with firmer more
adhesive more cohesive and more chewy texture Indicating that varieties with different starch
properties should be utilized in different end-products
Keywords quinoa starch texture cooked quinoa
Practical Application The research provided the starch characteristics of different quinoa
varieties showing correlations between starch and cooked quinoa texture These results can help
breeders and food manufacturers to better understand quinoa starch properties and the use of
cultivars for different food product applications
81
Introduction
Quinoa (Chenopodium quinoa Willd) is a pseudocereal from the Andean mountains in
South America Quinoa is garnering greater attention worldwide because of its high protein
content and balanced essential amino acids As in other crops starch is one of the major
components of quinoa seed Starch content structure molecular composition pasting thermal
properties and other characteristics may influence the cooking quality and texture of cooked
quinoa
The total starch content of quinoa seed has been reported to range from 32 to 69
(Abugoch 2009) Starch granules are small (1-2μm) compared to those of rice and barley (Tari et
al 2003) Amylose content of quinoa starch was reported to range from 35 to 225 (Abugoch
2009) generally lower than that of other crops Amylose content exhibited significant influence
on the texture of cooked quinoa (Ong and Blanshard 1995) Similarly cooked rice texture was
correlated to starch amylose and chain length (Ong and Blanshard 1995 Ramesh et al 1999)
and leaching of amylose and amylopectin during cooking (Patindol et al 2010) However
amylose-lipid complex and amylose leaching properties have not been studied in quinoa cultivars
with diverse genetic backgrounds Perdon et al (1999) indicated that starch retrogradation was
positively correlated with firmness and stickiness of cooked milled rice during storage and
similar correlations would be anticipated for quinoa
Starch swelling power and water solubility influenced wheat and rice noodle quality and
texture (Crosbie 1991 McCormick et al 1991 Konik et al 1993 Ross et al 1997 Bhattacharya
et al 1999) whereas the role of starch swelling powerwater solubility in the texture of cooked
quinoa has not been reported
82
The texture of rice starch gels has been studied Gel texture was influenced by treatment
temperature incorporation of glucomannan and sugar concentration (Charoenrein et al 2011
Jiang et al 2011 Sun et al 2014) The texture of quinoa starch gel however has not been
reported
Gelatinization temperature enthalpy and pasting properties of starch were correlated
with the texture of cooked rice (Ong and Blanshard 1995 Champagne et al 1999 Limpisut and
Jindal 2002) The correlations between starch thermal properties pasting properties and cooked
quinoa texture however have also not been reported
Starch is an important component of grains and exhibits significant influence on the
texture of cooked rice noodles and other foods The texture of cooked quinoa has been studied
previously (Wu et al 2014) however the correlation of starch and cooked quinoa texture
nevertheless remained unclear The objectives of the present study were to understand 1) the
starch characteristics of different quinoa varieties and 2) the correlations between the starch
characteristics and the texture of cooked quinoa
Materials and Methods
Starch isolation
Eleven varieties and two commercial quinoa samples were included in this study (Table
1) Quinoa starch was isolated using a method modified from Lindeboom et al (2005) and Qian
et al (1999) Two hundred grams of seed were steeped in 1000 mL NaOH (03 wv) overnight
at 4 degC and rinsed with distilled water three times to remove the saponins The rinsed quinoa
was ground in a Waring blender (Conair Corp Stamford CT USA) for 15 min The slurry
was screened through a series of sieves US No 40 100 and 200 mesh sieves with openings of
83
425 150 and 74 μm respectively Distilled water was added and stirred to speed up the
filtration Filter residue was discarded whereas the filtrate was centrifuged under 2000 times g for 20
min The supernatant was decanted and the top brown layer of sediment (protein and lipids) was
gently scraped loose and discarded The remaining pellet was resuspended in distilled water and
centrifuged again This resuspension-centrifuge process was repeated three times or until the
brown topmost layer was all removed The white starch pellet was then dispersed in 95 ethanol
and centrifuged under 2000 times g for 10 min The supernatant was discarded and the starch pellet
was air-dried and gently ground using a mortar and pestle
α-amylase activity
The activity of α-amylase was determined using a Megazyme Kit (Megazyme
International Ireland Co Wicklow Ireland)
Apparent total amylose content degree of amylose-lipid complex
Apparent amylose content was determined using a cold NaOH method (Mahmood et al
2007) with modification Sample of 10 mg was weighed into a 20 mL microcentrifuge tube To
the sample was added 150 μL of 95 ethanol and 900 μL of 1M NaOH mixed vigorously and
kept on a shaker overnight at room temperature The starch solution of 200 μL was removed and
combined with 1 mL of 005 M citric acid 800 μL iodine solution (02 g I2 2 g KI in 250 mL
distilled water) and 10 mL distilled water reaching a final volume of 12 mL The solution was
chilled in a refrigerator for 20 min The absorbance at 620nm was determined using a
spectrophotometer (Shimadzu Biospec-1601 DNAProteinEnzyme Analyzer Shimadzu corp
Kyoto Japan) A standard curve was created using a dilution series of amylose amylopectin
84
proportions of 010 19 28 37 46 and 55 respectively (Sigma-Aldrich Co LLC St Louis
MO USA)
Total amylose content was determined using the same method for apparent amylose
except that lipids in the starch samples were removed in advance The starch was defatted using
hexane and ultrasonic treatment as follows One gram of starch was dissolved in 15 mL hexane
and set in an ultrasonic water bath for 2 hours The suspension was then centrifuged at 1000 times g
for 1 min The supernatant was discarded and the procedure was repeated a second time The
sample was then dried in a fume hood overnight
Degree of amylose-lipid complex = [total amylose ndash apparent amylose] total amylose times 100
Amylose leaching properties
Amylose leaching was determined using the modified method of Hoover and Ratnayake
(2002) Starch (025 g) was mixed with 5 mL distilled water and heated at 60 degC for 30 min
then cooled in ice water and centrifuged at 2000 times g for 10 min Supernatant of 1 mL was added
to 800 μL iodine solution and 102 mL distilled water to achieve the same volume of 12 mL as
in the apparent amylose test The solution was chilled in a refrigerator for 20 min and the
absorbance at 620 nm was determined The amylose leaching was expressed as mg of amylose
leached from 100 g of starch
Starch pasting properties
Starch pasting properties were determined using the Rapid Visco Analyzer RVA-4
(Newport Scientific Pty Ltd Narrabeen Australia) Starch (3 g) was added to 25 mL distilled
water mixed and heated in the RVA using the following procedure The initial temperature was
50 ordmC and increased to 93 ordmC within 8 min at a constant rate held at 95 ordmC from 8 min to 24 min
85
cooled to 50 ordmC from 24 min to 28 min and held at 50 ordmC from 29 min to 40 min The result was
expressed in RVU units (RVU = cP12)
Starch gel texture
Starch gel texture was determined using a TA-XT2i Texture Analyzer (Texture
Technologies Corp Hamilton MA USA) The starch gels were prepared in the RVA using the
same procedure as for pasting properties Then the starch gels were stored at 4 degC for 24 hours
The testing procedure followed the method of Jiang et al (2011) with modification The gel
cylinder (3 cm high and 35 cm diameter) was compressed using a TA-25 cylinder probe at the
speed of pre-test 20 mms test 05 mms and post-test 05 mms to 10 mm deformation Two
compressions were conducted with an interval time of 20 s Hardness springiness and
cohesiveness were obtained from the TPA (Texture Profile Analysis) graph (x-axis distance and
y-axis force) Hardness (g) was expressed by the maximum force of the first peak springiness
was the ratio of distance (time) to peak 2 to distance to peak 1 cohesiveness was the ratio of the
second positive area under the compression curve to that of the first positive area
Freeze-thaw stability
Freeze-thaw stability was determined using the modified method from Lindeboom et al
(2005) and Charoenrein et al (2005) Starch slurry was cooked using the RVA with 125 g
starch and 25 mL distilled water The starch suspensions were heated at 60 degC from 0 ndash 2 min
the temperature was increased to 105 degC from 3 ndash 8 min with a constant rate and held at 105 degC
from 9 - 11 min The cooked samples were stored at -18 degC for 20 hours and then kept at room
temperature for 4 hours Water was decanted and the weight difference was determined The
86
freeze-thaw cycle was repeated five times The freeze-thaw stability was expressed as water loss
after each freeze-thaw cycle
Starch thermal properties
Thermal properties of starch were determined using Differential Scanning Calorimetry
(DSC) (Lindeboom et al 2005) Starch samples of 10 mg were weighed into aluminum pans
(Perkin-Elmer Kit No 219-0062) with 20 μL distilled water The pans were sealed and the
suspensions were incubated at room temperature (25 degC) for 2 hours to achieve equilibrium The
pans were then scanned at 10 degCmin from 25 degC to 120 degC The onset temperature (To) peak
temperature (Tp) and completion temperature (Tc) were the temperature to start the peak reach
the peak and complete the peak respectively Additionally enthalpy of gelatinization was
determined by the area under the peak
Swelling power and solubility
Swelling power and water solubility of starch were obtained at 93 degC (Vandeputte et al
2003) Starch samples of 05 g were added to 12 mL distilled water and mixed vigorously The
suspensions were immediately set in a water bath with a rotating rack at 93 degC for 30 min The
suspensions were then cooled in ice water for 2 min and centrifuged at 3000 g for 15 min The
supernatant was carefully removed with a pipette and the weight of wet sediment was recorded
The removed supernatants were dried in a 105 degC oven over night The weight of dry sediment
was recorded The swelling power and water solubility were expressed using the following
equations
Swelling power = wet sediment weight [dry sample weight times (1 ndash water solubility))
Water solubility = dry sediment weight dry sample weight times 100
87
Swelling power is expressed as a unitless ratio
Statistical analysis
All experiments were repeated three times Multiple comparisons were conducted using
Fisherrsquos LSD in SAS 92 (SAS Inst Cary NC USA) Correlations were calculated using
PROC CORR code in SAS 92 A P value of 005 was considered as the level of significance
unless otherwise specified
Results
Starch content and composition
Total starch content of quinoa seeds on a dry basis ranged from 532 g 100 g in the
variety lsquoBlackrsquo to 751 g 100 g in a commercial sample named lsquoYellow Commercialrsquo (Table 2)
Varieties lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo were lower in total
starch content all below 60 g100 g The Port Townsend seeds and commercial seeds contained
higher levels of starch mostly over 70 g100 g
Apparent amylose contents ranged from 27 in lsquo49ALCrsquo to 169 in lsquoCahuilrsquo all
lower than the corn starch standard which was 264 Varieties lsquoCahuilrsquo lsquoBlackrsquo and lsquoYellow
Commercialrsquo contained higher apparent amylose 147 to 169 It is worth noting that
lsquo49ALCrsquo contained the lowest apparent and total amylose contents 27 and 47 respectively
Total amylose of the other varieties ranged from 111 in lsquoQQ63rsquo to 173 in lsquoCahuilrsquo
The degree of amylose-lipid complex differed among the samples ranging from 34 in
lsquoCahuilrsquo to 43 in lsquo49ALCrsquo and lsquoCol6197rsquo Statistically however only lsquo49ALCrsquo and
lsquoCol6197rsquo were significantly higher than lsquoCahuilrsquo in degree of amylose-lipid complex
Starch properties
88
Amylose leaching property exhibited great differences among samples (Table 3)
lsquo49ALCrsquo and lsquo1ESPrsquo showed the highest amylose leaching at 862 and 716 mg 100 g starch
respectively lsquoCahuilrsquo lsquoJapanese Stainrsquo and lsquoRed Commercialrsquo were the lowest with amylose
leaching less than 100 mg 100 g starch lsquoBlackrsquo and lsquoBlancarsquo were relatively low as well with
210 and 171 mg amylose leaching 100 g starch The other varieties were intermediate and
ranged from 349 to 552 mg 100 g starch
Water solubility of quinoa starch ranged from 07 to 45 all lower than that of corn
starch which was 79 lsquoJapanese Strainrsquo lsquoQQ63rsquo lsquoCommercial Yellowrsquo and lsquoPeruvian Redrsquo
were the highest in water solubility 26 to 45 The starch water solubility in the other varieties
was between 10 and 19
Swelling power of quinoa starch ranged from 170 to 282 all higher than that of corn
starch (89) lsquo49ALCrsquo and lsquo1ESPrsquo showed the highest swelling powers 282 and 276
respectively lsquoYellow Commercialrsquo and lsquoRed Commercialrsquo showed relatively lower swelling
power 188 and 196 respectively The remaining varieties did not exhibit differences in
swelling power with values between 253 and 263
α-Amylase activity
Activity of α-amylase in quinoa flour separated the samples to three groups (Table 3)
lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo showed high α-amylase activity from
086 CU to 116 CU (Ceralpha Unit) lsquoBlackrsquo lsquo49ALCrsquo and lsquoCopacabanarsquo were lower in α-
amylase activity 043 031 and 020 CU respectively The other varieties and commercial
samples exhibited particularly low α-amylase activities with the values lower than 01 CU
Starch gel texture
89
Texture of starch gels included hardness springiness and cohesiveness (Table 4)
Hardness of starch gel of lsquoCahuilrsquo and lsquoJapanese Strainrsquo represented the highest and the lowest
values 900 and 201 g respectively Hardness of the other varieties ranged from 333 g in
lsquo49ALCrsquo to 725 g in lsquoBlackrsquo
lsquoJapanese Strainrsquo and lsquoYellow Commercialrsquo exhibited the highest and lowest springiness
values of the starch gels 092 and 071 respectively Springiness of other starch samples ranged
from 075 to 085 and were not significantly different from each other
Cohesiveness of starch gels ranged from 053 to 089 The starch gels of lsquoJapanese
Strainrsquo lsquoCol6197rsquo and lsquoCopacabanarsquo were more cohesive at 089 083 and 078 respectively
The starch gels of lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquo1ESPrsquo were moderately cohesive
with the cohesiveness of 072 ndash 073 Other varieties exhibited less cohesive starch gels lsquoQQ63rsquo
and commercial samples showed the least cohesive starch gels 053 ndash 057 For comparison the
hardness springiness and cohesiveness of the corn starch gel was 721 084 and 073
respectively These values were among the upper-to-middle range of those counterpart values of
the texture of quinoa starch gels
Starch thermal properties
Thermal properties of quinoa starch include gelatinization temperature and enthalpy
(Table 5) Onset temperature To of quinoa starch ranged from 515 ordmC in lsquoYellow Commercialrsquo to
586 ordmC in lsquoBlancarsquo Peak temperature Tp ranged from 595 ordmC in lsquoRed Commercialrsquo to 654 ordmC
in lsquoJapanese Strainrsquo Conclusion temperature ranged from 697 ordmC in lsquoCol6197rsquo to 788 ordmC in
lsquoJapanese Strainrsquo The commercial samples exhibited lower gelatinization temperatures To Tp
90
and Tc of the corn starch were 560 626 and 743 ordmC respectively They were within the ranges
of those values of the quinoa starches
Enthalpy refers to the energy required during starch gelatinization The enthalpy of
quinoa starch ranged from 99 to 116 Jg Starch from lsquoCahuilrsquo exhibited the highest enthalpy
116 Jg higher than that of lsquo49ALCrsquo and lsquoQQ63rsquo However enthalpies of other samples were
not significantly different Corn starch enthalpy was 105 Jg comparable to those of quinoa
starches
Starch pasting properties
Starch viscosity was investigated using the RVA (Table 6) Peak viscosity of quinoa
starches ranged from 193 to 344 RVU Varieties lsquoBlancarsquo and lsquoCahuilrsquo showed the highest peak
viscosities 344 and 342 RVU respectively lsquoJapanese Strainrsquo and lsquoQQ63rsquo were lowest in starch
peak viscosity 193 and 213 RVU respectively The peak viscosity of corn starch was 255 RVU
falling within the middle range of quinoa peak viscosities
The tough is the minimum viscosity after the first peak The trrough of quinoa starch
ranged from 137 to 301 RVU The starches of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and
lsquoOro de Vallersquo showed highest trough values from 252 to 301 RVU lsquo49ALCrsquo lsquo1ESPrsquo
lsquoCopacabanarsquo lsquoJapanese Strainrsquo and lsquoQQ63rsquo were lowest in trough ranging from 137 to 186
RVU The trough of corn starch was 131 RVU lower than that of all quinoa starches
Starch breakdown of lsquo49ALCrsquo was 119 RVU higher than that of other samples except
corn starch which was 124 RVU lsquoJapanese Strainrsquo and lsquoOro de Vallersquo showed the lowest
breakdowns 12 and 17 RVU respectively Breakdown of the other samples ranged from 39 to
97 RVU
91
Final viscosity of lsquoCahuilrsquo starch was 405 RVU significantly higher than that of other
varieties At the other extreme final viscosity of lsquo49ALCrsquo starch was 225 RVU significantly
lower than that of the other varieties The final viscosity of corn starch was 283 RVU close to
that of lsquoJapanese Strainrsquo and lsquoQQ63rsquo but lower than that of the other quinoa samples
The highest setback was observed with lsquo1ESPrsquo starch (140 RVU) At the other extreme
the setback of lsquoOro de Vallersquo was 53 RVU which was lower than the other quinoa samples
Additionally setbacks of lsquoBlancarsquo lsquo49ALCrsquo and lsquoJapanese stainrsquo starches were also among the
lower range varying from 82 RVU to 88 RVU The remaining varieties exhibited higher setback
from 101 RVA to 127 RVU Setback of corn starch was 152 RVU significantly higher than all
the other quinoa starches
RVA peak times of quinoa starches varied significantly among the samples lsquoJapanese
Strainrsquo lsquoBlancarsquo lsquoCahuilrsquo and lsquoOro de Vallersquo required longer time to reach the peak viscosity
with peak times of 105 to 113 min Other varieties showed shorter peak times between 79 to
99 min The starch of lsquo49ALCrsquo however only needed 64 min to reach peak viscosity shorter
than those of other quinoa samples The peak time of corn starch was 73 min shorter than those
of quinoa starches except lsquo49ALCrsquo
Freeze-thaw stability of starch
Freeze-thaw stability of starches was expressed as the water loss () of each freeze-thaw
cycle Quinoa starch samples and corn starch showed similar trends in freeze-thaw stability
Most water loss occurred after cycles 1 and 2 Starch gels on average (excluding lsquo49ALCrsquo) lost a
cumulative total of 522 ndash 689 of water after cycle 2 and a total of 745 ndash 823 after cycle 5
Furthermore the starch gels of lsquoQQ63rsquo and lsquo1ESPrsquo lost the least water indicating higher freeze-
92
thaw stability Conversely the starch gel of lsquoJapanese Strainrsquo lost the most water in every cycle
indicating the lowest degree of freeze-thaw stability
lsquo49ALCrsquo and lsquo1ESPrsquo starches exhibited freeze-thaw behavior that was different
compared to the other samples After freezing the samples of lsquo49ALCrsquo and lsquo1ESPrsquo produced
gels that were less rigid more viscous than the other samples Further they did not lose as much
water after the first cycle The sample of lsquo1ESPrsquo however turned into a solid gel from cycle 2 to
5 And the water loss of the lsquo1ESPrsquo gel was close to that of other samples during cycles 2 and 5
Correlations between starch properties and the texture of cooked quinoa
Correlations between starch properties and texture of cooked quinoa were examined
(Table 7) using texture profile analysis (TPA) of cooked quinoa of Wu et al (2014) Total starch
content was moderately correlated with adhesiveness of cooked quinoa (r = -048 P = 009) but
was not significantly correlated with any of the other texture parameters Conversely apparent
amylose content was highly correlated with all texture parameters (067 le r le 072) Total
amylose content also exhibited significant correlations with all texture parameters (056 le r le
061) Furthermore the degree of amylose-lipid complex was negatively correlated with all
texture parameters (-070 le r le -060) and amylose leaching proportion was highly correlated
with the texture of cooked quinoa (-084 le r le -074)
Water solubility and swelling power of starch were not observed to correlate well with
any of the texture parameters Higher α-amylase activity tended to yield more adhesive (r = 055)
and more cohesive (r = 051 P = 007) texture However α-amylase activity was not correlated
with the hardness gumminess or chewiness of cooked quinoa
93
Some texture parameters of starch gels were associated with the texture parameters of
cooked quinoa The hardness of starch gels was not correlated with the hardness of cooked
quinoa but was weakly correlated with adhesiveness (r = 059) Weakly positive correlations
were found between starch gel hardness and cooked quinoa cohesiveness gumminess and
chewiness (049 le r le 051 P le 010) Springiness and cohesiveness of starch gels were not
correlated with the measured textural properties of cooked quinoa
Onset gelatinization temperature (To) of starch exhibited weak correlations with
adhesiveness (r = 049 P = 009) and cohesiveness (r = 051 P = 007) but was not correlated
with the other texture parameters Peak gelatinization temperature (Tp) of starch was correlated
with cohesiveness (r = 056) and hardness adhesiveness gumminess and chewiness (047 le r le
056 P le 010) No correlation was found with conclusion temperature (Tc) and texture Starch
enthalpy did correlate with the texture parameters (r = 064 in hardness 069 le r le 072 in other
texture parameters)
Starch viscosity measurements were variably correlated with the texture of cooked
quinoa Peak viscosity correlated adhesiveness (r = 054 P = 006) and cohesiveness (r = 047 P
= 010) but not with the other texture parameters Trough was more highly correlated with
adhesiveness cohesiveness gumminess and chewiness (r = 077 in adhesiveness 055 le r le
063 in other texture parameters)
It is interesting to note that starch breakdown only correlated with adhesiveness of
cooked quinoa (r = -060) and not with any other texture parameter Setback was not correlated
with any texture parameter These two RVA parameters breakdown and setback are usually
considered to be important indexes of end-use quality In quinoa however breakdown and
94
setback of starch apparently are not predictive of cooked quinoa texture In addition final
viscosity was also correlated with adhesiveness (r = 068) and cohesiveness (r = 058) and
correlated moderately with gumminess and chewiness (r = 053 P = 006) Peak time was
correlated with adhesiveness (r = 077) cohesiveness (r = 068) gumminess (r = 060) and
chewiness (r = 060) and to a lesser extent with hardness (r = 053 P = 006)
Correlations between starch properties and seed DSC RVA characteristics
Total starch content correlated with seed hardness (r = -073) seed coat proportion (r = -
071) and starch viscosities (peak viscosity trough and final viscosity) (-068 lt r lt -060) and
also to a lesser extent with seed density (r = 054 P = 006) and starch thermal properties (To
Tp and enthalpy) (-051 lt r lt -049 008 lt P lt009) (Table 8)
Water solubility of starch was correlated with starch viscosity such as peak viscosity (r =
-049 P = 009) and breakdown (r = -048 P = 010) Swelling power was only correlated with
peak time (r = -054 P = 006) (data not shown)
Apparent amylose content was correlated with protein content (r = 058) and optimal
cooking time (r = 056) but total amylose content did not show either of these correlations Both
apparent and total amylose contents were correlated with starch gel hardness starch enthalpy
and starch viscosity such as trough breakdown final viscosity and peak time
The degree of amylose-lipid complex exhibited negative correlations with seed protein
content (r = -07) and optimal cooking time of quinoa seed (r = -067) Moreover amylose
leaching was negatively correlated with protein content (r = -062) starch gel hardness (r = --
064) starch Tp (r = -058) and enthalpy (r = -064) optimal cooking time (r = -055) and starch
viscosities such as breakdown (r = 062) and peak time (r = -081) Additionally α-amylase
95
activity was correlated with protein content (r = 066) seed density (r = -072) seed coat
proportion (r = 055) starch To (r = 061) and starch viscosities such as peak viscosity (r =
070) trough (r = 072) and final viscosity (r = 061)
Discussion
Starch content and composition
Total starch content does influence the functional and processing properties of cereals
The total starch content of quinoa was reported to be between 32 and 69 (Abugoch 2009)
Among our varieties most of the Port Townsend varieties and commercial quinoa contained
more than 69 starch It is interesting to note that the Port Townsend samples lsquo49ALCrsquo lsquo1ESPrsquo
lsquoCol6197rsquo and lsquoQQ63rsquo were also more sticky or more adhesive after cooking than other
varieties These varieties may exhibit better performance in extrusion products or in beverages
which require high viscosity
Amylose content affects texture and gelation properties The proportion of amylose and
amylopectin impacts the functionality of cereals in this study both apparent and total amylose
contents were determined Total amylose includes those amylose molecules that are complexed
with lipids
Amylose content of quinoa was reported to range from 35 to 225 dry basis
(Abugoch 2009) generally lower than that of common cereals which is around 25 Overall
both apparent and total amylose contents of the quinoa in the present study fell within the range
which has been reported lsquo49ALCrsquo was an exception showing significantly lower apparent and
total amylose contents of 27 and 47 respectively Thus this variety is close to be being a
lsquowaxyrsquo which refers to the cereal starches that are comprised of mostly amylopectin (99) and
96
little amylose (~1) As the waxy wheat showed an excellent expansion during extrusion
(Kowalski et al 2014) lsquo49ALCrsquo is a promising variety to produce breakfast cereal or extruded
snacks
The degree of amylose-lipid complex showed great variability among the samples 34 ndash
433 whereas the value in wheat flour was reported to be 32 (Bhatnagar and Hanna 1994) or
13 to 23 (Zeng et al 1997) Degree of amylose-lipid complex showed significant and
negative correlations with all texture parameters such as hardness adhesiveness cohesiveness
gumminess and chewiness
The effect of amylose-lipid complex on product texture has been reported in previous
studies The degree of amylose-lipid complex correlated with the texture (hardness and
crispness) and quality (radial expansion) of corn-based snack (Thachil et al 2014) Wokadala et
al (2012) indicated that amylose-lipid complexes played a significant role in starch biphasic
pasting
Starch properties
Amylose leaching was also highly variable among the quinoa varieties 35 ndash 862 mg
100g starch Vandeputte et al (2003) studied amylose leaching of waxy and normal rice
starches The amylose leaching values at 65 ordmC were below 1 of starch comparable with those
in quinoa starch Pronounced increase of amylose leaching was observed at the temperatures
higher than 95 ordmC Patindol et al (2010) found that both amylose and amylopectin leached out
during cooking rice The proportion of the leached amylose and amylopectin influenced the
texture of cooked rice We found similar results indicating correlations between amylose
leaching and texture of cooked quinoa
97
Water solubility of quinoa starch was significantly lower than that of corn starch whereas
swelling power of quinoa starch was higher than that of corn starch Both water solubility and
swelling power were determined at 95 ordmC Lindeboom et al (2005) determined swelling power
and solubility of quinoa starch among eight varieties at 65 75 85 and 95 ordmC The water
solubility at 95 ordmC ranged from 01 to 47 which was lower than the corn starch standard of
100 The swelling power at 95 ordmC ranged from 164 to 526 lower than the corn starch
standard of 549 The quinoa starch in this study showed a narrower range of swelling power
170 to 282
α-Amylase activity
The quinoa in this study had significantly different α-amylase activity (003 ndash 116 CU)
Previous studies reported low α-amylase activity in quinoa compared to oat (Maumlkinen et al
2013) and traditional malting cereals (Hager et al 2014) Moreover the activity of α-amylase
indicates the degree of seed germination and the availability of sugars for fermentation In the
study of Hager et al (2014) α-amylase activity increased from 0 to 35 CU during 72 h
germination
Texture of starch gel
Starch gel texture has been previously studied on corn and rice starches but not on
quinoa starch Hardness of rice starch gel was reported to be 339 g by Charoenrein et al (2011)
and 116 g by Jiang et al (2011) Hardness of corn starch was reported to be around 100 g in the
study of Sun et al (2014) much lower than the standard corn starch hardness in this study 721
g Compared to those of rice and corn starch quinoa starch gel exhibited harder texture which
may be caused by either genetic variation or different processing procedures to form the gel
98
Additionally springiness and cohesiveness of rice starch gel were reported as 085 and 055
respectively (Jiang et al 2011) Quinoa starch gel exhibited comparable springiness and higher
cohesiveness than those of rice starch gel
Thermal properties of quinoa starch
The thermal properties of quinoa starch in this study were comparable to those of rice
starch (Cai et al 2014) The study of Lindeboom et al (2005) however found lower
gelatinization temperatures and higher enthalpies compared to the present study which may be
due to varietal difference
Furthermore correlation between thermal properties of quinoa starch and flour (Wu et al
2014) was investigated Gelatinization temperatures To Tp and Tc of starch and whole seed
flour were highly correlated especially To and Tp exhibited high r of 088 The enthalpy of
starch and flour however was not significantly correlated In this case quinoa flour can be used
to estimate quinoa starch gelatinization temperatures but not the enthalpy Additionally since
flour is easier to prepare compared to starch further studies can be conducted with a larger
number of quinoa samples to model the prediction of starch thermal properties using flour
thermal properties
Starch pasting properties
Viscosity and pasting properties of starch play a significant role in the functionality of
cereals Jane et al (1999) studied the pasting properties of starch from cereals such as maize
rice wheat barley amaranth and millet The peak viscosities ranged from 58 RVU in barley to
219 RVU in sweet rice lower than those of most quinoa starches except lsquoJapanese Strainrsquo and
lsquoQQ63rsquo Final viscosities ranged from 54 RVU in barley to 208 RVU in cattail millet all lower
99
than those of the quinoa starches in the present study Setback of cereal starches mostly ranged
from 6 RVU in waxy amaranth to 74 RVU in non-waxy maize lower than those of most quinoa
starches except lsquoOre de Vallersquo Cattail millet starch exhibited the setback of 208 RVU higher
than those of quinoa starches
The relationships between RVA pasting parameters of quinoa starch and flour were
studied by Wu et al (2014) Final viscosity of starch and flour was correlated negatively (r = -
063 P = 002) The other RVA parameters did not exhibit significant correlation between starch
and flour RVA In other words RVA of quinoa flour cannot be used to predict RVA of quinoa
starch In addition to starch the fiber and protein in whole quinoa flour may influence the
viscosity As quinoa is normally utilized as whole grain or whole grain flour instead of refined
flour the flour RVA should be a better indication on the end-use functionality
Freeze-thaw stability of starch
Quinoa starches in the present study did not show high stability during freeze and thaw
cycles Praznik et al (1999) studied freeze-thaw stability of various cereal starches Similar to
the present study Praznik et al concluded quinoa starches exhibited low freeze-thaw stability
Conversely Ahamed et al (1996) found quinoa starch exhibited excellent freeze-thaw stability
Unfortunately the variety was not indicated Overall it is reasonable to assert that for some
quinoa cultivars the starch may have better freeze-thaw stability than in other cultivars
However most quinoa varieties in published studies did not show good freeze-thaw stability
Correlations between starch characteristics and texture of cooked quinoa
The quinoa starch characteristics correlated with the texture of cooked quinoa in some
aspects Total starch content however did not show any strong correlations with TPA
100
parameters as was initially expected Since quinoa is consumed as whole grain or whole flour
fiber and bran may exhibit more influence on the texture than anticipated from the impact of
starch alone
The quinoa varieties with higher apparent and total amylose contents tended to yield a
harder stickier more cohesive more gummy and chewy texture Similar correlations are found
with cooked rice noodle and corn-based extrusion snacks The hardness of cooked rice was
positively correlated with amylose content and negatively correlated with adhesiveness (Yu et al
2009) Epstein et al (2002) reported that full waxy noodles were softer thicker less adhesive
and chewy and more cohesive and springy compared to normal noodles and partial waxy
noodles Increased amylose content in a corn-based extrusion snack resulted in higher amylose-
lipid formation and softer texture (Thachil et al 2014)
Higher levels of amylose-lipid complex in starch were associated with softer less
adhesive less cohesive and less gummy and less chewy cooked quinoa The correlation between
the degree of amylose-lipid complex and texture of cooked rice or quinoa has not been
previously reported Kaur and Singh (2000) however found that amylose-lipid complex
increased with longer cooking time of rice flour Additionally cooking time is a key factor to
determine texture ndash the longer a cereal is cooked the softer less sticky less cohesive and less
gummy and chewy the texture
Correlations were found between amylose leaching and cooked quinoa TPA parameters
especially hardness gumminess and chewiness with r of -082 Increased amylose leaching
yielded a softer gel made from potato starch (Hoover et al 1994) However the correlations of
101
amylose leaching and α-amylase activity with texture of end product for quinoa have not been
reported previously
Swelling power and water solubility were reported to influence the texture of wheat and
rice noodle (Crosbie 1991 McCormick et al 1991 Konik et al 1993 Ross et al 1997
Bhattacharya et al 1999) However in the present report no correlation was found between
swelling power water solubility and the texture of cooked quinoa Additionally the study of
Ong and Blanshard (1995) indicated a positive correlation between enthalpy and the texture of
cooked rice Similar results were found in this study
RVA is a fast and reliable way to predict flour functionality and end-use properties
Pasting properties of rice flour have been used to predict texture of cooked rice (Champagne et
al 1999 Limpisut and Jindal 2002) In our previous study cooked quinoa texture correlated
negatively with the final viscosity and setback of quinoa flour (Wu et al 2014) In this study
texture correlated with trough breakdown final viscosity and peak time of quinoa starch
However RVA of quinoa flour and starch did not correlate with each other Flour RVA might be
a convenient way to predict cooked quinoa texture
Correlations between starch properties and seed DSC RVA characteristics
Quinoa with higher total starch tended to have a thinner seed coat This makes sense
because starch protein lipids and fiber are the major components of seed An increase in one
component will result in a proportional decrease in the other component contents
Additionally the starch RVA parameters (except peak viscosity) can be used to estimate
apparent or total amylose content based on their correlations Further studies should be
conducted with a larger sample size of quinoa and a more accurate prediction model can be built
102
The samples with lower protein or those requiring shorter cooking time tended to contain
higher levels of amylose-lipid complex Additionally amylose-lipid complex was reported to
influence the texture of extrusion products (Bhatnagar and Hanna 1994 Thachil et al 2014) For
this reason protein and optimal cooking time are promising indicators of the behavior of quinoa
during extrusion
Conclusions
In summary starch content composition and characteristics were significantly different
among quinoa varieties Amylose content degree of amylose-lipid complex and amylose
leaching property of quinoa starch exhibited great variances and strong correlations with texture
of cooked quinoa Additionally starch gel texture pasting properties and thermal properties
were different among varieties and different from those of rice and corn starches Enthalpy
RVA trough final viscosity and peak time exhibited significant correlations with cooked quinoa
texture Overall starch characteristics greatly influenced the texture of cooked quinoa
Acknowledgments
This project was supported by the USDA Organic Research and Extension Initiative
(NIFAGRANT11083982) The authors acknowledge Girish Ganjyal and Shyam Sablani for
using the Differential Scanning Calorimetry (DSC) thanks to Stacey Sykes for editing support
Author Contributions
G Wu and CF Morris designed the study together and established the starch isolation
protocol G Wu collected test data and drafted the manuscript CF Morris and KM Murphy
edited the manuscript KM Murphy provided quinoa samples
103
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581-31
Ahamed NT Singhal RS Kulkarni PR Pal M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 31(1)99-103
Araujo-Farro PC Podadera G Sobral PJA Menegalli FC 2010 Development of films based on
quinoa (Chenopodium quinoa Willd) starch Carbohydr Polym 81(4)839-48
Bhatnagar S Hanna MA 1994 Amylose-lipid complex formation during single-screw extrusion
of various corn starches Cereal Chem 71(6)582-6
Bhattacharya M Zee SY Corke H 1999 Physicochemical properties related to quality of rice
noodles Cereal Chem 76(6)861-7
Cai J Yang Y Man J Huang J Wang Z Zhang C Gu M Liu Q Wei C 2014 Structural and
functional properties of alkali-treated high-amylose rice starch Food Chem 145245-53
Champagne ET 2004 The rice grain and its gross composition In Champagne ET editor Rice
chemistry and technology St Paul Minn American Association of Cereal Chemists p 88
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5)764-71
104
Charoenrein S Tatirat O Rengsutthi K Thongngam M 2011 Effect of konjac glucomannan on
syneresis textural properties and the microstructure of frozen rice starch gels Carbohydr
Polym 83(1)291-6
Crosbie GB 1991 The relationship between starch swelling properties paste viscosity and
boiled noodle quality in wheat flours J Cereal Sci 13(2)145-50
De Pilli T Derossi A Talja R Jouppila K Severini C 2012 Starchndashlipid complex formation
during extrusion-cooking of model system (rice starch and oleic acid) and real food (rice
starch and pistachio nut flour) Eur Food Res Technol 234(3)517-25
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(waxy) genes J Cereal Sci 35(1) 51-63
Hager AS Maumlkinen OE Arendt EK 2014 Amylolytic activities and starch reserve mobilization
during the germination of quinoa Eur Food Res Technol 239(4)621-7
Hoover R Ratnayake WS 2002 Starch characteristics of black bean chick pea lentil navy bean
and pinto bean cultivars grown in Canada Food Chem 78(4)489-98
Hoover R Vasanthan T Senanayake NJ Martin AM 1994 The effects of defatting and heat-
moisture treatment on the retrogradation of starch gels from wheat oat potato and lentil
Carbohydr Res 261(1)13-24
105
Jane J Chen Y Lee L McPherson A Wong K Radosavljevic M Kasemsuwan T 1999 Effects
of amylopectin branch chain length and amylose content on the gelatinization and pasting
properties of starch 1 Cereal Chem 76(5)629-37
Jiang Q Xu X Jin Z Tian Y Hu X Bai Y 2011 Physico-chemical properties of rice starch
gels Effect of different heat treatments J Food Eng 107(3)353-7
Kaur K Singh N 2000 Amylose-lipid complex formation during cooking of rice flour Food
Chem 71(4)511-7
Konik CM Miskelly DM Gras PW 1993 Starch swelling power grain hardness and protein
relationship to sensory properties of japanese noodles Starch - Staumlrke 45(4)139-44
Kowalski R Morris C Ganjyal G 2015 Extrusion characteristics thermal and rheological
properties of soft white wheat flour in comparison with regular wheat flour Cereal Chem
92(2)145-53
Limpisut P Jindal VK 2002 Comparison of rice flour pasting properties using Brabender
Viscoamylograph and Rapid Visco Analyser for evaluating cooked rice texture Starch‐
Staumlrke 54(8)350-7
Lindeboom N Chang PR Falk KC Tyler RT 2005 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2)216-22
Mahmood T Turner MA Stoddard FL 2007 Comparison of methods for colorimetric amylose
determination in cereal grains Starch‐Staumlrke 59(8)357-65
106
Maumlkinen OE Zannini E Arendt EK 2013 Germination of oat and quinoa and evaluation of the
malts as gluten free baking ingredients Plant Foods Hum Nutr 68(1)90-5
Matos M Timgren A Sjoo M Dejmek P Rayner M 2013 Preparation and encapsulation
properties of double Pickering emulsions stabilized by quinoa starch granules Colloids and
Surfaces A 423147-53
McCormick K Panozzo J Hong S 1991 A swelling power test for selecting potential noodle
quality wheats Aust J Agric Res 42(3)317-23
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine structure of amylopectin J Cereal Sci 21(3)251-60
Ong MH Blanshard JMV 1995 Texture determinants of cooked parboiled rice II
Physicochemical properties and leaching behaviour of rice J Cereal Sci 21(3)261-9
Pagno CH Costa TMH de Menezes EW Benvenutti EV Hertz PF Matte CR Tosati JV
Monteiro AR Rios AO Flores SH 2015 Development of active biofilms of quinoa
(Chenopodium quinoa W) starch containing gold nanoparticles and evaluation of
antimicrobial activity Food Chem 173755-62
Patindol J Gu X Wang YJ 2010 Chemometric analysis of cooked rice texture in relation to
starch fine structure and leaching characteristics Starch - Staumlrke 62(3-4)188-97
Perdon AA Siebenmorgen TJ Buescher RW Gbur EE 1999 Starch retrogradation and texture
of cooked milled rice during storage J Food Sci 64(5)828-32
107
Praznik W Mundigler N Kogler A Pelzl B Huber A Wollendorfer M 1999 Molecular
background of technological properties of selected starches Starch‐Staumlrke 51(6) 197-211
Qian J Kuhn M 1999 Characterization of Amaranthus cruentus and Chenopodium quinoa
starch Starch‐Staumlrke 51(4)116-20
Ramesh M Zakiuddin Ali S Bhattacharya KR 1999 Structure of rice starch and its relation to
cooked-rice texture Carbohydr Polym 38(4)337-47
Rayner M Sjoumlouml M Timgren A Dejmek P 2012 Quinoa starch granules as stabilizing particles
for production of Pickering emulsions Faraday Discuss 158(1)139-55
Ross AS Quail KJ Crosbie GB 1997 Physicochemical properties of Australian flours
influencing the texture of yellow alkaline noodles Cereal Chem 74(6)814-20
Sun Q Xing Y Qiu C Xiong L 2014 The pasting and gel textural properties of corn starch in
glucose fructose and maltose syrup PloS one 9(4)e95862
Thachil MT Chouksey MK Gudipati V 2014 Amylose-lipid complex formation during
extrusion cooking effect of added lipid type and amylose level on corn-based puffed snacks
Int J Food Sci Tech 49(2)309-16
Vandeputte GE Derycke V Geeroms J Delcour JA 2003 Rice starches II Structural aspects
provide insight into swelling and pasting properties J Cereal Sci 38(1)53-9
Wokadala OC Ray SS Emmambux MN 2012 Occurrence of amylosendashlipid complexes in teff
and maize starch biphasic pastes Carbohydr Polym 90(1)616-22
108
Wu G Morris C F Murphy K M 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79(11)2337-45
Yu S Ma Y Sun DW 2009 Impact of amylose content on starch retrogradation and texture of
cooked milled rice during storage J Cereal Sci 50(2)139-44
Zeng M Morris CF Batey IL Wrigley CW 1997 Sources of variation for starch gelatinization
pasting and gelation properties in wheat Cereal Chem 74(1)63-71
109
Table 1-Quinoa varieties tested
Variety Original Seed Source Location
Black White Mountain Farm White Mountain Farm Colo USA
Blanca White Mountain Farm White Mountain Farm Colo USA
Cahuil White Mountain Farm White Mountain Farm Colo USA
Cherry Vanilla Wild Garden Seeds Philomath Oregon
WSUa Organic Farm Pullman Wash USA
Oro de Valle Wild Garden Seeds Philomath Oregon
WSUa Organic Farm Pullman Wash USA
49ALC USDA Port Townsend Wash USA
1ESP USDA Port Townsend Wash USA
Copacabana USDA Port Townsend Wash USA
Col6197 USDA Port Townsend Wash USA
Japanese Strain USDA Port Townsend Wash USA
QQ63 USDA Port Townsend Wash USA
Yellow Commercial Multi Organics company Bolivia
Red Commercial Multi Organics company Bolivia a WSU Washington State Univ
110
Table 2-Starch content and composition
Variety Total starch
(g 100 g)
Apparent amylose
()
Total
amylose ()
Degree of amylose
lipid complex ()
Black 532f 153a 159ab 96bc
Blanca 595de 102cd 163a 361ab
Cahuil 622d 169a 173a 34c
Cherry Vanilla
590de 105cd 116bc 164abc
Oro de Valle 573ef 114bcd 166a 300abc
49ALC 674c 27e 47d 426a
1ESP 705bc 86d 152abc 389ab
Copacabana 734ab 120bc 153abc 222abc
Col6197 725ab 102cd 140abc 433a
Japanese Strain
723ab 116bcd 165ab 305abc
QQ63 713abc 84d 111c 241abc
Yellow Commercial
751a 147ab 150abc 118abc
Red Commercial
691bc 100cd 164a 375ab
Corn starch - 264 - -
111
Table 3-Starch properties and α-amylase activity
Variety Amylose leaching (mg 100 g starch)
Water solubility ()
Swelling power
α-Amylase activity (CU)
Black 210ef 16de 260bcd 043d
Blanca 171efg 10de 260bcd 086c
Cahuil 97fg 16cde 253cd 106b
Cherry Vanilla 394d 15de 253cd 116a
Oro de Valle 420d 16de 245d 103b
49ALC 862a 07e 282a 031e
1ESP 716b 13de 276ab 003g
Copacabana 438cd 14de 263bc 020f
Col6197 552c 19cd 257cd 009g
Japanese Strain 31fg 45a 170f 005g
QQ63 315de 26bc 262bc 008g
Yellow Commercial
349d 32b 188e 005g
Red Commercial 35g 26bc 196e 003g
Corn starch - 79 89 -
112
Table 4-Texture of starch gel
Variety Hardness (g) Springiness Cohesiveness
Black 725ab 082ab 064cd
Blanca 649abc 083ab 072bc
Cahuil 900a 085ab 072bc
Cherry Vanilla 607abc 078bc 072bc
Oro de Valle 448abc 078bc 064cd
49ALC 333bc 081bc 061cd
1ESP 341bc 081bc 073bc
Copacabana 402bc 084ab 078ab
Col6197 534abc 083ab 083ab
Japanese Strain 765ab 092a 089a
QQ63 201c 078bc 053d
Yellow Commercial 436bc 071c 057d
Red Commercial 519abc 075bc 055d
Corn starch 721 084 073
113
Table 5-Thermal properties of starch
Variety Gelatinization temperature Enthalpy (Jg)
To (ordmC) Tp (ordmC) Tc (ordmC)
Black 560b 639bc 761bc 112abc
Blanca 586a 652ab 754bcd 113abc
Cahuil 582a 648ab 755bcd 116a
Cherry Vanilla 563b 627cd 747bcd 111abc
Oro de Valle 562b 623d 739cd 106abc
49ALC 524ef 598f 747bcd 101bc
1ESP 530de 608ef 738cd 103abc
Copacabana 565b 622d 731de 106abc
Col6197 540cd 598f 697f 105abc
Japanese Strain 579a 654a 788a 104abc
QQ63 545c 616de 766ab 99c
Yellow Commercial 515f 599f 708ef 107abc
Red Commercial 520ef 595f 700 f 116ab
Corn starch 560 626 743 105
114
Table 6-Pasting properties of starch
Variety Peak viscosity
(RVU)a
Trough
(RVU)
Breakdown
(RVU)
Final viscosity
(RVU)
Setback
(RVU)
Peak time
(min)
Black 293abc 252abc 41efg 363ab 111abcd 92e
Blanca 344a 301a 42defg 384ab 82de 111ab
Cahuil 342ab 297a 45def 405a 108abcd 106bc
Cherry Vanilla 313abc 263abc 50de 369ab 106abcd 99d
Oro de Valle 294abc 277ab 17fg 330abc 53e 105c
49ALC 256cde 137f 119a 225d 88cde 64i
1ESP 269bcd 172ef 97ab 313bc 140a 79h
Copacabana 258cde 186def 72bcd 308bc 122abc 81gh
Col6197 270bcd 231bcd 39efg 347ab 116abcd 86fg
Japanese Strain 193e 181def 12g 264cd 83de 113a
QQ63 213de 152f 60cde 254cd 101bcd 88ef
Yellow Commercial
290abc 223cde 67bcde 350ab 127ab 93de
Red Commercial 327abc 242bc 85bc 366ab 125ab 92ef
Corn 255 131 124 283 152 73 aRVU = cP12
115
Table 7-Correlation coefficients between starch properties and texture of cooked quinoaa
Hardness Adhesiveness Cohesiveness Gumminess Chewiness
Total starch content
-032ns -048 -043ns -039ns -039ns
Apparent amylose content
069 072 069 072 072
Actual amylose content
061 062 056 061 061
Degree of amylose-lipid complex
-065 -060 -070 -070 -070
Amylose leaching
-082 -075 -074 -082 -082
α-Amylase activity
018ns 055 051 032ns 032ns
Starch gel hardness
042ns 059 051 049 049
DSC
To 034ns 049 051 041ns 041ns
Tp 047 052 056 052 052
ΔH 064 072 069 070 070
RVA
Peak viscosity 031ns 054 047 041ns 041ns
Trough 044ns 077 063 055 055
Breakdown -034ns -060 -044ns -038ns -038ns
Final viscosity 045ns 068 058 053 053
Peak time 053 077 068 060 060
ns non-significant difference P lt 010 P lt 005 P lt 001 aTPA is the Texture Profile Analysis of cooked quinoa data were presented in Wu et al (2014)
116
Table 8-Correlations between starch properties and seed DSC RVA characteristicsa
Total
starch content
Water solubility
Apparent amylose content
Total amylose content
Degree of amylose-lipid complex
Amylose leaching
α-Amylase activity
Protein -047ns 023ns 058 031ns -069 -062 066
Seed hardness
-073 -041ns -003ns -021ns -020ns 019ns 053
Bulk density
054 049 -020ns -015ns 031ns 019ns -072
Seed coat proportion
-071 -041ns 027ns 021ns -028ns -038ns 055
Starch gel hardness
-045ns 017 ns 065 053 -044ns -064 046ns
Starch DSC
To -049 -004ns 041ns 043ns -033ns -049 061
Tp -050 010ns 047ns 045ns -042ns -058 052
Enthalpy -051 -011ns 059 055 -041ns -064 049
Starch viscosity
Peak viscosity
-066 -049 028ns 027ns -020ns -023ns 070
Trough -068 -017ns 056 057 -031ns -052 072
Breakdown
022ns -048 -061 -067 027ns 062 -025ns
Final viscosity
-060 -022ns 063 060 -037ns -046ns 061
Peak time -032ns 045ns 058 072 -029ns -081 043ns
117
Cooking quality
Optimal cooking time
-043ns 019ns 056 040ns -067 -055 029ns
ns non-significant difference P lt 010 P lt 005 P lt 001 aSeed characteristics data were presented in Wu et al (2014)
118
Chapter 5 Quinoa Seed Quality Response to Sodium Chloride and
Sodium Sulfate Salinity
Submitted to the Frontiers in Plant Science
Research Topic Protein crops Food and feed for the future
Abstract
Quinoa (Chenopodium quinoa Willd) is an Andean grain with an edible seed that both contains
high protein content and provides high quality protein with a balanced amino acid profile
Quinoa is a halophyte adapted to harsh environments with highly saline soil In this study four
quinoa varieties were grown under six salinity treatments and two levels of fertilization and then
evaluated for quinoa seed quality characteristics including protein content seed hardness and
seed density Concentrations of 8 16 and 32 dS m-1 of NaCl and Na2SO4 as well as a no-salt
control were applied to the soil medium across low (1 g N 029 g P 029 g K per pot) and high
(3 g N 085 g P 086 g K per pot) fertilizer treatments Seed protein content differed across soil
salinity treatments varieties and fertilization levels Protein content of quinoa grown under
salinized soil ranged from 130 to 167 comparable to that from normal conditions NaCl
and Na2SO4 exhibited different impacts on protein content Whereas the different concentrations
of NaCl did not show differential effects on protein content the seed from 32 dS m-1 Na2SO4
contained the highest protein content Seed hardness differed among varieties and was
moderately influenced by salinity level (P = 009) Seed density was affected significantly by
119
variety and Na2SO4 concentration but was unaffected by NaCl concentration The plants from 8
dS m-1 Na2SO4 soil had lower density (066 gcm3) than those from 16 dS m-1 and 32 dS m-1
Na2SO4 074 and 072gcm3 respectively This paper identifies changes in critical seed quality
traits of quinoa as influenced by soil salinity and fertility and offers insights into variety
response and choice across different abiotic stresses in the field environment
Key words quinoa soil salinity protein content hardness density
120
Introduction
Quinoa (Chenopodium quinoa Willd) has garnered much attention in recent years
because it is an excellent source of plant-based protein and is highly tolerance of soil salinity
Because soil salinity affects between 20 to 50 of irrigated arable land worldwide (Pitman and
Lauchli 2002) the question of how salinity affects seed quality in a halophytic crop like quinoa
needs to be addressed Protein content in most quinoa accessions has been reported to range from
12 to 17 depending on variety environment and inputs (Rojas et al 2015) This range
tends to be higher than the protein content of wheat barley and rice which were reported to be
105- 14 8-14 and 6-7 respectively (Shih 2006 Orth and Shellenberger1988 Cai et
al 2013) Additionally quinoa has a well-balanced complement of essential amino acids
Specifically quinoa is rich in lysine which is considered the first limiting essential amino acid in
cereals (Taylor and Parker 2002) Protein quality such as Protein Efficiency Ratio is similar to
that of casein (Ranhotra et al 1993) Furthermore with a lack of gluten protein quinoa can be
safely consumed by gluten sensitiveintolerant population (Zevallos et al 2014)
Quinoa shows exceptional adaption to harsh environments such as drought and salinity
(Gonzaacutelez et al 2015) Soil salinity reduces crop yields and is a worldwide problem In the
United States approximately 54 million acres of cropland in forty-eight States were occupied by
saline soils while another 762 million acres are at risk of becoming saline (USDA 2011) The
salinity issue leads producers to grow more salt-tolerant crops such as quinoa
Many studies have focused on quinoarsquos tolerance to soil salinity with a particular
emphasis on plant physiology (Ruiz-Carrasco et al 2011 Adolf et al 2012 Cocozza et al
121
2013 Shabala et al 2013) and agronomic characteristics such as germination rate plant height
and yield (Prado et al 2000 Chilo et al 2009 Peterson and Murphy 2015 Razzaghi et al
2012) For instance Razzaghi et al (2012) showed that the seed number per m2 and seed yield
did not decrease as salinity increased from 20 to 40 dS m-1 in the variety Titicaca Ruiz-Carrasco
et al (2011) reported that under 300 mM NaCl germination and shoot length were significantly
reduced whereas root length was inhibited in variety BO78 variety PRJ biomass was less
affected and exhibited the greatest increase in proline concentration Jacobsen et al (2000)
suggested that stomatal conductance leaf area and plant height were the characters in quinoa
most sensitive to salinity Wilson et al (2002) examined salinity stress of salt mixtures of
MgSO4 Na2SO4 NaCl and CaCl2 (3 ndash 19 dS m-1) No significant reduction in plant height and
fresh weight were observed In a comparison of the effects of NaCl and Na2SO4 on seed yield
quinoa exhibited greater tolerance to Na2SO4 than to NaCl (Peterson and Murphy 2015)
Few studies have focused on the influence of salinity on seed quality in quinoa Karyotis
et al (2003) conducted a field experiment in Greece (80 m above sea level latitude 397degN)
With the exception of Chilean variety lsquoNo 407rsquo seven other varieties exhibited significant
increases in protein (13 to 33) under saline-sodic soil with electrical conductivity (EC) of
65 dS m-1 Mineral contents of phosphorous iron copper and boron did not decrease under
saline conditions Koyro and Eisa (2008) found a significant increase in protein and a decrease in
total carbohydrates under high salinity (500 mM) Pulvento et al (2012) indicated that fiber and
saponin contents increased under saline conditions with well watersea water ratio of 11
compared to those under normal soil
122
Protein is one of the most important nutritional components of quinoa seed The content
and quality of protein contribute to the nutritional value of quinoa Additionally seed hardness is
an important trait in crops such as wheat and soybeans For instance kernel hardness highly
influences wheat end-use quality (Morris 2002) and correlates with other seed quality
parameters such as ash content semolina yield and flour protein content (Hruškovaacute and Švec
2009) Hardness of soybean influenced water absorption seed coat permeability cookability
and overall texture (Zhang et al 2008) Quinoa seed hardness was correlated with the texture of
cooked quinoa influencing hardness chewiness and gumminess and potentially consumer
experience (Wu et al 2014) Furthermore seed density is also a quality index and is negatively
correlated with the texture of cooked quinoa such as hardness cohesiveness chewiness and
gumminess (Wu et al 2014)
Chilean lowland varieties have been shown to be the most well-adapted to temperate
latitudes (Bertero 2003) and therefore they have been extensively utilized in quinoa breeding
programs in both Colorado State University and Washington State University (Peterson and
Murphy 2015) For these reasons Chilean lowland varieties were evaluated in the present study
The objectives of this study were to 1) examine the effect of soil salinity on the protein content
seed hardness and density of quinoa varieties 2) determine the effect of different levels of two
agronomically important soil salts NaCl and Na2SO4 on seed quality and 3) test the influence
of fertilization levels on salinity tolerance of quinoa The present study illustrates the different
influence of NaCl and Na2SO4 on quinoa seed quality and provides better guidance for variety
selection and agronomic planning in highly saline environments
Materials and Methods
123
Genetic material
Quinoa germplasms were obtained from Dr David Brenner at the USDA-ARS North
Central Regional Plant Introduction Station in Ames Iowa The four quinoa varieties CO407D
(PI 596293) UDEC-1 (PI 634923) Baer (PI 634918) and QQ065 (PI 614880) were originally
sourced from lowland Chile CO407D was released by Colorado State University in 1987
UDEC-1 Baer and QQ065 were varieties from northern central and southern locations in Chile
with latitudes of 3463deg S 3870deg S and 4250deg S respectively
Experimental design
A controlled environment greenhouse study was conducted using a split-split-plot
randomized complete block design with three replicates per treatment Factors included four
quinoa varieties two fertility levels and seven salinity treatments (three concentration levels
each of NaCl and Na2SO4) Three subsamples each representing a single plant were evaluated
for each treatment combination Quinoa variety was treated as the main plot salinity level as the
sub-plot and fertilization as the sub-sub-plot Salinity levels included 8 16 and 32 dS m-1 of
NaCl and Na2SO4 The details of controlling salinity levels were described by Peterson and
Murphy (2015) In brief fertilization was provided by a mixture of alfalfa meal
monoammonium phosphate and feather meal Low fertilization level referred to 1 g of N 029 g
of P and 029 g of K in each pot and high fertilization level referred to 3 g of N 086 g of P and
086 g of K in each pot Each pot contained about 1 L of Sunshine Mix 1 (Sun Gro Horticulture
Bellevue WA) (dry density of 100 gL water holding capacity of ca 480 gL potting mix) The
124
entire experiment was conducted twice with the planting dates of September 10th 2011 and
October 7th 2011
Seed quality tests
Protein content of quinoa was determined using the Dumas combustion nitrogen method
(LECO Corp Joseph Mich USA) (AACCI Method 46-3001) A factor of 625 was used to
convert nitrogen to protein Seed hardness was determined using the Texture Analyzer (TA-
XT2i) (Texture Technologies Corp Scarsdale NY) and a modified rice kernel hardness method
(Krishnamurthy and Giroux 2001) A single quinoa kernel was compressed until the point of
fracture using a 1 cm2 cylinder probe traveling at 5 mms Repeat measurements were taken on 9
random kernels The seed hardness was recorded as the average peak force (Kg) of the repeated
measures
Seed density was determined using a pycnometer (Pentapyc 5200e Quantachrome
Instruments Boynton Beach FL) Quinoa seed was placed in a closed micro container and
compressed nitrogen was suffused in the container Pressure in the container was recorded both
with and without nitrogen The volume of the quinoa sample was calculated by comparing the
standard pressure obtained with a stainless steel ball Density was the seed weight divided by the
displaced volume Seed density was collected on only the second greenhouse experiment
Statistical analysis
Data were analyzed using the PROC GLM procedure in SAS (SAS Institute Cary NC)
Greenhouse experiment repetition was treated as a random factor in protein content and seed
hardness analysis Variety salinity and fertilization were treated as fixed factors Fisherrsquos LSD
125
Test was used to access multiple comparisons Pearson correlation coefficients between protein
hardness and density were obtained via PROC CORR procedure in SAS using the treatment
means
Results
Protein
Variety salinity and fertilization all exhibited highly significant effects on protein
content (P lt 0001) (Table 1) The greatest contribution to variation in seed protein was due to
fertilization (F = 40247) In contrast salinity alone had a relatively minor effect and the
varieties responded similarly to salinity as evidenced by a non-significant interaction The
interactions however were found in variety x fertilization as well as in salinity x fertilization
both of which were addressed in later paragraphs It is worth noting that the two experiments
produced different seed protein contents (F = 4809 P lt0001) experiment x variety interaction
was observed (F = 1494 P lt0001) (data not shown) Upon closer examination this interaction
was caused by variety QQ065 which produced an overall mean protein content of 129 in
experiment 1 and 149 in experiment 2 Protein contents of the other three varieties were
essentially consistent across the two experiments
Across all salinity and fertilization treatments the variety protein means ranged from
130 to 167 (data not shown) As expected high fertilization resulted in an increase in
protein content across all varieties The mean protein contents under high and low fertilization
were 158 and 136 respectively (Table 2) The means of Baer and CO407D were the
126
highest 151 and 149 respectively QQ065 contained 141 protein significantly lower
than the other varieties
Even though salinity effects were relatively smaller than fertilization and variety effects
salinity still had a significant effect on protein content (Table 1) The two types of salt exhibited
different impacts on protein (Table 2) Protein content did not differ according to different
concentrations of NaCl with means (across varieties and fertilization levels) from 147 to
149 Seed from 32 dS m-1 Na2SO4 however contained higher protein (152) than that from
8 dS m-1 and 16 dS m-1 Na2SO4 (144 and 142 respectively)
A significant interaction of salinity x fertilization was detected indicating that salinity
differentially impacted seed protein content under high and low fertilization level (Figure 1)
Within the high fertilizer treatment protein content in the seed from 32dS m-1 Na2SO4 was
significantly higher (167) than all other samples which did not differ from each other (~13)
Within the low fertilizer treatment protein content of seeds from 8 dS m-1 and 16 dS m-1
Na2SO4 were significantly lower than those from the NaCl treatments and 32dS m-1 Na2SO4
The significant interaction between variety and fertilization (Table 1) was due to the
different response of QQ065 Protein mean of QQ065 from high fertilization was 144 lower
than the other varieties CO407D UDEC-1 and Baer exhibited a decline of 16 - 18 in
protein under low fertilization while QQ065 dropped only 5
Hardness
Variety exhibited the greatest influence on seed hardness (F = 21059 P lt0001)
whereas fertilization did not show any significant effect (Table 1) Salinity exhibited a moderate
127
effect (F = 200 P = 009) Varieties responded consistently to salinity under various fertilization
levels since neither variety x salinity nor salinity x fertilization interaction was significant
However a variety x fertilization interaction was observed which will be discussed in a later
paragraph Similar to the situation in protein content experiment repetition exhibited a
significant influence on seed hardness Whereas the hardness of CO407D was consistent across
the two greenhouse experiments the hardness of other three varieties all decreased by 8 to 9
Mean hardness was significantly different among varieties CO407D had the hardest
seeds with hardness mean of 100 kg (Table 3) UDEC-1 was softer at 94 kg whereas Baer and
QQ065 were the softest and with similar hardness means of 77 kg and 74 kg respectively
Salinity exhibited a moderate impact on seed hardness (P = 009) The highest hardness
mean was observed under 16 dS m-1 Na2SO4 whereas the lowest was under 8 dS m-1 NaCl with
means of 89 and 83 kg respectively
A significant fertilization x variety interaction was found for seed hardness The hardness
of UDEC-1 and Baer did not differ across fertilization level whereas CO407D was harder under
low fertilization and QQ065 was harder under high fertilization
Seed density
Variety and salinity both significantly affected seed density whereas fertilization did not
show a significant influence (Table 1) The greatest contribution to variation in seed density was
due to variety (F = 2282) Salinity exhibited a relatively smaller effect yet still significant (F =
282 P lt005) Neither variety x salinity interaction nor salinity x fertilization interaction was
observed which indicated that varieties similarly responded to salinity under high and low
128
fertilization levels An interaction of variety x fertilization was found and the details were
presented later
Across all salinity and fertilization treatments CO407D had the highest mean density
080 gcm3 followed by Baer with 069 gcm3 (Table 4) UDEC-1 and QQ065 had the lowest and
similar densities (~065 gcm3)
With regard to salinity effect the Na2SO4 treatments exhibited differential influence on
seed density Density means did not significantly change due to the increased concentration of
NaCl ranging from 068 to 071 gcm3 (Table 4) The samples from 8 dS m-1 Na2SO4 soil had
lower density (066 gcm3) than those from 16 dS m-1 and 32 dS m-1 Na2SO4 074 and
072gcm3 respectively
A significant variety x fertilization interaction was found With closer examination
UDEC-1 and Baer yielded higher density seeds under high fertilization whereas CO407D and
QQ065 did not differ in density between fertilization treatments
Correlations of protein hardness and density
Correlation coefficients among seed protein content hardness and density are shown in
Table 5 No significant correlation was detected between protein content and seed hardness
However both protein content and hardness were correlated with seed density The overall
correlation coefficient was low (r = 019 P = 003) between density and protein A marginally
significant correlation was found between density and protein content of the seeds from NaCl
salinized soil under low fertilization No correlation was found between density and protein
content of the seeds from NaCl salinized soil under high fertilization or Na2SO4 salinized soil
129
The overall correlation coefficient was 038 (P lt 00001) between density and hardness
The low fertilization samples from both NaCl and Na2SO4 soil showed significant correlations
between density and hardness with coefficients of 051 and 047 (both P lt 0005) The high
fertility quinoa did not exhibit any correlation between density and hardness
Correlation with yield leaf greenness index plant height and seed minerals contents
Correlation between seed quality and yield leaf greenness index plant height and seed
mineral concentration were obtained using data from Peterson and Murphy (2015) (Table 6)
Seed hardness significantly correlated with yield and plant height (r = 035 and 031
respectively) Protein content and density however did not correlate with yield leaf greenness
or plant height Correlations were found between quality indices and the concentration of
different minerals Protein was negatively correlated with Cu and Mg (r = -052 and -050
respectively) Hardness was negatively correlated with Cu P and Zn (r = -037 -056 -029
respectively) but was positively correlated with Mn (r = 057) Density was negatively
correlated with Cu (r = -035)
Discussion
Protein
Although salinity exhibited a significant effect on seed protein content the impact was
relatively minor compared to fertilization and variety effects In another words over a wide
range of saline soil quinoa can grow and yield seeds with stable protein content
130
Protein content of quinoa growing under salinized soil ranged from 127 to 167 (data
not shown) within the general range of protein content under non-saline conditions which was
12 to 17 (Rojas et al 2015) Saline soil did not cause a significant decrease in seed protein
It is interesting to notice that the samples from 32 dS m-1 Na2SO4 tended to contain the highest
protein especially in variety QQ065 The studies of Koyro and Eisa (2008) and Karyotis et al
(2003) also indicated that protein content significantly increased under high salinity (NaCl)
whereas total carbohydrates decreased In contrast Ruffino et al (2009) found that quinoa
protein decreased under 250 mM NaCl salinity in a growth chamber experiment It is reasonable
to conclude that salinity exhibits contrasting effects on different quinoa genotypes QQ065 and
CO407D both significantly increased in protein under 32 dS m-1 Na2SO4 however the yield
decline was 519 and 245 respectively (Peterson and Murphy 2015) This result indicted
that CO407D was the variety most optimally adapted to severe sodic saline soil tested in this
study
Na2SO4 level exhibited a significant influence on protein content whereas NaCl level did
not In the study of Koyro and Eisa (2008) however seed protein of the quinoa variety Hualhuas
(origin from Peru) increased under the highest salinity level of 500 mM NaCl compared to lower
NaCl levels (0 ndash 400 mM) This disagreement of NaCl influence may be due to diversity of
genotypes It is worth noting that quinoa protein contents in this paper were primarily above 13
based on wet weight (as-is-moisture of approximately ~8 -10) even under saline soil and low
fertilization level This protein content is generally equal to or higher than that of other crops
such as barley and rice (Wu 2015) In conclusion quinoa maintained high and stable protein
content under salinity stress
131
Hardness
Quinoa seed hardness was only moderately affected by salinity (P = 009) indicating that
quinoa primarily maintained seed texture when growing under a wide range of saline soil
CO407D exhibited the hardest seed (100 kg) whereas Baer and QQ065 were relatively soft (74
ndash 77 kg) A previous study indicated a hardness range of 58 ndash 109 kg among 11 quinoa
varieties and 2 commercial samples (Wu et al 2014) The commercial samples had hardness
values of 62 kg and 71 kg Since commercial samples generally maintain stable quality and
indicate an acceptable level for consumers seed hardness around 7 kg as in Baer and QQ065
should be considered as acceptable quality The hardness of CO407D was close to that of the
colored variety lsquoBlackrsquo (100 kg) which had a thicker seed coat than that of the yellow seeded
varieties It was reported that a thicker seed coat is related to harder texture (Fraczek et al 2005)
Even though the greenhouse is a highly controlled environment and the two experiments
were conducted in similar seasons (planted in September and October respectively) seed protein
and hardness were still different across the two experiments However ANOVA indicated
modest-to-no significant interactions with salinity and fertilization such that responses to salinity
and fertilization were consistent with little or no change in rank order Even though experiment x
variety was significant the F-values were relatively low compared to the major effects such as
variety and fertilization and neither of them was crossing interaction This is a particularly
noteworthy result for breeders farmers and processors
Density
132
The range of seed density under salinity 055 ndash 089 gcm3 was comparable to the
density range of 13 quinoa samples (058 ndash 076 gcm3 ) (Wu et al 2014) Generally CO407D
had higher seed density (071 ndash 089 gcm3) which indicated that seed density in this variety was
affected by salinity stress In contrast the density of QQ065 did not change according to salinity
type or concentration which indicated a stable quality under saline soil
Correlations
The correlation between seed hardness and density was only significant under low fertilization
but not under high fertilization The high fertilization level in the greenhouse experiment
exceeded the amount of fertilizer that would normally be applied in field environments whereas
the low fertilization level is closer to the field situation Therefore correlation between hardness
and density may still exist in field trials
Conclusions
Under saline soil conditions quinoa did not show any marked decrease in seed quality
such as protein content hardness and density Protein content even increased under high Na2SO4
concentration (32 dS m-1) Varieties exhibited great differential reactions to fertilization and
salinity levels QQ065 maintained a similar level of hardness and density whereas seed of
CO407D was both harder and higher density under salinity stress If only seed quality is
considered then QQ065 is the most well-adapted variety in this study
The influences of NaCl and Na2SO4 were different The higher concentration of Na2SO4
tended to increase protein content and seed density whereas NaCl concentration did not exhibit
any significant difference on those quality indexes
133
Acknowledgement
The research was funded by USDA Organic Research and Extension Initiative project
number NIFAGRANT11083982 The authors acknowledge Alecia Kiszonas for assisting in the
data analysis
Author contributions
Peterson AJ set up the experiment design in the greenhouse and grew harvested and
processed quinoa samples Wu G collected seed quality data such as protein content seed
hardness and density Peterson AJ and Wu G together processed the data Wu G also drafted the
manuscript Murphy KM and Morris CF edited the manuscript
Conflict of interest statement
The authors declared to have no conflict of interest
134
References
AACC International Approved Methods of Analysis Method 46-3001 Crude protein ndash
Combustion method Approved November 8 1995 Reapproved November 3 1999
Availablenline only AACCI St Paul MN
Adolf VI Shabala S Andersen MN Razzaghi F Jacobsen SE 2012 Varietal differences of
quinoas tolerance to saline conditions Plant Soil 357 117ndash29
Bertero HD 2003 Response of developmental processes to temperature and photoperiod in
quinoa (Chenopodium quinoa Willd) Food Rev Int 19 87ndash97
Cai S Yu G Chen X Huang Y Jiang X Zhang G Jin X 2013 Grain protein content variation
and its association analysis in barley BMC Plant Boil 13 35
Chilo G Molina MV Carabajal R Ochoa M 2009 Temperature and salinity effects on
germination and seedling growth on two varieties of Chenopodium quinoa Agri-Scientia 26
15ndash22
Cocozza C Pulvento C Lavini A Riccardi M dAndria R Tognetti R 2013 Effects of
increasing salinity stress and decreasing water availability on ecophysiological traits of
quinoa (Chenopodium quinoa Willd) grown in a mediterranean-type agroecosystem J Agron
Crop Sci 199 229ndash40
Fraczek J Hebda T Slipek Z Kurpaska S 2005 Effect of seed coat thickness on seed hardness
Can Biosyst Eng 47 41ndash5
135
Gonzaacutelez JA Eisa SSS Hussin SAES Prado FE 2015 Quinoa an Incan crop to face global
changes in agriculture In Murphy KM Matanguihan J editors Quinoa Improvement and
Sustainable Production Hoboken NJ John Wiley Sons p 7ndash11
Hruškovaacute M Švec I 2009 Wheat hardness in relation to other quality factors Czech J Food Sci
27 240ndash8
Jacobsen S Quispe H Mujica A 2000 Quinoa an alternative crop for saline soils in the Andes
in Scientist and Farmer Partners in Research for the 21st Century (Program Report 1999-
2000) ed International Potato Center (Peru) 403ndash8
Jancurovaacute M Minarovicovaacute L Dandar A 2009 Quinoandasha review Czech J Food Sci 27 71ndash9
Karyotis T Iliadis C Noulas C Mitsibonas T 2003 Preliminary research on seed production
and nutrient content for certain quinoa varieties in a salinendashsodic soil J Agron Crop Sci 189
402ndash8
Koyro HW Eisa S 2008 Effect of salinity on composition viability and germination of seeds of
Chenopodium quinoa Willd Plant Soil 302 79-90
Krishnamurthy K Giroux MJ 2001 Expression of wheat puroindoline genes in transgenic rice
enhances grain softness Nat Biotechnol 19 162ndash6
Morris CF 2002 Puroindolines the molecular genetic basis of wheat grain hardness Plant mol
Biol 48 633ndash47
136
Orth RA Shellenberger JA 1988 Chapter 1 Origin production and utilization of wheat In
Pomeranz Y editor Wheat Chemistry and Technology 3th edition St Paul MN American
Association of Cereal Chemists Inc p 11ndash2
Peterson A Murphy K 2015 Tolerance of lowland quinoa cultivars to sodium chloride and
sodium sulfate salinity Crop Sci 55 331ndash8
Pitman MG Laumluchli A 2002 Global impact of salinity and agricultural ecosystems In Laumluchli
A Luumlttge U editors Netherlands Springer p 3ndash20
Prado FE Boero C Gallardo M Gonzaacutelez JA 2000 Effect of NaCl on germination growth and
soluble sugar content in Chenopodium quinoa Willd seeds Bot Bull Acad Sinica 41 27ndash34
Pulvento C Riccardi M Lavini A Iafelice G Marconi E dAndria R 2012 Yield and quality
characteristics of quinoa grown in open field under different saline and non-saline irrigation
regimes J Agron Crop Sci 198 254ndash63
Ranhotra G Gelroth J Glaser B Lorenz K Johnson D 1993 Composition and protein
nutritional quality of quinoa Cereal Chem 70 303ndash5
Razzaghi F Ahmadi SH Jacobsen SE Jensen CR Andersen MN 2012 Effects of salinity and
soilndashdrying on radiation use efficiency water productivity and yield of quinoa (Chenopodium
quinoa Willd) J Agron Crop Sci 198 173ndash84
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile D
137
Bertero D Nieto C editors State of the Art Report of Quinoa in the World in 2013 Rome
FAO amp CIRAD p 67-8
Ruffino A Rosa M Hilal M Gonzaacutelez J Prado F 2010 The role of cotyledon metabolism in the
establishment of quinoa (Chenopodium quinoa)seedlings growing under salinity Plant Soil
326 213ndash24
Ruiz-Carrasco K Antognoni F Coulibaly A K Lizardi S Covarrubias A Martiacutenez E A
Shabala S Hariadi Y Jacobsen SE 2013 Genotypic difference in salinity tolerance in quinoa is
determined by differential control of xylem Na+ loading and stomatal density J Plant Physiol
170 906ndash14
Shih FF 2006 Chapter 6 Rice protein In Champagne ET editor Rice Chemistry and
Technology 3rd edition St Paul MN American Association of Cereal Chemists Inc p
143-4
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Taylor JRN Parker ML editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science amp Business Media p 96-101
USDA (United States Department of Agriculture) 2011 Soil and water resources conservation
act (RCA) P 31 Access from
httpwwwnrcsusdagovInternetFSE_DOCUMENTSstelprdb1044939pdf
Wilson C Read J Abo-Kassem E 2002 Effect of mixed-salt salinity on growth and ion
relations of a quinoa and a wheat variety J Plant Nutri 25 2689ndash704
138
Wu G Morris CF Murphy KM 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79 2337ndash45
Wu G 2015 Chapter 11 Nutritional properties of quinoa In Murphy KM Matanguihan J
editors Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp
Sons Inc p 193-205
Zhang B Chen P Chen CY Wang D Shi A Hou A Ishibashi T 2008 Quantitative trait loci
mapping of seed hardness in soybean Crop Sci 48 1341ndash9
Zevallos VF Herencia LI Chang F Donnelly S Ellis HJ Ciclitira PJ 2014 Gastrointestinal
effects of eating quinoa (Chenopodium quinoa Willd) in celiac patients Am J Gastroenterol
109 270ndash8
Zurita-Silva A 2011 Variation in salinity tolerance of four lowland genotypes of quinoa
(Chenopodium quinoa Willd) as assessed by growth physiological traits and sodium
transporter gene expression Plant Physiol Bioch 49 1333ndash41
139
Table 1-Analysis of variance with F-values for protein content hardness and density of quinoa seed
Effect F-values
Protein Hardness Density
Model 524 360 245
Variety 2463 21059 2282
Salinity 975 200dagger 282
Fertilization 40247 107 260
Variety x Salinity 096 098 036
Variety x Fertilization 2062 1094 460
Salinity x Fertilization 339 139 071
Variety x Salinity x Fertilization 083 161dagger 155
dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the 001 probability level Significant at the lt0001 probability level
140
Table 2-Salinity variety and fertilization effects on quinoa seed protein content ()
Salinity Protein content ()
Variety Protein content ()
Fertilization Protein content ()
8 dS m-1 NaCl 147bc1 CO407D 149ab High 158a
16 dS m-1 NaCl 148ab UDEC-1 147b Low 136b
32 dS m-1 NaCl 149ab Baer 151a
8 dS m-1 Na2SO4 144cd QQ065 141c
16 dS m-1 Na2SO4 142d
32 dS m-1 Na2SO4 152a 1Different letters in a given column indicate significant differences (P lt 005)
141
Table 3-Salinity variety and fertilization effects on quinoa seed hardness (kg)
Salinity Hardness (kg)1 Variety Hardness (kg)
8 dS m-1 NaCl 83 CO407D 100a2
16 dS m-1 NaCl 87 UDEC-1 94b
32 dS m-1 NaCl 85 Baer 77c
8 dS m-1 Na2SO4 87 QQ065 74c
16 dS m-1 Na2SO4 89
32 dS m-1 Na2SO4 88 1Hardness was significant at the 009 probability level 2Different letters in a given column indicate significant differences (P lt 005)
142
Table 4-Salinity variety and fertilization effects on quinoa seed density (g cm3)
Salinity density (g cm3) Variety density (g cm3)
8 dS m-1 NaCl 069bc1 CO407D 080a
16 dS m-1 NaCl 068bc UDEC-1 066bc
32 dS m-1 NaCl 071abc Baer 069b
8 dS m-1 Na2SO4 066c QQ065 065c
16 dS m-1 Na2SO4 074a
32 dS m-1 Na2SO4 072ab 1Different letters in a given column indicate significant differences (P lt 005)
143
Table 5-Correlation coefficients of protein hardness and density of quinoa seed
Correlation All NaCl Na2SO4
High fertilization
Low fertilization
High fertilization
Low fertilization
Protein -Density 019 013ns 029dagger 026ns 019ns
Hardness - Density 038 027ns 051 022ns 047
ns Not significant dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the lt0001 probability level
144
Table 6-Correlation coefficients of quinoa seed quality and agronomic performance and seed mineral content
Protein Hardness Density
Yield 004 035 006
Plant Height -004 031 011
Cu -052 -037 -035
Mg -050 004 0
Mn -006 057 025dagger
P -001 -056 -015
Zn -004 -029 -028dagger
dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the 001 probability level Significant at the lt0001 probability level
145
Figure 1-Protein content () of quinoa in response to combined fertility and salinity treatments
146
Chapter 6 Lexicon development and consumer acceptance
of cooked quinoa
ABSTRACT
Quinoa is becoming increasingly popular with an expanding number of varieties being
commercially available In order to compare the sensory properties of these quinoa varieties a
common sensory lexicon needs to be developed Thus the objective of this study was to develop
a lexicon of cooked quinoa and examine consumer acceptance of various varieties A trained
panel (n = 9) developed appropriate aroma tasteflavor texture and color descriptors to describe
cooked quinoa and evaluated 21 quinoa varieties Additionally texture of the cooked quinoa was
determined using a texture analyzer Results indicated panelists using this developed lexicon
could distinguish among these quinoa varieties showing significant differences in aromas
tasteflavors and textures Specifically quinoa variety effects were observed for the aromas of
caramel nutty buttery grassy earthy and woody tasteflavor of sweet bitter grain-like nutty
earthy and toasty and texture of firm cohesive pasty adhesive crunchy chewy astringent and
moist The varieties lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Drsquo exhibited adhesive texture that has not
been seen in any commercialized quinoa Subsequent consumer evaluation (n = 102) on 6
selected samples found that the lsquoPeruvian Redrsquo was the most accepted overall while the least
accepted was lsquoQQ74rsquo Partial least squares analysis on the consumer and trained panel data
indicated that overall consumer liking was driven by higher intensities of grassy aroma and firm
and crunchy texture The attributes of pasty moist and adhesive were less accepted by
consumers This overall liking was highly correlated with consumer liking of texture (r = 096)
147
tasteflavor (r = 095) and appearance (r = 091) of cooked quinoa From the present study the
quinoa lexicon and key drivers of consumer acceptance can be utilized in the industry to evaluate
quinoa product quality and processing procedures
Keywords quinoa lexicon sensory evaluation
Practical application The lexicon of cooked quinoa can be used by breeders to screen quinoa
varieties Furthermore the lexicon will useful in the food industry to evaluate quinoa ingredients
from multiple farms harvest years processing procedures and product development
148
Introduction
Quinoa is classified as a pseudocereal like amaranth and buckwheat With its high
protein content and balanced essential amino acid profile quinoa is becoming popular
worldwide From 1992 to 2012 quinoa exports increased dramatically from 600 tons to 37000
tons (Furche et al 2015) Quinoa price in retail stores increased from $9kg in 2013 to $13kg -
$20kg in 2015 (Arco 2015) Quinoa has been incorporated into numerous products including
bread cookies pasta cakes and chocolates (Pop et al 2014 Alencar et al 2015 Casas Moreno
et al 2015 Wang et al 2015) Some of these products are gluten-free foods thus targeting the
gluten-sensitive market segment (Wang et al 2015)
Popularity of quinoa inspired US researchers to breed varieties that are compatible with
local weather and soil conditions which greatly differ from quinoarsquos original land the Andean
mountain region Since 2010 Washington State University has been breeding quinoa in the
Pacific Northwest region of United States Of the quinoa varieties evaluated in the breeding
program agronomic attributes of interest include high yield consistent performance over years
and tolerance to drought salinity heat and diseases (Peterson and Murphy 2013 Peterson
2013) However beyond agronomic attributes the grain sensory profiles of these quinoa
varieties are also important to assist in breeding decisions as well as screening
genotypescultivars for various food applications
In order to provide a complete descriptive profile of the cooked quinoa a trained sensory
evaluation should be used along with a complete lexicon of the sensory attributes of importance
Currently no quinoa lexicon is available and descriptions of quinoa sensory properties are
149
limited From currently published research papers attributes describing quinoa taste have been
limited to bitter sweet earthy and nutty (Koziol 1991 Lorenz and Coulter 1991 Repo-Carrasco
et al 2003 Stikic et al 2012 Foumlste M et al 2014) and texture of cooked quinoa has been
described as creamy smooth and crunchy (Abugoch 2009) Thus to address the lack of quinoa
lexicon one objective of this study is to develop a lexicon describing the sensory properties of
quinoa
Beyond developing a lexicon to describe quinoa consumer preference of the different
quinoa varieties is also of great interest Most previous sensory studies in quinoa focused on
acceptance of quinoa-containing products while consumer acceptance on plain grain of quinoa
varieties has not been studied Because of the lack of cooked quinoa studies with consumers rice
may be considered as a model to study quinoa because of their similar cooking process Tomlins
et al (2005) found consumer preference of rice was driven by the attributes of uniform clean
bright translucent and cream with consumers not liking the brown color of cooked rice and
unshelled paddy in raw rice In another study Suwannaporn et al (2008) found consumer
acceptance of rice products was significantly influenced by convenience grain variety and
traditionnaturalness
This study presenting a quinoa lexicon along with consumer acceptance of quinoa
varieties provides critical information for both the breeding programs and food industry
researchers Given the predicted importance of texture in consumer acceptance of quinoa texture
analysis was conducted to evaluate the parameters of hardness adhesiveness cohesiveness
chewiness and gumminess in quinoa samples
150
This lexicon describing the sensory attributes of cooked quinoa will be a useful tool to
evaluate quinoa varieties compare samples from different farms harvest years seed quality and
cleaning processing procedures Finally the sensory attributes driving consumersrsquo liking can be
utilized to evaluate optimal quinoa quality and target different consumers based on preference
Materials and methods
Quinoa samples
The present study included twenty-one quinoa samples harvested in 2014 which included
sixteen varieties from Finnriver Organic Farm (Finnriver WA) and five commercial samples
from Bolivia and Peru (Table 1)
Quinoa preparation
Following harvest the samples from Finnriver Farm were cleaned in a Clipper Office
Tester (Seedburo Des Plainies IL USA) to separate mixed weed seeds and threshed materials
Furthermore the samples were soaked for 30 min rubbed manually under running water and
dried at 43 ordmC until the moisture reached lt 11 Generally a moisture of 12 - 14 is
considered safe for grain storage (Hoseney 1989)
To prepare quinoa samples for sensory evaluation samples were soaked for 30 min and
mixed with water at a 12 ratio These mixtures were brought to a boil and simmered for 20 min
Following cooking the quinoa was cooled to room temperature Samples of cooked quinoa (10
g) were served in 30 mL plastic containers with lids (SOLO Lakeforest IL USA) Quinoa
151
samples were cooked and placed in covered cups within 2 h before evaluation Unsalted
crackers plastic cups used as cuspidors and napkins were provided to each panelist
Trained sensory evaluation panel
This project was approved by the Institutional Review Board of Washington State
University Sensory panelists (n = 9) were recruited via email announcements Panelists were
selected based on their interest in quinoa and availability All participants signed the Informed
Consent Form They received non-monetary incentives for each training session and a large non-
monetary reward at the completion of the formal evaluation
Demographic information was collected using a questionnaire Panelists included 4
females and 5 males ranging in age from 21 to 60 (mean age of 35) Regarding quinoa
consumption frequency four panelists frequently consumed quinoa (few times per month to
everyday) whereas five panelists rarely consumed quinoa As quinoa is a novel crop to most of
the world this was expected Since rice is a comparable model of quinoa frequency of rice
consumption was also considered with all panelists being frequent rice consumers
Sensory training and lexicon development
The training consisted of 12 sessions of 15 hours totaling 18 hours In the early stages
of the panel training attribute terms and references were discussed Panelists were first presented
with samples in covered plastic containers The samples widely varied in their sensory attributes
and included the varieties of lsquoBlackrsquo lsquoBolivian Redrsquo and lsquoBolivian Whitersquo The panelists
developed terms to describe the appearance aroma flavor taste and texture of the samples
Additionally the same samples were evaluated by an experienced sensory evaluation panel with
152
terms collected from this set of evaluators Terms were collected from panelists professionals
and literature describing rice (Meilgaard et al 2007 Limpawattana and Shewfelt 2010) The
term list was presented and discussed with panelist consensus being used to determine which
sensory terms appeared in the final lexicon
The final lexicon and associated definitions are presented in Table 2 This lexicon
included the sensory attributes of color (black red yellow) aroma (caramel grain-like bean-
like nutty buttery starchy grassygreen earthymusty woody) tasteflavor (sweet bitter grain-
like bean-like nutty earthy and toasted) and texture (soft-firm separate-cohesive pasty
adhesivenesssticky crunchycrumblycrisp chewygummy astringent and waterymoist)
References standards for each attribute were introduced The references were discussed and
modified until the panelists were in agreement Panelists reviewed the reference standards at the
beginning of each training session Since aroma varies over time all aroma references were
prepared 1-2 h before training During training three to four quinoa samples were evaluated and
discussed in each session The ability to detect attribute differences and the reproducibility of
panelists were both monitored and visualized using spider graphs and line graphs Using this
feedback panelists were calibrated paying extra attention to those attributes that were outside of
the panel standard deviation Practice sessions were continued until the panelists accurately and
consistently assessed varietal differences of quinoa
The protocols applied to evaluate samples and references were consistent among
panelists At the start of the evaluation the sample cup was shaken to allow the aroma to
accumulate in the headspace Panelists then lifted the cover and immediately took three short
sharp sniffs to evaluate the aroma Panelists then determined the color and its intensity Finally
153
panelists used the spoon to place the sample in-mouth and evaluate the tasteflavor and texture
Between each sample panelists rinsed their palate using water and unsalted crackers A 15-cm
line scale with 15-cm indentations on each end was used to determine the intensity of attributes
The values of 15 and 135 represented the extremely low and high intensity respectively Using
the lexicon panelists were trained to sense and quantify the attributes of cooked quinoa on
aroma color tasteflavor and texture
Following the development of the lexicon formal evaluations were conducted in the
sensory booths under white lights Compusensereg Five (Guelph Ontario Canada) provided scales
and programs for evaluation and collected results Panelists followed the protocol and used the
lexicon and 15-cm scales to evaluate the sensory attributes of the cooked quinoa samples
Twenty-one quinoa samples were tested in duplicate Panelists attended one session per day and
four sessions in total During each session panelists evaluated 10 or 11 samples with a 30 s
break after each sample and a 10 min break after the fifth sample Each variety was assigned
with a random three-digit code and the serving order was randomized
Consumer acceptance panel
From the 21 samples evaluated by the trained panelists six were selected for consumer
evaluation These six samples selected were diverse in color tasteflavor and texture as defined
by the trained panel results Consumers (n = 102) were recruited from Pullman WA Of the
consumers 49 were male and 52 were female with age ranging from 19 to 64 (mean age of 33)
The consumers showed different familiarity with quinoa with 29 indicating that they were
154
familiar with quinoa 40 having tried quinoa a few times and 32 having never tried quinoa
before All consumers had consumed rice before
The project was approved by the Institutional Review Board of Washington State
University Each consumer signed an Informed Consent Form and received a non-monetary
incentive at the end of evaluation The evaluation was conducted in the sensory booths under
white light Six quinoa samples were assigned with three-digit code and randomly presented to
each consumer using monadic presentation Quinoa samples were cooked and distributed in
evaluation cups and lidded (~10 gcup) the day before stored at 4 degC overnight and placed at
room temperature (25 degC) for 1 h prior to evaluation
During evaluation consumers followed the protocol instructions and indicated the degree
of acceptance of aroma color appearance tasteflavor texture and overall liking using a 7-point
hedonic scale (1 = dislike extremely 7 = like extremely) provided by Compusensereg Five
(Guelph Ontario Canada) A comments section was provided at the end of each sample
evaluation to gather additional opinions and information Between samples panelists took a 30 s
break and cleansed their palates using unsalted crackers and water
Texture Profile Analysis by instrument (TPA)
The texture of 21 cooked quinoa samples were conducted using a TA-XT2i Texture
Analyzer (Texture Technologies Corp Hamilton MA USA) (Wu et al 2014) Samples were
cooked using the same procedure as in the trained panel evaluation and cooled to room
temperature prior to evaluation
Statistical analysis
155
Sample characteristics and trained panel results were analyzed using three-way ANOVA
and mean separation (Fisherrsquos LSD) PCA was performed on the trained panel data Using
trained panel data and consumer evaluation data partial least square regression analysis was
performed Additionally correlations between instrument tests and panel evaluation on texture
and tasteflavor were determined XLSTAT 2013 (Addinsoft Paris France) was used for all data
analysis
Results and Discussion
Lexicon Development
A lexicon was created to describe the sensory attributes of cooked quinoa (Table 2) A
total of 27 attributes were included in the lexicon based on color (black red yellow) aroma
(caramel grain-like bean-like nutty buttery starchy grassygreen earthymusty and woody)
tasteflavor (sweet bitter grain-like bean-like nutty earthy and toasted) and texture (firm
cohesive pasty adhesivenesssticky crunchy chewygummy astringent and waterymoist)
Rice is considered as a good model of quinoa lexicon developments since both products
have common preparation methods The lexicon for cooked rice has been developed for the
aroma tasteflavor and texture properties of rice (Lyon et al 1999 Meullenet et al 2000
Limpawattana and Shewfelt 2010) Many attributes from these previously developed rice
lexicons can be applied to cooked quinoa For instance rice aroma and flavor notes such as
starchy woody grain nutty buttery earthy sweet bitter and astringent are also present in
quinoa Hence those notes were also included in the lexicon of cooked quinoa in present study
with quinoa varieties showing differences in these attributes
156
This present lexicon presents some sensory attributes not found to be significantly
different among the quinoa varieties These attributes include grain-like bean-like and starchy
aroma bean-like flavor and chewy texture Even though the trained panel did not detect
differences in this study future studies may find differences among other quinoa varieties for
these attributes so they were kept in the lexicon For instance the flavoraroma notes of
lsquorancidoxidizedrsquo lsquosourrsquo lsquometallicrsquo may also be present in other quinoa varieties or have these
attributes develop during storage as has been shown in rice (Meullenet et al 2000)
The lexicon also expanded the vocabularies to describe quinoa This lexicon is a
valuable tool with multiple practical applications such as describing and screening quinoa
varieties in breeding and evaluating post-harvest process and cooking methods
Lexicon Application Evaluation of the 21 quinoa samples
The effects of panelist replicate and quinoa variety on aroma tasteflavor and texture of
cooked quinoa were evaluated (n = 9) (Table 3) The quinoa variety exhibited significant
influences on most attributes listed in the lexicon (P lt 005) except for grain-like bean-like and
starchy aroma and bean-like flavor Generally quinoa variety effects were greater in the
perceived texture of cooked quinoa than in the aroma and flavor attributes however bitterness
was also highly significant among varieties Although panelists were trained over 18 h and
references were used for calibration significant panelist effects were still observed Based on the
inherent variation of human subjects such panelist effects commonly occur in sensory evaluation
of a complex product (Muntildeoz 2003) In future studies increased training and practice to further
clarify attribute definitions may reduce panelist effects (Muntildeoz 2003)
157
Examining the details of aroma attributes quinoa variety effect significantly influenced
the aroma attributes of caramel nutty buttery grassy earthy and woody (Figure 1) Principal
Components Analysis (PCA) was performed in order to visualize differences among the
varieties For aroma the first two components described 669 of the variation among quinoa
samples PC1 was primarily defined by the grassy and woody aromas while PC2 was primarily
described by more starchy and grain-like aromas The proximity of the attributes to a specific
quinoa sample reflected its degree of association For instance lsquoCalifornia Tricolorrsquo was most
commonly described by earthy woody grassy bean-like and nutty aroma lsquoTemukorsquo exhibited
sweet and grain-like aroma Yellowwhite quinoa such as lsquoTiticacarsquo lsquoRed Headrsquo lsquoQuF9P39-51rsquo
and lsquoPeruvian Whitersquo showed significantly more nutty (6) aroma compared to brown and red
quinoa varieties (48 ndash 51) (Table 1S) lsquoBlackrsquo lsquoCahuilrsquo and lsquoPeruvian Redrsquo exhibited more
grassy aroma (47 ndash 49) compared to lsquoTiticacarsquo lsquoLinaresrsquo and lsquoNL-6rsquo (38 ndash 39) lsquoBlackrsquo
showed the most earthy aroma (54) among all varieties
PCA was also performed to show how the varieties differed in their flavortaste
properties (Figure 2) The first two components described 646 of the varietal differences The
lsquoBlackrsquo variety was found to have more bitter and earthy flavors lsquoPeruvian Whitersquo was most
commonly described by sweet and nutty flavor and lack of earthy flavors lsquoTemukorsquo was mostly
defined by its bitter taste and lack of sweetness nutty grain-like and toasty flavors Overall
sweet and bitter taste and grain-like nutty earthy and toasty flavor exhibited significant
difference among quinoa varieties (plt005) The lsquoQuF9P39-51rsquo lsquoKaslaearsquo lsquoBolivian Whitersquo
and lsquoPeruvian Whitersquo were assigned the highest values in sweet taste (46 ndash 47) significantly
sweeter than lsquoBlackrsquo lsquoCherry Vanillarsquo lsquoTemukorsquo lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCalifornia Tricolorrsquo
158
(36 ndash 40)(Table 4) lsquoTemukorsquo and lsquoCherry Vanillarsquo were the most bitter samples (56 and 52
respectively) It is worth noting that the commercial samples were assigned the lowest bitterness
scores ranging from 22 ndash 27 significantly lower than the field trial varieties (34 ndash 56) Similar
to earthy aroma lsquoBlackrsquo also exhibited the earthiest flavor (52) Additionally lsquoCahuilrsquo and
lsquoCalifornia Tricolorrsquo showed high scores in earthy flavor (both 48) Toasty flavor varied from
38 in lsquoLinaresrsquo and lsquoQuF9P1-20rsquo to 51 in lsquoCahuilrsquo
Quinoa bitterness is caused by saponin compounds present on the seed coat It has been
reported that saponin can be removed by abrasion pearling and rinsing (Taylor and Parker
2002) However in the present study despite two cleaning process steps (airscreen and rinsing)
there was still bitter flavor remained Besides processing genetic background can also affect
saponin content Some sweet quinoa varieties (lsquoSajamarsquo lsquoKurmirsquo lsquoAynoqrsquoarsquo lsquoKrsquoosuntildearsquo and
lsquoBlanquitarsquo in Bolivia and lsquoBlancade Juninrsquo in Peru) have been developed with total seed
saponin content lower than 110 mg100 g (Quiroga et al 2015) However these varieties are not
adapted to the growing conditions in the Pacific Northwest (Peterson and Murphy 2015) The
quinoa varieties in WSU breeding program are primarily from Chilean lowland and those
varieties are more highly adapted to temperate areas In this case sweet quinoa varieties from
Bolivia and Peru were not included in this study However in 2015 a saponin-free quinoa
variety lsquoJessiersquo was grown in different locations of Washington State with a comparable yield
to bitter varieties The sensory evaluation of this new variety lsquoJessiersquo would be meaningful
Earthy which may be referred to as moldy and musty is caused by geosmin (a bicyclic
alcohol with formula C12H22O) which produced by actinobacteria (Gerber 1968) Samples with a
dark color (lsquoBlackrsquo lsquoCalifornia Tricolorrsquo and lsquoCahuilrsquo) tended to exhibit more earthy aroma and
159
flavor Possibly the pericarpseed coat composition of dark quinoa favors the actinobacteria-
producing geosmin
Overall texture attributes of cooked quinoa exhibited greater differences in values
(Figure 3) Among commercial quinoa varieties the red quinoa was firmer more gummy and
more chewy in texture compared to the yellowwhite commercial quinoa Several WSU field trial
varieties (lsquoQQ74rsquo lsquoLinaresrsquo and CO407D) exhibited greater variation in adhesiveness The first
two PCA factors explained 817 of the variation among samples lsquoPeruvian Redrsquo was most
accurately described by firm and crunchy texture and a lack of pasty sticky and cohesive
texture In contrast lsquoLinaresrsquo lsquoCO407Daversquo and lsquoQQ74rsquo were mostly described as pasty sticky
and cohesive yet lacking in firmness and crunchiness Mixed color or red color samples
(lsquoPeruvian Redrsquo lsquoBlackrsquo lsquoCahuilrsquo and lsquoCalifornia Tricolorrsquo) tended to be both firmer and
crunchier compared to the samples with light color However some yellow samples such as
lsquoTiticacarsquo and lsquoKU-2rsquo also had hard texture The varieties lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Daversquo
had the softest texture and also exhibited the least crunchy but the most pasty sticky and moist
texture Additionally compared to field trial varieties commercial samples tended to be lower in
intensity for the attributes of cohesiveness pastiness adhesiveness and astringency Moreover
astringent is the dry and puckering mouth feeling which is caused by the combination of tannins
and salivary proteins The differences found in this study among quinoa varieties may be caused
by processing protocols (removal of tannins to various degrees) or diverse genetic backgrounds
Consumer acceptance
160
Consumers evaluated six selected quinoa samples including the field trial varieties of
lsquoBlackrsquo lsquoTiticacarsquo lsquoQQ74rsquo and the commercial samples of lsquoPeruvian Redrsquo lsquoBolivian Redrsquo and
lsquoBolivian Whitersquo The selected samples were diverse in color texture and included both WSU
field trial varieties and commercial quinoa Among the field trial varieties the lsquoBlackrsquo variety
exhibited more grassy aroma earthy flavor and chewy texture lsquoTiticacarsquo had more caramel
aroma and lsquoQQ74rsquo was more adhesive than the other samples
The quinoa varieties varied significantly in consumer acceptance of color appearance
taste flavor texture and overall acceptance (P lt 0001) (Table 5) Overall lsquoPeruvian Redrsquo was
more accepted by consumers compared to lsquoTiticacarsquo and lsquoQQ74rsquo lsquoBlackrsquo received a similar
level of acceptance with all the commercial samples and the acceptance of lsquoTiticacarsquo did not
differ from lsquoBolivian Redrsquo and lsquoBolivian Whitersquo In aroma acceptance no significant difference
was found among the varieties In color lsquoPeruvian Redrsquo and lsquoBolivian Redrsquo received
significantly higher scores In appearance lsquoPeruvian Redrsquo was rated higher than all other
varieties except lsquoBolivian Redrsquo while lsquoQQ74rsquo gained the lowest rate Additionally lsquoQQ74rsquo was
less accepted in tasteflavor than all commercial samples but did not differ from other field trial
varieties lsquoBlackrsquo and lsquoTiticacarsquo Furthermore the texture of lsquoQQ74rsquo was the least accepted and
other varieties did not show any significant differences
However low acceptance in adhesive texture of cooked quinoa does not indicate the
adhesive quinoa varieties will not have market potential Adhesiveness in cooked rice is
correlated with high amylopectin and low amylose (Mossman et al 1983 Sowbhagya et al
1987) Hence adhesive quinoa may also contain low amylose Additionally previous studies
found waxy cereal or starch (0 amylose and 100 amylopectin) exhibited excellent
161
performance in extrusion Kowalski et al (2014) found that waxy wheat extrudates exhibited
nearly twice the expansion ratio as that of normal wheat Koumlksel et al (2004) found hulless waxy
barley to be promising for extrusion using low shear screw configuration Van Soest et al (1996)
reported high elongation (500) in extruded maize starch Consequently the adhesive quinoa
varieties have great potential to apply in extruded or other puffed foods
Consumer preference of the sensory attributes was analyzed using Partial Least Square
Regression (PLS) (Figure 4) The attributes presented by lsquoPeruvian Redrsquo including lsquograssyrsquo
aroma lsquograinyrsquo flavors and lsquofirmrsquo and lsquocrunchyrsquo textures were preferred among consumers The
less preferred attributes included lsquopastyrsquo lsquowaterymoistrsquo lsquoadhesiversquo and lsquocohesiversquo all attributes
used to describe the lsquoQQ74rsquo variety Overall acceptance was driven by crunchy texture (r =
090) but negatively correlated with lsquocohesiversquo lsquopastyrsquo and lsquoadhesiversquo texture (r = -096 -087
and -089 respectively) Specifically aroma acceptance of cooked quinoa was negatively
correlated with lsquowoodyrsquo (r = -083) Texture acceptance was positively correlated with lsquofirmrsquo(r =
084) and lsquocrunchyrsquo (r = 094) but was negatively correlated with lsquocohesiversquo (r = -096) lsquopastyrsquo
(r = -095) lsquoadhesiversquo (r = -096) and lsquomoistrsquo (r = -085) Even though lsquoearthyrsquo is a common
attribute in foods such as mushroom and beets this study on quinoa indicated that earthy aroma
and flavor were not the attributes driving consumersrsquo liking of cooked quinoa Color and
appearance did not exhibit significant correlation with color intensity of cooked quinoa
however the varieties with red or dark colors (lsquoPeruvian Redrsquo lsquoBolivian Redrsquo and lsquoBlackrsquo)
were more highly accepted by consumers compared to samples with light color (lsquoTiticacarsquo
lsquoBolivian Whitersquo lsquoQQ74rsquo) In sum consumers preferred cooked quinoa with grassy aroma firm
and crunchy texture and lack of woody aroma and low cohesive pasty or adhesive texture
162
The variety lsquoBlackrsquo was accepted at a similar level as commercial samples in aroma
tasteflavor texture and overall evaluation With a closer examination of the consumer
demographic consumers who were more familiar with quinoa rated the lsquoBlackrsquo quinoa variety
with higher scores (average of 7) compared to those panelists less familiar with quinoa who
assigned lower average scores (59) (Figure 1S) This tricolor quinoa (browndark mixture) is not
as common as red and yellowwhite quinoa in the US market However the potential of tricolor
quinoa may be great due to the relative high consumer acceptance as well as high gain yield in
the field
Instrumental Texture Profile Analysis (TPA)
The physical properties of cooked quinoa were determined using the texture analyzer
(Table 6) Samples differed in all six texture parameters lsquoNL-6rsquo lsquoPeruvian Redrsquo lsquoBolivian Redrsquo
and lsquoCalifornia Tricolorrsquo exhibited the hardest texture while lsquoTemukorsquo lsquoQQ74rsquo lsquoIslugarsquo
lsquoLinaresrsquo and lsquoCO407Daversquo displayed the lowest hardness values Consistent with trained panel
evaluation lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Daversquo were more adhesive than all other varieties
lsquoTiticacarsquo was the springiest variety while lsquoKaslaearsquo and lsquoQuF9P1-20rsquo were the least springy
varieties The commercial samples with the exception of lsquoPeruvian Whitersquo exhibited a more
gummy texture lsquoTiticacarsquo and lsquoBolivian Whitersquo were the chewiest samples In contrast varieties
of lsquoTemukorsquo lsquoQQ74rsquo lsquoIslugarsquo lsquoLinaresrsquo lsquoQuF9P1-20rsquo and lsquoCO407Daversquo showed the least
gummy and chewy texture The result was comparable to an earlier study (Wu et al 2014)
Similarly quinoa varieties with darker color (orangeredbrowndark) tended to yield harder
texture compared to the varieties with light color (whiteyellow) which is caused by the thicker
seed coat in dark colored quinoa In this study adhesive quinoa varieties lsquoQQ74rsquo lsquoLinaresrsquo and
163
lsquoCO407Daversquo were found to have higher adhesiveness values (-17 kgs to -13 kgs) compared
to other varieties previously reported (-029 kgs to 0) (Wu et al 2014)
Correlations of instrumental tests and trained panel evaluations of texture were
significant for hardness and adhesiveness (r = 070 and -063 respectively) (Table 7) Since
adhesiveness was calculated from the first negative peak area of the TPA graph a negative
correlation coefficient was observed but still indicating a high level of agreement between
instrumental and panel tests Springiness tested by TPA was not correlated with texture
attributes
Cohesiveness from the instrumental test was negatively correlated with cohesiveness
from the trained panel texture evaluation (r = -066) Instrumental cohesiveness also exhibited
positive correlations with the trained panel evaluation of firmness and crunchiness (r = 080 and
076 respectively) and negative correlations with pastiness adhesiveness moistness (r = -072
-075 and -082 respectively) Upon a closer examination of the definitions in the instrumental
test cohesiveness was defined as lsquohow well the product withstands a second deformation relative
to its resistance under the first deformationrsquo and is calculated as the ratio of second peak area to
first peak area (Wiles et al 2004) In the sensory lexicon cohesiveness was defined as lsquodegree
to which a substance is compressed between the teeth before it breaksrsquo (Szczesniak 2002) These
differential definitions or explanations of these attributes may have caused the different results
Additionally the gumminess and chewiness from the instrumental evaluation were not
significantly correlated with their counterpart notes from the trained panel evaluations but
correlated with other sensory attributes evaluated by the trained panel Instrumental gumminess
164
was positively correlated with firm and crunchy textures(r = 079 and 078 respectively) but
negatively correlated with cohesive pasty adhesive and moist (r = -067 -068 -075 and -
078 respectively) Additionally a positive correlation was found between instrumental
chewiness and firmness from the panel evaluation (r = 057) whereas negative correlations were
found between instrumental chewiness and panel evaluated cohesiveness pastiness
adhesiveness and moistness (r = -043 -045 -055 and -052 respectively) In the instrumental
texture profile gumminess is calculated by hardness multiplied by cohesiveness and chewiness
is calculated by gumminess multiplied by springiness (Epstein et al 2002) Hence gumminess
was significantly correlated with hardness and cohesiveness and chewiness was significantly
correlated with gumminess In another study of Lyon et al (2000) pasty and adhesive were
expressed as lsquoinitial starchy coatingrsquo and lsquoself-adhesivenessrsquo respectively in cooked rice and
were both negatively correlated with instrumental hardness Generally the instrument test is
more accurate and stable but the parameter or sensory attributes were relatively limited Sensory
panels are able to use various vocabularies to describe the food however accuracy and precision
of panel evaluations were lower than for the instrument Consequently both tools can be
important in sensory evaluation depending on the objectives and resources availability
Future Studies
A lexicon of cooked quinoa was firstly developed in this paper Further discussion and
improvement of the lexicon are necessary and require cooperation with industry and chefs The
lexicon is not only useful in categorizing varieties but also can be used to evaluate post-harvest
practice cooking protocols and other quinoa foodsdishes Additionally quinoa seed quality
varies among years and locations and sensory properties also change over different
165
environments To validate the sensory profile of varieties especially adhesiveness evaluation
should be repeated on the samples from other years and locations Finally multiple dishes food
types should be included in future consumer evaluation studies to identify the best application of
different varieties
Conclusion
A lexicon of cooked quinoa was developed based on aroma tastefavor texture and
color Using the lexicon the trained panel conducted descriptive analysis evaluation on 16
quinoa varieties from field trials and 5 commercial samples Many sensory attributes exhibited
significant differences among quinoa samples especially texture attributes
Consumer evaluations (n = 102) were conducted on six selected samples with diverse
color texture and origin Commercial samples and the variety lsquoBlackrsquo were better accepted by
consumers The adhesive variety lsquoQQ74rsquo was the least accepted quinoa variety in the plain
cooked quinoa dish However because of its cohesive texture lsquoQQ74rsquo shows possible
application in other dishes and foods such as quinoa sushi and extruded snacks Furtherly Partial
Least Square Regression indicated the consumerrsquos preferred attributes were grassy aroma and
firm and crunchy texture while the attributes of pasty adhesive and cohesive were not liked by
consumers
Correlations of panel evaluation and instrumental test were observed in hardness and
adhesiveness However chewiness and gumminess were not significant correlated between panel
test and instrumental test Further training should be addressed to clarify the definitions of
sensory attributes With the assistance and calibration from instruments such as the texture
166
analyzer and electronic tongue panel training can be more efficient and panelists can be more
accurate at evaluation
Acknowledgements
The study was funded by the USDA Organic Research and Extension Initiative
(NIFAGRANT11083982) The authors acknowledge Washington State University Sensory
Facility and their technicians Beata Vixie and Karen Weller The authors also acknowledge
Sergio Nunez de Arco and Sarah Connolly to provide commercial samples Thanks to Raymond
Kinney Max Wood and Hanna Walters who managed the plants harvested the seeds and
collected the data of yield and 1000-seed weight on field trial quinoa varieties Thanks also go to
the USDA-ARS Western Wheat Quality Lab which provided equipment for protein and ash tests
and the texture analyzer
Author contributions
CF Ross and G Wu together designed the study G Wu conducted panel training
collected and processed data and drafted the manuscript KM Murphyrsquos research group provided
the quinoa samples and assisted cleaning process CF Ross CF Morris and KM Murphy edited
the manuscript
167
References
Abugoch LEJ 2009 Chapter 1 quinoa (Chenopodium quinoa Willd) Adv Food Nutr Res
581ndash31
Arco SND Quinoas Calling In Murphy KM Matanguihan J editors Quinoa improvement
and sustainable production Hoboken NJ John Wiley amp Sons Inc p 211
Casas Moreno MM Barreto-Palacios V Gonzalez-Carrascosa R Iborra-Bernad C Andres-Bello
A Martiacutenez-Monzoacute J Garciacutea-Segovia P 2015 Evaluation of textural and sensory properties
on typical spanish small cakes designed using alternative flours J Culinary Sci Technol 13
19-28
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(Waxy) genes J Cereal Sci 35 51-63
Foumlste M Nordlohne SD Elgeti D Linden MH Heinz V Jekle M Becker T Impact of quinoa
bran on gluten-free dough and bread characteristics Eur Food Res Technol 2014 239 767-
75
Furche C Salcedo S Krivonos E Rabczuk P Jara B Fernaacutendez D Correa F 2015 Chapter 41
International quinoa trade In Bazile D Bertero D Nieto C editors State of the art report
on quinoa in 2013 Rome FAO amp CIRAD p 317 ndash 20
Gerber NN1968 Geosmin from microorganisms is trans-1 10-dimethyl-trans-9-decalol
Tetrahedron Lett 9 2971-4
168
Koumlksel H Ryu GH Basman A Demiralp H Ng PK 2004 Effects of extrusion variables on the
properties of waxy hulless barley extrudates FoodNahrung 48 19-24
Kowalski RJ Morris CF Ganjyal GM 2015 Waxy soft white wheat extrusion characteristics
and thermal and rheological propertiesCereal Chem 92 145-53
Koziol MJ 1991 Afrosimetric estimation of threshold saponin concentration for bitterness in
quinoa (Chenopodium quinoa Willd) J Sci Food Agr 54 211-9
Limpawattana M Shewfelt R 2010 Flavor lexicon for sensory descriptive profiling of different
rice types J Food Sci 75 199-205
Lorenz K Coulter L Quinoa flour in baked products Plant Food Hum Nutr 1991 41 213-23
Lyon BG Champagne ET Vinyard BT Windham WR Barton FE Webb BD McKenzie KS
1999 Effects of degree of milling drying condition and final moisture content on sensory
texture of cooked rice Cereal Chem 76 56-62
Lyon BG Champagne ET Vinyard BT Windham WR 2000 Sensory and instrumental
relationships of texture of cooked rice from selected cultivars and postharvest handling
practices Cereal Chem 77 64-9
Meilgaad MC Civille GV Carr BT 2007 Chapter 11 The spectrum descriptive analysis
method In Meilgaad MC Civille GV Carr BT Sensory evaluation techniques Boca Raton
FL CRC Press p 225 ndash 32
169
Meullenet JF Marks BP Hankins JA Griffin VK Daniels MJ 2000 Sensory quality of cooked
long-grain rice as affected by rough rice moisture content storage temperature and storage
duration Cereal Chem 77 259 ndash 63
Mossman AP Fellers DA Suzuki H 1983 Rice stickiness I Determination of rice stickiness
with an Instron tester Cereal Chem 60 286ndash92
Muntildeoz AM 2003 Training time in descriptive analysis In Moskowitz HR Muntildeoz AM and
Gacula MC editors Viewpoints and controversies in sensory science and consumer product
testing Trumbull Food amp Nutrition Press Inc p 351 ndash 6
Peterson AJ Murphy KM 2015 Quinoa cultivation for temperate North America
considerations and areas for investigation In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 173-92
Palmer GH 1994 Chapter 5 Storage In Hoseney RC editor Cereal science and technology
2nd edition St Paul MN American Association of Cereal Chemisty Inc p 107
Pop A Muste S Man S Mureșan C 2014 Improvement of tagliatelle quality by addition of red
quinoa flour Bulletin UASVM Food Sci Tech 71 225-6
Pulvento C Riccardia M Biondib S Orsinic F Jacobsend SE Ragabe R DrsquoAndriaa R Lavinia
A 2015 Chapter 613 Quinoa in Italy research and perspectives In Bazile D Bertero D
Nieto C editors State of the art report on quinoa in 2013 Rome FAO amp CIRAD p 460
Quiroga C Escalera R Aroni G Bonifacio A Gonzaacutelez JA Villca M Saravia R Ruiz A 2015
Chapter 31 Traditional processes and technological innovations in quinoa harvesting
170
processing and industrialization In Bazile D Bertero D Nieto C editors State of the art
report of quinoa in the world in 2013 Rome FAO amp CIRAD p 231
Repo-Carrasco R Espinoza C Jacobsen SE 2003 Nutritional value and use of the Andean
crops quinoa (Chenopodium quinoa) and kantildeiwa (Chenopodium pallidicaule) Food Rev Int
19 179-89
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile
D Bertero D Nieto C editors State of the art report on quinoa in 2013 Rome FAO amp
CIRAD p 67
Sowbhagya CM Ramesh BS Bhattacharya KR 1987 The relationship between cooked-rice
texture and physicochemical characteristics of rice J Cereal Sci 5 287ndash97
Suwannaporn P Linnemann A and Chaveesuk R 2008 Consumer preference mapping for rice
product concepts Brit Food J 110 595-606
Stikic R Glamoclija D Demin M Vucelic-Radovic B Jovanovic Z Milojkovic-Opsenica D
Milovanovic M 2012 Agronomical and nutritional evaluation of quinoa seeds
(Chenopodium quinoa Willd) as an ingredient in bread formulations J Cereal Sci 55 132-8
Szczesniak AS 2002 Texture is a sensory property Food Qual Prefer 13 215-25
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Belton PS JRN Taylor editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science Business Media p 108 ndash 10
171
Tomlins KI Manful JT Larwer P and Hammond L 2005 Urban consumer preferences and
sensory evaluation of locally produced and imported rice in West Africa Food Qual Prefer
16 79-89
Van Soest JJG De Wit D Vliegenthart JFG 1996 Mechanical properties of thermoplastic waxy
maize starch J Appl Polym Sci 61 1927-37
Wang S Opassathavorn A Zhu F 2015 Influence of quinoa flour on quality characteristics of
cookie bread and Chinese steamed bread J Texture Stud 46 281-92
Wiles JL Green BW Bryant R 2004 Texture profile analysis and composition of a minced
catfish product J Texture Stud 35 325-37
Wu G Morris C F Murphy K M 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79 2337-45
172
Table 1-Quinoa samples
Varietya Color Source
Titicaca Yellowwhite Denmark
Black Blackbrown mixture White Mountain Farm Colorado USA
KU-2 Yellowwhite Washington USA
Cahuil Brownorange mixture White Mountain Farm Colorado USA
Red Head Yellowwhite Wild Garden Seed Oregon USA
Cherry Vanilla Yellowwhite Wild Garden Seed Oregon USA
Temuko Yellowwhite Washington USA
QuF9P39-51 Yellowwhite Washington USA
Kaslaea Yellowwhite MN USA
QQ74 Yellowwhite Chile
Isluga Yellowwhite Chile
Linares Yellowwhite Washington USA
Puno Yellowwhite Denmark
QuF9P1-20 Yellowwhite Washington USA
NL-6 Yellowwhite Washington USA
CO407Dave Yellowwhite White Mountain Farm Colorado USA
Bolivian White White Bolivia
Bolivian Red Red Bolivia
California Tricolor
Blackbrown mixture California USA
Peruvian Red Red Peru
Peruvian White White Peru aThe first 16 varieties (Tititcaca ndash CO407Dave) were grown in Chimacum WA
173
Table 2-Lexicon of cooked quinoa as developed by the trained panelists (n = 9)
Attribute Intensitya Reference Definition
Aroma
Caramel 10 1 piece of caramel candy (Kraft) (81 g) in 100 mL water
Aromatics associated with caramel tastes
Grain-like 10 Cooked brown rice (15 g) (Great Value)
Rice like wheaty sorghum like
Bean-like 8 Cooked red bean (10 g) (Great Value)
Aromatics associated with cooked beans or bean protein
Nutty 10 Dry roasted peanuts (10 g) (Planters)c
Aromatics associated with roasted nuts
Buttery 10 Unsalted butter (1cm1cm01cm) (Tillamook)c
Aromatics associated with natural fresh butter
Starchy 10 Wheat flour water (11 ww) (Great Value)c
Aromatics associated with the starch
Grassygreen 9 Fresh cut grass collected 1 h before usingc
Aromatics associated with grass
Earthymusty 8 Sliced raw button mushrooms (fresh cut)c
Aromatic reminiscent of decaying vegetative matters and damp black soil root like
Woody 7 Toothpicks (20)c Aromatics reminiscent of dry cut wood cardboard
TasteFlavor
Sweet 3 9 2 and 5 (ww) sucrose solution (CampH pure cane sugar)b
Basic taste sensation elicited by sugar
Bitter 5 8 mgL quinine sulfate acid (Sigma)
Basic taste sensation elicited by caffeine
174
Grain-like 10 Cooked brown rice (Great Value)
Tasted associated with cooked grain such as rice
Bean-like 10 Cooked red beans (Great Value)
Beans bean protein
Nutty 10 Dry roasted peanut (Planters)c Taste associated with roasted nuts
Earthy 7 Sliced raw button mushrooms (fresh)
Taste associated with decaying vegetative matters and damp black soil
Toasted 10 Toasted English muffin (at 6 of a toaster) (Franze Original English Muffin)
Taste associated with toast
Texturee
Soft - Firm 3
7
Firm tofu (Azumaya)b
Brown rice (Great Value)
Force required to compress a substance between molar teeth (in the case of solids) or between tongue and palate (in the case of semi-solids)d
Separate - Cohesive
15
7
Cracker (Premium unsalted cracker)
Cake (Sponge cake Walmart Bakery)
Degree to which a substance is compressed between the teeth before it breaks
Pasty
10 Mashed potato (Great Value Mashed Potatoes powder)
Smooth creamy pulpy slippery
Adhesiveness sticky
10
3
Sticky rice (Koda Farms Premium Sweet Rice)
Brown rice (Great Value)
Force required to remove the material that adheres to the mouth (the palate and teeth) during the normal eating process
Crunchy 13 Thick cut potato chip (Tostitos Restaurant Style
Force with which a sample crumbles cracks or shatters
175
Tortilla Chips)b
Chewygummy
15
7
Gummy Bear (Haribo Gold-Bears mixed flavor)
Brown rice (Great Value)
Length of time (in sec) required to masticate the sample at a constant rate of force application to reduce it to a consistency suitable for swallowing
Astringent 12
6
Tannic acid (2gL)
Tannic acid (1gL) (Sigma)
Puckering or tingling sensation elicited by grape juice
Waterymoist 10
3
Salad tomato (Natural Sweet Cherubs)
Brown rice (Great Value)
Degree of wet or dry
Color
Red 4 9
N-W8M Board Walke
N-W16N Ballet Barree
Yellow 3 10
15B-2U Sandy Toese 15B-7
N Summer Harveste
Black 3 10
N-C32N Strong Influencee N-C4M Trench Coate
aReference intensities were based on a 15-cm scale with 0 = extremely low and 15 = extremely high bMeilgaad et al (2007) cLimpawattana and Shewfelt (2010) dTexture definitions in Szczesniak (2002) were used eAce Hardware color chip
176
Table 3-Significance and F-value of the effects of panelist replicate and quinoa variety on aroma flavor and texture of cooked quinoa as determined using a trained panel (n = 9)
Attribute Panelist Replicate Quinoa Variety PanelistVariety
Aroma
Caramel 26548 093 317 174
Grain-like 7338 000 125 151
Bean-like 7525 029 129 135
Nutty 6274 011 322 118
Buttery 21346 003 301 104
Starchy 12094 1102 094 135
Grassy 17058 379dagger 282 162
Earthy 12946 239 330 198
Woody 13178 039 269 131
TasteFlavor
Sweet 6745 430 220 137
Bitter 9368 1290 2059 236
Grain-like 7681 392 222 206
Bean-like 7039 122 142 141
Nutty 7209 007 169 153
Earthy 9313 131 330 177
Toasted 10975 015 373 184
Texture
Firm 1803 022 1587 141
Cohesive 14750 011 656 208
Pasty 3919 2620 1832 205
Adhesive 2439 287dagger 5740 183
177
Crunchy 13649 001 1871 167
Chewy 3170 870 150dagger 167
Astringent 10183 544 791 252
Waterymoist 10281 369dagger 1809 164
daggerP lt 010 P lt 005 P lt 001 P lt 0001
178
Table 4-Mean separation of significant tasteflavor attributes of cooked quinoa determined by the trained panel Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Sweet Bitter Grain-like Nutty Earthy Toasty
Titicaca 40cdef1 39bcde 73abc 51abcdef 44bcdef 47abcd
Black 36f 42bcd 69bcde 49def 52a 46abcd
KU2 41bcdef 38cde 73abc 52abcdef 40fg 44bcdefg
Cahuil 41abcdef 44b 70bcde 50abcdef 48abc 51a
Red Head 42abcd 43bc 72abcd 51abcdef 42defg 44bcdefg
Cherry Vanilla 40def 52a 66e 48ef 44bcdef 40fghi
Temuko 36ef 56a 68cde 47f 43cdef 40ghi
QuF9P39-51 47a 34e 73abc 48def 40efg 46abcde
Kaslaea 47ab 39bcde 70bcde 55ab 44bcdef 45bcdefg
QQ74 40def 38cde 66e 50abcdef 45bcde 42defghi
Isluga 41bcdef 41bcd 69cde 55a 46bcd 47abcd
Linares 39def 40bcd 65e 49cdef 43def 38i
Puno 44abcd 39bcde 72abcd 51abcdef 45bcde 43cdefghi
QuF9P1-20 42abcdef 43bc 69bcde 53abcd 45bcde 38i
NL-6 38def 37de 72abcd 55a 45bcd 44bcdefgh
CO 407 Dave 41bcdef 40bcd 67de 51abcdef 41defg 39hi
Bolivian White 47ab 22f 69bcde 50bcdef 42def 41efghi
Bolivian Red 42abcde 24f 72abcd 53abcdef 43cdef 46bcde
California Tricolor 40def 27f 74ab 53abcde 48ab 48ab
Peruvian Red 43abcd 25f 75a 48ef 45bcde 47abc
Peruvian White 46abc 26f 70bcde 55abc 37g 45bcdef
179
Table 5-Mean separation of consumer preference Different letters within a column indicate consumer evaluation scores were different among quinoa samples at P lt 005
Samples Aroma Color Appearance TasteFlavor Texture Overall
Black 56a 63b 61bc 61abc 65a 63ab
QQ74 61a 56c 53d 56c 53b 53c
Titicaca 60a 57bc 56cd 58bc 63a 59bc
Peruvian Red 60a 72a 70a 65a 68a 67a
Bolivian Red 60a 69a 66ab 64ab 67a 64ab
Bolivian White 57a 59bc 58c 62ab 63a 62ab
180
Table 6-Hardness adhesiveness cohesiveness springiness gumminess and chewiness of the cooked quinoa samples as determined using Texture Profile Analysis (TPA)
Variety Hardness
(kg)
Adhesiveness
(kgs)
Cohesiveness Springiness Gumminess
(kg)
Chewiness
(kg)
Titicaca 505abc1 -02ab 08abc 15a 384bc 599a
Black 545ab -01a 07bcd 10abc 404abc 404ab
KU-2 490abcd -01a 07bcd 09abc 363bcd 332abc
Cahuil 464bcde -01a 07bcd 08abc 344cd 281bc
Red Head 412defg -03ab 06ef 09abc 246ef 225bc
Cherry Vanilla 391efgh -02ab 05fgh 08abc 208fg 178bc
Temuko 328gh -09c 04hi 08abc 147g 120c
QuF9P39-51 451cde -02ab 07de 10abc 297de 272bc
Kaslaea 493abcd -02ab 07bcd 06c 359cd 227bc
QQ74 312h -17e 04i 09abc 132g 119c
Isluga 362fgh -05b 05ghi 08abc 171fg 137bc
Linares 337gh -16de 05ghi 09abc 159g 146bc
Puno 504abc -01a 06ef 10abc 301de 301bc
QuF9P1-20 438cdef -02ab 06fg 05c 242ef 137bc
NL-6 555a -01a 07cde 09abc 376bcd 350abc
CO407Dave 357fgh -13d 04hi 09abc 160g 141bc
Bolivian White 441cdef -01ab 05fg 14ab 242ef 340abc
Bolivian Red 572a -01ab 08ab 14ab 440ab 593a
California Tricolor
572a -01a 08a 08bc 477a 361abc
Peruvian Red 568a 00a 08ab 08abc 439ab 342abc
Peruvian White 459bcde -01a 08abc 11abc 347cd 394abc
181
Table 7-Correlation of trained panel texture evaluation data and instrumental TPA over the 21 quinoa varieties
Variables Hardness Adhesiveness Cohesiveness Gumminess Chewiness Firm 070 059 080 079 057 Cohesive -060 -051 -066 -067 -043 Pasty -060 -070 -072 -068 -045 Adhesive -067 -063 -075 -075 -055 Crunchy 072 054 076 078 055 Moist -066 -066 -082 -078 -052
daggerP lt 01 P lt 005 P lt 001 P lt 0001
182
Figure 1-Principal component Analysis (PCA) biplot of aroma evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil Red Head
Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white Kaslaea
QQ74
Isluga
Linares
Puno
QuF9P1-20 NL-6
CO 407 Dave
Bolivia white
Bolivia red California Tricolor
Caramel Grain-like
Bean-like Nutty
Buttery Starchy
Grassy
Earthy
Woody
-25
-2
-15
-1
-05
0
05
1
15
2
-3 -25 -2 -15 -1 -05 0 05 1 15 2 25 3 35 4
F2 (2
455
)
F1 (4234 )
183
Figure 2-Principal component Analysis (PCA) biplot of tasteflavor evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil
Red Head Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white
Kaslaea
QQ74 Isluga
Linares
Puno
QuF9P1-20
NL-6
CO 407 Dave
Bolivia white
Bolivia red
California Tricolor
Sweet
Bitter Grain-like
Bean-like
Nutty
Earthy
Toasted
-3
-2
-1
0
1
2
3
-4 -3 -2 -1 0 1 2 3 4 5
F2 (3
073
)
F1 (3391 )
184
Figure 3-Principal component Analysis (PCA) biplot of texturemouthfeel evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil
Red Head Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white
Kaslaea
QQ74 Isluga
Linares
Puno
QuF9P1-20
NL-6
CO 407 Dave
Bolivia white
Bolivia red California Tricolor
Firm Cohesive
Pasty
Adhesive
Crunchy
Chewy Astringent
Moist
-2
-15
-1
-05
0
05
1
15
2
25
-3 -25 -2 -15 -1 -05 0 05 1 15 2 25 3 35
F2 (2
212
)
F1 (5959 )
185
Figure 4-Partial Least Squares (PLS) biplot correlating aroma color appearance tasteflavor texture and overall attributes evaluated by the trained panel (n = 9) to the consumer panel (n = 102) for 6 cooked quinoa samples (Consumer acceptances are in bold italics)
Grainy aroma
Beany aroma
Nutty aroma
Buttery
Starchy
Grassy
Earthy
Woody
Sweet
Bitter grainy flavor
Beany flavor
Earthy flavor Nutty flavor
Toasty
Firm Cohesive
Pasty
Adhesive
Crunchy
Chewy
Astringent
Waterymoist
Aroma
Color Appearance TasteFlavor
Texture Overall
Black
Bolivia red
QQ74
Bolivia white
Commercial Red
Titicaca
-1
-075
-05
-025
0
025
05
075
1
-1 -075 -05 -025 0 025 05 075 1
t2
t1
186
Supplementary tables
Table 1S-Mean separation of significant aroma attributes of cooked quinoa determined by the trained panel (n = 9) Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Caramel Nutty Buttery Green Earthy Woody
Titicaca 59a1 60a 45abc 39fg 42defgh 37cdef
Black 46g 50efg 38ef 47abc 54a 46a
KU2 50efg 51defg 41cdef 40efg 38h 35ef
Cahuil 56abc 53bcdefg 43abcd 49a 48b 39bcde
Red Head 55abcd 60a 45abc 44bcde 46bcd 41bc
Cherry Vanilla 52cdef 54bcdef 43abcde 43bcdef 46bcdef 37bcdef
Temuko 55abcd 56abcde 44abc 40defg 41efgh 37bcdef
QuF9P39-51 58ab 60a 46ab 42bcdefg 44bcdefg 36def
Kaslaea 53bcde 55abcde 42abcde 41defg 40gh 37bcdef
QQ74 50efg 48fg 39def 42defg 45bcdef 38bcdef
Isluga 52cdef 57abc 43abcd 43bcdefg 46bcde 39bcde
Linares 52cdef 54bcdef 42bcde 38g 44bcdefg 37cdef
Puno 56abc 56abcde 46ab 42cdefg 46bcdef 38bcdef
QuF9P1-20 53bcdef 58ab 44abcd 42cdefg 44bcdefg 40bcd
NL-6 57abc 53bcdefg 44abcd 39fg 44bcdefg 35def
CO 407 Dave 51def 54abcde 46ab 40efg 42defgh 34f
Bolivian White 53bcde 57abcd 46ab 43bcdef 43cdefgh 39bcd
Bolivian Red 52cdef 51defg 42bcde 43bcdefg 44bcdefg 37bcdef
California Tricolor 54abcde 51cdefg 38ef 44abcd 48bc 41ab
Peruvian Red 48fg 48g 36f 47ab 46bcdef 38bcdef
Peruvian White 54abcde 60a 48a 45abcd 41fgh 40bc
187
Table 2S-Mean separation of significant texture attributes of cooked quinoa determined by the trained panel Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Firm Cohesive Pasty Adhesive Crunchy Astringent Moist
Titicaca 70ab 63efgh 37ghi 37ghi 56bc 47d 38hij
Black 71ab 63efgh 32i 38ghi 58b 55abc 35jk
KU2 66bcd 64efg 38fghi 37ghi 49de 46de 38hij
Cahuil 68abc 61fghi 37ghi 36hi 56bc 55ab 37ij
Red Head 57fgh 68bcde 46cde 49d 45ef 55ab 48de
Cherry Vanilla 56gh 65cdef 49c 44def 43fg 55ab 49de
Temuko 49ij 70abcd 56b 57c 39gh 59a 51cd
QuF9P39-51 61defg 65def 47cd 40efgh 48def 48cd 42fgh
Kaslaea 60defg 62fghi 40defgh 40fgh 51cd 51bcd 42gh
QQ74 44j 70abc 60ab 81ab 37hi 46def 57ab
Isluga 52hi 66cdef 43cdef 55c 44efg 50bcd 48de
Linares 45j 75a 65a 86a 33i 47d 61a
Puno 58efgh 60fghij 41defg 43efg 52cd 47d 47def
QuF9P1-20 52hi 65def 43cdefg 46de 44fg 55ab 47defg
NL-6 64cde 61fghi 40efgh 41efgh 51cd 46de 46efg
CO 407 Dave 45j 72ab 59ab 80b 35hi 47d 55bc
Bolivian White 56gh 61fghi 38fghi 41efgh 50de 34g 48de
Bolivian Red 62cdef 59hij 34hi 36hi 56bc 38g 42fgh
California Tricolor 68abc 56j 32i 33i 60ab 39efg 39hij
Peruvian Red 74a 57ij 35hi 33i 64a 39fg 31k
Peruvian White 60defg 59ghij 38fghi 37hi 48def 34g 40hi
188
Figure-1S Demographic influence on preference of variety lsquoBlackrsquo
75a
66ab 61bc
54c
61bc
0
1
2
3
4
5
6
7
8
75 50 25 None Other
Liking score of lsquoBlackrsquo
Proportion of organic food consumption
52b
64a 65a 69a 70a
57ab 59ab
0
1
2
3
4
5
6
7
8
Everyday 4-5 timesper week
2-3 timesper week
Once aweek
A fewtimes per
month
Aboutevery 6months
Other
Liking score of lsquoBlackrsquo
Frequency of rice consumption
189
Chapter 7 Conclusions
Quinoa quality is a complex topic with seed composition influencing sensory and
physical properties This dissertation evaluated the seed characteristics composition flour
properties and cooking quality of 13 quinoa samples Differences in seed morphology and
composition contributed to the texture of cooked quinoa The seeds with higher raw seed
hardness lower bulk density or higher seed coat proportion yielded a firmer gummier and
chewier texture after cooking Higher protein content correlated with harder more adhesive
more cohesive gummier and chewier texture of cooked quinoa Additionally flour peak
viscosity breakdown final viscosity and setback exhibited influence on different texture
parameters Cooking time and water uptake ratio also significantly influence the texture whereas
cooking loss did not show any correlation with texture Starch characteristics also significantly
differed among quinoa varieties (Chapter 3) Amylose content ranged from 27 to 169
among 13 quinoa samples The quinoa samples with higher amylose proportion or higher starch
enthalpy tended to yield harder stickier more cohesive and chewier quinoa These studies on
seed quality seed characteristics compositions and cooking quality provided useful information
to food industry professionals to use in the development of quinoa products using appropriate
quinoa varieties Indices such protein content and flour viscosity (RVA) can be quickly
determined and exhibited strong correlations with cooked quinoa texture Furthur study should
develop a prediction model using protein content or RVA parameters to predict the texture of
cooked quinoa In this way food manufactures can quickly predict the texture or functionality of
quinoa varieties and then determine their specific application Moreover many of the test
methods were using the methods used in rice such as kernel hardness texture of cooked quinoa
190
thermal properties (DSC) and cooking qualities Such methods should be standardized in near
future as those defined by AACC (American Association of Cereal Chemists) The development
of standard methods allows for easier comparisons among different studies In Chapter 4 the
seed quality response to soil salinity and fertilization was studied Quinoa protein content
increased under high Na2SO4 concentration (32 dS m-1) The variety lsquoQQ065rsquo maintained similar
levels of hardness and density under salinity stress and is considered to be the best adapted
variety among four varieties The variety can be applied in salinity affected areas Future studies
can be applied on salinity drought influence on quinoa amino acids profile starch composition
fiber content and saponins content
Sensory evaluation of cooked quinoa was further examined in Chapter 5 Using a trained
panel the lexicon for cooked quinoa was developed Using this lexicon the sensory profiles of
16 field trial varieties and 5 commercial quinoa samples were generated Varietal differences
were observed in the aromas of caramel nutty buttery grassy earthy and woody tasteflavor of
sweet bitter grain-like nutty earthy and toasty and texture of firm cohesive pasty adhesive
crunchy chewy astringent and moist Subsequent consumer evaluation on 6 selected quinoa
samples indicated lsquoPeruvian Redrsquo was the most accepted overall whereas a sticky variety lsquoQQ74rsquo
was the least accepted Partial least square analysis using trained panel data and consumer
acceptance data indicated that overall consumer liking was driven by grassy aroma and firm and
crunchy texture The lexicon and the attributes driving consumer-liking can be utilized by
breeders and farmers to evaluate their quinoa varieties and products The information is also
useful to the food industry to evaluate ingredients from different locations and years improve
processing procedures and develop products
191
Overall the dissertation provided significant information of quinoa seed quality and
sensory characteristics among different varieties including both commercialized samples and
field trial samples not yet available in market Several quinoa varieties increasingly grown in
US were included in the studies The variety lsquoCherry Vanillarsquo and lsquoTiticacarsquo are among the
varieties gaining the best yields in US Their seed characteristics and sensory attributes
described in this dissertation should be helpful for industry professionals in their research and
product development Varieties include lsquoTiticacarsquo lsquoCherry Vanillarsquo and lsquoBlackrsquo Additionally
important tools were developed in quinoa evaluation including texture analysis using TPA and
the lexicon of cooked quinoa
As with any set of studies other research questions arise to be addressed in future
research First saponins the compounds introducing bitter taste in quinoa require further study
Sweet quinoa varieties (saponins content lt 011) should be bred and adapted to the US
Although many consumers may like the bitter taste and especially the potential health benefits of
saponins it is important to provide consumers choices of both bitter and non-bitter quinoa types
To assist the breeding of sweet quinoa genetic markers can be developed and associated with the
phenotype of saponin content As for the methods testing saponin content the foam method is
quick but not accurate whereas the GC method is accurate but requires long sample preparation
time and high capital investment An accurate more affordable and more efficient method such
as one using a spectrophotometer should be developed
Second one important nutritional value of quinoa is the balanced essential amino acids
The essential amino acids profiles change according to environment (drought and saline soil)
quinoa variety and processing (cleaning milling and cooking) and these changes should be
192
further studied It is important to prove quinoa seed maintains the rich essential amino acids even
growing under marginal conditions or being subjected to cleaning processes such as abrasion
and washing
Third betalains are the compounds contributing to the color of quinoa seed and providing
potential health benefits Betalain content type (relate to diverse colors) and their genetic loci in
quinoa can be further investigated Color diversity is one of the attractive properties in quinoa
seeds However the commercialized quinoa samples are in white or red color while more quinoa
varieties present orange purple brown and gray colors More choices of quinoa colorstypes
may attract more consumers
Finally sensory evaluation of quinoa varieties should be applied to the samples from
multiple years and locations since environment can significantly influence the sensory attributes
Also in addition to plain cooked quinoa more quinoa dishes can be involved in consumer
acceptance studies as different quinoa varieties may be suitable for various dishes
iv
QUINOA SEED QUALITY AND SENSORY EVALUATION
Abstract
by Geyang Wu PhD Washington State University
May 2016
Co-Chairs Carolyn F Ross Craig F Morris
Quinoa is a grain that has garnered increasing interest in recent years from global
markets as well as in academic research The studies in this dissertation focused on quinoa seed
quality and sensory evaluation among diverse quinoa varieties with potential adaptation to
growing conditions in Washington State The objectives in the dissertation were to study quinoa
seed quality as well as the sensory attributes of cooked quinoa as defined by both trained and
consumer panelists Regarding quinoa seed quality we investigated seed characteristics
(diameter weight density hardness seed coat proportion) seed composition (protein and ash
content) flour viscosity and thermal properties quinoa cooking quality and texture of cooked
quinoa Additionally the functional characteristics of quinoa were studied including the
determination of amylose content starch swelling power and water solubility texture of starch
gel and starch thermal properties Results indicated texture of cooked quinoa was significantly
influenced by protein content flour viscosity quinoa cooking quality amylose content and
starch enthalpy In addition the influences of soil salinity and fertility on quinoa seed quality
were evaluated The variety lsquoQQ065rsquo exhibited increased protein content and maintained similar
levels of hardness and density under salinity stress and is considered to be the best adapted
v
variety among four varieties Finally sensory evaluation studies on cooked quinoa were
conducted A lexicon of cooked quinoa was developed including the sensory attributes of aroma
tasteflavor texture and color Results from the trained and consumer panel indicated that
consumer liking of quinoa was positively influenced by grassy aroma and firm and crunchy
texture These results represent valuable information to quinoa breeders in the determination of
seed quality of diverse quinoa varieties In the food industry the results of seed quality and
sensory studies (lexicon and consumer-liking) can be utilized to evaluate quinoa ingredients from
multiple locations or years determine the efficiency of post-harvest processing and develop
appropriate products according to the properties of the specific quinoa variety Overall this
dissertation contributed to the growing body of research describing the chemical physical and
sensory properties of quinoa
vi
TABLE OF CONTENTS
Page
ACKNOWLEDGMENTS iii
ABSTRACT iv-v
LIST OF TABLES ix-xi
LIST OF FIGURES xii-xiii
CHAPTERS
1 Introduction 1
References 6
2 Literature review 9
References 26
Tables 41
Figures44
3 Evaluation of texture differences among varieties of cooked quinoa 46
Abstract 46
Introduction 48
Materials and Methods 51
Results 54
Discussion 60
vii
Conclusion 63
References 65
Tables 71
Figures78
4 Quinoa starch characteristics and their correlation with
texture of cooked quinoa 80
Abstract 80
Introduction 81
Materials and Methods 82
Results 87
Discussion 95
Conclusion 102
References 103
Tables 109
5 Quinoa seed quality response to sodium chloride and
Sodium sulfate salinity 118
Abstract 118
Introduction 120
Materials and Methods 122
Results 125
Discussion 123
viii
Conclusion 132
References 134
Tables 139
Figure 145
6 Lexicon development and sensory attributes of cooked quinoa 146
Abstract 146
Introduction 148
Materials and Methods 150
Results and Discussion 155
Conclusion 165
References 167
Tables 172
Figures183
7 Conclusions 189
ix
LIST OF TABLES
Page
CHAPTER 2
Table 1 Essential amino acid of quinoa protein and FAOWHO suggested requirement (mgg
protein) 41
Table 2 Quinoa vitamin content (mg100g) 42
Table 3 Quinoa mineral content (mgmg ) 43
CHAPTER 3
Table 1 Varieties of quinoa used in the experimenthelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip71
Table 2 Seed characteristics and composition 72
Table 3 Texture profile analysis (TPA) of cooked quinoa 73
Table 4 Cooking quality of quinoa 74
Table 5 Pasting properties of quinoa flour by RVA 75
Table 6 Thermal properties of quinoa flour by Differential Scanning Calorimetry (DSC) 76
Table 7 Correlation coefficients between quinoa seed characteristics composition and
processing parameters and TPA texture of cooked quinoa 77
CHAPTER 4
Table 1 Quinoa varieties tested 109
Table 2 Starch content and composition 110
Table 3 Starch properties and α-amylase activity 111
Table 4 Texture of starch gel 112
Table 5 Thermal properties of starch 113
x
Table 6 Pasting properties of starch 114
Table 7 Correlation coefficients between starch properties and texture of cooked quinoa 115
Table 8 Correlations between starch properties and seed DSC RVA characteristics 116
CHAPTER 5
Table 1 Analysis of variance with F-values for protein content hardness and density of quinoa
seed 139
Table 2 Salinity variety and fertilization effects on quinoa seed protein content () 140
Table 3 Salinity variety and fertilization effects on quinoa seed hardness (kg) 141
Table 4 Salinity variety and fertilization effects on quinoa seed density (g cm3) 142
Table 5 Correlation coefficients of protein hardness and density of quinoa seed 143
Table 6 Correlation coefficients of quinoa seed quality and agronomic performance and seed
mineral content144
CHAPTER 6
Table 1 Quinoa samples 172
Table 2 Lexicon of cooked quinoa as developed by the trained panelists (n = 9) 173
Table 3 Significance and F-value of the effects of panelist replicate and quinoa variety on
aroma flavor and texture of cooked quinoa as determined using a trained panel (n = 9) 176
Table 4 Mean separation of significant tasteflavor attributes of cooked quinoa determined by
the trained panel Different letters within a column indicate attribute intensities were different
among quinoa samples at P lt 005 as determined using Fisherrsquos LSD 178
Table 5 Mean separation of consumer preference Different letters within a column indicate
consumer evaluation scores were different among quinoa samples at P lt 005 179
xi
Table 6 Hardness adhesiveness cohesiveness springiness gumminess and chewiness of the
cooked quinoa samples as determined using Texture Profile Analysis (TPA) Different letters
within a column indicate attribute intensities were different among quinoa samples at P lt 005
180
Table 7 Correlation of trained panel texture evaluation data and instrumental TPA over the 21
quinoa varieties 181
Table 1S Mean separation of significant aroma attributes of cooked quinoa determined by the
trained panel (n = 9) Different letters within a column indicate attribute intensities were different
among quinoa samples at P lt 005 as determined using Fisherrsquos LSD 186
Table 2S Mean separation of significant texture attributes of cooked quinoa determined by the
trained panel Different letters within a column indicate attribute intensities were different among
quinoa samples at P lt 005 as determined using Fisherrsquos LSD 187
xii
LIST OF FIGURES
Page
CHAPTER 2
Figure 1 Quinoa seed section and two-layered pericarp under perianth (Wu et al 2014) 44
Figure 2 Figure 2-Quinoa seed structure (Prego et al 1998) 45
CHAPTER 3
Figure 1 Rapid Visco Analyzer (RVA) graph of lsquoCherry Vanillarsquo and lsquoRed Commercialrsquo quinoa
flours 78
Figure 2 Seed coat image by SEM 79
CHAPTER 5
Figure 1 Protein content () of quinoa in response to combined fertility and
salinity treatments 145
CHAPTER 6
Figure 1 Principal component Analysis (PCA) biplot of aroma evaluations by the trained
sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 182
Figure 2 Principal component Analysis (PCA) biplot of tasteflavor evaluations by the trained
sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 183
xiii
Figure 3 Principal component Analysis (PCA) biplot of texturemouthfeel evaluations by the
trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 184
Figure 4 Partial Least Squares (PLS) biplot correlating aroma color appearance tasteflavor
texture and overall attributes evaluated by the trained panel (n = 9) to the consumer panel (n =
102) for 6 quinoa samples (Consumer acceptances are in bold italics) 185
Figure-1S Demographic influence on preference of variety lsquoBlackrsquo 188
xiv
Dedication
This dissertation is dedicated to those who are interested in quinoa
the beautiful small grain providing nutrition and fun
1
Chapter 1 Introduction
Quinoa is growing rapidly in the global market largely due to its high nutritional value
and potential application in a wide range of products Bolivia and Peru are the major producers
and exporters of quinoa In Peru production increased from 31824 MT (Metric Ton) in 2007 to
108000 MT in 2015 (USDA 2015) In 2013 organic quinoa from Bolivia and Peru were sold at
averages of $8000MT and $7000MT respectively (Nuntildeez de Acro 2015) Of all countries the
US and Canada import the most quinoa and comprise 53 and 15 of the global imports
respectively (Carimentrand et al 2015) Quinoa yield is on average 600 kgha with yield
varying greatly and among varieties and environments (Garcia et al 2004) The total production
cost is $720ha in the southern Altiplano region of Bolivia and the farm-gate price reached
$60kg in 2013 (Nuntildeez de Acro 2015) With 2600 kg annual quinoa yield in a small 3 ha farm
the revenue would be $15390 which could potentially raise a family out of poverty (Nuntildeez de
Acro 2015)
Quinoa possesses many sensory properties Food texture refers to those qualities of a
food that can be felt with the fingers tongue palate or teeth (Sahin and Sumnu 2006) Texture is
one of most significant properties of food products Quinoa has unique texture ndash creamy smooth
and a little crunchy (James 2009) The texture of cooked quinoa is not only influenced by seed
structure but also determined by compounds such as starch and protein However publications
describing the texture of cooked quinoa are limited
Seed characteristics and structure are important factors influencing the textual properties
of cooked quinoa seed Quinoa is a dicotyledonous plant species very different from
2
monocotyledonous cereal grains The majority of the seed is the middle perisperm of which cells
have very thin walls and angular-shaped starch grains (Prego et al 1998) The two-layer
endosperm of the quinoa seed consists of living thick-walled cells rich in proteins and lipids but
without starch The protein bodies found in the embryo and endosperm lack crystalloids and
contain one or more globoids of phytin (Prego 1998) Given the structure of quinoa the seed
properties such as seed size hardness and seed coat proportion may influence the texture of the
cooked quinoa Nevertheless correlations between seed characteristics seed structure and
texture of cooked quinoa have not been performed
Beside the physical properties of seed the seed composition will influence the texture as
well Protein and starch are the major components in quinoa while their correlation to texture
has not been studied Starch characteristics and structures significantly influence the texture of
the end product Starch granules of quinoa is very small (1-2μm) compared to that of rice and
barley (Tari et al 2003) Quinoa starch is lower in amylose content (11 of starch) (Ahamed
1996) which may yield the hard texture Chain length of amylopectin also influences hardness of
food product (Ong and Blanshard 1995) In sum the influence of quinoa seed composition and
characteristics on cooked product should be studied
In addition to seed quality and characteristics the sensory attributes of quinoa are also
significant as they influence consumer acceptance and the application of the quinoa variety
However there is a lack of lexicon to describe the sensory attributes of cooked quinoa Rice is
considered as a model when studying quinoa sensory attributes because they are cooked in
similar ways The lexicon of cooked rice were developed and defined in the study of Champagne
3
et al (2004) Sewer floral starchygrain hay-likemusty popcorn green beans sweet taste
sour and astringent were among those attributes
Consumer acceptance is of great interested to breeders farmers and the food industry
Acceptability of quinoa bread was studied by Rosell et al (2009) and Chlopicka et al (2012)
Gluten free quinoa spaghetti (Chillo et al 2008) and dark chocolate with 20 quinoa
(Schumacher et al 2010) were evaluated using a sensory panel However cooked quinoa the
most common way of consuming quinoa has not been studied for its sensory properties and
consumer preference Additionally consumer acceptance of quinoa may be influenced by the
panelistsrsquo demographic such as origin food culture familiarity with less common grains and
quinoa and opinion of a healthy diet Furthermore compared to instrumental tests sensory
evaluation tests are generally more expensive and time consuming hence correlations of sensory
panel and instrumental data are of interest If correlations exist instrumental analyses can be
used to substitute or complement sensory panel evaluation
Based on the above discussion this dissertation focused on the study of seed
characteristics quality and texture of cooked quinoa and starch characteristics among various
quinoa varieties Seed quality under saline soil conditions was also investigated To develop the
sensory profiles of cooked quinoa a trained panel developed and validated a lexicon for cooked
quinoa while a consumer panel evaluated their acceptance of different quinoa varieties From
these data the drivers of consumer liking were determined
The dissertation is divided into 7 chapters Chapter 1 is an introduction of the topic and
overall objectives of the studies Chapter 2 provides a literature review of recent progress in
4
quinoa studies including quinoa seed structure and compositions physical properties flour
properties health benefits and quinoa products Chapter 3 was published in Journal of Food
Science under the title of lsquoEvaluation of texture differences among varieties of cooked quinoarsquo
The objectives of Chapter 3 were to study the texture difference among varieties of cooked
quinoa and evaluate the correlation between the texture and the seed characters and
composition cooking process flour pasting properties and thermal properties
Chapter 4 includes the manuscript entitled lsquoQuinoa starch characteristics and their
correlation with texture of cooked quinoarsquo The objectives of Chapter 4 were to determine starch
characteristics of quinoa among different varieties and investigate the correlations between the
starch characteristics and cooking quality of quinoa
Chapter 5 has been submitted to Frontier in Plant Science under the title lsquoQuinoa seed
quality response to sodium chloride and sodium sulfate salinityrsquo In Chapter 5 quinoa seed
quality grown under salinity stress was assessed Four quinoa varieties were grown under six
salinity treatments and two levels of fertilization and then quinoa seed quality characteristics
such as protein content seed hardness and seed density were evaluated
Chapter 6 is the manuscript entitled lsquoLexicon development and sensory attributes of
cooked quinoarsquo In Chapter 6 a lexicon of cooked quinoa was developed using a trained panel
The lexicon provided descriptions of the sensory attributes of aroma tasteflavor texture and
color with references developed for each attribute The trained panel then applied this lexicon to
the evaluation of 16 field trial quinoa varieties from WSU and 5 commercial quinoa samples
from Bolivia and Peru A consumer panel also evaluated their acceptance of 6 selected quinoa
5
samples Using data from the trained panel and the consumer panel the key sensory attributes
driving consumer liking were determined Finally Chapter 7 presents the conclusions and
recommendations for future studies
6
References
Nuntildeez de Acro Chapter 12 Quinoarsquos calling In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 211 ndash 25
Ahamed NT Singhal RS Kulkarni PR Pal M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 31 99-103
Ando H Chen Y Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food Components in
Fractions of Quinoa Seed Food Sci Technol Res 8(1) 80-4
Carimentrand A Baudoin A Lacroix P Bazile D Chia E 2015 Chapter 41 International
quinoa trade In D Bazile D Bertero and C Nieto editors State of the Art Report of
Quinoa in the World in 2013 Rome FAO amp CIRAD p 316 ndash 29
Champagne ET Bett-Garber KL McClung AM Bergman C 2004 Sensory characteristics of
diverse rice cultivars as influenced by genetic and environmental factors Cereal Chem 81
237-43
Chillo S Civica V Iannetti M Mastromatteo M Suriano N Del Nobile M 2010 Influence of
repeated extrusions on some properties of non-conventional spaghetti J Food Eng 100 329-
35
Chlopicka J Pasko P Gorinstein S Jedryas A Zagrodzki P 2012 Total phenolic and total
flavonoid content antioxidant activity and sensory evaluation of pseudocereal breads LWT-
Food Sci Technol 46 548-55
7
Garcia M Raes D Allen R Herbas C 2004 Dynamics of reference evapotranspiration in the
Bolivian highlands (Altiplano) Agr Forest Meteorol 125(1) 67-82
James LEA 2009 Quinoa (Chenopodium quinoa Willd) composition chemistry nutritional
and functional properties Adv Food Nutr Res 58 1-31
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine structure of amylopectin J Cereal Sci 21 251-60
Perdon AA Siebenmorgen TJ Buescher RW Gbur EE 1999 Starch retrogradation and texture
of cooked milled rice during storage J Food Sci 64 828-32
Prego I Maldonado S Otegui M 1998 Seed structure and localization of reserves in
Chenopodium quinoa Ann Bot 82(4) 481-8
Ramesh M Ali SZ Bhattacharya KR1999 Structure of rice starch and its relation to cooked-
rice texture Carbohydr Polym 38 337-47
Rosell CM Cortez G Repo-Carrasco R 2009 Bread making use of Andean crops quinoa
kantildeiwa kiwicha and tarwi Cereal Chem 86 386-92
Sahin S Sumnu SG 2006 Physical properties of foods Springer Science amp Business Media
P39 ndash 109
Schumacher AB Brandelli A Macedo FC Pieta L Klug TV de Jong EV 2010 Chemical and
sensory evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J
Food Sci Technol 47 202-6
8
Tari TA Annapure US Singhal RS Kulkarni PR 2003 Starch-based spherical aggregates
screening of small granule sized starches for entrapment of a model flavouring compound
vanillin Carbohydr Polym 53 45-51
USDA US Department of Agriculture 2015a Peru Quinoa outlook Access from
httpwwwfasusdagovdataperu-quinoa-outlook
9
Chapter 2 Literature Review
Introduction
Quinoa (Chenopodium quinoa Willd) is a dicotyledonous pseudocereal from the Andean
region of South America The plant belongs to a complex of allotetraploid taxa (2n = 4x = 36)
which includes Chenopodium berlandieri subsp berlandieri Chenopodium berlandieri subsp
nuttalliae Chenopodium hircinum and Chenopodium quinoa (Gomez-Pando 2015 Matanguihan
et al 2015) Closely related species include the weed lambsquarter (Chenopodium album)
amaranth (Amaranth palmeri) sugar beet (Beta vulgaris L) and spinach (Spinacea oleracea L)
(Maughan et al 2004) Quinoa plant is C3 specie with 90 self-pollenating (Gonzalez et al
2011) Quinoa was domesticated approximately 5000 ndash 7000 years ago in the Lake Titicaca area
in Bolivia and Peru (Gonzalez et al 2015) Quinoa produces small oval-shaped seeds with a
diameter of 2 mm and a weight of 2 g ndash 46 g 1000-seed (Wu et al 2014) The seed color varies
and can be white yellow orange red purple brown or gray White and red quinoas are the most
common commercially available varietals in the US marketplace (Data from online resources
and local stores in Pullman WA) With such small seeds quinoa provides excellent nutritional
value such as high protein content balanced essential amino acids high proportion of
unsaturated fatty acids rich vitamin B complex vitamin E and minerals antioxidants such as
phenolics and betalains and rich dietary fibers (Wu 2015) For these reasons quinoa is
recognized as a ldquocompleterdquo food (Taverna et al 2012)
10
This chapter reviewed publications in quinoa varieties global development seed
structure and constituents quinoa health benefits physical properties and thermal properties
quinoa flour characteristics processing and quinoa products
Quinoa varieties
There are 16422 quinoa accessions or genetypes conserved worldwide 14502 of which
are conserved in genebanks from the Andean region (Rojas et al 2013) Bolivia and Peru
manage 13023 quinoa accessions (80 of world total accessions) in 140 genebanks (Rojas and
Pinto 2015)
Based on genetic diversity adaptation and morphological characteristics five ecotypes
of quinoa have been identified in the Andean region including valley quinoa Altiplano quinoa
salar quinoa sea level quinoa and subtropical quinoa (Tapia et al 1980) The sea-level ecotype
or Chilean lowland ecotype is the best adapted to temperate climate and high summer
temperature (Peterson and Murphy 2015a)
Adaptation
Quinoa has shown excellent adaptation to marginal or extreme environments and such
adaptation was summarized by Gonzalez et al (2015) Quinoa growing areas range from sea
level to 4200 masl (meters above sea level) with growing temperature rangeing from -4 to 38 ordmC
The plant has adapted to drought-stressed environments but can also grow in areas with
humidity ranging from 40 to 88 Quinoa can grow in marginal soil conditions such as dry
(Garcia et al 2003) infertile (Sanchez et al 2003) and with wide pH range from acidic to basic
(Jacobsen and Stolen 1993) Quinoa has also adapted to high salinity soil (equal to sea salt level
11
or 40 dSm) (Koyro and Eisa 2008 Hariadi et al 2011 Peterson and Murphy 2015b)
Furthermore quinoa has shown tolerance to frost at -8 to -4 ordmC (Jacobsen et al 2005)
Even though quinoa varieties are remarkably diverse and able to adapt to extreme
conditions time and resources are required to breed the high-yielding varieties that are adapted
to regional environments in North America Challenges to achieving strong performance include
yield waterlogging pre-harvest sprouting weed control and tolerance to disease insect pests
and animal stress (Peterson and Murphy 2015a) The breeding work not only needs the effort
from breeders and researchers but also demands the participation and collaboration of local
farmers
In addition to being widely grown in South America quinoa has also recently been
grown in North America Europe Australia Africa and Asia In US quinoa cultivation and
breeding started in the 1980s by the efforts from seed companies private individuals and
Colorado State University (Peterson and Murphy 2015a) Since 2010 Washington State
University has been breeding quinoa in the Pacific Northwest to suit the diverse environmental
conditions including rainfall and temperature Peterson and Murphy (2015a) found the major
challenges in North America included heat susceptibility downy mildew (Plasmopara viticola)
saponin removal weed stress and insect stress (such as aphids and Lygus sp)
With high nutritional value quinoa is recognized as significant in food security and
treating malnutrition issue in developing countries (Rojas 2011) Maliro and Guwela (2015)
reviewed quinoa breeding in Africa Initial experiments showed quinoa can grow well in Malawi
and Kenya in both warm and cool areas The quinoa grain yields in Malawi and Kenya are 3-4
12
tonha which are comparable to the yields in South America However the challenge remains to
adopt quinoa into the local diet and cultivate a quinoa consuming market
Physical Properties of Quinoa
Physical properties of seed refer to seed morphology size gravimetric properties
(weight density and porosity) aerodynamic properties and hardness which are critical to
technology and equipment designed for post-harvest process such as seed cleaning
classification aeration drying and storage (Vilche et al 2003)
The quinoa seed is oval-shaped with a diameter of approximately 18 to 22 mm (Bertero
et al 2004 Wu et al 2014) Mean 1000-seed weight of quinoa is around 27 g (Bhargava et al
2006) and a range of 15 g to 45 g has been observed among varieties (Wu et al 2014)
Commercial quinoa from Bolivia tends to have higher 1000-seed weight of 38 g to 45 g
Additionally bulk density ranges from 066 gmL to 075 gmL in most varieties (Wu et al
2014) Porosity refers to the fraction of space in bulk seed which is not occupied by the seed
(Thompson and Isaac 1976) The porosity of quinoa is 23 (Vilche et al 2003) while that of
rice is 50 to 60 (Kunze et al 2004)
Terminal velocity is the air velocity at which seeds remain in suspension This parameter
is important in cleaning quinoa to remove impurities such as dockage hollow and immature
kernels and mixed weed seeds Vilche et al (2003) reported the terminal velocity of 081 ms-1
while the value of rice was 6 ms-1 to 77 ms-1 (Razavi and Farahmandfar 2008)
Seed hardness or crushing strength is used as a rough estimation of moisture content in
rice (Kunze et al 2004) The hardness of quinoa seed can be tested using a texture analyzer (Wu
13
et al 2014) A stainless cylinder (10 mm in diameter) compressed one quinoa seed to 90 strain
at the rate of 5 mms Because of hardness variation among individual seeds at least six
measurements were required Among the thirteen quinoa samples that were tested hardness
ranged from 58 kg to 110 kg (Wu et al 2014)
Quinoa Seed Structure
Grain structure of quinoa was described in detail by Taylor and Parker (2002) On the
outside of grain is a perianth which can be easily removed during cleaning or rubbing
Sometimes betalain pigments concentrate on this perianth layer and the seed shows bright purple
or golden colors However this color will disappear with the removal of the perianth Inside the
perianth is two-layered pericarp with papillose surface (Figure 1) Beneath the pericarp a seed
coat or episperm is located The seed coat can be white yellow orange red brown or black
Red and white quinoa share the largest market share with consumers exhibiting increasing
interest in brownblack mixed products such as lsquoCalifornia Tricolorrsquo(data from Google
Shopping Amazon and local stores in Pullman WA)
The main seed is enveloped in outside layers and the structure was depicted by Prego et
al (1998) (Figure 2) The embryo (two cotyledons and radicle) coils around a center pericarp
which occupies ~40 of seed volume (Fleming and Galwey 1998) Protein and lipid bodies are
primarily present in the embryo whereas starch granules provide storage in the thin-walled
perisperm Minerals of phosphorus potassium and magnesium are concentrated in phytin
globoids located in the embryo and calcium is located in the pericarp (Konishi et al 2004)
Quinoa Seed Constituents
14
Quinoa is known as a lsquocomplete foodrsquo (James 2009) The seed composition was recently
reviewed by Wu (2015) and Maradini Filho et al (2015) In sum the high nutritional value of
quinoa arises from its high protein content complete and balanced essential amino acids high
proportion of unsaturated fatty acids high concentrations of vitamin B complex vitamin E and
minerals and high phenolic and betalain content
A protein range of 12 to 17 in quinoa has been reported by most studies (Rojas et al
2015) This protein content is higher than wheat (8 to 14 ww) (Halverson and Zeleny 1988)
and rice (4 - 105 ww) (Champagne et al 2004) Additionally quinoa contains all essential
amino acids at concentrations exceeding the suggested requirements from FAOWHO (Table 1)
Quinoa is also gluten-free because it is lacking in prolamins Prolamins are a group of
storage proteins that are rich in proline Prolamins can interact with water and form the gluten
structure which cannot be tolerated by those with celiac disease (Fasano et al 2003) Quinoa and
rice both contain low prolamins (72 and 89 of total protein respectively) and are
considered gluten-free crops Prolamins in wheat (called gliadin) comprise 285 of its total
protein and in maize this concentration of prolamin is 245 (Koziol 1992)
The protein quality of quinoa protein was reported by Ruales and Nair (1992) In raw
quinoa the net protein utilization (NPU) was 757 biological value (BV) was 826 and
digestibility (TD) was 917 all of which were slightly lower than those of casein The
digestibility of quinoa protein is comparable to that of other high quality food proteins such as
soy beans and skim milk (Taylor and Parker 2002) The Protein Efficiency Ratio (PER) in
quinoa ranges from 195 to 31 and is similar to that of casein (Gross et al 1989 Guzmaacuten-
15
Maldonado and Paredes-Lopez 2002) Regarding functional properties of quinoa protein isolates
Eugenia et al (2015) found Bolivian quinoa exhibited the highest thermal stability oil binding
capacity and water binding capacity at acidic pH The Peruvian samples showed the highest
water binding capacity at basic pH and the best foaming capacity at pH 5
Quinoa starch content ranges from 58 to 64 of the dry seed weight (Vega‐Gaacutelvez et
al 2010) Quinoa possesses a small granule size of 06 to 2 μm similar to that of amaranth (1 to
2 μm) and much smaller than those of other grains such as rice wheat oat barley and
buckwheat (2 to 36 μm) (Lindeboom et al 2004) The amylose content in quinoa starch tends to
be lower than found in common grains A range of 3 to 20 was reported by Lindeboom et al
(2005) whereas amylose content is around 25 in cereals As in most cereals quinoa starch is
type A in X-ray diffraction pattern (Ando et al 2002) Li et al (2016) found significant variation
among 26 commercial quinoa samples in the physicochemical properties of starch such as gel
texture thermal and pasting parameters which were strongly affected by apparent amylose
content
Quinoa lipids comprise 55 to 71 of dry seed weight in most reports (Maradini Filho
et al 2015) Ando et al (2002) found quinoa (cultivar Real TKW from Bolivia) perisperm and
embryo contained 50 and 102 total fatty acids respectively Among these fatty acids
unsaturated fatty acids such as oleic linoleic and linolenic comprised 875 Ogungbenle
(2003) reported the properties of quinoa lipids The values of acid iodine peroxide and
saponification were 05 54 24 and 192 respectively
16
Quinoa micronutrients of vitamins and minerals and the relative lsquoreference daily intakersquo
are summarized in Table 2 and 3 respectively Compared to Daily Intake References quinoa
provides a good source of Vitamin B1 B2 and B9 and Vitamin E as well as minerals such as
magnesium phosphorous iron and copper
Quinoa is one of the crops representing diversity in color including white vanilla
yellow orange red brown gray and dark Besides the anthocyannins in dark quinoa (Paśko et
al 2009) the major pigment in quinoa is betalain primarily presenting in seed coat and the
compounds can be subdivided into red-violet betacyannins and yellow-orange betaxanthins
(Tang et al 2015) Betalain is a water-soluble pigment which is permitted quantum satis as a
natural food colorant and applied in fruit yogurt ice cream jams chewing gum sauces and
soups (Esatbeyoglu et al 2015) Additionally betalain potentially offers health benefits such as
antioxidant activity anti-inflammation activity preventing low-density lipoprotein (LDL)
oxidation and DNA damage (Benavente-Garcia and Castillo 2008 Esatbeyoglu et al 2015)
Saponins
Saponins are compounds on the seed coat of quinoa that confer a bitter taste The
compounds are considered to be a defense system against herbivores and pathogens Regarding
chemical structure saponins are a group of glycosides consisting of a hydrophilic carbohydrate
chain (such as arabinose glucose galactose xylose and rhamnose) and a hydrophobic aglycone
(Kuljanabhagavad and Wink 2009) Chemical structures of aglycones were summarized by
Kuljanabhagavad and Wink (2009)
17
Saponins have been considered as anti-nutrient because of haemolytic activity which
refers to the breakdown of red blood cells (Khalil and El-Adawy 1994) However saponins
exhibited health benefit functions such as anti-inflammation (Yao et al 2009) antibacterial
antimicrobial activity (Killeen et al 1998) anti-tumor activity (Shao et al 1996) and
antioxidant activity (Guumllccedilin et al 2006) Furthermore saponins have medicinal use Sun et al
(2009) reported saponins can activate immune system and were used as vaccine adjuvants
Saponins also exhibited anti-cancer activity (Man et al 2010)
Even though saponins have potential health benefits their bitter taste is not pleasant to
consumers To address the bitterness found in bitter quinoa varieties (gt 011 saponin content)
sweet quinoa varieties were bred through conventional genetic selection to contain a lower
saponin content (lt 011 saponin content) For instance lsquoSajamarsquo lsquoKurmirsquo lsquoAynoqarsquo
lsquoKosunarsquo and lsquoBlanquitarsquo in Bolivia lsquoBlanca de Juninrsquo in Peru and lsquoTunkahuanrsquo in Ecuador are
considered sweet quinoa varieties (Quiroga et al 2015) Unfortunately varieties from Bolivia
Peru and Ecuador do not adapt to temperate climates such as those found in the Pacific
Northwest in US and Europe A sweet variety called lsquoJessiersquo exhibits acceptable yield in Pacific
Northwest and has a great market potential Further development of sweet quinoa varieties
adapted to local climate will happen in near future
To remove saponins both dry and wet processing methods have been developed The wet
method or moist method refers to washing quinoa while rubbing the grain with hands or by a
stone Repo-Carrasco et al (2003) suggested the best washing conditions of 20 min soaking 20
min stirring with a water temperature of 70 degC The wet method becomes costly due to the
required drying process Additionally quinoa grain may begin to germinate during wet cleaning
18
The dry method or abrasive dehulling uses mechanical abrasion to polish the grain and
remove the saponins A dehulling process was reported by Reichert et al (1986) using Tanential
Abrasive Dehulling Device (TADD) and removal of 6 - 15 of kernel was required to reduce
the saponins content to lower than 011 Additionally a TM-05 Taka-Yama testing mill was
used in the quinoa pearling process (to 20 - 30 pearling degree) (Goacutemez-Caravaca et al
2014) The dry method is relatively cheaper than wet method and does not generate saponin
waste water The saponin removal efficiency of the dry and washing methods were reported to be
87 and 72 respectively (Reichert et al 1986 Gee et al 1993) A combination of dry and wet
methods was recommended to obtain the efficient cleaning (Repo-Carrasco et al 2003)
Since quinoa is such an expensive crop a 25 to 30 weight lost during the cleaning
process represents a substantial loss on an industrial scale In addition mineral phenolic and
fiber content may dramatically decrease during processing resulting in a loss of nutritional
value Hence cleaning process should be further optimized to reach lower grain weight loss
while maintain an efficient saponins elimination
Removed saponins can be utilized as side products Since saponins also have excellent
foaming property they can be applied in cosmetics and foods as foam-stabilizing and
emulsifying agents (Yang et al 2010) detergents (Chen et al 2010) and preservatives
(Taormina et al 2006)
Saponin content is important to analyze since it highly influences the taste of quinoa
Traditionally the afrosimetric method or foam method was used to estimate saponins content In
this method saponon content is calculated from foam height after shaking quinoa and water
19
mixture for a specific time (Koziol 1991) This afrosimetric method is fast and affordable and
can be used by farmers as a quick estimation of saponin content however the method is not very
accurate The foam stability varies among samples A more accurate method was developed
using Gas Chromatography (GC) (Ridout et al 1991) Using this method quinoa flour was first
defatted using a Soxhlet extraction and then hydrolyzed in reflux for 3 h with a methanol
solution of HCl (2 N) The hydrolysis product sapogenins were extracted with ethyl acetate and
derivatized with bis-(trimethylsilyl) trifluoroacetamide (BSTFA) and dry pyridine and then
tested using GC Generally GC method is a more solid and accurate method compared to foam
method however GC also requires high capital investment as well as long and complex sample
preparation For quinoa farmers and food manufactures fast and affordable methods to test
saponins content in quinoa need to be developed
Saponins have been an important topic in quinoa research Future studies in this area can
include 1) breeding and commercialization of saponin-free or sweet quinoa varieties with high
yield and high agronomy performance (resistance to biotic and abiotic stresses) 2) development
of quick and low cost detection method of saponin content and 3) application of saponin in
medicine foods and cosmetics can be further explored
Health benefits
Simnadis et al (2015) performed a meta-analysis of 18 studies which used animal models
to assess the physiological effects associated with quinoa consumption From these studies
purported physiological effects of quinoa consumption included decreased weight gain
improved lipid profile (decrease LDL and cholesterol) and improved capacity to respond to
20
oxidative stress Simnadis et al (2015) pointed out that the presence of saponins protein and
20-hydroxyecdysone (affects energy homeostasis and intestinal fat absorption) contributed to
those benefit effects
Furthermore Ruales et al (2002) found increased plasma levels of IGF-1 (insulin-like
growth factor) in 50-65 month-old boys after consuming a quinoa infant food for 15 days This
result implicated the potential of quinoa to reduce childhood malnutrition In another study of 22
students (aged 18 to 45) the daily consumption of a quinoa cereal bar for 30 days significantly
decreased triglycerides cholesterol and LDL compared to those parameters prior to quinoa
consumption These results suggest that quinoa intake may reduce the risk of developing
cardiovascular disease (Farinazzi-Machado et al 2012) De Carvalho et al (2014) studied the
influence of quinoa on over-weight postmenopausal women Consumption of quinoa flakes (25
gd for 4 weeks) was found to reduce serum triglycerides and TBARS (thiobarbituric acid
reactive substances) and increase GSH (glutathione) and urinary excretion of enterolignans
compared to those indexes before consuming quinoa flakes
Quinoa flour properties
Functional properties of quinoa flour were determined by Ogungbenle (2003) Quinoa
flour has high water absorption capacity (147) and low foaming capacity (9) and stability
(2) Water absorption capacity was determined by the volume of water retained per gram of
quinoa flour during 30-min mixing at 24 ordmC (Beuchat 1977) The water absorption of quinoa was
higher than that of fluted pumpkin seed (85) soy flour (130) and pigeon pea flour (138)
which implies the potential use of quinoa flour in viscous foods such as soups doughs and
21
baked products Additionally foaming capacity was determined by the foam volumes before and
after whipping of 8 protein solution at pH 70 (Coffmann and Garciaj 1977) Then foam
samples were inverted and dripped though 2 mm wire screen in to beakers The foam stability
was determined by the weight of liquid released from foam after a specific time and the original
weight of foam (Coffmann and Garciaj 1977) Furthermore minimum protein solubility was
observed at pH 60 similar to that of pearl millet and higher than pigeon pea (pH 50) and fluted
pumpkin seed (pH 40) Relatively high solubility of quinoa protein in acidic condition implies
the potential application of quinoa protein in acidic food and carbonated beverages
Wu et al (2014) studied flour viscosity among 13 quinoa samples with large variations
reported among samples The ranges of peak viscosity final viscosity and setback were 59
RVU ndash 197 RVU 56 RVU ndash 203 RVU and -62 RVU ndash 73 RVU respectively which were
comparable to those of rice flour (Zhou et al 2003) Flour viscosity significantly influence
texture of quinoa and rice (Champagne et al 1998 Wu et al 2014)
Ruales et al (1993) studied processing influence on the physico-chemical characteristics
of quinoa flour The process included cooking and autoclaving of the seeds drum drying of
flour and extrusion of the grits Autoclaved quinoa samples exhibited the lowest degree of starch
gelatinization (325) whereas precookeddrum dried quinoa samples were 974 Higher
polymer degradation was found in the cooked samples compared to the autoclaved samples
Water solubility in cooked samples (54 to 156) and autoclaved samples (70 to 96) increased
with the processing time (30 to 60 min cooking and 10 to 30 min autoclaving)
Thermal Properties of quinoa
22
Thermal properties of quinoa flour (both starch and protein) have been determined using
Differential Scanning Calorimetry (DSC) (Abugoch et al 2009) A quinoa flour suspension was
prepared in 20 (ww) concentration The testing temperature was raised from 27 to 120 degC at a
rate of 10 degCmin Two peaks in the DSC graph referenced the starch gelatinization temperature
at 657 degC and protein denaturalization at 989 degC Enthalpy refers to the energy required to
complete starch gelatinization or protein denaturazition In the study of Abugoch et al (2009)
the enthalpy was 59 Jg for starch and 22 Jg for proteins in quinoa
Product development with quinoa
Quinoa has been used in different products such as spaghetti bread and cookies to
enhance nutritional value including a higher protein content and more balanced amino acid
profile Chillo et al (2008) evaluated the quality of spaghetti from amaranth and quinoa flour
Compared to durum semolina spaghetti the spaghetti with amaranth and quinoa flour exhibited
equal breakage susceptibility higher cooking loss and lower instrumental stickiness The
sensory acceptance scores were not different from the control The solid loss weight increase
volume increase adhesiveness and moisture of a corn and quinoa mixed spaghetti were 162thinspg
kgminus1 23 times 26 times 20907thinspg and 384thinspg kgminus1 respectively (Caperuto et al 2001)
Schoenlechner et al (2010) found the optimal combination of 60 buckwheat 20 amaranth
and 20 quinoa yielded an improved dough matrix compared to other flour combinations With
the addition of 6 egg white powder and 12 emulsifier (distilled monoglycerides) this gluten-
free pasta exhibited acceptable firmness and cooking quality compared to wheat pasta
23
Stikic et al (2012) added 20 quinoa seeds in bread formulations which resulted in the
similar dough development time and stability compared to those of wheat dough even though
the bread specific volume was lower (63 mLg) compared to wheat bread (67 mLg) The
protein content of bread increased by 2 (ww) and sensory characteristics were lsquoexcellentrsquo as
evaluated by five trained expert panelists Iglesias-Puig et al (2015) found 25g100 g quinoa
flour substitution in wheat bread showed small depreciation in bread quality in terms of loaf
volume crumb firmness and acceptability whereas the nutritional value increased in dietary
fiber minerals protein and healthy fats Rizzello et al (2016) selected strains (lactic acid
bacteria) to develop a quinoa sourdough A wheat bread with 20 (ww) quinoa sourdough
exhibited improved nutritional (such as protein digestibility and quality) textural and sensory
features Quinoa leaves were also applied to bread making (Świeca et al 2014) With the
replacement of wheat flour by 1 to 5 (ww) quinoa leaves the bread crumb exhibited increased
firmness cohesiveness and gumminess Antioxidant activity and phenolic contents both
significantly increased compared to wheat bread
Pagamunici et al (2014) developed three gluten-free cookies with rice and quinoa flour
with 15 26 and 36 (ww) quinoa flour proportions respectively The formulation with
36 quinoa flour had the highest alpha-linolenic acid and mineral content and the cookie
displayed excellent sensory characteristics as evaluated by 80 non-trained consumer panelists
Another study optimized a gluten-free quinoa formulation with 30 quinoa flour 25 quinoa
flakes and 45 corn starch (Brito et al 2015) The cookie was characterized as a product rich in
essential amino acids linolenic acid minerals and dietary fiber This cookie was among those
24
products using the highest quinoa flour content (55 ww) while still received acceptable
sensory scores
Repo-Carrasco-Valencia and Serna (2011) introduced an extrusion process in Peru
Quinoa flour was tempered to 12 moisture for extrusion During extrusion total and insoluble
dietary fiber decreased by 5 to 17 and 13 to 29 respectively whereas the soluble dietary
fiber significantly increased by 38 to 71 Additionally the radical scavenging activity was
also increased in extruded quinoa compared to raw quinoa
Schumacher et al (2010) developed a dark chocolate with addition of 20 quinoa An
improved nutritional value was observed in 9 (ww) increase in vitamin E 70 - 104
increases in amino acids of cysteine tyrosine and methionine This quinoa dark chocolate
received over 70 acceptance index from sensory panel
Gluten-free beer is of increasing interest in the market (Dezelak et al 2014) Ogungbenle
(2003) found quinoa has high D-xylose and maltose and low glucose and fructose content
suggesting its potential use in malted drink de Meo et al (2011) applied alkaline steeping to
pseudocereal and found its positive effects on pseudocereals malt production by increasing total
soluble nitrogen and free amino nitrogen Kamelgard (2012) patented a method to create a
quinoa-based beverage fermented by a yeast Saccharomyces cerevisiae The beverage can be
distilled and aged to form gluten-free liquor Dezelak et al (2014) processed a quinoa beer-like
beverage (fermented with Saccharomyces pastorianus TUM 3470) resulting in a product with a
nutty aroma low alcohol content and rich in minerals and amino acids However further
development of the brewing procedure was necessary since the beverage showed a less attractive
25
appearance (near to black color and greyish foam) and astringent mouthfeel Compared to barley
brewing attributes of quinoa exhibited lower malt extracts longer saccharification times higher
values in total protein fermentable amino nitrogen content and iodine test
Processing quinoa grain to dried edible product and sweet quinoa product were developed
by Scanlin and Burnett (2010) The edible quinoa product was processed through pre-
conditioning (abrasion and washing) moist heating (steam cooking and pressure cooking) dry
heating (baking toasting and dehydrating) and post-production treatment As for sweet quinoa
product germination and malting processing were applied Caceres et al (2014) patented a
process to extract peptides and maltodextrins from quinoa flour and the extracts were applied in
a gel-format food as a supplement during and after physical activity
26
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flour proteins (Chenopodium quinoa Willd) during storage Int J Food Sci Tech 44(10)
2013-20
Abugoch LE Romero N Tapia CA Silva J Rivera M 2008 Study of some physicochemical
and functional properties of quinoa (Chenopodium quinoa Willd) protein isolates J Agric
Food Chem 56(12) 4745-50
Ando H Chen Y Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food Components in
Fractions of Quinoa Seed Food Sci Technol Res 8(1) 80-4
Benavente-Garcia O Castillo J 2008 Update on uses and properties of citrus flavonoids new
findings in anticancer cardiovascular and anti-inflammatory activity J Agric Food Chem
56(15) 6185-205
Bertero HD de la Vega AJ Correa G Jacobsen SE Mujica A 2004 Genotype and genotype-
by-environment interaction effects for grain yield and grain size of quinoa (Chenopodium
quinoa Willd) as revealed by pattern analysis of international multi-environment trials Field
Crops Res 89(2ndash3) 299-318
Beuchat LR 1977 Functional and electrophoretic characteristics of succinylated peanut flour
protein J Agric Food Chem 25(2) 258-61
Bhargava A Shukla S Rajan S Ohri D 2006 Genetic diversity for morphological and quality
traits in quinoa (Chenopodium quinoa Willd) Germplasm Genet Resour Crop Evol 54(1)
167-73
27
Brito IL de Souza EL Felex SSS Madruga MS Yamashita F Magnani M 2015 Nutritional
and sensory characteristics of gluten-free quinoa (Chenopodium quinoa Willd)-based
cookies development using an experimental mixture design J Food Sci Technol 52(9) 5866-
73
Caceres JIE Calderon PD Lira FO 2014 Method for the formulation of a gel-format foodstuff
for use as a nutritional foodstuff enriched with peptides and maltodextrins obtained from
quinoa flour Google Patents
Caperuto LC Amaya-Farfan J Camargo CRO 2001 Performance of quinoa (Chenopodium
quinoa Willd) flour in the manufacture of gluten-free spaghetti J Sci Food Agric 81(1) 95-
101
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5) 764-71
Champagne ET Wood DF Juliano BO Bechtel D 2004 Chapter 4 The rice grain and its gross
composition In Champagne ET editor Rice Chemistry and Technology 3rd edition St
Paul MN American Association of Cereal Chemists Inc p 88 ndash 9
Chen YF Yang CH Chang MS Ciou YP Huang YC 2010 Foam properties and detergent
abilities of the saponins from Camellia oleifera Int J Mol Sci11(11) 4417-25
28
Chillo S Laverse J Falcone PM Del Nobile MA 2008 Quality of spaghetti in base amaranthus
wholemeal flour added with quinoa broad bean and chick pea J Food Process Eng 84(1)
101-7
Coffmann CW Garciaj VV 1977 Functional properties and amino acid content of a protein
isolate from mung bean flour Int J Food Sci Technol 12(5) 473-84
De Carvalho FG Oviacutedio PP Padovan GJ Jordao Junior AA Marchini JS Navarro AM 2014
Metabolic parameters of postmenopausal women after quinoa or corn flakes intakendasha
prospective and double-blind study Int J Food Sci Nutr 65(3) 380-5
Deželak M Zarnkow M Becker T Košir IJ 2014 Processing of bottom-fermented gluten-free
beer-like beverages based on buckwheat and quinoa malt with chemical and sensory
characterization J Inst Brew 120(4) 360-70
Farinazzi-Machado FMV Barbalho SM Oshiiwa M Goulart R Pessan Junior O 2012 Use of
cereal bars with quinoa (Chenopodium quinoa W) to reduce risk factors related to
cardiovascular diseases Food Sci Technol(Campinas) 32(2) 239-44
Fasano A Berti I Gerarduzzi T Not T Colletti RB Drago S Hill ID 2003 Prevalence of celiac
disease in at-risk and not-at-risk groups in the United States a large multicenter study Arch
Intern Med 163(3) 286-92
Fleming JE Galwey NW 1998 Quinoa (Chenopodium quinoa Willd) nutritional quality and
technological aspects as human food In Belton PS Taylor JRN editors Increasing the
29
utilisation of sorghum buckwheat grain amaranth and quinoa for improved nutrition
Norwich UK Institute of Food Research p 49-64
Friedman M Brandon DL 2001 Nutritional and health benefits of soy proteins J Agric Food
Chem 49(3)1069-86
Garcia M Raes D Jacobsen SE 2003 Evapotranspiration analysis and irrigation requirements
of quinoa (Chenopodium quinoa) in the Bolivian highlands Agr Water Manage 60(2) 119-
34
Gee JM Price KR Ridout CL Wortley GM Hurrell RF Johnson IT 1993 Saponins of quinoa
(Chenopodium quinoa) effects of processing on their abundance in quinoa products and their
biological effects on intestinal mucosal tissue J Sci Food Agric 63(2) 201-9
Goacutemez-Caravaca AM Iafelice G Verardo V Marconi E Caboni MF 2014 Influence of
pearling process on phenolic and saponin content in quinoa (Chenopodium quinoa Willd)
Food Chem 157 174-8
Gomez-Pando L 2015 Chapter 6 Quinoa breeding In Murphy KM Matanguihan J editors
Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p
87 ndash 97
Gonzaacutelez JA Bruno M Valoy M Prado FE 2011 Genotypic variation of gas exchange
parameters and leaf stable carbon and nitrogen isotopes in ten quinoa cultivars grown under
drought J Agron Crop Sci 197(2) 81-93
30
Gonzaacutelez JA Eisa SSS Hussin SAES and Prado FE 2015 Chapter 1 Quinoa An Incan Crop
to Face Global Changes in Agriculture In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 182-6
Graf BL Rojas-Silva P Rojo LE Delatorre-Herrera J Baldeoacuten ME Raskin I 2015 Innovations
in health value and functional food development of quinoa (Chenopodium quinoa Willd)
Comp Rev Food Sci Food Safety 14(4) 431-45
Gross R Koch F Malaga I de Miranda A Schoeneberger H Trugo L 1989 Chemical
composition and protein quality of some local Andean food sources Food Chem 34(1) 25-
34
Guumllccedilin İ Mshvildadze V Gepdiremen A Elias R 2006 The antioxidant activity of a
triterpenoid glycoside isolated from the berries of Hedera colchica 3-O-(β-d-
glucopyranosyl)-hederagenin Phytother Res 20(2) 130-4
Guzmaacuten-Maldonado S Paredes-Lopez O 2002 Functional products of plants indigenous to
Latin America amaranth quinoa common beans and botanicals In Shi J Mazza G
Maguer ML editors Functional foods Biochemical and processing aspects CRC Press p
293-328
Halverson J Zeleny L 1988 Chapter 2 Criteria of wheat quality In Pomeranz Y editor
Wheat Chemistry and Technology 3rd edition St Paul MN American Association of
Cereal Chemists Inc p 25 ndash 6
31
Hariadi Y Marandon K Tian Y Jacobsen SE Shabala S 2011 Ionic and osmotic relations in
quinoa (Chenopodium quinoa Willd) plants grown at various salinity levels J Exp Bot
62(1) 185-93
Iglesias-Puig E Monedero V Haros M 2015 Bread with whole quinoa flour and bifidobacterial
phytases increases dietary mineral intake and bioavailability LWT-Food Sci Technol 60(1)
71-7
Jacobsen SE Monteros C Christiansen J Bravo L Corcuera L Mujica A 2005 Plant responses
of quinoa (Chenopodium quinoa Willd) to frost at various phenological stages Eur J Agron
22(2) 131-9
Jacobsen SE Stoslashlen O 1993 Quinoa-morphology phenology and prospects for its production as
a new crop in Europe Eur J Agron 2(1) 19-29
James LEA 2009 Quinoa (Chenopodium quinoa Willd) composition chemistry nutritional
and functional properties Adv Food Nutr Res 58 1-31
Kamelgard JI 2012 Quinoa-based beverages and method of creating quinoa-based beverages
Google Patents
Khalil A El-Adawy T 1994 Isolation identification and toxicity of saponin from different
legumes Food Chem 50(2) 197-201
Killeen GF Madigan CA Connolly CR Walsh GA Clark C Hynes MJ Power RF 1998
Antimicrobial saponins of Yucca schidigera and the implications of their in vitro properties
for their in vivo impact J Agric Food Chem 46(8) 3178-86
32
Konishi Y Hirano S Tsuboi H Wada M 2004 Distribution of minerals in quinoa
(Chenopodium quinoa Willd) seeds Biotechnol Appl Biochem 68(1) 231-4
Koyro HW Eisa SS 2008 Effect of salinity on composition viability and germination of seeds
of Chenopodium quinoa Willd Plant Soil 302(1-2) 79-90
Kozioł M1992 Chemical composition and nutritional evaluation of quinoa (Chenopodium
quinoa Willd) J Food Compost Anal 5(1) 35-68
Kuljanabhagavad T Wink M 2009 Biological activities and chemistry of saponins from
Chenopodium quinoa Willd Phytochem Rev 8(2) 473-90
Kunze OR Lan Y and Wratten FT 2004 Chapter 8 Physical and mechanical properties of rice
In Champagne ET editor Rice Chemistry and Technology 3rd edition St Paul MN
American Association of Cereal Chemists Inc p 193 ndash 211
Li G Wang S Zhu F 2016 Physicochemical properties of quinoa starch Carbohydr Polym 137
328-38
Lindeboom N Chang PR Falk KC Tyler RT 2005 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2) 216-22
Lindeboom N Chang PR Tyler RT 2004 Analytical biochemical and physicochemical aspects
of starch granule size with emphasis on small granule starches a review Starch-Staumlrke 56(3-
4) 89-99
Man S Gao W Zhang Y Huang L Liu C 2010 Chemical study and medical application of
saponins as anti-cancer agents Fitoterapia 81(7) 703-14
33
Maradini Filho AM Pirozi MR Da Silva Borges JT Pinheiro SantAna HM Paes Chaves JB
Dos Reis Coimbra JS 2015 Quinoa nutritional functional and antinutritional aspects Crit
Rev Food Sci Nutr (just-accepted)
Matanguihan JB Jellen EN and Kolano A 2015 Chapter 7 Quinoa cytogenetics molecular
genetics and diversity In Murphy KM Matanguihan J editors Quinoa Improvement and
Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 109-24
Maughan PJ Bonifacio A Jellen EN Stevens MR Coleman CE Ricks M Mason SL Jarvis
DE Gardunia BW Fairbanks DJ 2004 A genetic linkage map of quinoa (Chenopodium
quinoa) based on AFLP RAPD and SSR markers Theor Appl Genet 109(6) 1188-95
de Meo B Freeman G Marconi O Booer C Perretti G Fantozzi P 2011 Behaviour of Malted
Cereals and Pseudo-Cereals for Gluten-Free Beer Production J Inst Brew 117(4) 541-6
Ogungbenle H 2003 Nutritional evaluation and functional properties of quinoa (Chenopodium
quinoa) flour Int J Food Sci Nutr 54(2) 153-8
Ogungbenle HN 2003 Nutritional evaluation and functional properties of quinoa (Chenopodium
quinoa) flour Int J Food Sci Nutr 54(2) 153-8
Quiroga C Escalera R Aroni G Bonifacio A Gonzaacutelez JA Villca M Saravia R Ruiz A 2015
Chapter 31 Traditional processes and Technological Innovations in Quinoa Harvesting
Processing and Industrialization In D Bazile D Bertero and C Nieto editors State of the
Art Report of Quinoa in the World in 2013 Rome FAO amp CIRAD p 213 - 4
34
Pagamunici LM Gohara AK Souza AHP Bittencourt PRS Torquato AS Batiston WP
Matsushita M 2014 Using chemometric techniques to characterize gluten-free cookies
containing the whole flour of a new quinoa cultivar J Brazil Chem Soc 25 219-28
Paśko P Bartoń H Zagrodzki P Gorinstein S Fołta M Zachwieja Z 2009 Anthocyanins total
polyphenols and antioxidant activity in amaranth and quinoa seeds and sprouts during their
growth Food Chem 115(3) 994-8
Peterson AJ Murphy KM 2015a Chapter 10 Quinoa Cultivation for Temperate North America
Considerations and Areas for Investigation In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 182-6
Peterson A Murphy K 2015b Tolerance of lowland quinoa cultivars to sodium chloride and
sodium sulfate salinity Crop Sci 55(1) 331-8
Prego I Maldonado S Otegui M 1998 Seed structure and localization of reserves in
Chenopodium quinoa Ann Bot 82(4) 481-8
Ranhotra GS Gelroth JA Glaser BK Lorenz KJ Johnson DL 1993 Composition and protein
nutritional quality of quinoa Cereal Chem 70(3)303-5
Razavi SMA Farahmandfar R 2008 Effect of hulling and milling on the physical properties of
rice grains Int Agrophys 22(4) 353-9
Reichert R Tatarynovich J Tyler R 1986 Abrasive dehulling of quinoa (Chenopodium quinoa)
effect on saponin content as determined by an adapted hemolytic assay Cereal Chem 63(6)
471-5
35
Repo-Carrasco-Valencia RAM Serna LA 2011 Quinoa (Chenopodium quinoa Willd) as a
source of dietary fiber and other functional components Food Sci Technol (Campinas) 31
225-30
Repo-Carrasco R Espinoza C Jacobsen SE 2003 Nutritional value and use of the Andean crops
quinoa (Chenopodium quinoa) and kantildeiwa (Chenopodium pallidicaule) Food Rev Int 19(1-
2) 179-89
Ridout CL Price KR Dupont MS Parker ML Fenwick GR 1991 Quinoa saponinsmdashanalysis
and preliminary investigations into the effects of reduction by processing J Sci Food Agric
54(2) 165-76
Rizzello CG Lorusso A Montemurro M Gobbetti M 2016 Use of sourdough made with
quinoa (Chenopodium quinoa) flour and autochthonous selected lactic acid bacteria for
enhancing the nutritional textural and sensory features of white bread Food Microbiol 56 1-
13
Rojas W 2011 Quinoa an ancient crop to contribute to world food security Santiago Chile
FAO Oficina Regional para America Latina y el Caribe
Rojas W Pinto M Alanoca C Goacutemez-Pando L Leoacuten-Lobos P Alercia A Diulgheroff S
Padulosi S Bazile D 2013 Estado de la conservacioacuten ex situ de los recursos geneacuteticos de
quinua In Didier B Daniel BH Carlos N editors Estado del arte de la quinua en el mundo
en Libro de resuacutemenes Santiago FAO p 20-21
36
Rojas W Pinto M 2015 Chapter 8 Ex situ conservation of quinoa the bolivian experience In
Murphy KM Matanguihan J editors Quinoa Improvement and Sustainable Production
Hoboken NJ John Wiley amp Sons Inc p 128-30
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile D
Bertero D Nieto C editors State of the Art Report of Quinoa in the World in 2013 Rome
FAO amp CIRAD p 67
Ruales J Nair BM 1992 Nutritional quality of the protein in quinoa (Chenopodium quinoa
Willd) seeds Plant Foods Hum Nutr 42(1) 1-11
Ruales J Nair BM 1993 Saponins phytic acid tannins and protease inhibitors in quinoa
(Chenopodium quinoa Willd) seeds Food Chem 48(2)137-43
Ruales J Valencia S Nair B 1993 Effect of processing on the physico-chemical characteristics
of quinoa flour (Chenopodium quinoa Willd) Starch - Staumlrke 45(1)13-9
Ruales J Grijalva YD Lopez-Jaramillo P Nair BM 2002 The nutritional quality of an infant
food from quinoa and its effect on the plasma level of insulin-like growth factor-1 (IGF-1) in
undernourished children Int J Food Sci Nutr 53(2) 143-54
Sanchez HB Lemeur R Damme PV Jacobsen SE 2003 Ecophysiological analysis of drought
and salinity stress of quinoa (Chenopodium quinoa Willd) Food Rev Int 19(1-2) 111-9
Scanlin LA Burnett C (2010) Quinoa grain processing and products Google Patents
37
Schoenlechner R Drausinger J Ottenschlaeger V Jurackova K Berghofer E 2010 Functional
Properties of Gluten-Free Pasta Produced from Amaranth Quinoa and Buckwheat Plant
Foods Hum Nutr 65(4) 339-49
Schumacher AB Brandelli A Macedo FC Pieta L Klug TV de Jong EV 2010 Chemical and
sensory evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J
Food Sci Technol 47(2) 202-6
Shao Y Chin CK Ho CT Ma W Garrison SA Huang MT 1996 Anti-tumor activity of the
crude saponins obtained from asparagus Cancer Lett 104(1) 31-6
Simnadis TG Tapsell LC Beck EJ 2015 Physiological Effects Associated with Quinoa
Consumption and Implications for Research Involving Humans a Review Plant Foods Hum
Nutr 70(3) 238-49
Steffolani ME Villacorta P Morales-Soriano E Repo-Carrasco R Leoacuten AE Perez GT 2015
Physico-chemical and functional characterization of protein isolated from different quinoa
varieties (Chenopodium quinoa Willd) Cereal Chem (Accepted for publication)
Stevens MR Coleman CE Parkinson SE Maughan PJ Zhang HB Balzotti MR Kooyman DL
Arumuganathan K Bonifacio A Fairbanks DJ Jellen EN Stevens JJ 2006 Construction of
a quinoa (Chenopodium quinoa Willd) BAC library and its use in identifying genes
encoding seed storage proteins Theor Appl Genet 112(8) 1593-600
Stikic R Glamoclija D Demin M Vucelic-Radovic B Jovanovic Z Milojkovic-Opsenica D
Jacobsen SE Milovanovic M 2012 Agronomical and nutritional evaluation of quinoa seeds
38
(Chenopodium quinoa Willd) as an ingredient in bread formulations J Cereal Sci 55(2)
132-8
Sun HX Xie Y Ye YP 2009 Advances in saponin-based adjuvants Vaccine 27(12) 1787-96
Świeca M Sęczyk Ł Gawlik-Dziki U Dziki D 2014 Bread enriched with quinoa leaves - The
influence of protein-phenolics interactions on the nutritional and antioxidant quality Food
Chem 162 54-62
Tang Y Li X Zhang B Chen PX Liu R Tsao R 2015 Characterisation of phenolics betanins
and antioxidant activities in seeds of three Chenopodium quinoa Willd genotypes Food
Chem 166 380-8
Taormina PJ Simpson PG Bertera EA Komitopoulou E 2006 Beverage preservatives Google
Patents
Tapia M Mujica A Canahua A 1980 Origen y distribucion geografica y sistemas de
produccion de la quinua (Chenopodium quinoa Wild) Publicacion Universidad Nacional
Tecnica del Altiplano
Taverna LG Leonel M Mischan MM 2012 Changes in physical properties of extruded sour
cassava starch and quinoa flour blend snacks Food Sci Technol (Campinas) 32 826-34
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Taylor JRN Parker ML editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science amp Business Media p 96-9
39
Thompson R Isaacs G 1967 Porosity determinations of grains and seeds with an air-
comparison pycnometer T ASAE 10(5) 693-6
Vega-Gaacutelvez A Miranda M Vergara J Uribe E Puente L Martiacutenez EA 2010 Nutrition facts
and functional potential of quinoa (Chenopodium quinoa willd) an ancient Andean grain a
review J Sci Food Agric 90(15) 2541-7
USDA US Department of Agriculture Agricultrual Research Service 2015 USDA national
nutrient database for standard reference Release 18 Nutrient Data Laboratory Home Page
Available from httpwwwarsusdagovServicesdocshtmdocid=8964
Vilche C Gely M Santalla E 2003 Physical Properties of Quinoa Seeds Biosyst Eng 86(1) 59-
65
Wu G Morris CF Murphy KM 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79(11) 2337-45
Wu G Chapter 11 Nutritional properties of quinoa In Murphy KM Matanguihan J editors
Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc
p193 ndash 205
Yang CH Huang YC Chen YF Chang MH 2010 Foam properties detergent abilities and long-
term preservative efficacy of the saponins from J Food Drug Anal 18(3) 4417-25
Yao Y Yang X Shi Z Ren G 2014 Anti-inflammatory activity of saponins from quinoa
(Chenopodium quinoa Willd) Seeds in lipopolysaccharide-stimulated raw 2647
Macrophages Cells J Food Sci 79(5) 1018-23
40
Zhou Z Robards K Helliwell S Blanchard C 2003 Effect of rice storage on pasting properties
of rice flour Food Res Int 36(6) 625-34
41
Table 1-Essential amino acid of quinoa protein and FAOWHO suggested requirement (mgg protein)
Essential amino acid Quinoa protein a FAOWHO suggested requirement b
Histidine 258 18
Isoleucine 433 25
Leucine 736 55
Lysine 525 51
Methionine amp Cysteine 273 25
Phenylalanine amp Tyrosine 803 47
Threonine 439 27
Tryptophan 385 7
Valine 506 32
a) Abugoch et al (2008) b) Friedman and Brandon (2001)
42
Table 2-Quinoa vitamins content (mg100g)
Quinoa a-d Reference Daily Intake
Thianmin (B1) 029-038 15
Riboflavin (B2) 030-039 17
Niacin (B3) 106-152 20
Pyridoxine (B6) 0487 20
Folate (B9) 0781 04
Ascorbic acid (C) 40 60
α-Tocopherol (VE) (IU) 537 30
Β-Carotene 039 NR
a (Koziol 1992) b (Ruales and Nair 1993) c (Ranhotra et al 1993) d (USDA 2015)
43
Table 3-Quinoa minerals content (mgmg )
Whole graina RDI b
K 8257 NR
Mg 4526 400
Ca 1213 1000
P 3595 1000
Fe 95 18
Mn 37 NR
Cu 07 2
Zn 08 15
Na 13 NR
(aAndo et al 2002 bUSDA 2015)
44
Figure 1-Quinoa seed section and two-layered pericarp under perianth (Wu et al 2014)
45
Figure 2-Quinoa seed structure (Prego et al 1998)
(PE pericarp SC seed coat C cotyledons SA shoot apex H hypocotylradicle axis R radicle F funicle EN endosperm P perisperm Bar = 500 μm)
46
Chapter 3 Evaluation of Texture Differences among Varieties of
Cooked Quinoa
Published manuscript
Wu G Morris C F amp Murphy K M (2014) Evaluation of texture differences among
varieties of cooked quinoa Journal of Food Science 79(11) S2337-S2345
ABSTRACT
Texture is one of the most significant factors for consumersrsquo experience of foods Texture
differences of cooked quinoa were studied among thirteen different varieties Correlations
between the texture parameters and seed composition seed characteristics cooking quality flour
pasting properties and flour thermal properties were determined The results showed that texture
of cooked quinoa was significantly differed among varieties lsquoBlackrsquo lsquoCahuilrsquo and lsquoRed
Commercialrsquo yielded harder texture while lsquo49ALCrsquo lsquo1ESPrsquo and lsquoCol6197rsquo showed softer
texture lsquo49ALCrsquo lsquo1ESPrsquo lsquoCol6197rsquo and lsquoQQ63rsquo were more adhesive while other varieties
were not sticky The texture profile correlated to physical-chemical properties in different ways
Protein content was positively correlated with all the texture profile analysis (TPA) parameters
Seed hardness was positively correlated with TPA hardness gumminess and chewiness at P le
009 Seed density was negatively correlated with TPA hardness cohesiveness gumminess and
chewiness whereas seed coat proportion was positively correlated with these TPA parameters
Increased cooking time of quinoa was correlated with increased hardness cohesiveness
gumminess and chewiness The water uptake ratio was inversely related to TPA hardness
47
gumminess and chewiness RVA peak viscosity was negatively correlated with the hardness
gumminess and chewiness (P lt 007) breakdown was also negatively correlated with those TPA
parameters (P lt 009) final viscosity and setback were negatively correlated with the hardness
cohesiveness gumminess and chewiness (P lt 005) setback was correlated with the
adhesiveness as well (r = -063 P = 002) Onset gelatinization temperature (To) was
significantly positively correlated with all the texture profile parameters and peak temperature
(Tp) was moderately correlated with cohesiveness whereas neither conclusion temperature (Tc)
nor enthalpy correlated with the texture of cooked quinoa This study provided information for
the breeders and food industry to select quinoa with specific properties for difference use
purposes
Keywords cooked quinoa variety texture profile analysis (TPA) RVA DSC
Practical Application The research described in this paper indicates that the texture of different
quinoa varieties varies significantly The results can be used by quinoa breeders and food
processors
48
Introduction
Quinoa (Chenopodium quinoa Willd) a pseudocereal (Lindeboom et al 2007) is known as
a complete food due to its high nutritional value (Jancurovaacute et al 2009) Protein content of dry
quinoa grain ranges from 8 to 22 (Jancurovaacute et al 2009) Quinoa protein is high in nutritive
quality with an excellent balance of essential amino acids (Abugoch et al 2008) Quinoa is also a
gluten-free crop (Alvarez-Jubete et al 2010) Quinoa consumption in the US and Europe has
increased dramatically over the past decade but these regions rely on imports primarily from
Bolivia and Peru (Food and Agriculture Organization of the United Nations FAO 2013) For
these reasons greater knowledge of quinoa grain quality is needed
Quinoa is traditionally cooked as a whole grain similar to rice or milled into flour and made
into pasta and breads (Food and Agriculture Organization of the United Nations FAO 2013)
Quinoa can also be processed by extrusion drum-drying and autoclaving (Ruales et al 1993)
Commercial quinoa products include pasta bread cookies muffins cereal snacks drinks
flakes baby food and diet supplements (Ruales et al 2002 Del Castillo et al 2009 Cortez et al
2009 Demirkesen et al 2010 Schumacher et al 2010)
Texture is one of most significant properties of food that affects the consuming experience
Food texture refers to those qualities of a food that can be felt with the fingers tongue palate or
teeth (Vaclavik and Christian 2003) Cooked quinoa has a unique texture described as creamy
smooth and slightly crunchy (Abugoch 2009) Texture can be influenced by the seed structure
composition cooking quality and thermal properties However we know of no report which
documents the texture of cooked quinoa and the factors that affect it
49
Quinoa has small seeds compared to most cereals and seed size may affect the texture of
cooked quinoa Seed characteristics and structure are the significant factors potentially affecting
the textural properties of processed food Rousset et al (1995) indicated that the length and
lengthwidth ratio of rice kernels was associated with a wide range of texture attributes including
crunchy brittle elastic juicy pasty sticky and mealy which were determined by a sensory
panel The correlation between quinoa seed characteristics and cooked quinoa texture has not
been studied
Quinoa is consumed as whole grain without removing the bran unlike most rice and wheat
The insoluble fiber and non-starch polysaccharides in the seed coat can affect mouth feel and
texture Hence seed coat proportion may contribute to the texture of cooked quinoa Mohapatra
and Bal (2006) reported that the milling degree of rice positively influenced cohesiveness and
adhesiveness of cooked rice but was negatively correlated to hardness
Quinoa seed qualities such as the size hardness weight density and seed coat proportion
may influence the water binding capacity of seed during thermal processing thereby affecting
the texture of the cooked cereal (Fitzgerald et al 2003) Nevertheless correlations between seed
characteristics and texture of cooked quinoa have not been previously described
Seed composition may influence texture as well Higher protein content was reported to
cause reduced stickiness and harder texture of cooked rice (Ramesh et al 2000) Quinoa seeds
contain approximately 60 starch (Ando et al 2002) Starch granules are particularly small (05
- 3μm) Amylose content of quinoa is as low as 11 (Ahamed et al 1996) while the amylose
proportion in most cereals such as wheat is around 25 (Zeng et al 1997 BeMiller and Huber
50
2008) Amylose content of starch correlated positively with the hardness of cooked rice and
cooked white salted noodles (Ong and Blanshard 1995 Epstein et al 2002 Baik and Lee 2003)
Flour pasting properties can greatly influence the texture of cooked products Their
correlation has not been illustrated in quinoa while some research have been conducted on
cooked rice A lower peak viscosity and positive setback are associated with a harder texture
while a higher peak viscosity breakdown and lower setback are associated with a sticky texture
in cooked rice (Limpisut and Jindal 2002) Champagne et al (1999) indicated that adhesiveness
had strong correlations with Rapid Visco Analyzer (RVA) measurements Ramesh et al (2000)
reported that harder cooked rice texture was associated with a lower peak viscosity and positive
setback while sticky rice had a higher peak viscosity higher breakdown and lower setback
The gelatinization temperature of quinoa starch ranges from 54ordmC to 71ordmC (Ando et al
2002) lower than that of rice barley and wheat starches (Marshall 1994 Tang 2004 Tang et al
2005) Gelatinization temperature likely plays an important role in waxy rice quality (Perdon and
Juliano 1975 Juliano et al 1987) but was not correlated to the eating quality of normal rice
(Ramesh et al 2000) Despite a considerable amount of work having been conducted on the
thermal properties of cereal starch little is known about the relationship between quinoa flour
thermal properties and cooked quinoa texture
The correlation of quinoa cooking quality and texture has not been previously reported In
rice cooking quality exhibited strong correlations to the texture profile analysis (TPA) Cooking
time has been reported to correlate positively with hardness and negatively with adhesiveness of
cooked rice (Mohapatra and Bal 2006) Higher water uptake ratio and volume expansion ratio
were associated with softer more adhesive and more cohesive texture of cooked rice
51
(Mohapatra and Bal 2006) Cooking loss has been reported to improve firmness but decrease
juiciness (Rousset et al 1995)
There is a need to further study the texture of cooked quinoa and its determining factors
The objective of this paper is to study the texture difference among varieties of cooked quinoa
and evaluate the correlation between the texture and the seed characters and composition
cooking process flour pasting properties and thermal properties
Materials and Methods
Seed characteristics
Eleven varieties and two commercial lots of quinoa are listed in Table 1 The two grain
lots were referred as lsquoYellow Commercialrsquo and lsquoRed Commercialrsquo according to the seed color
Seed size (diameter) was determined by lining up and measuring the length of 20 seeds Average
seed diameter was calculated from three repeated measurements Bulk density of seed was
measured by the weightvolume method Seed weight was determined gravimetrically Seed
hardness was determined using the texture analyzer TAndashXT2i (Texture Technology Corp
Scarsdale NY USA) A cylinder of 10 mm in diameter compressed one seed to 90 strain at
the rate of 5 mms The force (kg) was recorded as the seed hardness Seed coat proportions were
determined by a Scanning Electron Microscope (SEM) FEI Quanta 200F (FEI Corp Hillsboro
OR USA) The seed was cross-sectioned and the SEM image was captured under 800times
magnification The seed coat proportions were measured using the software ruler in micrometers
Chemical compositions
Whole quinoa flour was prepared using a cyclone sample mill (UDY Corporation Fort
Collins CO USA) equipped with a 05 mm screen and was used for compositional analysis
52
pasting viscosity and thermal properties Ash and moisture content of quinoa flour were tested
according to the Approved Method 08-0101 and 44-1502 respectively (AACCI 2012) Protein
content was determined by a nitrogen analyzer coupled with a thermo-conductivity detector
(LECO Corporation Joseph MI USA) The factor of 625 was used to calculate the protein
content from the nitrogen content (Approved Method 46-3001 AACCI 2012) Protein and ash
were calculated on a dry weight basis
Cooking protocol
The cooking protocol of quinoa was modified from a rice cooking method (Champagne
et al 1998) Five grams of quinoa seed were soaked for 20 min in 10 mL deionized water in a
flask Soaking is required to remove the bitter saponins (Pappier et al 2008) and enhance
cooking quality (Mohapatra and Bal 2006) The mixture was then boiled for 2 min and the flask
was set in boiling water for 18 min The flask was covered to prevent water loss
Cooking quality
Two grams of quinoa seed were cooked in 20 mL deionized water for 20 min and extra
water was removed Cooking time was determined when the middle white part of the seed
completely disappeared (Mohapatra and Bal 2006) The water uptake ratio was calculated from
the seed weight ratio before and after cooking Cooking volume was the seed volume after
cooking Cooking loss was the total of soluble and insoluble matter in the cooking water
(Rousset et al 1995) Three mL of cooking water of each sample was placed on an aluminum
pan and dried at 130 ordmC overnight The weight of dry solids in the pan was used to calculate the
cooking loss
Texture profile analysis (TPA)
53
Texture profile analysis (TPA) was used to determine the texture of cooked quinoa
according to a modified method for cooked rice texture (Champagne et al 1999) Two grams of
cooked quinoa were arranged on the texture analyzer platform as close to one layer as possible
A stainless steel plate (50 mm times 40 mm times 10 mm) compressed the cooked quinoa from 5 mm to
01 mm at 5 mmsec The compression was conducted twice The texture analyzer generated a
graph with time as the x-axis and force as the y-axis Six parameters were calculated from the
graph (Epstein et al 2002) Hardness is the height of the first peak adhesiveness is the area 3
cohesiveness is area 2 divided by area 1 springiness is distance 1 divided by distance 2
gumminess is hardness multiplied by cohesiveness chewiness is gumminess multiplied by
springiness In the present study no significant differences or correlations were obtained for
springiness As such this parameter will not be included except to describe the overall result (see
below)
Flour viscosity
Quinoa flour pasting viscosity was determined using the Rapid Visco Analyzer (RVA)
RVA-4 (Newport Scientific Pty Ltd Narrabeen Australia) Quinoa flour (43 g) was added to
25 mL deionized water in an aluminum cylinder container The contents were immediately
mixed and heated following the instrument program The temperature was increased from 50 ordmC
to 93 ordmC in 8 min at a constant rate was held at 95 ordmC from 8 to 24 min cooled to 50 ordmC from 24
to 28 min and held at 50 ordmC from 29 to 40 min The program generated a graph with time against
shear force (Figure 1) expressed in RVU (cP = RVU times 12)
Two peaks representing peak viscosity and final viscosity are normally included in the
RVA graph Peak time was the time to reach the first peak Holding strength or trough is the
54
minimum viscosity after the first peak Breakdown is the viscosity difference between peak and
minimum viscosity Setback is the viscosity difference between final and minimum viscosity
Pasting temperature and the time to reach the peak were also recorded
Thermal properties using Differential Scanning Calorimetry (DSC)
Thermal properties of quinoa flour were determined by Differential Scanning
Calorimetry (DSC) Tzero Q2000 (TA instruments New Castle DE USA) The protocol was a
modification of the method of Abugoch et al (2009) Quinoa flour (02 g) was added to 200 μL
deionized water and mixed on a vortex mixer for 10 s to form a slurry Ten to twelve milligrams
of slurry was added to an aluminum pan by pipette The pan was sealed and placed at the center
of DSC platform An empty pan was used as reference The temperature was increased from 25
ordmC to 120 ordmC at 10 ordmCmin then equilibrated to 25 ordmC Gelatinization temperature and enthalpy
were determined from the graph
Statistical analysis
All experiments were repeated three times The hypothesis tests of normality and equal
variance multiple comparisons (Fisherrsquos LSD) and correlation studies were conducted by SAS
92 (SAS Institute Cary NC) A P-value of 005 is considered as the level of statistical
significance unless otherwise specified
Results
Seed characteristics and flour composition
Quinoa seed characteristics and composition are shown in Table 2 Quinoa seeds were
small compared to cereals such as rice wheat and maize Diameters of quinoa seed mostly
ranged between 19 to 22 mm except for lsquoJapanese Strainrsquo which was significantly smaller (15
55
mm) Seed hardness was significantly different among varieties ranging from 583 k g in
lsquoCol6197rsquo to 1096 kg in lsquoOro de Vallersquo Bulk seed density of quinoa varied from 063 kgL in
lsquoBlancarsquo to 081 kgL in lsquoJapanese Strainrsquo Varieties from White Mountain farm and the WSU
Organic Farm were lower in bulk density most of which were below 07 kgL The commercial
and Port Townsend samples were higher in density most of which were around 075 kgL
Thousand-seed weights of quinoa were particularly low ranging from 18 g in lsquoJapanese Strainrsquo
to 41g in lsquoRed Commercialrsquo Seed coat proportion was also significantly different among
varieties Three layers are shown in the seed coat (Figure 2) The varieties lsquoBlackrsquo and lsquoBlancarsquo
had the thickest seed coat (38 and 97 μm respectively) with coat proportions of 40 and 45
respectively lsquoYellow Commercialrsquo and lsquo1ESPrsquo had the thinnest seed coats (15 and 16 μm
respectively) with the coat proportion of 07 and 05 respectively The difference was
almost ten-fold among the varieties
Protein and ash content of quinoa flour
Protein content varied from 113 in lsquo1ESPrsquo to 170 in lsquoCahuilrsquo lsquoCherry Vanillarsquo and
lsquoOro de Vallersquo also had high protein contents of 160 and 156 respectively Ash content
ranged from 12 in the Commercial Yellow seed to 40 in lsquoQQ63rsquo comparable to that in rice
flour (Champagne 2004)
Texture of cooked quinoa
The hardness of cooked quinoa ranged from 20 g for lsquo49ALCrsquo and lsquoCol6197rsquo to 347
kg for lsquoBlackrsquo (Table 3) lsquoOro de Vallersquo and lsquoBlancarsquo were relatively hard varieties with TPA
hardness of 285 kg and 306 kg respectively whereas lsquo1ESPrsquo lsquoJapanese Strainrsquo and lsquoQQ63rsquo
were softer with a hardness of 245 kg 293 kg and 297 kg respectively
56
Adhesiveness is the extent to which seeds stick to each other the probe and the stage
lsquo49ALCrsquo lsquo1ESPrsquo lsquoCol6197rsquo and lsquoQQ63rsquo were significantly stickier with adhesiveness value
of -029 kgs -027 kgs -023 kgs and -020 kgs respectively All other varieties exhibited
lower adhesiveness with values less than 010 kgs Visual examination of the cooked samples
showed that with the more adhesive varieties the seeds stuck together as with sticky rice while
for other varieties the grains were separated
Cohesiveness of cooked lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo was
significantly higher with values from 068 to 071 respectively while those of lsquo49ALCrsquo lsquo1ESPrsquo
and lsquoCol6197rsquo were lower at 054 056 and 053 respectively Springiness is the recovery
from crushing or the elastic recovery (Tsuji 1981 Seguchi et al 1998) Cooked quinoa of all
varieties exhibited excellent elastic recovery properties with springiness values approximating
10
Gumminess is the combination of hardness and cohesiveness Chewiness is gumminess
multiplied by springiness As springiness values were all close to 10 gumminess and chewiness
of cooked quinoa were very similar in value lsquoBlackrsquo lsquoBlancarsquo and lsquoCahuilrsquo were highest in
gumminess and chewiness 24 kg 22 kg and 23 kg respectively while lsquo1ESPrsquo lsquo49ALCrsquo and
lsquoCol6197rsquo were lowest at 14 kg 11 kg and 11 kg respectively The difference among varieties
was greater than three-fold
Cooking quality
Cooking quality of quinoa is shown in Table 4 Cooking time varied from 119 min in
lsquoCol6197rsquo to 192 min in lsquoBlackrsquo cultivar and was significantly correlated with all TPA texture
parameters Longer cooking time also correlated with higher protein content (r = 052 P = 007)
57
Water uptake ratio varied from 25 to 4 fold in lsquoQQ63rsquo and lsquoCol6197rsquo respectively Water
uptake ratio was negatively correlated to seed hardness (r = 052 P = 004) Harder seeds tended
to absorb less water during cooking Cooking volume ranged from 107 mL to 137 mL and did
not significantly correlate with other properties Cooking loss ranged from 035 to 176 and
differed among varieties but was not correlated with water uptake ratio cooking time or cooking
volume
Quinoa flour pasting properties by RVA
Pasting viscosity of quinoa whole seed flour was determined using the Rapid Visco
Analyzer (RVA) The results are shown in Table 5 Peak viscosity differed among varieties
Varieties could be categorized into three groups based on peak viscosity The peak viscosity of
lsquoQQ63rsquo lsquoCol6197rsquo lsquo1ESPrsquo lsquoJapanese Strainrsquo lsquoYellow Commercialrsquo lsquoCopacabanarsquo and lsquoRed
Commercialrsquo varied from 144 to 197 RVU The peak viscosity of lsquoBlancarsquo lsquoBlackrsquo lsquo49ALCrsquo
and lsquoCahuilrsquo ranged from 98 to 116 RVU while those of lsquoOro de Vallersquo and lsquoCherry Vanillarsquo
were 59 and 66 RVU respectively
Trough viscosity namely the minimum viscosity after the first peak showed more than a
three-fold difference among varieties As in the case of peak viscosity the trough of different
varieties can be categorized into the same three groups
Breakdown is the difference between the peak and minimum viscosity lsquoQQ63rsquo lsquo1ESPrsquo
and lsquoJapanese Strainrsquo showed large breakdowns of 51 51 and 62 RVU respectively
Breakdown of lsquoCherry Vanillarsquo lsquoOro de Vallersquo and the Commercial Yellow seed were lower at
12 10 and 11 RVU respectively Breakdown of the other varieties ranged from 18 to 36 RVU
58
The final viscosity of the Commercial Yellow seed was 203 RVU the highest among all
varieties Final viscosity of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo
ranged from 56 to 82 RVU and was lower than that of other varieties which ranged from 106 to
190 RVU
Setback is the difference between final and trough viscosity Setback of lsquoRed
Commercialrsquo lsquoCahuilrsquo and lsquoBlackrsquo were all negative -62 -11 and -6 RVU respectively which
indicated that the final viscosity of these cultivars was lower than their trough viscosity Setback
of lsquoBlancarsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo were slightly positive at 2 2 and 6 RVU
respectively while those of other cultivars were much greater between 42 and 73 RVU Peak
time which is the time to reach the first peak ranged from 93 to 115 min The pasting
temperature was 93 ordmC and not different among the varieties
Thermal properties of quinoa flour using DSC
Thermal properties of quinoa flour were determined using DSC Gelatinization
temperatures (To onset temperature Tp peak temperature Tc conclusion temperature) and
gelatinization enthalpies are shown in Table 6 To of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry
Vanillarsquo and lsquoJapanese Strainrsquo were not different from each other and ranged from 645 ordmC to
659 ordmC To of lsquoOro de Vallersquo lsquoCopacabanarsquo lsquoCol6197rsquo and lsquoQQ63rsquo ranged from 605 ordmC to
631 ordmC while other varieties were lower and ranged from 544 ordmC to 589 ordmC Tp ranged from
675 ordmC in the Commercial Yellow seed to 752 ordmC in lsquoCahuilrsquo Tc ranged from 780 ordmC in lsquoRed
Commercialrsquo to 850ordmC in the lsquoJapanese Strainrsquo Enthalpy of quinoa flour differed among
varieties The range was from 11 Jg in lsquoYellow Commercialrsquo to 18 Jg in lsquoBlancarsquo
Correlations between physical-chemical properties and cooked quinoa texture
59
A summary of correlation coefficients between quinoa physical-chemical properties and
TPA texture profile parameters of cooked quinoa are shown in Table 7 Seed hardness was found
to be positively related to the TPA hardness gumminess and chewiness of cooked quinoa (P lt
009) Seed bulk density was negatively correlated to hardness cohesiveness gumminess and
chewiness while seed coat proportion was positively correlated to those parameters Protein
content of quinoa exhibited a positive relationship with TPA hardness (P = 008) and
adhesiveness cohesiveness gumminess and chewiness No significant correlation was observed
between the seed size 1000 seed weight ash content and the texture properties of cooked
quinoa
Cooking time of quinoa was highly positively correlated with all of the TPA texture
profile parameters Water uptake ratio during cooking was found to be significantly associated
with hardness gumminess and chewiness of cooked quinoa while cooking volume also showed
a modest correlation to hardness (r = -047 P = 010) Cooking loss was not correlated with any
texture parameter
Flour pasting viscosity was significantly correlated with texture of cooked quinoa Peak
viscosity and breakdown exhibited negative correlations with the hardness gumminess and
chewiness of cooked quinoa (P lt 010) Breakdown was also negatively associated with the
cohesiveness (r = -051 P lt 010) Final viscosity and setback were found to be negatively
correlated to hardness cohesiveness gumminess and chewiness while setback also exhibited a
significant correlation to adhesiveness (r = -064 P = 002)
60
Considering thermal properties To exhibited strong positive correlations with all texture
parameters Tp was found to be moderately related to cohesiveness (r = 050 P = 008) Neither
Tc nor enthalpy was significantly correlated to the TPA parameters of cooked quinoa
Discussion
Seed characteristics
Harder seed yielded harder gummier and chewier TPA texture after cooking The
varieties with lower seed bulk density or thicker seed coat yielded a firmer more cohesive
gummier and chewier texture Likely the condensed cells and non-starch polysaccharides of the
seed coat are a barrier between starch granules in the middle perisperm and water molecules
outside the seed
Seed composition
Higher protein appeared to contribute to a firmer more adhesive gummier and chewier
texture of cooked quinoa as evidenced by the TPA parameters Protein has been reported to play
a significant role in the texture of cooked rice and noodles (Ramesh et al 2000 Martin and
Fitzgerald 2002 Saleh and Meullenet 2007 Xie et al 2008 Hou et al 2013) According to the
previous studies proteins affect the food texture through three major routes (1) binding of water
(Saleh and Meullenet 2007) (2) interacting reversibly with starch bodies (Chrastil 1993) and (3)
forming networks via disulphide bonds which restrict starch granule swelling and water
hydration (Saleh and Meullenet 2007)
Cooking quality
Cooking time was found to be a key factor for cooked quinoa texture as it was closely
associated with most texture attributes Other cooking qualities such as the water uptake ratio
61
cooking volume and cooking loss were not significantly correlated to texture In the study of
rice the cooking time of rice positively correlated with hardness negatively with cohesiveness
and not significantly with adhesiveness (Mohapatra and Bal 2006) The higher water uptake ratio
and volume expansion ratio were negatively associated with softer more adhesive and more
cohesive texture This result agrees with the study on cooked rice Rousset et al (1995) study
indicated that longer cooking time greater water uptake and cooking loss related to the softer
less crunchy and more pasty texture
Flour pasting properties
The varieties with a higher peak viscosity in flour had a softer less gummy and less
chewy texture after cooking The cultivars with higher final peak viscosity yielded a softer less
cohesive less gummy and chewy texture The varieties with a greater breakdown such as
lsquoQQ63rsquo lsquo1ESPrsquo and lsquoJapanese Strainrsquo were softer in TPA parameter Breakdown has been
reported to negatively correlate with the proportion of long chain amylopectin (Han and
Hamaker 2001) Long chain amylopectin may form intra- or inter-molecular interactions with
protein and lipids and result in a firmer or harder texture (Ong and Blanshard 1995)
Quinoa varieties with a lower setback were harder after cooking compared to those with a
higher setback In rice conversely setback was positively correlated with amylose content
(Varavinit et al 2003) which would positively influence the hardness of cooked rice (Ong and
Blanshard 1995 Champagne et al 1999) Unlike rice and many other cereals where the amylose
content is approximately 25-29 the amylose proportion in quinoa starch is lower on the order
of 11 (Ahamed et al 1996) Amylose may play a different role in cooked quinoa hardness
compared to other cereals
62
Starch viscosity has been reported to significantly affect the texture of cooked rice
Champagne et al (1999) used the RVA measurements to predict TPA of cooked rice and found
that adhesiveness strongly correlated to RVA parameters Harder rice was correlated with lower
peak viscosity and positive setback while stickier rice had a higher peak viscosity breakdown
and lower setback (Ramesh et al 2000) The difference between quinoa and rice seed structure
and starch composition and the difference of texture determining methods may contribute to the
different trends in correlation
Thermal properties
The gelatinization temperature of quinoa flour ranged from 55 ordmC to 85 ordmC lower than
that of whole rice flour which was 70 ordmC to 103 ordmC (Marshall 1994) This result agrees with the
previous study on quinoa flour (Ando et al 2002) The quinoa varieties with higher To exhibited
a firmer more adhesive more cohesive gummier and chewier texture Higher Tp was associated
with increased cohesiveness The enthalpy of quinoa flour ranged from 11 to 18 Jg about one-
tenth that of whole rice flour (141 ndash 151 Jg) (Marshall 1994) indicating that it takes less
energy to cook quinoa than cook rice
Thermal properties of quinoa flour were generally correlated with flour pasting
properties Higher To and Tp were correlated with lower flour peak viscosity and lower trough
The result is comparable to the previous study of Sandhu and Singh (2007) who found that
gelatinization temperature and enthalpy of corn starch strongly influenced the peak breakdown
final and setback viscosity The thermal properties of quinoa flour were not correlated with
breakdown and setback likely was due to other composition factors in the flour such as protein
and fiber
63
Conclusions
The texture of cooked quinoa varied markedly among the different varieties indicating
that genetics management or geographic origin may all be important considerations for quinoa
quality As such differences in seed morphology and chemical composition appear to contribute
to quinoa processing parameters and cooked texture Harder seed yielded a firmer gummier and
chewier texture both lower seed density and high seed coat proportion related to a firmer more
cohesive gummier and chewier texture Seed size and weight appeared to be largely unrelated to
the texture of the cooked quinoa Protein content was a key factor apparently influencing texture
Higher protein content was related to harder more adhesive and cohesive gummier and chewier
texture Cooking time and water uptake ratio significantly affected the texture of cooked quinoa
whereas cooking volume moderately affected the hardness cooking loss was not correlated with
texture RVA peak viscosity was negatively correlated with the hardness gumminess and
chewiness breakdown was also negatively correlated with those TPA parameters Final viscosity
and setback were negatively correlated with the hardness cohesiveness gumminess and
chewiness Setback was correlated with the adhesiveness as well Gelatinization temperature To
affected all the texture profile parameters positively Tp slightly related to the cohesiveness
while Tc and enthalpy were not correlated with the texture
Acknowledgements
This project was supported by funding from the USDA Organic Research and Extension
Initiative project number NIFA GRANT11083982 The authors acknowledge Stacey Sykes and
Alecia Kiszonas for editing support
Author Contributions
64
G Wu and CF Morris designed the study together G Wu collected test data and drafted the
manuscript CF Morris and KM Murphy edited the manuscript KM Murphy provided
samples and project oversight
65
References
AACC International 2012 Approved Methods of Analysis Method 08-0101 Ash - Basic
method Approved April 13 1961 Method 44-1502 Moisture ndash Air-Oven Methods (130ordmC)
Approved October 30 1975 Method 46-3001 Crude protein ndash Combustion method
Approved November 8 1995 Reapproved November 3 1999 Available online only
AACCI St Paul MN
Abugoch LE Romero N Tapia CA Silva J Rivera M 2008 Study of some physicochemical
and functional properties of quinoa (Chenopodium quinoa Willd) protein isolates J Agric
Food Chem 564745-50
Abugoch LEJ 2009 Chapter 1 Quinoa (Chenopodium quinoa Willd) Adv Food Nutr Res
581-31
Abugoch L Castro E Tapia C Antildeoacuten MC Gajardo P Villarroel A 2009 Stability of quinoa
flour proteins (Chenopodium quinoa Willd) during storage Int J Food Sci Tech 442013-20
Ahamed NT Singhal RS Kulkami PR Palb M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 3199-103
Alvarez-Jubete L Arendt EK Gallagher E 2010 Nutritive value of pseudocereals and their
increasing use as functional gluten-free ingredients Trends in Food Sci Tech 21(2)106-13
Ando H Chen YC Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food components in
fractions of quinoa seed Food Sci Technol Res 8(1)80-4
66
Baik BK Lee MR 2003 Effects of starch amylose content of wheat on textural properties of
white salted noodles Cereal Chem 80304-9
BeMiller JN Huber KC 2008 Carbohydrates In Damdaran S Parkin KL Fennema OR editors
Food chemistry Boca Raton CRC Press p 121
Champagne ET Lyon BG Min BK Vinyard BT Bett KL Barton IIFE Webb BD Kohlwey DE
1998 Effects of postharvest processing on texture profile analysis of cooked rice Cereal
Chem 75(2)181-6
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5)764-71
Champagne ET 2004 The rice grain and its gross composition In Champagne ET editor Rice
chemistry and technology St Paul Minn American Association of Cereal Chemists p 88
Chrastil J 1993 Enzyme activities in preharvest rice grains J Agric Food Chem 41(12)2245-8
Cortez G Repo-Carrasco R Rosell CM 2009 Breadmaking use of andean crops quinoa kantildeiwa
kiwicha and tarwi Cereal Chem 86(4)386-92
Del Castillo V Lescano G Armada M 2009 Foods formulation for people with celiac disease
based on quinoa (Chenopodium quinoa) cereal flours and starches mixtures Archivos
Latinoamericanos De Nutricion 59(3)332-36
67
Demirkesen I Mert B Sumnu G Sahin S 2010 Rheological properties of gluten-free bread
formulations J Food Eng 96(2)295-303
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(Waxy) genes J Cereal Sci 3551-63
Fitzgerald MA Martin M Ward RM Park WD Shead HJ 2003 Viscosity of rice flour a
rheological and biological study J Agric Food Chem 51(8) 2295-9
Food and Agriculture Organization of the United Nations (FAO) 2013 The international year of
quinoa Available from httpwwwfaoorgquinoa-2013en Accessed 2013 February 20
Han XZ Hamaker BR 2001 Amylopectin fine structure and rice starch paste breakdown J
Cereal Sci 34(3)279-84
Hou GG Saini R Ng PKW 2013 Relationship between physicochemical properties of wheat
flour wheat protein composition and textural properties of cooked chinese white salted
noodles Cereal Chem 90(5)419-29
Jancurovaacute M Minarovicova L Dandar A 2009 Quinoa ndash a review Czech J Food Sci 27(2)71-9
Juliano BO Villareal RM Bantildeos L 1987 Varietal differences in physicochemical properties of
waxy rice starch Starch - Staumlrke 39(9)298-301
68
Limpisut P Jindal VK 2002 Comparison of rice flour pasting properties using brabender
viscoamylograph and rapid visco analyser for evaluating cooked rice texture Starch - Staumlrke
54(8)350-7
Lindeboom N Chang PR Falk KC Tyler RT 2007 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2)216-22
Marshall WE 1994 Starch gelatinization in brown and milled rice a study using differential
scanning calorimetry In Marshall WE Wadsworth IJ editors Rice science and technology
New York NY Marcel Dekker Inc p 222
Martin M Fitzgerald MA 2002 Proteins in rice grains influence cooking properties J Cereal Sci
36(3)285-94
Mohapatra D Bal S 2006 Cooking quality and instrumental textural attributes of cooked rice
for different milling fractions J Food Eng 73(3)253-9
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine stucture of amylopectin J Cereal Sci 21(3)251-60
Pappier U Fernandez Pinto V Larumbe G Vaamonde G 2008 Effect of processing for saponin
removal on fungal contamination of quinoa seeds (Chenopodium quinoa Willd) Int J Food
Microbiol 125(2)153-7
Perdon AA Juliano BO 1975 Gel and molecular properties of waxy rice starch Starch - Staumlrke
27(3)69-71
69
Ramesh M Bhattacharya KR Mitchell JR 2000 Developments in understanding the basis of
cooked-rice texture Crit Rev Food Sci Nutr 40(6)449-60
Rousset S Pons B Pilandon C 1995 Sensory texture profile grain physico-chemical
characteristics and instrumental measurements of cooked rice J Texture Stud 26(2)119-35
Ruales J Valencia S Nair B 1993 Effect of processing on the physico-chemical characteristics
of quinoa flour (Chenopodium quinoa Willd) Starch - Staumlrke 45(1)13-9
Ruales J de Grijalva Y Lopez-Jaramillo P Nair BM 2002 The nutritional quality of an infant
food from quinoa and its effect on the plasma level of insulin-like growth factor-1 (IGF-1) in
undernourished children Int J Food Sci Nutr 53(2)143-54
Saleh MI Meullenet JF 2007 Effect of protein disruption using proteolytic treatment on cooked
rice texture properties J Texture Stud 38(4)423-37
Sandhu KS Singh N 2007 Some properties of corn starches II Physicochemical gelatinization
retrogradation pasting and gel textural properties Food Chem 101(4)1499-507
Schumacher A Brandelli A Macedo F Pieta L Klug T Jong E 2010 Chemical and sensory
evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J Food
Sci Tech 47(2)202-6
Seguchi M Hayashi M Kanenaga K Ishihara C Noguchi S1998 Springiness of pancake and
its relation to binding of prime starch to tailings in stored wheat flour Cereal Chem
75(1)37-42
70
Tang H 2004 Relationship between functionality and structure in barley starches Carbohydr
Polym 57(2)145-52
Tang H Mitsunaga T Kawamura Y 2005 Functionality of starch granules in milling fractions
of normal wheat grain Carbohyd Polym 59(1)11-7
Tsuji S 1981 Texture measurement of cooked rice kernels using the multiple-point mensuration
method 1 J Texture Stud 12(2)93-105
Vaclavik VA Christian EW 2003 Evaluation of food quality In Vaclavik V Christian EW
editors Essentials of food science New York NY Kluwer AcademicPlnum Publishers p 4
Varavinit S Shobsngob S Varanyanond W Chinachoti P Naivikul O 2003 Effect of amylose
content on gelatinization retrogradation and pasting properties of flours from different
cultivars of thai rice Starch - Staumlrke 55(9)410-5
Xie L Chen N Duan B Zhu Z Liao X 2008 Impact of proteins on pasting and cooking
properties of waxy and non-waxy rice J Cereal Sci 47(2)372-9
Zeng M Morris CF Batey IL Wrigley CW 1997 Sources of variation for starch gelatinization
pasting and gelation properties in wheat Cereal Chem 7463-71
71
Table 1-Varieties of quinoa used in the experiment
Variety Original Seed Source Location
Black White Mountain Farm White Mountain Farm Colorado US
Blanca White Mountain Farm White Mountain Farm Colorado US
Cahuil White Mountain Farm White Mountain Farm Colorado US
Cherry Vanilla Wild Garden Seeds Philomath Oregon WSUa Organic Farm Pullman Washington US
Oro de Valle Wild Garden Seeds Philomath Oregon WSUa Organic Farm Pullman Washington US
49ALC USDA Port Townsend Washington US
1ESP USDA Port Townsend Washington US
Copacabana USDA Port Townsend Washington US
Col6197 USDA Port Townsend Washington US
Japanese Strain USDA Port Townsend Washington US
QQ63 USDA Port Townsend Washington US
Yellow Commercial Multi Organics company Bolivia
Red Commercial Multi Organics company Bolivia a WSU - Washington State University
72
Table 2-Seed characteristics and compositiona
Variety Diameter (mm)
Hardness (kg)
Bulk Density (gmL)
Seed Coat Proportion ()
Protein ()
Ash ()
Black 21bc 994b 0584d 37bc 143d 215hi
Blanca 22ab 608l 0672c 89a 135e 284ef
Cahuil 21abc 772e 0757a 49b 170a 260fg
Cherry Vanilla 19e 850d 0717b 41b 160b 239gh
Oro de Valle 19e 1096a 0715b 43b 156b 305de
49ALC 19de 935c 0669c 26cd 127g 348bc
1ESP 19e 664h 0672c 10f 113i 248gh
Copacabana 20cd 643i 0671c 44b 129g 361b
Col6197 19e 583m 0657c 24de 118h 291ef
Japanese Strain 15f 618k 0610d 21def 148cd 324cd
QQ63 19e 672g 0661c 45b 135f 401a
Yellow Commercial
21abc 622j 0663c 14ef 146c 198i
Red Commercial 22a 706f 0730ab 26cd 145cd 226hi a Mean values with different letters within a column are significantly different (P lt 005)
73
Table 3-Texture profile analysis (TPA)a of cooked quinoa
Variety Hardness (kg)
Adhesiveness (kgs)
Cohesiveness Gumminess (kg)
Chewiness (kg)
Black 347a -004a 069ab 24a 24a
Blanca 306bcd -003a 071a 22abc 22abc
Cahuil 327abc -003a 071a 23ab 23ab
Cherry Vanilla 278de -002a 071a 20cd 20cd
Oro de Valle 285d -001a 068ab 19cd 19cd
49ALC 209f -029c 054d 11ef 11ef
1ESP 245e -027bc 056d 14e 14e
Copacabana 305bcd -010a 068ab 21bcd 21bcd
Col6197 202f -023bc 053d 11ef 11ef
Japanese Strain 293d -008a 066bc 19cd 19cd
QQ63 297cd -020b 062c 19d 19d
Yellow Commercial 306bcd -003a 069ab 21abc 21bc
Red Commercial 338ab -005a 068ab 23ab 23ab a Mean values with different letters within a column are significantly different (P lt 005)
74
Table 4-Cooking qualitya of quinoa
Variety Optimal Cooking Time (min)
Water uptake ()
Cooking Volume (mL)
Cooking Loss ()
Black 192a 297c 109c 065f
Blanca 183abc 344b 130ab 067f
Cahuil 169de 357ab 137a 102c
Cherry Vanilla 165ef 291c 107c 102c
Oro de Valle 173cde 238d 109c 102c
49ALC 136h 359ab 126b 043g
1ESP 153g 373ab 132ab 035h
Copacabana 157fg 379ab 127b 175a
Col6197 119i 397a 126b 176a
Japanese Strain 166def 371ab 116c 106b
QQ63 177bc 244d 126b 067f
Yellow Commercial 187ab 372ab 129ab 076d
Red Commercial 155fg 276cd 132ab 071e a Mean values with different letters within a column are significantly different (P lt 005)
75
Table 5-Pasting properties of quinoa flour by RVAa
Variety Peak Viscosity (RVU)
Trough
(RVU)
Breakdown
(RVU)
Final Viscosity (RVU)
Setback (RVU)
Peak Time (min)
Black 102g 81e 21e 75g -6f 102e
Blanca 98g 80e 18e 82g 2e 99f
Cahuil 116f 85e 31d 74g -11f 104de
Cherry Vanilla
66h 54g 12f 57h 2e 97fg
Oro de Valle
59h 50g 10f 56h 6e 93h
49ALC 107fg 71f 36c 132e 62b 97fg
1ESP 161cd 110c 51b 174c 64b 98fg
Copacabana 175b 141b 34cd 190b 49c 106cd
Col6197 155de 133b 22e 177bc 44cd 108bc
Japanese Strain
172bc 109c 62a 159d 50c 96gh
QQ63 144e 94d 51b 167cd 73a 97fg
Yellow Commercial
172bc 162a 11f 203a 41d 109b
Red Commercial
197a 168a 29d 106f -62g 115a
a Mean values with different letters within a column are significantly different (P lt 005)
76
Table 6-Thermal properties of quinoa flour by Differential Scanning Calorimetry (DSC)a
Gelatinization Temperature (ordmC)
Variety To Tp Tc Enthalpy (Jg)
Black 656a 725c 818abcd 15abc
Blanca 658a 743ab 819abcd 18a
Cahuil 659a 752a 839ab 16ab
Cherry Vanilla 649ab 741ab 823abc 12c
Oro de Valle 631bc 719cd 809abcde 12bc
49ALC 579e 714d 810bcde 15abc
1ESP 544f 690f 785de 15abc
Copacabana 630c 715cd 802cde 14abc
Col6197 605d 689f 785de 15abc
Japanese Strain 645abc 740b 850a 12c
QQ63 630c 702e 784de 13bc
Yellow Commercial 570e 676g 790cde 11c
Red Commercial 589de 693ef 780e 12c a Mean values with different letters within a column are significantly different (P lt 005)
77
Table 7-Correlation coefficients between quinoa seed characteristics composition and processing parameters and TPA texture of cooked quinoaa
Hardness Adhesiveness Cohesiveness Gumminess Chewiness
Seed Hardness 051 002ns 028ns 049 049
Bulk Density -055 -044ns -063 -060 -060
Seed Coat Proportion 074 038ns 055 072 072
Protein 050 077 075 057 057
Cooking Time 077 062 074 076 076
Water Uptake Ratio -058 -025ns -046ns -056 -056
Cooking Volume -048 -014ns -032ns -046ns -046ns
Peak Viscosity -051 -014ns -041ns -053 -054
Breakdown -048 -047ns -051 -053 -053
Final Viscosity -069 -043ns -060 -070 -070
Setback -058 -064 -059 -060 -060
To 059 054 061 061 061
Tp 042ns 041ns 050 045ns 046ns a ns non-significant difference P lt 010 P lt 005 P lt 001
78
Figure 1-Rapid Visco Analyzer (RVA) graph of lsquoCherry Vanillarsquo and lsquoRed Commercialrsquo
quinoa flours ( lsquoCherry Vanillarsquo lsquoRed Commercialrsquo Temperature)
Time (min)
0 10 20 30 40
Vis
cosi
ty (R
VU
)
0
50
100
150
200
250
Tem
pera
ture
(degC
)
50
100
150
200
79
Figure 2-Seed coat image by SEM
(1 whole seed section P-perisperm C-cotyledon 2 three layers of quinoa seed coat
3 seed coat of lsquoCherry Vanillarsquo 382 microm 4 seed coat of lsquo1ESPrsquo 95microm)
4 3
2 1
P
C C
80
Chapter 4 Quinoa Starch Characteristics and Their Correlation with
Texture of Cooked Quinoa
ABSTRACT
Starch composition and physical properties strongly influence the functionality and end-
quality of cereals Here correlations between starch characteristics and seed quality cooking
properties and texture were investigated Starch characteristics differed among the eleven
experimental varieties and two commercial quinoa tested The total starch content of seed ranged
from 532 to 751 g 100 g Total starch amylose content ranged from 27 to 169 and the
degree of amylose-lipid complex ranged from 34 to 433 The quinoa samples with higher
amylose tended to yield harder stickier more cohesive more gummy and more chewy texture
after cooking With higher degree of amylose-lipid complex or amylose leaching the cooked
quinoa tended to be softer and less chewy Higher starch enthalpy correlated with firmer more
adhesive more cohesive and more chewy texture Indicating that varieties with different starch
properties should be utilized in different end-products
Keywords quinoa starch texture cooked quinoa
Practical Application The research provided the starch characteristics of different quinoa
varieties showing correlations between starch and cooked quinoa texture These results can help
breeders and food manufacturers to better understand quinoa starch properties and the use of
cultivars for different food product applications
81
Introduction
Quinoa (Chenopodium quinoa Willd) is a pseudocereal from the Andean mountains in
South America Quinoa is garnering greater attention worldwide because of its high protein
content and balanced essential amino acids As in other crops starch is one of the major
components of quinoa seed Starch content structure molecular composition pasting thermal
properties and other characteristics may influence the cooking quality and texture of cooked
quinoa
The total starch content of quinoa seed has been reported to range from 32 to 69
(Abugoch 2009) Starch granules are small (1-2μm) compared to those of rice and barley (Tari et
al 2003) Amylose content of quinoa starch was reported to range from 35 to 225 (Abugoch
2009) generally lower than that of other crops Amylose content exhibited significant influence
on the texture of cooked quinoa (Ong and Blanshard 1995) Similarly cooked rice texture was
correlated to starch amylose and chain length (Ong and Blanshard 1995 Ramesh et al 1999)
and leaching of amylose and amylopectin during cooking (Patindol et al 2010) However
amylose-lipid complex and amylose leaching properties have not been studied in quinoa cultivars
with diverse genetic backgrounds Perdon et al (1999) indicated that starch retrogradation was
positively correlated with firmness and stickiness of cooked milled rice during storage and
similar correlations would be anticipated for quinoa
Starch swelling power and water solubility influenced wheat and rice noodle quality and
texture (Crosbie 1991 McCormick et al 1991 Konik et al 1993 Ross et al 1997 Bhattacharya
et al 1999) whereas the role of starch swelling powerwater solubility in the texture of cooked
quinoa has not been reported
82
The texture of rice starch gels has been studied Gel texture was influenced by treatment
temperature incorporation of glucomannan and sugar concentration (Charoenrein et al 2011
Jiang et al 2011 Sun et al 2014) The texture of quinoa starch gel however has not been
reported
Gelatinization temperature enthalpy and pasting properties of starch were correlated
with the texture of cooked rice (Ong and Blanshard 1995 Champagne et al 1999 Limpisut and
Jindal 2002) The correlations between starch thermal properties pasting properties and cooked
quinoa texture however have also not been reported
Starch is an important component of grains and exhibits significant influence on the
texture of cooked rice noodles and other foods The texture of cooked quinoa has been studied
previously (Wu et al 2014) however the correlation of starch and cooked quinoa texture
nevertheless remained unclear The objectives of the present study were to understand 1) the
starch characteristics of different quinoa varieties and 2) the correlations between the starch
characteristics and the texture of cooked quinoa
Materials and Methods
Starch isolation
Eleven varieties and two commercial quinoa samples were included in this study (Table
1) Quinoa starch was isolated using a method modified from Lindeboom et al (2005) and Qian
et al (1999) Two hundred grams of seed were steeped in 1000 mL NaOH (03 wv) overnight
at 4 degC and rinsed with distilled water three times to remove the saponins The rinsed quinoa
was ground in a Waring blender (Conair Corp Stamford CT USA) for 15 min The slurry
was screened through a series of sieves US No 40 100 and 200 mesh sieves with openings of
83
425 150 and 74 μm respectively Distilled water was added and stirred to speed up the
filtration Filter residue was discarded whereas the filtrate was centrifuged under 2000 times g for 20
min The supernatant was decanted and the top brown layer of sediment (protein and lipids) was
gently scraped loose and discarded The remaining pellet was resuspended in distilled water and
centrifuged again This resuspension-centrifuge process was repeated three times or until the
brown topmost layer was all removed The white starch pellet was then dispersed in 95 ethanol
and centrifuged under 2000 times g for 10 min The supernatant was discarded and the starch pellet
was air-dried and gently ground using a mortar and pestle
α-amylase activity
The activity of α-amylase was determined using a Megazyme Kit (Megazyme
International Ireland Co Wicklow Ireland)
Apparent total amylose content degree of amylose-lipid complex
Apparent amylose content was determined using a cold NaOH method (Mahmood et al
2007) with modification Sample of 10 mg was weighed into a 20 mL microcentrifuge tube To
the sample was added 150 μL of 95 ethanol and 900 μL of 1M NaOH mixed vigorously and
kept on a shaker overnight at room temperature The starch solution of 200 μL was removed and
combined with 1 mL of 005 M citric acid 800 μL iodine solution (02 g I2 2 g KI in 250 mL
distilled water) and 10 mL distilled water reaching a final volume of 12 mL The solution was
chilled in a refrigerator for 20 min The absorbance at 620nm was determined using a
spectrophotometer (Shimadzu Biospec-1601 DNAProteinEnzyme Analyzer Shimadzu corp
Kyoto Japan) A standard curve was created using a dilution series of amylose amylopectin
84
proportions of 010 19 28 37 46 and 55 respectively (Sigma-Aldrich Co LLC St Louis
MO USA)
Total amylose content was determined using the same method for apparent amylose
except that lipids in the starch samples were removed in advance The starch was defatted using
hexane and ultrasonic treatment as follows One gram of starch was dissolved in 15 mL hexane
and set in an ultrasonic water bath for 2 hours The suspension was then centrifuged at 1000 times g
for 1 min The supernatant was discarded and the procedure was repeated a second time The
sample was then dried in a fume hood overnight
Degree of amylose-lipid complex = [total amylose ndash apparent amylose] total amylose times 100
Amylose leaching properties
Amylose leaching was determined using the modified method of Hoover and Ratnayake
(2002) Starch (025 g) was mixed with 5 mL distilled water and heated at 60 degC for 30 min
then cooled in ice water and centrifuged at 2000 times g for 10 min Supernatant of 1 mL was added
to 800 μL iodine solution and 102 mL distilled water to achieve the same volume of 12 mL as
in the apparent amylose test The solution was chilled in a refrigerator for 20 min and the
absorbance at 620 nm was determined The amylose leaching was expressed as mg of amylose
leached from 100 g of starch
Starch pasting properties
Starch pasting properties were determined using the Rapid Visco Analyzer RVA-4
(Newport Scientific Pty Ltd Narrabeen Australia) Starch (3 g) was added to 25 mL distilled
water mixed and heated in the RVA using the following procedure The initial temperature was
50 ordmC and increased to 93 ordmC within 8 min at a constant rate held at 95 ordmC from 8 min to 24 min
85
cooled to 50 ordmC from 24 min to 28 min and held at 50 ordmC from 29 min to 40 min The result was
expressed in RVU units (RVU = cP12)
Starch gel texture
Starch gel texture was determined using a TA-XT2i Texture Analyzer (Texture
Technologies Corp Hamilton MA USA) The starch gels were prepared in the RVA using the
same procedure as for pasting properties Then the starch gels were stored at 4 degC for 24 hours
The testing procedure followed the method of Jiang et al (2011) with modification The gel
cylinder (3 cm high and 35 cm diameter) was compressed using a TA-25 cylinder probe at the
speed of pre-test 20 mms test 05 mms and post-test 05 mms to 10 mm deformation Two
compressions were conducted with an interval time of 20 s Hardness springiness and
cohesiveness were obtained from the TPA (Texture Profile Analysis) graph (x-axis distance and
y-axis force) Hardness (g) was expressed by the maximum force of the first peak springiness
was the ratio of distance (time) to peak 2 to distance to peak 1 cohesiveness was the ratio of the
second positive area under the compression curve to that of the first positive area
Freeze-thaw stability
Freeze-thaw stability was determined using the modified method from Lindeboom et al
(2005) and Charoenrein et al (2005) Starch slurry was cooked using the RVA with 125 g
starch and 25 mL distilled water The starch suspensions were heated at 60 degC from 0 ndash 2 min
the temperature was increased to 105 degC from 3 ndash 8 min with a constant rate and held at 105 degC
from 9 - 11 min The cooked samples were stored at -18 degC for 20 hours and then kept at room
temperature for 4 hours Water was decanted and the weight difference was determined The
86
freeze-thaw cycle was repeated five times The freeze-thaw stability was expressed as water loss
after each freeze-thaw cycle
Starch thermal properties
Thermal properties of starch were determined using Differential Scanning Calorimetry
(DSC) (Lindeboom et al 2005) Starch samples of 10 mg were weighed into aluminum pans
(Perkin-Elmer Kit No 219-0062) with 20 μL distilled water The pans were sealed and the
suspensions were incubated at room temperature (25 degC) for 2 hours to achieve equilibrium The
pans were then scanned at 10 degCmin from 25 degC to 120 degC The onset temperature (To) peak
temperature (Tp) and completion temperature (Tc) were the temperature to start the peak reach
the peak and complete the peak respectively Additionally enthalpy of gelatinization was
determined by the area under the peak
Swelling power and solubility
Swelling power and water solubility of starch were obtained at 93 degC (Vandeputte et al
2003) Starch samples of 05 g were added to 12 mL distilled water and mixed vigorously The
suspensions were immediately set in a water bath with a rotating rack at 93 degC for 30 min The
suspensions were then cooled in ice water for 2 min and centrifuged at 3000 g for 15 min The
supernatant was carefully removed with a pipette and the weight of wet sediment was recorded
The removed supernatants were dried in a 105 degC oven over night The weight of dry sediment
was recorded The swelling power and water solubility were expressed using the following
equations
Swelling power = wet sediment weight [dry sample weight times (1 ndash water solubility))
Water solubility = dry sediment weight dry sample weight times 100
87
Swelling power is expressed as a unitless ratio
Statistical analysis
All experiments were repeated three times Multiple comparisons were conducted using
Fisherrsquos LSD in SAS 92 (SAS Inst Cary NC USA) Correlations were calculated using
PROC CORR code in SAS 92 A P value of 005 was considered as the level of significance
unless otherwise specified
Results
Starch content and composition
Total starch content of quinoa seeds on a dry basis ranged from 532 g 100 g in the
variety lsquoBlackrsquo to 751 g 100 g in a commercial sample named lsquoYellow Commercialrsquo (Table 2)
Varieties lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo were lower in total
starch content all below 60 g100 g The Port Townsend seeds and commercial seeds contained
higher levels of starch mostly over 70 g100 g
Apparent amylose contents ranged from 27 in lsquo49ALCrsquo to 169 in lsquoCahuilrsquo all
lower than the corn starch standard which was 264 Varieties lsquoCahuilrsquo lsquoBlackrsquo and lsquoYellow
Commercialrsquo contained higher apparent amylose 147 to 169 It is worth noting that
lsquo49ALCrsquo contained the lowest apparent and total amylose contents 27 and 47 respectively
Total amylose of the other varieties ranged from 111 in lsquoQQ63rsquo to 173 in lsquoCahuilrsquo
The degree of amylose-lipid complex differed among the samples ranging from 34 in
lsquoCahuilrsquo to 43 in lsquo49ALCrsquo and lsquoCol6197rsquo Statistically however only lsquo49ALCrsquo and
lsquoCol6197rsquo were significantly higher than lsquoCahuilrsquo in degree of amylose-lipid complex
Starch properties
88
Amylose leaching property exhibited great differences among samples (Table 3)
lsquo49ALCrsquo and lsquo1ESPrsquo showed the highest amylose leaching at 862 and 716 mg 100 g starch
respectively lsquoCahuilrsquo lsquoJapanese Stainrsquo and lsquoRed Commercialrsquo were the lowest with amylose
leaching less than 100 mg 100 g starch lsquoBlackrsquo and lsquoBlancarsquo were relatively low as well with
210 and 171 mg amylose leaching 100 g starch The other varieties were intermediate and
ranged from 349 to 552 mg 100 g starch
Water solubility of quinoa starch ranged from 07 to 45 all lower than that of corn
starch which was 79 lsquoJapanese Strainrsquo lsquoQQ63rsquo lsquoCommercial Yellowrsquo and lsquoPeruvian Redrsquo
were the highest in water solubility 26 to 45 The starch water solubility in the other varieties
was between 10 and 19
Swelling power of quinoa starch ranged from 170 to 282 all higher than that of corn
starch (89) lsquo49ALCrsquo and lsquo1ESPrsquo showed the highest swelling powers 282 and 276
respectively lsquoYellow Commercialrsquo and lsquoRed Commercialrsquo showed relatively lower swelling
power 188 and 196 respectively The remaining varieties did not exhibit differences in
swelling power with values between 253 and 263
α-Amylase activity
Activity of α-amylase in quinoa flour separated the samples to three groups (Table 3)
lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo showed high α-amylase activity from
086 CU to 116 CU (Ceralpha Unit) lsquoBlackrsquo lsquo49ALCrsquo and lsquoCopacabanarsquo were lower in α-
amylase activity 043 031 and 020 CU respectively The other varieties and commercial
samples exhibited particularly low α-amylase activities with the values lower than 01 CU
Starch gel texture
89
Texture of starch gels included hardness springiness and cohesiveness (Table 4)
Hardness of starch gel of lsquoCahuilrsquo and lsquoJapanese Strainrsquo represented the highest and the lowest
values 900 and 201 g respectively Hardness of the other varieties ranged from 333 g in
lsquo49ALCrsquo to 725 g in lsquoBlackrsquo
lsquoJapanese Strainrsquo and lsquoYellow Commercialrsquo exhibited the highest and lowest springiness
values of the starch gels 092 and 071 respectively Springiness of other starch samples ranged
from 075 to 085 and were not significantly different from each other
Cohesiveness of starch gels ranged from 053 to 089 The starch gels of lsquoJapanese
Strainrsquo lsquoCol6197rsquo and lsquoCopacabanarsquo were more cohesive at 089 083 and 078 respectively
The starch gels of lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquo1ESPrsquo were moderately cohesive
with the cohesiveness of 072 ndash 073 Other varieties exhibited less cohesive starch gels lsquoQQ63rsquo
and commercial samples showed the least cohesive starch gels 053 ndash 057 For comparison the
hardness springiness and cohesiveness of the corn starch gel was 721 084 and 073
respectively These values were among the upper-to-middle range of those counterpart values of
the texture of quinoa starch gels
Starch thermal properties
Thermal properties of quinoa starch include gelatinization temperature and enthalpy
(Table 5) Onset temperature To of quinoa starch ranged from 515 ordmC in lsquoYellow Commercialrsquo to
586 ordmC in lsquoBlancarsquo Peak temperature Tp ranged from 595 ordmC in lsquoRed Commercialrsquo to 654 ordmC
in lsquoJapanese Strainrsquo Conclusion temperature ranged from 697 ordmC in lsquoCol6197rsquo to 788 ordmC in
lsquoJapanese Strainrsquo The commercial samples exhibited lower gelatinization temperatures To Tp
90
and Tc of the corn starch were 560 626 and 743 ordmC respectively They were within the ranges
of those values of the quinoa starches
Enthalpy refers to the energy required during starch gelatinization The enthalpy of
quinoa starch ranged from 99 to 116 Jg Starch from lsquoCahuilrsquo exhibited the highest enthalpy
116 Jg higher than that of lsquo49ALCrsquo and lsquoQQ63rsquo However enthalpies of other samples were
not significantly different Corn starch enthalpy was 105 Jg comparable to those of quinoa
starches
Starch pasting properties
Starch viscosity was investigated using the RVA (Table 6) Peak viscosity of quinoa
starches ranged from 193 to 344 RVU Varieties lsquoBlancarsquo and lsquoCahuilrsquo showed the highest peak
viscosities 344 and 342 RVU respectively lsquoJapanese Strainrsquo and lsquoQQ63rsquo were lowest in starch
peak viscosity 193 and 213 RVU respectively The peak viscosity of corn starch was 255 RVU
falling within the middle range of quinoa peak viscosities
The tough is the minimum viscosity after the first peak The trrough of quinoa starch
ranged from 137 to 301 RVU The starches of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and
lsquoOro de Vallersquo showed highest trough values from 252 to 301 RVU lsquo49ALCrsquo lsquo1ESPrsquo
lsquoCopacabanarsquo lsquoJapanese Strainrsquo and lsquoQQ63rsquo were lowest in trough ranging from 137 to 186
RVU The trough of corn starch was 131 RVU lower than that of all quinoa starches
Starch breakdown of lsquo49ALCrsquo was 119 RVU higher than that of other samples except
corn starch which was 124 RVU lsquoJapanese Strainrsquo and lsquoOro de Vallersquo showed the lowest
breakdowns 12 and 17 RVU respectively Breakdown of the other samples ranged from 39 to
97 RVU
91
Final viscosity of lsquoCahuilrsquo starch was 405 RVU significantly higher than that of other
varieties At the other extreme final viscosity of lsquo49ALCrsquo starch was 225 RVU significantly
lower than that of the other varieties The final viscosity of corn starch was 283 RVU close to
that of lsquoJapanese Strainrsquo and lsquoQQ63rsquo but lower than that of the other quinoa samples
The highest setback was observed with lsquo1ESPrsquo starch (140 RVU) At the other extreme
the setback of lsquoOro de Vallersquo was 53 RVU which was lower than the other quinoa samples
Additionally setbacks of lsquoBlancarsquo lsquo49ALCrsquo and lsquoJapanese stainrsquo starches were also among the
lower range varying from 82 RVU to 88 RVU The remaining varieties exhibited higher setback
from 101 RVA to 127 RVU Setback of corn starch was 152 RVU significantly higher than all
the other quinoa starches
RVA peak times of quinoa starches varied significantly among the samples lsquoJapanese
Strainrsquo lsquoBlancarsquo lsquoCahuilrsquo and lsquoOro de Vallersquo required longer time to reach the peak viscosity
with peak times of 105 to 113 min Other varieties showed shorter peak times between 79 to
99 min The starch of lsquo49ALCrsquo however only needed 64 min to reach peak viscosity shorter
than those of other quinoa samples The peak time of corn starch was 73 min shorter than those
of quinoa starches except lsquo49ALCrsquo
Freeze-thaw stability of starch
Freeze-thaw stability of starches was expressed as the water loss () of each freeze-thaw
cycle Quinoa starch samples and corn starch showed similar trends in freeze-thaw stability
Most water loss occurred after cycles 1 and 2 Starch gels on average (excluding lsquo49ALCrsquo) lost a
cumulative total of 522 ndash 689 of water after cycle 2 and a total of 745 ndash 823 after cycle 5
Furthermore the starch gels of lsquoQQ63rsquo and lsquo1ESPrsquo lost the least water indicating higher freeze-
92
thaw stability Conversely the starch gel of lsquoJapanese Strainrsquo lost the most water in every cycle
indicating the lowest degree of freeze-thaw stability
lsquo49ALCrsquo and lsquo1ESPrsquo starches exhibited freeze-thaw behavior that was different
compared to the other samples After freezing the samples of lsquo49ALCrsquo and lsquo1ESPrsquo produced
gels that were less rigid more viscous than the other samples Further they did not lose as much
water after the first cycle The sample of lsquo1ESPrsquo however turned into a solid gel from cycle 2 to
5 And the water loss of the lsquo1ESPrsquo gel was close to that of other samples during cycles 2 and 5
Correlations between starch properties and the texture of cooked quinoa
Correlations between starch properties and texture of cooked quinoa were examined
(Table 7) using texture profile analysis (TPA) of cooked quinoa of Wu et al (2014) Total starch
content was moderately correlated with adhesiveness of cooked quinoa (r = -048 P = 009) but
was not significantly correlated with any of the other texture parameters Conversely apparent
amylose content was highly correlated with all texture parameters (067 le r le 072) Total
amylose content also exhibited significant correlations with all texture parameters (056 le r le
061) Furthermore the degree of amylose-lipid complex was negatively correlated with all
texture parameters (-070 le r le -060) and amylose leaching proportion was highly correlated
with the texture of cooked quinoa (-084 le r le -074)
Water solubility and swelling power of starch were not observed to correlate well with
any of the texture parameters Higher α-amylase activity tended to yield more adhesive (r = 055)
and more cohesive (r = 051 P = 007) texture However α-amylase activity was not correlated
with the hardness gumminess or chewiness of cooked quinoa
93
Some texture parameters of starch gels were associated with the texture parameters of
cooked quinoa The hardness of starch gels was not correlated with the hardness of cooked
quinoa but was weakly correlated with adhesiveness (r = 059) Weakly positive correlations
were found between starch gel hardness and cooked quinoa cohesiveness gumminess and
chewiness (049 le r le 051 P le 010) Springiness and cohesiveness of starch gels were not
correlated with the measured textural properties of cooked quinoa
Onset gelatinization temperature (To) of starch exhibited weak correlations with
adhesiveness (r = 049 P = 009) and cohesiveness (r = 051 P = 007) but was not correlated
with the other texture parameters Peak gelatinization temperature (Tp) of starch was correlated
with cohesiveness (r = 056) and hardness adhesiveness gumminess and chewiness (047 le r le
056 P le 010) No correlation was found with conclusion temperature (Tc) and texture Starch
enthalpy did correlate with the texture parameters (r = 064 in hardness 069 le r le 072 in other
texture parameters)
Starch viscosity measurements were variably correlated with the texture of cooked
quinoa Peak viscosity correlated adhesiveness (r = 054 P = 006) and cohesiveness (r = 047 P
= 010) but not with the other texture parameters Trough was more highly correlated with
adhesiveness cohesiveness gumminess and chewiness (r = 077 in adhesiveness 055 le r le
063 in other texture parameters)
It is interesting to note that starch breakdown only correlated with adhesiveness of
cooked quinoa (r = -060) and not with any other texture parameter Setback was not correlated
with any texture parameter These two RVA parameters breakdown and setback are usually
considered to be important indexes of end-use quality In quinoa however breakdown and
94
setback of starch apparently are not predictive of cooked quinoa texture In addition final
viscosity was also correlated with adhesiveness (r = 068) and cohesiveness (r = 058) and
correlated moderately with gumminess and chewiness (r = 053 P = 006) Peak time was
correlated with adhesiveness (r = 077) cohesiveness (r = 068) gumminess (r = 060) and
chewiness (r = 060) and to a lesser extent with hardness (r = 053 P = 006)
Correlations between starch properties and seed DSC RVA characteristics
Total starch content correlated with seed hardness (r = -073) seed coat proportion (r = -
071) and starch viscosities (peak viscosity trough and final viscosity) (-068 lt r lt -060) and
also to a lesser extent with seed density (r = 054 P = 006) and starch thermal properties (To
Tp and enthalpy) (-051 lt r lt -049 008 lt P lt009) (Table 8)
Water solubility of starch was correlated with starch viscosity such as peak viscosity (r =
-049 P = 009) and breakdown (r = -048 P = 010) Swelling power was only correlated with
peak time (r = -054 P = 006) (data not shown)
Apparent amylose content was correlated with protein content (r = 058) and optimal
cooking time (r = 056) but total amylose content did not show either of these correlations Both
apparent and total amylose contents were correlated with starch gel hardness starch enthalpy
and starch viscosity such as trough breakdown final viscosity and peak time
The degree of amylose-lipid complex exhibited negative correlations with seed protein
content (r = -07) and optimal cooking time of quinoa seed (r = -067) Moreover amylose
leaching was negatively correlated with protein content (r = -062) starch gel hardness (r = --
064) starch Tp (r = -058) and enthalpy (r = -064) optimal cooking time (r = -055) and starch
viscosities such as breakdown (r = 062) and peak time (r = -081) Additionally α-amylase
95
activity was correlated with protein content (r = 066) seed density (r = -072) seed coat
proportion (r = 055) starch To (r = 061) and starch viscosities such as peak viscosity (r =
070) trough (r = 072) and final viscosity (r = 061)
Discussion
Starch content and composition
Total starch content does influence the functional and processing properties of cereals
The total starch content of quinoa was reported to be between 32 and 69 (Abugoch 2009)
Among our varieties most of the Port Townsend varieties and commercial quinoa contained
more than 69 starch It is interesting to note that the Port Townsend samples lsquo49ALCrsquo lsquo1ESPrsquo
lsquoCol6197rsquo and lsquoQQ63rsquo were also more sticky or more adhesive after cooking than other
varieties These varieties may exhibit better performance in extrusion products or in beverages
which require high viscosity
Amylose content affects texture and gelation properties The proportion of amylose and
amylopectin impacts the functionality of cereals in this study both apparent and total amylose
contents were determined Total amylose includes those amylose molecules that are complexed
with lipids
Amylose content of quinoa was reported to range from 35 to 225 dry basis
(Abugoch 2009) generally lower than that of common cereals which is around 25 Overall
both apparent and total amylose contents of the quinoa in the present study fell within the range
which has been reported lsquo49ALCrsquo was an exception showing significantly lower apparent and
total amylose contents of 27 and 47 respectively Thus this variety is close to be being a
lsquowaxyrsquo which refers to the cereal starches that are comprised of mostly amylopectin (99) and
96
little amylose (~1) As the waxy wheat showed an excellent expansion during extrusion
(Kowalski et al 2014) lsquo49ALCrsquo is a promising variety to produce breakfast cereal or extruded
snacks
The degree of amylose-lipid complex showed great variability among the samples 34 ndash
433 whereas the value in wheat flour was reported to be 32 (Bhatnagar and Hanna 1994) or
13 to 23 (Zeng et al 1997) Degree of amylose-lipid complex showed significant and
negative correlations with all texture parameters such as hardness adhesiveness cohesiveness
gumminess and chewiness
The effect of amylose-lipid complex on product texture has been reported in previous
studies The degree of amylose-lipid complex correlated with the texture (hardness and
crispness) and quality (radial expansion) of corn-based snack (Thachil et al 2014) Wokadala et
al (2012) indicated that amylose-lipid complexes played a significant role in starch biphasic
pasting
Starch properties
Amylose leaching was also highly variable among the quinoa varieties 35 ndash 862 mg
100g starch Vandeputte et al (2003) studied amylose leaching of waxy and normal rice
starches The amylose leaching values at 65 ordmC were below 1 of starch comparable with those
in quinoa starch Pronounced increase of amylose leaching was observed at the temperatures
higher than 95 ordmC Patindol et al (2010) found that both amylose and amylopectin leached out
during cooking rice The proportion of the leached amylose and amylopectin influenced the
texture of cooked rice We found similar results indicating correlations between amylose
leaching and texture of cooked quinoa
97
Water solubility of quinoa starch was significantly lower than that of corn starch whereas
swelling power of quinoa starch was higher than that of corn starch Both water solubility and
swelling power were determined at 95 ordmC Lindeboom et al (2005) determined swelling power
and solubility of quinoa starch among eight varieties at 65 75 85 and 95 ordmC The water
solubility at 95 ordmC ranged from 01 to 47 which was lower than the corn starch standard of
100 The swelling power at 95 ordmC ranged from 164 to 526 lower than the corn starch
standard of 549 The quinoa starch in this study showed a narrower range of swelling power
170 to 282
α-Amylase activity
The quinoa in this study had significantly different α-amylase activity (003 ndash 116 CU)
Previous studies reported low α-amylase activity in quinoa compared to oat (Maumlkinen et al
2013) and traditional malting cereals (Hager et al 2014) Moreover the activity of α-amylase
indicates the degree of seed germination and the availability of sugars for fermentation In the
study of Hager et al (2014) α-amylase activity increased from 0 to 35 CU during 72 h
germination
Texture of starch gel
Starch gel texture has been previously studied on corn and rice starches but not on
quinoa starch Hardness of rice starch gel was reported to be 339 g by Charoenrein et al (2011)
and 116 g by Jiang et al (2011) Hardness of corn starch was reported to be around 100 g in the
study of Sun et al (2014) much lower than the standard corn starch hardness in this study 721
g Compared to those of rice and corn starch quinoa starch gel exhibited harder texture which
may be caused by either genetic variation or different processing procedures to form the gel
98
Additionally springiness and cohesiveness of rice starch gel were reported as 085 and 055
respectively (Jiang et al 2011) Quinoa starch gel exhibited comparable springiness and higher
cohesiveness than those of rice starch gel
Thermal properties of quinoa starch
The thermal properties of quinoa starch in this study were comparable to those of rice
starch (Cai et al 2014) The study of Lindeboom et al (2005) however found lower
gelatinization temperatures and higher enthalpies compared to the present study which may be
due to varietal difference
Furthermore correlation between thermal properties of quinoa starch and flour (Wu et al
2014) was investigated Gelatinization temperatures To Tp and Tc of starch and whole seed
flour were highly correlated especially To and Tp exhibited high r of 088 The enthalpy of
starch and flour however was not significantly correlated In this case quinoa flour can be used
to estimate quinoa starch gelatinization temperatures but not the enthalpy Additionally since
flour is easier to prepare compared to starch further studies can be conducted with a larger
number of quinoa samples to model the prediction of starch thermal properties using flour
thermal properties
Starch pasting properties
Viscosity and pasting properties of starch play a significant role in the functionality of
cereals Jane et al (1999) studied the pasting properties of starch from cereals such as maize
rice wheat barley amaranth and millet The peak viscosities ranged from 58 RVU in barley to
219 RVU in sweet rice lower than those of most quinoa starches except lsquoJapanese Strainrsquo and
lsquoQQ63rsquo Final viscosities ranged from 54 RVU in barley to 208 RVU in cattail millet all lower
99
than those of the quinoa starches in the present study Setback of cereal starches mostly ranged
from 6 RVU in waxy amaranth to 74 RVU in non-waxy maize lower than those of most quinoa
starches except lsquoOre de Vallersquo Cattail millet starch exhibited the setback of 208 RVU higher
than those of quinoa starches
The relationships between RVA pasting parameters of quinoa starch and flour were
studied by Wu et al (2014) Final viscosity of starch and flour was correlated negatively (r = -
063 P = 002) The other RVA parameters did not exhibit significant correlation between starch
and flour RVA In other words RVA of quinoa flour cannot be used to predict RVA of quinoa
starch In addition to starch the fiber and protein in whole quinoa flour may influence the
viscosity As quinoa is normally utilized as whole grain or whole grain flour instead of refined
flour the flour RVA should be a better indication on the end-use functionality
Freeze-thaw stability of starch
Quinoa starches in the present study did not show high stability during freeze and thaw
cycles Praznik et al (1999) studied freeze-thaw stability of various cereal starches Similar to
the present study Praznik et al concluded quinoa starches exhibited low freeze-thaw stability
Conversely Ahamed et al (1996) found quinoa starch exhibited excellent freeze-thaw stability
Unfortunately the variety was not indicated Overall it is reasonable to assert that for some
quinoa cultivars the starch may have better freeze-thaw stability than in other cultivars
However most quinoa varieties in published studies did not show good freeze-thaw stability
Correlations between starch characteristics and texture of cooked quinoa
The quinoa starch characteristics correlated with the texture of cooked quinoa in some
aspects Total starch content however did not show any strong correlations with TPA
100
parameters as was initially expected Since quinoa is consumed as whole grain or whole flour
fiber and bran may exhibit more influence on the texture than anticipated from the impact of
starch alone
The quinoa varieties with higher apparent and total amylose contents tended to yield a
harder stickier more cohesive more gummy and chewy texture Similar correlations are found
with cooked rice noodle and corn-based extrusion snacks The hardness of cooked rice was
positively correlated with amylose content and negatively correlated with adhesiveness (Yu et al
2009) Epstein et al (2002) reported that full waxy noodles were softer thicker less adhesive
and chewy and more cohesive and springy compared to normal noodles and partial waxy
noodles Increased amylose content in a corn-based extrusion snack resulted in higher amylose-
lipid formation and softer texture (Thachil et al 2014)
Higher levels of amylose-lipid complex in starch were associated with softer less
adhesive less cohesive and less gummy and less chewy cooked quinoa The correlation between
the degree of amylose-lipid complex and texture of cooked rice or quinoa has not been
previously reported Kaur and Singh (2000) however found that amylose-lipid complex
increased with longer cooking time of rice flour Additionally cooking time is a key factor to
determine texture ndash the longer a cereal is cooked the softer less sticky less cohesive and less
gummy and chewy the texture
Correlations were found between amylose leaching and cooked quinoa TPA parameters
especially hardness gumminess and chewiness with r of -082 Increased amylose leaching
yielded a softer gel made from potato starch (Hoover et al 1994) However the correlations of
101
amylose leaching and α-amylase activity with texture of end product for quinoa have not been
reported previously
Swelling power and water solubility were reported to influence the texture of wheat and
rice noodle (Crosbie 1991 McCormick et al 1991 Konik et al 1993 Ross et al 1997
Bhattacharya et al 1999) However in the present report no correlation was found between
swelling power water solubility and the texture of cooked quinoa Additionally the study of
Ong and Blanshard (1995) indicated a positive correlation between enthalpy and the texture of
cooked rice Similar results were found in this study
RVA is a fast and reliable way to predict flour functionality and end-use properties
Pasting properties of rice flour have been used to predict texture of cooked rice (Champagne et
al 1999 Limpisut and Jindal 2002) In our previous study cooked quinoa texture correlated
negatively with the final viscosity and setback of quinoa flour (Wu et al 2014) In this study
texture correlated with trough breakdown final viscosity and peak time of quinoa starch
However RVA of quinoa flour and starch did not correlate with each other Flour RVA might be
a convenient way to predict cooked quinoa texture
Correlations between starch properties and seed DSC RVA characteristics
Quinoa with higher total starch tended to have a thinner seed coat This makes sense
because starch protein lipids and fiber are the major components of seed An increase in one
component will result in a proportional decrease in the other component contents
Additionally the starch RVA parameters (except peak viscosity) can be used to estimate
apparent or total amylose content based on their correlations Further studies should be
conducted with a larger sample size of quinoa and a more accurate prediction model can be built
102
The samples with lower protein or those requiring shorter cooking time tended to contain
higher levels of amylose-lipid complex Additionally amylose-lipid complex was reported to
influence the texture of extrusion products (Bhatnagar and Hanna 1994 Thachil et al 2014) For
this reason protein and optimal cooking time are promising indicators of the behavior of quinoa
during extrusion
Conclusions
In summary starch content composition and characteristics were significantly different
among quinoa varieties Amylose content degree of amylose-lipid complex and amylose
leaching property of quinoa starch exhibited great variances and strong correlations with texture
of cooked quinoa Additionally starch gel texture pasting properties and thermal properties
were different among varieties and different from those of rice and corn starches Enthalpy
RVA trough final viscosity and peak time exhibited significant correlations with cooked quinoa
texture Overall starch characteristics greatly influenced the texture of cooked quinoa
Acknowledgments
This project was supported by the USDA Organic Research and Extension Initiative
(NIFAGRANT11083982) The authors acknowledge Girish Ganjyal and Shyam Sablani for
using the Differential Scanning Calorimetry (DSC) thanks to Stacey Sykes for editing support
Author Contributions
G Wu and CF Morris designed the study together and established the starch isolation
protocol G Wu collected test data and drafted the manuscript CF Morris and KM Murphy
edited the manuscript KM Murphy provided quinoa samples
103
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Jane J Chen Y Lee L McPherson A Wong K Radosavljevic M Kasemsuwan T 1999 Effects
of amylopectin branch chain length and amylose content on the gelatinization and pasting
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Chem 71(4)511-7
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92(2)145-53
Limpisut P Jindal VK 2002 Comparison of rice flour pasting properties using Brabender
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Staumlrke 54(8)350-7
Lindeboom N Chang PR Falk KC Tyler RT 2005 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2)216-22
Mahmood T Turner MA Stoddard FL 2007 Comparison of methods for colorimetric amylose
determination in cereal grains Starch‐Staumlrke 59(8)357-65
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Maumlkinen OE Zannini E Arendt EK 2013 Germination of oat and quinoa and evaluation of the
malts as gluten free baking ingredients Plant Foods Hum Nutr 68(1)90-5
Matos M Timgren A Sjoo M Dejmek P Rayner M 2013 Preparation and encapsulation
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McCormick K Panozzo J Hong S 1991 A swelling power test for selecting potential noodle
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(Chenopodium quinoa W) starch containing gold nanoparticles and evaluation of
antimicrobial activity Food Chem 173755-62
Patindol J Gu X Wang YJ 2010 Chemometric analysis of cooked rice texture in relation to
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Perdon AA Siebenmorgen TJ Buescher RW Gbur EE 1999 Starch retrogradation and texture
of cooked milled rice during storage J Food Sci 64(5)828-32
107
Praznik W Mundigler N Kogler A Pelzl B Huber A Wollendorfer M 1999 Molecular
background of technological properties of selected starches Starch‐Staumlrke 51(6) 197-211
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starch Starch‐Staumlrke 51(4)116-20
Ramesh M Zakiuddin Ali S Bhattacharya KR 1999 Structure of rice starch and its relation to
cooked-rice texture Carbohydr Polym 38(4)337-47
Rayner M Sjoumlouml M Timgren A Dejmek P 2012 Quinoa starch granules as stabilizing particles
for production of Pickering emulsions Faraday Discuss 158(1)139-55
Ross AS Quail KJ Crosbie GB 1997 Physicochemical properties of Australian flours
influencing the texture of yellow alkaline noodles Cereal Chem 74(6)814-20
Sun Q Xing Y Qiu C Xiong L 2014 The pasting and gel textural properties of corn starch in
glucose fructose and maltose syrup PloS one 9(4)e95862
Thachil MT Chouksey MK Gudipati V 2014 Amylose-lipid complex formation during
extrusion cooking effect of added lipid type and amylose level on corn-based puffed snacks
Int J Food Sci Tech 49(2)309-16
Vandeputte GE Derycke V Geeroms J Delcour JA 2003 Rice starches II Structural aspects
provide insight into swelling and pasting properties J Cereal Sci 38(1)53-9
Wokadala OC Ray SS Emmambux MN 2012 Occurrence of amylosendashlipid complexes in teff
and maize starch biphasic pastes Carbohydr Polym 90(1)616-22
108
Wu G Morris C F Murphy K M 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79(11)2337-45
Yu S Ma Y Sun DW 2009 Impact of amylose content on starch retrogradation and texture of
cooked milled rice during storage J Cereal Sci 50(2)139-44
Zeng M Morris CF Batey IL Wrigley CW 1997 Sources of variation for starch gelatinization
pasting and gelation properties in wheat Cereal Chem 74(1)63-71
109
Table 1-Quinoa varieties tested
Variety Original Seed Source Location
Black White Mountain Farm White Mountain Farm Colo USA
Blanca White Mountain Farm White Mountain Farm Colo USA
Cahuil White Mountain Farm White Mountain Farm Colo USA
Cherry Vanilla Wild Garden Seeds Philomath Oregon
WSUa Organic Farm Pullman Wash USA
Oro de Valle Wild Garden Seeds Philomath Oregon
WSUa Organic Farm Pullman Wash USA
49ALC USDA Port Townsend Wash USA
1ESP USDA Port Townsend Wash USA
Copacabana USDA Port Townsend Wash USA
Col6197 USDA Port Townsend Wash USA
Japanese Strain USDA Port Townsend Wash USA
QQ63 USDA Port Townsend Wash USA
Yellow Commercial Multi Organics company Bolivia
Red Commercial Multi Organics company Bolivia a WSU Washington State Univ
110
Table 2-Starch content and composition
Variety Total starch
(g 100 g)
Apparent amylose
()
Total
amylose ()
Degree of amylose
lipid complex ()
Black 532f 153a 159ab 96bc
Blanca 595de 102cd 163a 361ab
Cahuil 622d 169a 173a 34c
Cherry Vanilla
590de 105cd 116bc 164abc
Oro de Valle 573ef 114bcd 166a 300abc
49ALC 674c 27e 47d 426a
1ESP 705bc 86d 152abc 389ab
Copacabana 734ab 120bc 153abc 222abc
Col6197 725ab 102cd 140abc 433a
Japanese Strain
723ab 116bcd 165ab 305abc
QQ63 713abc 84d 111c 241abc
Yellow Commercial
751a 147ab 150abc 118abc
Red Commercial
691bc 100cd 164a 375ab
Corn starch - 264 - -
111
Table 3-Starch properties and α-amylase activity
Variety Amylose leaching (mg 100 g starch)
Water solubility ()
Swelling power
α-Amylase activity (CU)
Black 210ef 16de 260bcd 043d
Blanca 171efg 10de 260bcd 086c
Cahuil 97fg 16cde 253cd 106b
Cherry Vanilla 394d 15de 253cd 116a
Oro de Valle 420d 16de 245d 103b
49ALC 862a 07e 282a 031e
1ESP 716b 13de 276ab 003g
Copacabana 438cd 14de 263bc 020f
Col6197 552c 19cd 257cd 009g
Japanese Strain 31fg 45a 170f 005g
QQ63 315de 26bc 262bc 008g
Yellow Commercial
349d 32b 188e 005g
Red Commercial 35g 26bc 196e 003g
Corn starch - 79 89 -
112
Table 4-Texture of starch gel
Variety Hardness (g) Springiness Cohesiveness
Black 725ab 082ab 064cd
Blanca 649abc 083ab 072bc
Cahuil 900a 085ab 072bc
Cherry Vanilla 607abc 078bc 072bc
Oro de Valle 448abc 078bc 064cd
49ALC 333bc 081bc 061cd
1ESP 341bc 081bc 073bc
Copacabana 402bc 084ab 078ab
Col6197 534abc 083ab 083ab
Japanese Strain 765ab 092a 089a
QQ63 201c 078bc 053d
Yellow Commercial 436bc 071c 057d
Red Commercial 519abc 075bc 055d
Corn starch 721 084 073
113
Table 5-Thermal properties of starch
Variety Gelatinization temperature Enthalpy (Jg)
To (ordmC) Tp (ordmC) Tc (ordmC)
Black 560b 639bc 761bc 112abc
Blanca 586a 652ab 754bcd 113abc
Cahuil 582a 648ab 755bcd 116a
Cherry Vanilla 563b 627cd 747bcd 111abc
Oro de Valle 562b 623d 739cd 106abc
49ALC 524ef 598f 747bcd 101bc
1ESP 530de 608ef 738cd 103abc
Copacabana 565b 622d 731de 106abc
Col6197 540cd 598f 697f 105abc
Japanese Strain 579a 654a 788a 104abc
QQ63 545c 616de 766ab 99c
Yellow Commercial 515f 599f 708ef 107abc
Red Commercial 520ef 595f 700 f 116ab
Corn starch 560 626 743 105
114
Table 6-Pasting properties of starch
Variety Peak viscosity
(RVU)a
Trough
(RVU)
Breakdown
(RVU)
Final viscosity
(RVU)
Setback
(RVU)
Peak time
(min)
Black 293abc 252abc 41efg 363ab 111abcd 92e
Blanca 344a 301a 42defg 384ab 82de 111ab
Cahuil 342ab 297a 45def 405a 108abcd 106bc
Cherry Vanilla 313abc 263abc 50de 369ab 106abcd 99d
Oro de Valle 294abc 277ab 17fg 330abc 53e 105c
49ALC 256cde 137f 119a 225d 88cde 64i
1ESP 269bcd 172ef 97ab 313bc 140a 79h
Copacabana 258cde 186def 72bcd 308bc 122abc 81gh
Col6197 270bcd 231bcd 39efg 347ab 116abcd 86fg
Japanese Strain 193e 181def 12g 264cd 83de 113a
QQ63 213de 152f 60cde 254cd 101bcd 88ef
Yellow Commercial
290abc 223cde 67bcde 350ab 127ab 93de
Red Commercial 327abc 242bc 85bc 366ab 125ab 92ef
Corn 255 131 124 283 152 73 aRVU = cP12
115
Table 7-Correlation coefficients between starch properties and texture of cooked quinoaa
Hardness Adhesiveness Cohesiveness Gumminess Chewiness
Total starch content
-032ns -048 -043ns -039ns -039ns
Apparent amylose content
069 072 069 072 072
Actual amylose content
061 062 056 061 061
Degree of amylose-lipid complex
-065 -060 -070 -070 -070
Amylose leaching
-082 -075 -074 -082 -082
α-Amylase activity
018ns 055 051 032ns 032ns
Starch gel hardness
042ns 059 051 049 049
DSC
To 034ns 049 051 041ns 041ns
Tp 047 052 056 052 052
ΔH 064 072 069 070 070
RVA
Peak viscosity 031ns 054 047 041ns 041ns
Trough 044ns 077 063 055 055
Breakdown -034ns -060 -044ns -038ns -038ns
Final viscosity 045ns 068 058 053 053
Peak time 053 077 068 060 060
ns non-significant difference P lt 010 P lt 005 P lt 001 aTPA is the Texture Profile Analysis of cooked quinoa data were presented in Wu et al (2014)
116
Table 8-Correlations between starch properties and seed DSC RVA characteristicsa
Total
starch content
Water solubility
Apparent amylose content
Total amylose content
Degree of amylose-lipid complex
Amylose leaching
α-Amylase activity
Protein -047ns 023ns 058 031ns -069 -062 066
Seed hardness
-073 -041ns -003ns -021ns -020ns 019ns 053
Bulk density
054 049 -020ns -015ns 031ns 019ns -072
Seed coat proportion
-071 -041ns 027ns 021ns -028ns -038ns 055
Starch gel hardness
-045ns 017 ns 065 053 -044ns -064 046ns
Starch DSC
To -049 -004ns 041ns 043ns -033ns -049 061
Tp -050 010ns 047ns 045ns -042ns -058 052
Enthalpy -051 -011ns 059 055 -041ns -064 049
Starch viscosity
Peak viscosity
-066 -049 028ns 027ns -020ns -023ns 070
Trough -068 -017ns 056 057 -031ns -052 072
Breakdown
022ns -048 -061 -067 027ns 062 -025ns
Final viscosity
-060 -022ns 063 060 -037ns -046ns 061
Peak time -032ns 045ns 058 072 -029ns -081 043ns
117
Cooking quality
Optimal cooking time
-043ns 019ns 056 040ns -067 -055 029ns
ns non-significant difference P lt 010 P lt 005 P lt 001 aSeed characteristics data were presented in Wu et al (2014)
118
Chapter 5 Quinoa Seed Quality Response to Sodium Chloride and
Sodium Sulfate Salinity
Submitted to the Frontiers in Plant Science
Research Topic Protein crops Food and feed for the future
Abstract
Quinoa (Chenopodium quinoa Willd) is an Andean grain with an edible seed that both contains
high protein content and provides high quality protein with a balanced amino acid profile
Quinoa is a halophyte adapted to harsh environments with highly saline soil In this study four
quinoa varieties were grown under six salinity treatments and two levels of fertilization and then
evaluated for quinoa seed quality characteristics including protein content seed hardness and
seed density Concentrations of 8 16 and 32 dS m-1 of NaCl and Na2SO4 as well as a no-salt
control were applied to the soil medium across low (1 g N 029 g P 029 g K per pot) and high
(3 g N 085 g P 086 g K per pot) fertilizer treatments Seed protein content differed across soil
salinity treatments varieties and fertilization levels Protein content of quinoa grown under
salinized soil ranged from 130 to 167 comparable to that from normal conditions NaCl
and Na2SO4 exhibited different impacts on protein content Whereas the different concentrations
of NaCl did not show differential effects on protein content the seed from 32 dS m-1 Na2SO4
contained the highest protein content Seed hardness differed among varieties and was
moderately influenced by salinity level (P = 009) Seed density was affected significantly by
119
variety and Na2SO4 concentration but was unaffected by NaCl concentration The plants from 8
dS m-1 Na2SO4 soil had lower density (066 gcm3) than those from 16 dS m-1 and 32 dS m-1
Na2SO4 074 and 072gcm3 respectively This paper identifies changes in critical seed quality
traits of quinoa as influenced by soil salinity and fertility and offers insights into variety
response and choice across different abiotic stresses in the field environment
Key words quinoa soil salinity protein content hardness density
120
Introduction
Quinoa (Chenopodium quinoa Willd) has garnered much attention in recent years
because it is an excellent source of plant-based protein and is highly tolerance of soil salinity
Because soil salinity affects between 20 to 50 of irrigated arable land worldwide (Pitman and
Lauchli 2002) the question of how salinity affects seed quality in a halophytic crop like quinoa
needs to be addressed Protein content in most quinoa accessions has been reported to range from
12 to 17 depending on variety environment and inputs (Rojas et al 2015) This range
tends to be higher than the protein content of wheat barley and rice which were reported to be
105- 14 8-14 and 6-7 respectively (Shih 2006 Orth and Shellenberger1988 Cai et
al 2013) Additionally quinoa has a well-balanced complement of essential amino acids
Specifically quinoa is rich in lysine which is considered the first limiting essential amino acid in
cereals (Taylor and Parker 2002) Protein quality such as Protein Efficiency Ratio is similar to
that of casein (Ranhotra et al 1993) Furthermore with a lack of gluten protein quinoa can be
safely consumed by gluten sensitiveintolerant population (Zevallos et al 2014)
Quinoa shows exceptional adaption to harsh environments such as drought and salinity
(Gonzaacutelez et al 2015) Soil salinity reduces crop yields and is a worldwide problem In the
United States approximately 54 million acres of cropland in forty-eight States were occupied by
saline soils while another 762 million acres are at risk of becoming saline (USDA 2011) The
salinity issue leads producers to grow more salt-tolerant crops such as quinoa
Many studies have focused on quinoarsquos tolerance to soil salinity with a particular
emphasis on plant physiology (Ruiz-Carrasco et al 2011 Adolf et al 2012 Cocozza et al
121
2013 Shabala et al 2013) and agronomic characteristics such as germination rate plant height
and yield (Prado et al 2000 Chilo et al 2009 Peterson and Murphy 2015 Razzaghi et al
2012) For instance Razzaghi et al (2012) showed that the seed number per m2 and seed yield
did not decrease as salinity increased from 20 to 40 dS m-1 in the variety Titicaca Ruiz-Carrasco
et al (2011) reported that under 300 mM NaCl germination and shoot length were significantly
reduced whereas root length was inhibited in variety BO78 variety PRJ biomass was less
affected and exhibited the greatest increase in proline concentration Jacobsen et al (2000)
suggested that stomatal conductance leaf area and plant height were the characters in quinoa
most sensitive to salinity Wilson et al (2002) examined salinity stress of salt mixtures of
MgSO4 Na2SO4 NaCl and CaCl2 (3 ndash 19 dS m-1) No significant reduction in plant height and
fresh weight were observed In a comparison of the effects of NaCl and Na2SO4 on seed yield
quinoa exhibited greater tolerance to Na2SO4 than to NaCl (Peterson and Murphy 2015)
Few studies have focused on the influence of salinity on seed quality in quinoa Karyotis
et al (2003) conducted a field experiment in Greece (80 m above sea level latitude 397degN)
With the exception of Chilean variety lsquoNo 407rsquo seven other varieties exhibited significant
increases in protein (13 to 33) under saline-sodic soil with electrical conductivity (EC) of
65 dS m-1 Mineral contents of phosphorous iron copper and boron did not decrease under
saline conditions Koyro and Eisa (2008) found a significant increase in protein and a decrease in
total carbohydrates under high salinity (500 mM) Pulvento et al (2012) indicated that fiber and
saponin contents increased under saline conditions with well watersea water ratio of 11
compared to those under normal soil
122
Protein is one of the most important nutritional components of quinoa seed The content
and quality of protein contribute to the nutritional value of quinoa Additionally seed hardness is
an important trait in crops such as wheat and soybeans For instance kernel hardness highly
influences wheat end-use quality (Morris 2002) and correlates with other seed quality
parameters such as ash content semolina yield and flour protein content (Hruškovaacute and Švec
2009) Hardness of soybean influenced water absorption seed coat permeability cookability
and overall texture (Zhang et al 2008) Quinoa seed hardness was correlated with the texture of
cooked quinoa influencing hardness chewiness and gumminess and potentially consumer
experience (Wu et al 2014) Furthermore seed density is also a quality index and is negatively
correlated with the texture of cooked quinoa such as hardness cohesiveness chewiness and
gumminess (Wu et al 2014)
Chilean lowland varieties have been shown to be the most well-adapted to temperate
latitudes (Bertero 2003) and therefore they have been extensively utilized in quinoa breeding
programs in both Colorado State University and Washington State University (Peterson and
Murphy 2015) For these reasons Chilean lowland varieties were evaluated in the present study
The objectives of this study were to 1) examine the effect of soil salinity on the protein content
seed hardness and density of quinoa varieties 2) determine the effect of different levels of two
agronomically important soil salts NaCl and Na2SO4 on seed quality and 3) test the influence
of fertilization levels on salinity tolerance of quinoa The present study illustrates the different
influence of NaCl and Na2SO4 on quinoa seed quality and provides better guidance for variety
selection and agronomic planning in highly saline environments
Materials and Methods
123
Genetic material
Quinoa germplasms were obtained from Dr David Brenner at the USDA-ARS North
Central Regional Plant Introduction Station in Ames Iowa The four quinoa varieties CO407D
(PI 596293) UDEC-1 (PI 634923) Baer (PI 634918) and QQ065 (PI 614880) were originally
sourced from lowland Chile CO407D was released by Colorado State University in 1987
UDEC-1 Baer and QQ065 were varieties from northern central and southern locations in Chile
with latitudes of 3463deg S 3870deg S and 4250deg S respectively
Experimental design
A controlled environment greenhouse study was conducted using a split-split-plot
randomized complete block design with three replicates per treatment Factors included four
quinoa varieties two fertility levels and seven salinity treatments (three concentration levels
each of NaCl and Na2SO4) Three subsamples each representing a single plant were evaluated
for each treatment combination Quinoa variety was treated as the main plot salinity level as the
sub-plot and fertilization as the sub-sub-plot Salinity levels included 8 16 and 32 dS m-1 of
NaCl and Na2SO4 The details of controlling salinity levels were described by Peterson and
Murphy (2015) In brief fertilization was provided by a mixture of alfalfa meal
monoammonium phosphate and feather meal Low fertilization level referred to 1 g of N 029 g
of P and 029 g of K in each pot and high fertilization level referred to 3 g of N 086 g of P and
086 g of K in each pot Each pot contained about 1 L of Sunshine Mix 1 (Sun Gro Horticulture
Bellevue WA) (dry density of 100 gL water holding capacity of ca 480 gL potting mix) The
124
entire experiment was conducted twice with the planting dates of September 10th 2011 and
October 7th 2011
Seed quality tests
Protein content of quinoa was determined using the Dumas combustion nitrogen method
(LECO Corp Joseph Mich USA) (AACCI Method 46-3001) A factor of 625 was used to
convert nitrogen to protein Seed hardness was determined using the Texture Analyzer (TA-
XT2i) (Texture Technologies Corp Scarsdale NY) and a modified rice kernel hardness method
(Krishnamurthy and Giroux 2001) A single quinoa kernel was compressed until the point of
fracture using a 1 cm2 cylinder probe traveling at 5 mms Repeat measurements were taken on 9
random kernels The seed hardness was recorded as the average peak force (Kg) of the repeated
measures
Seed density was determined using a pycnometer (Pentapyc 5200e Quantachrome
Instruments Boynton Beach FL) Quinoa seed was placed in a closed micro container and
compressed nitrogen was suffused in the container Pressure in the container was recorded both
with and without nitrogen The volume of the quinoa sample was calculated by comparing the
standard pressure obtained with a stainless steel ball Density was the seed weight divided by the
displaced volume Seed density was collected on only the second greenhouse experiment
Statistical analysis
Data were analyzed using the PROC GLM procedure in SAS (SAS Institute Cary NC)
Greenhouse experiment repetition was treated as a random factor in protein content and seed
hardness analysis Variety salinity and fertilization were treated as fixed factors Fisherrsquos LSD
125
Test was used to access multiple comparisons Pearson correlation coefficients between protein
hardness and density were obtained via PROC CORR procedure in SAS using the treatment
means
Results
Protein
Variety salinity and fertilization all exhibited highly significant effects on protein
content (P lt 0001) (Table 1) The greatest contribution to variation in seed protein was due to
fertilization (F = 40247) In contrast salinity alone had a relatively minor effect and the
varieties responded similarly to salinity as evidenced by a non-significant interaction The
interactions however were found in variety x fertilization as well as in salinity x fertilization
both of which were addressed in later paragraphs It is worth noting that the two experiments
produced different seed protein contents (F = 4809 P lt0001) experiment x variety interaction
was observed (F = 1494 P lt0001) (data not shown) Upon closer examination this interaction
was caused by variety QQ065 which produced an overall mean protein content of 129 in
experiment 1 and 149 in experiment 2 Protein contents of the other three varieties were
essentially consistent across the two experiments
Across all salinity and fertilization treatments the variety protein means ranged from
130 to 167 (data not shown) As expected high fertilization resulted in an increase in
protein content across all varieties The mean protein contents under high and low fertilization
were 158 and 136 respectively (Table 2) The means of Baer and CO407D were the
126
highest 151 and 149 respectively QQ065 contained 141 protein significantly lower
than the other varieties
Even though salinity effects were relatively smaller than fertilization and variety effects
salinity still had a significant effect on protein content (Table 1) The two types of salt exhibited
different impacts on protein (Table 2) Protein content did not differ according to different
concentrations of NaCl with means (across varieties and fertilization levels) from 147 to
149 Seed from 32 dS m-1 Na2SO4 however contained higher protein (152) than that from
8 dS m-1 and 16 dS m-1 Na2SO4 (144 and 142 respectively)
A significant interaction of salinity x fertilization was detected indicating that salinity
differentially impacted seed protein content under high and low fertilization level (Figure 1)
Within the high fertilizer treatment protein content in the seed from 32dS m-1 Na2SO4 was
significantly higher (167) than all other samples which did not differ from each other (~13)
Within the low fertilizer treatment protein content of seeds from 8 dS m-1 and 16 dS m-1
Na2SO4 were significantly lower than those from the NaCl treatments and 32dS m-1 Na2SO4
The significant interaction between variety and fertilization (Table 1) was due to the
different response of QQ065 Protein mean of QQ065 from high fertilization was 144 lower
than the other varieties CO407D UDEC-1 and Baer exhibited a decline of 16 - 18 in
protein under low fertilization while QQ065 dropped only 5
Hardness
Variety exhibited the greatest influence on seed hardness (F = 21059 P lt0001)
whereas fertilization did not show any significant effect (Table 1) Salinity exhibited a moderate
127
effect (F = 200 P = 009) Varieties responded consistently to salinity under various fertilization
levels since neither variety x salinity nor salinity x fertilization interaction was significant
However a variety x fertilization interaction was observed which will be discussed in a later
paragraph Similar to the situation in protein content experiment repetition exhibited a
significant influence on seed hardness Whereas the hardness of CO407D was consistent across
the two greenhouse experiments the hardness of other three varieties all decreased by 8 to 9
Mean hardness was significantly different among varieties CO407D had the hardest
seeds with hardness mean of 100 kg (Table 3) UDEC-1 was softer at 94 kg whereas Baer and
QQ065 were the softest and with similar hardness means of 77 kg and 74 kg respectively
Salinity exhibited a moderate impact on seed hardness (P = 009) The highest hardness
mean was observed under 16 dS m-1 Na2SO4 whereas the lowest was under 8 dS m-1 NaCl with
means of 89 and 83 kg respectively
A significant fertilization x variety interaction was found for seed hardness The hardness
of UDEC-1 and Baer did not differ across fertilization level whereas CO407D was harder under
low fertilization and QQ065 was harder under high fertilization
Seed density
Variety and salinity both significantly affected seed density whereas fertilization did not
show a significant influence (Table 1) The greatest contribution to variation in seed density was
due to variety (F = 2282) Salinity exhibited a relatively smaller effect yet still significant (F =
282 P lt005) Neither variety x salinity interaction nor salinity x fertilization interaction was
observed which indicated that varieties similarly responded to salinity under high and low
128
fertilization levels An interaction of variety x fertilization was found and the details were
presented later
Across all salinity and fertilization treatments CO407D had the highest mean density
080 gcm3 followed by Baer with 069 gcm3 (Table 4) UDEC-1 and QQ065 had the lowest and
similar densities (~065 gcm3)
With regard to salinity effect the Na2SO4 treatments exhibited differential influence on
seed density Density means did not significantly change due to the increased concentration of
NaCl ranging from 068 to 071 gcm3 (Table 4) The samples from 8 dS m-1 Na2SO4 soil had
lower density (066 gcm3) than those from 16 dS m-1 and 32 dS m-1 Na2SO4 074 and
072gcm3 respectively
A significant variety x fertilization interaction was found With closer examination
UDEC-1 and Baer yielded higher density seeds under high fertilization whereas CO407D and
QQ065 did not differ in density between fertilization treatments
Correlations of protein hardness and density
Correlation coefficients among seed protein content hardness and density are shown in
Table 5 No significant correlation was detected between protein content and seed hardness
However both protein content and hardness were correlated with seed density The overall
correlation coefficient was low (r = 019 P = 003) between density and protein A marginally
significant correlation was found between density and protein content of the seeds from NaCl
salinized soil under low fertilization No correlation was found between density and protein
content of the seeds from NaCl salinized soil under high fertilization or Na2SO4 salinized soil
129
The overall correlation coefficient was 038 (P lt 00001) between density and hardness
The low fertilization samples from both NaCl and Na2SO4 soil showed significant correlations
between density and hardness with coefficients of 051 and 047 (both P lt 0005) The high
fertility quinoa did not exhibit any correlation between density and hardness
Correlation with yield leaf greenness index plant height and seed minerals contents
Correlation between seed quality and yield leaf greenness index plant height and seed
mineral concentration were obtained using data from Peterson and Murphy (2015) (Table 6)
Seed hardness significantly correlated with yield and plant height (r = 035 and 031
respectively) Protein content and density however did not correlate with yield leaf greenness
or plant height Correlations were found between quality indices and the concentration of
different minerals Protein was negatively correlated with Cu and Mg (r = -052 and -050
respectively) Hardness was negatively correlated with Cu P and Zn (r = -037 -056 -029
respectively) but was positively correlated with Mn (r = 057) Density was negatively
correlated with Cu (r = -035)
Discussion
Protein
Although salinity exhibited a significant effect on seed protein content the impact was
relatively minor compared to fertilization and variety effects In another words over a wide
range of saline soil quinoa can grow and yield seeds with stable protein content
130
Protein content of quinoa growing under salinized soil ranged from 127 to 167 (data
not shown) within the general range of protein content under non-saline conditions which was
12 to 17 (Rojas et al 2015) Saline soil did not cause a significant decrease in seed protein
It is interesting to notice that the samples from 32 dS m-1 Na2SO4 tended to contain the highest
protein especially in variety QQ065 The studies of Koyro and Eisa (2008) and Karyotis et al
(2003) also indicated that protein content significantly increased under high salinity (NaCl)
whereas total carbohydrates decreased In contrast Ruffino et al (2009) found that quinoa
protein decreased under 250 mM NaCl salinity in a growth chamber experiment It is reasonable
to conclude that salinity exhibits contrasting effects on different quinoa genotypes QQ065 and
CO407D both significantly increased in protein under 32 dS m-1 Na2SO4 however the yield
decline was 519 and 245 respectively (Peterson and Murphy 2015) This result indicted
that CO407D was the variety most optimally adapted to severe sodic saline soil tested in this
study
Na2SO4 level exhibited a significant influence on protein content whereas NaCl level did
not In the study of Koyro and Eisa (2008) however seed protein of the quinoa variety Hualhuas
(origin from Peru) increased under the highest salinity level of 500 mM NaCl compared to lower
NaCl levels (0 ndash 400 mM) This disagreement of NaCl influence may be due to diversity of
genotypes It is worth noting that quinoa protein contents in this paper were primarily above 13
based on wet weight (as-is-moisture of approximately ~8 -10) even under saline soil and low
fertilization level This protein content is generally equal to or higher than that of other crops
such as barley and rice (Wu 2015) In conclusion quinoa maintained high and stable protein
content under salinity stress
131
Hardness
Quinoa seed hardness was only moderately affected by salinity (P = 009) indicating that
quinoa primarily maintained seed texture when growing under a wide range of saline soil
CO407D exhibited the hardest seed (100 kg) whereas Baer and QQ065 were relatively soft (74
ndash 77 kg) A previous study indicated a hardness range of 58 ndash 109 kg among 11 quinoa
varieties and 2 commercial samples (Wu et al 2014) The commercial samples had hardness
values of 62 kg and 71 kg Since commercial samples generally maintain stable quality and
indicate an acceptable level for consumers seed hardness around 7 kg as in Baer and QQ065
should be considered as acceptable quality The hardness of CO407D was close to that of the
colored variety lsquoBlackrsquo (100 kg) which had a thicker seed coat than that of the yellow seeded
varieties It was reported that a thicker seed coat is related to harder texture (Fraczek et al 2005)
Even though the greenhouse is a highly controlled environment and the two experiments
were conducted in similar seasons (planted in September and October respectively) seed protein
and hardness were still different across the two experiments However ANOVA indicated
modest-to-no significant interactions with salinity and fertilization such that responses to salinity
and fertilization were consistent with little or no change in rank order Even though experiment x
variety was significant the F-values were relatively low compared to the major effects such as
variety and fertilization and neither of them was crossing interaction This is a particularly
noteworthy result for breeders farmers and processors
Density
132
The range of seed density under salinity 055 ndash 089 gcm3 was comparable to the
density range of 13 quinoa samples (058 ndash 076 gcm3 ) (Wu et al 2014) Generally CO407D
had higher seed density (071 ndash 089 gcm3) which indicated that seed density in this variety was
affected by salinity stress In contrast the density of QQ065 did not change according to salinity
type or concentration which indicated a stable quality under saline soil
Correlations
The correlation between seed hardness and density was only significant under low fertilization
but not under high fertilization The high fertilization level in the greenhouse experiment
exceeded the amount of fertilizer that would normally be applied in field environments whereas
the low fertilization level is closer to the field situation Therefore correlation between hardness
and density may still exist in field trials
Conclusions
Under saline soil conditions quinoa did not show any marked decrease in seed quality
such as protein content hardness and density Protein content even increased under high Na2SO4
concentration (32 dS m-1) Varieties exhibited great differential reactions to fertilization and
salinity levels QQ065 maintained a similar level of hardness and density whereas seed of
CO407D was both harder and higher density under salinity stress If only seed quality is
considered then QQ065 is the most well-adapted variety in this study
The influences of NaCl and Na2SO4 were different The higher concentration of Na2SO4
tended to increase protein content and seed density whereas NaCl concentration did not exhibit
any significant difference on those quality indexes
133
Acknowledgement
The research was funded by USDA Organic Research and Extension Initiative project
number NIFAGRANT11083982 The authors acknowledge Alecia Kiszonas for assisting in the
data analysis
Author contributions
Peterson AJ set up the experiment design in the greenhouse and grew harvested and
processed quinoa samples Wu G collected seed quality data such as protein content seed
hardness and density Peterson AJ and Wu G together processed the data Wu G also drafted the
manuscript Murphy KM and Morris CF edited the manuscript
Conflict of interest statement
The authors declared to have no conflict of interest
134
References
AACC International Approved Methods of Analysis Method 46-3001 Crude protein ndash
Combustion method Approved November 8 1995 Reapproved November 3 1999
Availablenline only AACCI St Paul MN
Adolf VI Shabala S Andersen MN Razzaghi F Jacobsen SE 2012 Varietal differences of
quinoas tolerance to saline conditions Plant Soil 357 117ndash29
Bertero HD 2003 Response of developmental processes to temperature and photoperiod in
quinoa (Chenopodium quinoa Willd) Food Rev Int 19 87ndash97
Cai S Yu G Chen X Huang Y Jiang X Zhang G Jin X 2013 Grain protein content variation
and its association analysis in barley BMC Plant Boil 13 35
Chilo G Molina MV Carabajal R Ochoa M 2009 Temperature and salinity effects on
germination and seedling growth on two varieties of Chenopodium quinoa Agri-Scientia 26
15ndash22
Cocozza C Pulvento C Lavini A Riccardi M dAndria R Tognetti R 2013 Effects of
increasing salinity stress and decreasing water availability on ecophysiological traits of
quinoa (Chenopodium quinoa Willd) grown in a mediterranean-type agroecosystem J Agron
Crop Sci 199 229ndash40
Fraczek J Hebda T Slipek Z Kurpaska S 2005 Effect of seed coat thickness on seed hardness
Can Biosyst Eng 47 41ndash5
135
Gonzaacutelez JA Eisa SSS Hussin SAES Prado FE 2015 Quinoa an Incan crop to face global
changes in agriculture In Murphy KM Matanguihan J editors Quinoa Improvement and
Sustainable Production Hoboken NJ John Wiley Sons p 7ndash11
Hruškovaacute M Švec I 2009 Wheat hardness in relation to other quality factors Czech J Food Sci
27 240ndash8
Jacobsen S Quispe H Mujica A 2000 Quinoa an alternative crop for saline soils in the Andes
in Scientist and Farmer Partners in Research for the 21st Century (Program Report 1999-
2000) ed International Potato Center (Peru) 403ndash8
Jancurovaacute M Minarovicovaacute L Dandar A 2009 Quinoandasha review Czech J Food Sci 27 71ndash9
Karyotis T Iliadis C Noulas C Mitsibonas T 2003 Preliminary research on seed production
and nutrient content for certain quinoa varieties in a salinendashsodic soil J Agron Crop Sci 189
402ndash8
Koyro HW Eisa S 2008 Effect of salinity on composition viability and germination of seeds of
Chenopodium quinoa Willd Plant Soil 302 79-90
Krishnamurthy K Giroux MJ 2001 Expression of wheat puroindoline genes in transgenic rice
enhances grain softness Nat Biotechnol 19 162ndash6
Morris CF 2002 Puroindolines the molecular genetic basis of wheat grain hardness Plant mol
Biol 48 633ndash47
136
Orth RA Shellenberger JA 1988 Chapter 1 Origin production and utilization of wheat In
Pomeranz Y editor Wheat Chemistry and Technology 3th edition St Paul MN American
Association of Cereal Chemists Inc p 11ndash2
Peterson A Murphy K 2015 Tolerance of lowland quinoa cultivars to sodium chloride and
sodium sulfate salinity Crop Sci 55 331ndash8
Pitman MG Laumluchli A 2002 Global impact of salinity and agricultural ecosystems In Laumluchli
A Luumlttge U editors Netherlands Springer p 3ndash20
Prado FE Boero C Gallardo M Gonzaacutelez JA 2000 Effect of NaCl on germination growth and
soluble sugar content in Chenopodium quinoa Willd seeds Bot Bull Acad Sinica 41 27ndash34
Pulvento C Riccardi M Lavini A Iafelice G Marconi E dAndria R 2012 Yield and quality
characteristics of quinoa grown in open field under different saline and non-saline irrigation
regimes J Agron Crop Sci 198 254ndash63
Ranhotra G Gelroth J Glaser B Lorenz K Johnson D 1993 Composition and protein
nutritional quality of quinoa Cereal Chem 70 303ndash5
Razzaghi F Ahmadi SH Jacobsen SE Jensen CR Andersen MN 2012 Effects of salinity and
soilndashdrying on radiation use efficiency water productivity and yield of quinoa (Chenopodium
quinoa Willd) J Agron Crop Sci 198 173ndash84
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile D
137
Bertero D Nieto C editors State of the Art Report of Quinoa in the World in 2013 Rome
FAO amp CIRAD p 67-8
Ruffino A Rosa M Hilal M Gonzaacutelez J Prado F 2010 The role of cotyledon metabolism in the
establishment of quinoa (Chenopodium quinoa)seedlings growing under salinity Plant Soil
326 213ndash24
Ruiz-Carrasco K Antognoni F Coulibaly A K Lizardi S Covarrubias A Martiacutenez E A
Shabala S Hariadi Y Jacobsen SE 2013 Genotypic difference in salinity tolerance in quinoa is
determined by differential control of xylem Na+ loading and stomatal density J Plant Physiol
170 906ndash14
Shih FF 2006 Chapter 6 Rice protein In Champagne ET editor Rice Chemistry and
Technology 3rd edition St Paul MN American Association of Cereal Chemists Inc p
143-4
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Taylor JRN Parker ML editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science amp Business Media p 96-101
USDA (United States Department of Agriculture) 2011 Soil and water resources conservation
act (RCA) P 31 Access from
httpwwwnrcsusdagovInternetFSE_DOCUMENTSstelprdb1044939pdf
Wilson C Read J Abo-Kassem E 2002 Effect of mixed-salt salinity on growth and ion
relations of a quinoa and a wheat variety J Plant Nutri 25 2689ndash704
138
Wu G Morris CF Murphy KM 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79 2337ndash45
Wu G 2015 Chapter 11 Nutritional properties of quinoa In Murphy KM Matanguihan J
editors Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp
Sons Inc p 193-205
Zhang B Chen P Chen CY Wang D Shi A Hou A Ishibashi T 2008 Quantitative trait loci
mapping of seed hardness in soybean Crop Sci 48 1341ndash9
Zevallos VF Herencia LI Chang F Donnelly S Ellis HJ Ciclitira PJ 2014 Gastrointestinal
effects of eating quinoa (Chenopodium quinoa Willd) in celiac patients Am J Gastroenterol
109 270ndash8
Zurita-Silva A 2011 Variation in salinity tolerance of four lowland genotypes of quinoa
(Chenopodium quinoa Willd) as assessed by growth physiological traits and sodium
transporter gene expression Plant Physiol Bioch 49 1333ndash41
139
Table 1-Analysis of variance with F-values for protein content hardness and density of quinoa seed
Effect F-values
Protein Hardness Density
Model 524 360 245
Variety 2463 21059 2282
Salinity 975 200dagger 282
Fertilization 40247 107 260
Variety x Salinity 096 098 036
Variety x Fertilization 2062 1094 460
Salinity x Fertilization 339 139 071
Variety x Salinity x Fertilization 083 161dagger 155
dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the 001 probability level Significant at the lt0001 probability level
140
Table 2-Salinity variety and fertilization effects on quinoa seed protein content ()
Salinity Protein content ()
Variety Protein content ()
Fertilization Protein content ()
8 dS m-1 NaCl 147bc1 CO407D 149ab High 158a
16 dS m-1 NaCl 148ab UDEC-1 147b Low 136b
32 dS m-1 NaCl 149ab Baer 151a
8 dS m-1 Na2SO4 144cd QQ065 141c
16 dS m-1 Na2SO4 142d
32 dS m-1 Na2SO4 152a 1Different letters in a given column indicate significant differences (P lt 005)
141
Table 3-Salinity variety and fertilization effects on quinoa seed hardness (kg)
Salinity Hardness (kg)1 Variety Hardness (kg)
8 dS m-1 NaCl 83 CO407D 100a2
16 dS m-1 NaCl 87 UDEC-1 94b
32 dS m-1 NaCl 85 Baer 77c
8 dS m-1 Na2SO4 87 QQ065 74c
16 dS m-1 Na2SO4 89
32 dS m-1 Na2SO4 88 1Hardness was significant at the 009 probability level 2Different letters in a given column indicate significant differences (P lt 005)
142
Table 4-Salinity variety and fertilization effects on quinoa seed density (g cm3)
Salinity density (g cm3) Variety density (g cm3)
8 dS m-1 NaCl 069bc1 CO407D 080a
16 dS m-1 NaCl 068bc UDEC-1 066bc
32 dS m-1 NaCl 071abc Baer 069b
8 dS m-1 Na2SO4 066c QQ065 065c
16 dS m-1 Na2SO4 074a
32 dS m-1 Na2SO4 072ab 1Different letters in a given column indicate significant differences (P lt 005)
143
Table 5-Correlation coefficients of protein hardness and density of quinoa seed
Correlation All NaCl Na2SO4
High fertilization
Low fertilization
High fertilization
Low fertilization
Protein -Density 019 013ns 029dagger 026ns 019ns
Hardness - Density 038 027ns 051 022ns 047
ns Not significant dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the lt0001 probability level
144
Table 6-Correlation coefficients of quinoa seed quality and agronomic performance and seed mineral content
Protein Hardness Density
Yield 004 035 006
Plant Height -004 031 011
Cu -052 -037 -035
Mg -050 004 0
Mn -006 057 025dagger
P -001 -056 -015
Zn -004 -029 -028dagger
dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the 001 probability level Significant at the lt0001 probability level
145
Figure 1-Protein content () of quinoa in response to combined fertility and salinity treatments
146
Chapter 6 Lexicon development and consumer acceptance
of cooked quinoa
ABSTRACT
Quinoa is becoming increasingly popular with an expanding number of varieties being
commercially available In order to compare the sensory properties of these quinoa varieties a
common sensory lexicon needs to be developed Thus the objective of this study was to develop
a lexicon of cooked quinoa and examine consumer acceptance of various varieties A trained
panel (n = 9) developed appropriate aroma tasteflavor texture and color descriptors to describe
cooked quinoa and evaluated 21 quinoa varieties Additionally texture of the cooked quinoa was
determined using a texture analyzer Results indicated panelists using this developed lexicon
could distinguish among these quinoa varieties showing significant differences in aromas
tasteflavors and textures Specifically quinoa variety effects were observed for the aromas of
caramel nutty buttery grassy earthy and woody tasteflavor of sweet bitter grain-like nutty
earthy and toasty and texture of firm cohesive pasty adhesive crunchy chewy astringent and
moist The varieties lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Drsquo exhibited adhesive texture that has not
been seen in any commercialized quinoa Subsequent consumer evaluation (n = 102) on 6
selected samples found that the lsquoPeruvian Redrsquo was the most accepted overall while the least
accepted was lsquoQQ74rsquo Partial least squares analysis on the consumer and trained panel data
indicated that overall consumer liking was driven by higher intensities of grassy aroma and firm
and crunchy texture The attributes of pasty moist and adhesive were less accepted by
consumers This overall liking was highly correlated with consumer liking of texture (r = 096)
147
tasteflavor (r = 095) and appearance (r = 091) of cooked quinoa From the present study the
quinoa lexicon and key drivers of consumer acceptance can be utilized in the industry to evaluate
quinoa product quality and processing procedures
Keywords quinoa lexicon sensory evaluation
Practical application The lexicon of cooked quinoa can be used by breeders to screen quinoa
varieties Furthermore the lexicon will useful in the food industry to evaluate quinoa ingredients
from multiple farms harvest years processing procedures and product development
148
Introduction
Quinoa is classified as a pseudocereal like amaranth and buckwheat With its high
protein content and balanced essential amino acid profile quinoa is becoming popular
worldwide From 1992 to 2012 quinoa exports increased dramatically from 600 tons to 37000
tons (Furche et al 2015) Quinoa price in retail stores increased from $9kg in 2013 to $13kg -
$20kg in 2015 (Arco 2015) Quinoa has been incorporated into numerous products including
bread cookies pasta cakes and chocolates (Pop et al 2014 Alencar et al 2015 Casas Moreno
et al 2015 Wang et al 2015) Some of these products are gluten-free foods thus targeting the
gluten-sensitive market segment (Wang et al 2015)
Popularity of quinoa inspired US researchers to breed varieties that are compatible with
local weather and soil conditions which greatly differ from quinoarsquos original land the Andean
mountain region Since 2010 Washington State University has been breeding quinoa in the
Pacific Northwest region of United States Of the quinoa varieties evaluated in the breeding
program agronomic attributes of interest include high yield consistent performance over years
and tolerance to drought salinity heat and diseases (Peterson and Murphy 2013 Peterson
2013) However beyond agronomic attributes the grain sensory profiles of these quinoa
varieties are also important to assist in breeding decisions as well as screening
genotypescultivars for various food applications
In order to provide a complete descriptive profile of the cooked quinoa a trained sensory
evaluation should be used along with a complete lexicon of the sensory attributes of importance
Currently no quinoa lexicon is available and descriptions of quinoa sensory properties are
149
limited From currently published research papers attributes describing quinoa taste have been
limited to bitter sweet earthy and nutty (Koziol 1991 Lorenz and Coulter 1991 Repo-Carrasco
et al 2003 Stikic et al 2012 Foumlste M et al 2014) and texture of cooked quinoa has been
described as creamy smooth and crunchy (Abugoch 2009) Thus to address the lack of quinoa
lexicon one objective of this study is to develop a lexicon describing the sensory properties of
quinoa
Beyond developing a lexicon to describe quinoa consumer preference of the different
quinoa varieties is also of great interest Most previous sensory studies in quinoa focused on
acceptance of quinoa-containing products while consumer acceptance on plain grain of quinoa
varieties has not been studied Because of the lack of cooked quinoa studies with consumers rice
may be considered as a model to study quinoa because of their similar cooking process Tomlins
et al (2005) found consumer preference of rice was driven by the attributes of uniform clean
bright translucent and cream with consumers not liking the brown color of cooked rice and
unshelled paddy in raw rice In another study Suwannaporn et al (2008) found consumer
acceptance of rice products was significantly influenced by convenience grain variety and
traditionnaturalness
This study presenting a quinoa lexicon along with consumer acceptance of quinoa
varieties provides critical information for both the breeding programs and food industry
researchers Given the predicted importance of texture in consumer acceptance of quinoa texture
analysis was conducted to evaluate the parameters of hardness adhesiveness cohesiveness
chewiness and gumminess in quinoa samples
150
This lexicon describing the sensory attributes of cooked quinoa will be a useful tool to
evaluate quinoa varieties compare samples from different farms harvest years seed quality and
cleaning processing procedures Finally the sensory attributes driving consumersrsquo liking can be
utilized to evaluate optimal quinoa quality and target different consumers based on preference
Materials and methods
Quinoa samples
The present study included twenty-one quinoa samples harvested in 2014 which included
sixteen varieties from Finnriver Organic Farm (Finnriver WA) and five commercial samples
from Bolivia and Peru (Table 1)
Quinoa preparation
Following harvest the samples from Finnriver Farm were cleaned in a Clipper Office
Tester (Seedburo Des Plainies IL USA) to separate mixed weed seeds and threshed materials
Furthermore the samples were soaked for 30 min rubbed manually under running water and
dried at 43 ordmC until the moisture reached lt 11 Generally a moisture of 12 - 14 is
considered safe for grain storage (Hoseney 1989)
To prepare quinoa samples for sensory evaluation samples were soaked for 30 min and
mixed with water at a 12 ratio These mixtures were brought to a boil and simmered for 20 min
Following cooking the quinoa was cooled to room temperature Samples of cooked quinoa (10
g) were served in 30 mL plastic containers with lids (SOLO Lakeforest IL USA) Quinoa
151
samples were cooked and placed in covered cups within 2 h before evaluation Unsalted
crackers plastic cups used as cuspidors and napkins were provided to each panelist
Trained sensory evaluation panel
This project was approved by the Institutional Review Board of Washington State
University Sensory panelists (n = 9) were recruited via email announcements Panelists were
selected based on their interest in quinoa and availability All participants signed the Informed
Consent Form They received non-monetary incentives for each training session and a large non-
monetary reward at the completion of the formal evaluation
Demographic information was collected using a questionnaire Panelists included 4
females and 5 males ranging in age from 21 to 60 (mean age of 35) Regarding quinoa
consumption frequency four panelists frequently consumed quinoa (few times per month to
everyday) whereas five panelists rarely consumed quinoa As quinoa is a novel crop to most of
the world this was expected Since rice is a comparable model of quinoa frequency of rice
consumption was also considered with all panelists being frequent rice consumers
Sensory training and lexicon development
The training consisted of 12 sessions of 15 hours totaling 18 hours In the early stages
of the panel training attribute terms and references were discussed Panelists were first presented
with samples in covered plastic containers The samples widely varied in their sensory attributes
and included the varieties of lsquoBlackrsquo lsquoBolivian Redrsquo and lsquoBolivian Whitersquo The panelists
developed terms to describe the appearance aroma flavor taste and texture of the samples
Additionally the same samples were evaluated by an experienced sensory evaluation panel with
152
terms collected from this set of evaluators Terms were collected from panelists professionals
and literature describing rice (Meilgaard et al 2007 Limpawattana and Shewfelt 2010) The
term list was presented and discussed with panelist consensus being used to determine which
sensory terms appeared in the final lexicon
The final lexicon and associated definitions are presented in Table 2 This lexicon
included the sensory attributes of color (black red yellow) aroma (caramel grain-like bean-
like nutty buttery starchy grassygreen earthymusty woody) tasteflavor (sweet bitter grain-
like bean-like nutty earthy and toasted) and texture (soft-firm separate-cohesive pasty
adhesivenesssticky crunchycrumblycrisp chewygummy astringent and waterymoist)
References standards for each attribute were introduced The references were discussed and
modified until the panelists were in agreement Panelists reviewed the reference standards at the
beginning of each training session Since aroma varies over time all aroma references were
prepared 1-2 h before training During training three to four quinoa samples were evaluated and
discussed in each session The ability to detect attribute differences and the reproducibility of
panelists were both monitored and visualized using spider graphs and line graphs Using this
feedback panelists were calibrated paying extra attention to those attributes that were outside of
the panel standard deviation Practice sessions were continued until the panelists accurately and
consistently assessed varietal differences of quinoa
The protocols applied to evaluate samples and references were consistent among
panelists At the start of the evaluation the sample cup was shaken to allow the aroma to
accumulate in the headspace Panelists then lifted the cover and immediately took three short
sharp sniffs to evaluate the aroma Panelists then determined the color and its intensity Finally
153
panelists used the spoon to place the sample in-mouth and evaluate the tasteflavor and texture
Between each sample panelists rinsed their palate using water and unsalted crackers A 15-cm
line scale with 15-cm indentations on each end was used to determine the intensity of attributes
The values of 15 and 135 represented the extremely low and high intensity respectively Using
the lexicon panelists were trained to sense and quantify the attributes of cooked quinoa on
aroma color tasteflavor and texture
Following the development of the lexicon formal evaluations were conducted in the
sensory booths under white lights Compusensereg Five (Guelph Ontario Canada) provided scales
and programs for evaluation and collected results Panelists followed the protocol and used the
lexicon and 15-cm scales to evaluate the sensory attributes of the cooked quinoa samples
Twenty-one quinoa samples were tested in duplicate Panelists attended one session per day and
four sessions in total During each session panelists evaluated 10 or 11 samples with a 30 s
break after each sample and a 10 min break after the fifth sample Each variety was assigned
with a random three-digit code and the serving order was randomized
Consumer acceptance panel
From the 21 samples evaluated by the trained panelists six were selected for consumer
evaluation These six samples selected were diverse in color tasteflavor and texture as defined
by the trained panel results Consumers (n = 102) were recruited from Pullman WA Of the
consumers 49 were male and 52 were female with age ranging from 19 to 64 (mean age of 33)
The consumers showed different familiarity with quinoa with 29 indicating that they were
154
familiar with quinoa 40 having tried quinoa a few times and 32 having never tried quinoa
before All consumers had consumed rice before
The project was approved by the Institutional Review Board of Washington State
University Each consumer signed an Informed Consent Form and received a non-monetary
incentive at the end of evaluation The evaluation was conducted in the sensory booths under
white light Six quinoa samples were assigned with three-digit code and randomly presented to
each consumer using monadic presentation Quinoa samples were cooked and distributed in
evaluation cups and lidded (~10 gcup) the day before stored at 4 degC overnight and placed at
room temperature (25 degC) for 1 h prior to evaluation
During evaluation consumers followed the protocol instructions and indicated the degree
of acceptance of aroma color appearance tasteflavor texture and overall liking using a 7-point
hedonic scale (1 = dislike extremely 7 = like extremely) provided by Compusensereg Five
(Guelph Ontario Canada) A comments section was provided at the end of each sample
evaluation to gather additional opinions and information Between samples panelists took a 30 s
break and cleansed their palates using unsalted crackers and water
Texture Profile Analysis by instrument (TPA)
The texture of 21 cooked quinoa samples were conducted using a TA-XT2i Texture
Analyzer (Texture Technologies Corp Hamilton MA USA) (Wu et al 2014) Samples were
cooked using the same procedure as in the trained panel evaluation and cooled to room
temperature prior to evaluation
Statistical analysis
155
Sample characteristics and trained panel results were analyzed using three-way ANOVA
and mean separation (Fisherrsquos LSD) PCA was performed on the trained panel data Using
trained panel data and consumer evaluation data partial least square regression analysis was
performed Additionally correlations between instrument tests and panel evaluation on texture
and tasteflavor were determined XLSTAT 2013 (Addinsoft Paris France) was used for all data
analysis
Results and Discussion
Lexicon Development
A lexicon was created to describe the sensory attributes of cooked quinoa (Table 2) A
total of 27 attributes were included in the lexicon based on color (black red yellow) aroma
(caramel grain-like bean-like nutty buttery starchy grassygreen earthymusty and woody)
tasteflavor (sweet bitter grain-like bean-like nutty earthy and toasted) and texture (firm
cohesive pasty adhesivenesssticky crunchy chewygummy astringent and waterymoist)
Rice is considered as a good model of quinoa lexicon developments since both products
have common preparation methods The lexicon for cooked rice has been developed for the
aroma tasteflavor and texture properties of rice (Lyon et al 1999 Meullenet et al 2000
Limpawattana and Shewfelt 2010) Many attributes from these previously developed rice
lexicons can be applied to cooked quinoa For instance rice aroma and flavor notes such as
starchy woody grain nutty buttery earthy sweet bitter and astringent are also present in
quinoa Hence those notes were also included in the lexicon of cooked quinoa in present study
with quinoa varieties showing differences in these attributes
156
This present lexicon presents some sensory attributes not found to be significantly
different among the quinoa varieties These attributes include grain-like bean-like and starchy
aroma bean-like flavor and chewy texture Even though the trained panel did not detect
differences in this study future studies may find differences among other quinoa varieties for
these attributes so they were kept in the lexicon For instance the flavoraroma notes of
lsquorancidoxidizedrsquo lsquosourrsquo lsquometallicrsquo may also be present in other quinoa varieties or have these
attributes develop during storage as has been shown in rice (Meullenet et al 2000)
The lexicon also expanded the vocabularies to describe quinoa This lexicon is a
valuable tool with multiple practical applications such as describing and screening quinoa
varieties in breeding and evaluating post-harvest process and cooking methods
Lexicon Application Evaluation of the 21 quinoa samples
The effects of panelist replicate and quinoa variety on aroma tasteflavor and texture of
cooked quinoa were evaluated (n = 9) (Table 3) The quinoa variety exhibited significant
influences on most attributes listed in the lexicon (P lt 005) except for grain-like bean-like and
starchy aroma and bean-like flavor Generally quinoa variety effects were greater in the
perceived texture of cooked quinoa than in the aroma and flavor attributes however bitterness
was also highly significant among varieties Although panelists were trained over 18 h and
references were used for calibration significant panelist effects were still observed Based on the
inherent variation of human subjects such panelist effects commonly occur in sensory evaluation
of a complex product (Muntildeoz 2003) In future studies increased training and practice to further
clarify attribute definitions may reduce panelist effects (Muntildeoz 2003)
157
Examining the details of aroma attributes quinoa variety effect significantly influenced
the aroma attributes of caramel nutty buttery grassy earthy and woody (Figure 1) Principal
Components Analysis (PCA) was performed in order to visualize differences among the
varieties For aroma the first two components described 669 of the variation among quinoa
samples PC1 was primarily defined by the grassy and woody aromas while PC2 was primarily
described by more starchy and grain-like aromas The proximity of the attributes to a specific
quinoa sample reflected its degree of association For instance lsquoCalifornia Tricolorrsquo was most
commonly described by earthy woody grassy bean-like and nutty aroma lsquoTemukorsquo exhibited
sweet and grain-like aroma Yellowwhite quinoa such as lsquoTiticacarsquo lsquoRed Headrsquo lsquoQuF9P39-51rsquo
and lsquoPeruvian Whitersquo showed significantly more nutty (6) aroma compared to brown and red
quinoa varieties (48 ndash 51) (Table 1S) lsquoBlackrsquo lsquoCahuilrsquo and lsquoPeruvian Redrsquo exhibited more
grassy aroma (47 ndash 49) compared to lsquoTiticacarsquo lsquoLinaresrsquo and lsquoNL-6rsquo (38 ndash 39) lsquoBlackrsquo
showed the most earthy aroma (54) among all varieties
PCA was also performed to show how the varieties differed in their flavortaste
properties (Figure 2) The first two components described 646 of the varietal differences The
lsquoBlackrsquo variety was found to have more bitter and earthy flavors lsquoPeruvian Whitersquo was most
commonly described by sweet and nutty flavor and lack of earthy flavors lsquoTemukorsquo was mostly
defined by its bitter taste and lack of sweetness nutty grain-like and toasty flavors Overall
sweet and bitter taste and grain-like nutty earthy and toasty flavor exhibited significant
difference among quinoa varieties (plt005) The lsquoQuF9P39-51rsquo lsquoKaslaearsquo lsquoBolivian Whitersquo
and lsquoPeruvian Whitersquo were assigned the highest values in sweet taste (46 ndash 47) significantly
sweeter than lsquoBlackrsquo lsquoCherry Vanillarsquo lsquoTemukorsquo lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCalifornia Tricolorrsquo
158
(36 ndash 40)(Table 4) lsquoTemukorsquo and lsquoCherry Vanillarsquo were the most bitter samples (56 and 52
respectively) It is worth noting that the commercial samples were assigned the lowest bitterness
scores ranging from 22 ndash 27 significantly lower than the field trial varieties (34 ndash 56) Similar
to earthy aroma lsquoBlackrsquo also exhibited the earthiest flavor (52) Additionally lsquoCahuilrsquo and
lsquoCalifornia Tricolorrsquo showed high scores in earthy flavor (both 48) Toasty flavor varied from
38 in lsquoLinaresrsquo and lsquoQuF9P1-20rsquo to 51 in lsquoCahuilrsquo
Quinoa bitterness is caused by saponin compounds present on the seed coat It has been
reported that saponin can be removed by abrasion pearling and rinsing (Taylor and Parker
2002) However in the present study despite two cleaning process steps (airscreen and rinsing)
there was still bitter flavor remained Besides processing genetic background can also affect
saponin content Some sweet quinoa varieties (lsquoSajamarsquo lsquoKurmirsquo lsquoAynoqrsquoarsquo lsquoKrsquoosuntildearsquo and
lsquoBlanquitarsquo in Bolivia and lsquoBlancade Juninrsquo in Peru) have been developed with total seed
saponin content lower than 110 mg100 g (Quiroga et al 2015) However these varieties are not
adapted to the growing conditions in the Pacific Northwest (Peterson and Murphy 2015) The
quinoa varieties in WSU breeding program are primarily from Chilean lowland and those
varieties are more highly adapted to temperate areas In this case sweet quinoa varieties from
Bolivia and Peru were not included in this study However in 2015 a saponin-free quinoa
variety lsquoJessiersquo was grown in different locations of Washington State with a comparable yield
to bitter varieties The sensory evaluation of this new variety lsquoJessiersquo would be meaningful
Earthy which may be referred to as moldy and musty is caused by geosmin (a bicyclic
alcohol with formula C12H22O) which produced by actinobacteria (Gerber 1968) Samples with a
dark color (lsquoBlackrsquo lsquoCalifornia Tricolorrsquo and lsquoCahuilrsquo) tended to exhibit more earthy aroma and
159
flavor Possibly the pericarpseed coat composition of dark quinoa favors the actinobacteria-
producing geosmin
Overall texture attributes of cooked quinoa exhibited greater differences in values
(Figure 3) Among commercial quinoa varieties the red quinoa was firmer more gummy and
more chewy in texture compared to the yellowwhite commercial quinoa Several WSU field trial
varieties (lsquoQQ74rsquo lsquoLinaresrsquo and CO407D) exhibited greater variation in adhesiveness The first
two PCA factors explained 817 of the variation among samples lsquoPeruvian Redrsquo was most
accurately described by firm and crunchy texture and a lack of pasty sticky and cohesive
texture In contrast lsquoLinaresrsquo lsquoCO407Daversquo and lsquoQQ74rsquo were mostly described as pasty sticky
and cohesive yet lacking in firmness and crunchiness Mixed color or red color samples
(lsquoPeruvian Redrsquo lsquoBlackrsquo lsquoCahuilrsquo and lsquoCalifornia Tricolorrsquo) tended to be both firmer and
crunchier compared to the samples with light color However some yellow samples such as
lsquoTiticacarsquo and lsquoKU-2rsquo also had hard texture The varieties lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Daversquo
had the softest texture and also exhibited the least crunchy but the most pasty sticky and moist
texture Additionally compared to field trial varieties commercial samples tended to be lower in
intensity for the attributes of cohesiveness pastiness adhesiveness and astringency Moreover
astringent is the dry and puckering mouth feeling which is caused by the combination of tannins
and salivary proteins The differences found in this study among quinoa varieties may be caused
by processing protocols (removal of tannins to various degrees) or diverse genetic backgrounds
Consumer acceptance
160
Consumers evaluated six selected quinoa samples including the field trial varieties of
lsquoBlackrsquo lsquoTiticacarsquo lsquoQQ74rsquo and the commercial samples of lsquoPeruvian Redrsquo lsquoBolivian Redrsquo and
lsquoBolivian Whitersquo The selected samples were diverse in color texture and included both WSU
field trial varieties and commercial quinoa Among the field trial varieties the lsquoBlackrsquo variety
exhibited more grassy aroma earthy flavor and chewy texture lsquoTiticacarsquo had more caramel
aroma and lsquoQQ74rsquo was more adhesive than the other samples
The quinoa varieties varied significantly in consumer acceptance of color appearance
taste flavor texture and overall acceptance (P lt 0001) (Table 5) Overall lsquoPeruvian Redrsquo was
more accepted by consumers compared to lsquoTiticacarsquo and lsquoQQ74rsquo lsquoBlackrsquo received a similar
level of acceptance with all the commercial samples and the acceptance of lsquoTiticacarsquo did not
differ from lsquoBolivian Redrsquo and lsquoBolivian Whitersquo In aroma acceptance no significant difference
was found among the varieties In color lsquoPeruvian Redrsquo and lsquoBolivian Redrsquo received
significantly higher scores In appearance lsquoPeruvian Redrsquo was rated higher than all other
varieties except lsquoBolivian Redrsquo while lsquoQQ74rsquo gained the lowest rate Additionally lsquoQQ74rsquo was
less accepted in tasteflavor than all commercial samples but did not differ from other field trial
varieties lsquoBlackrsquo and lsquoTiticacarsquo Furthermore the texture of lsquoQQ74rsquo was the least accepted and
other varieties did not show any significant differences
However low acceptance in adhesive texture of cooked quinoa does not indicate the
adhesive quinoa varieties will not have market potential Adhesiveness in cooked rice is
correlated with high amylopectin and low amylose (Mossman et al 1983 Sowbhagya et al
1987) Hence adhesive quinoa may also contain low amylose Additionally previous studies
found waxy cereal or starch (0 amylose and 100 amylopectin) exhibited excellent
161
performance in extrusion Kowalski et al (2014) found that waxy wheat extrudates exhibited
nearly twice the expansion ratio as that of normal wheat Koumlksel et al (2004) found hulless waxy
barley to be promising for extrusion using low shear screw configuration Van Soest et al (1996)
reported high elongation (500) in extruded maize starch Consequently the adhesive quinoa
varieties have great potential to apply in extruded or other puffed foods
Consumer preference of the sensory attributes was analyzed using Partial Least Square
Regression (PLS) (Figure 4) The attributes presented by lsquoPeruvian Redrsquo including lsquograssyrsquo
aroma lsquograinyrsquo flavors and lsquofirmrsquo and lsquocrunchyrsquo textures were preferred among consumers The
less preferred attributes included lsquopastyrsquo lsquowaterymoistrsquo lsquoadhesiversquo and lsquocohesiversquo all attributes
used to describe the lsquoQQ74rsquo variety Overall acceptance was driven by crunchy texture (r =
090) but negatively correlated with lsquocohesiversquo lsquopastyrsquo and lsquoadhesiversquo texture (r = -096 -087
and -089 respectively) Specifically aroma acceptance of cooked quinoa was negatively
correlated with lsquowoodyrsquo (r = -083) Texture acceptance was positively correlated with lsquofirmrsquo(r =
084) and lsquocrunchyrsquo (r = 094) but was negatively correlated with lsquocohesiversquo (r = -096) lsquopastyrsquo
(r = -095) lsquoadhesiversquo (r = -096) and lsquomoistrsquo (r = -085) Even though lsquoearthyrsquo is a common
attribute in foods such as mushroom and beets this study on quinoa indicated that earthy aroma
and flavor were not the attributes driving consumersrsquo liking of cooked quinoa Color and
appearance did not exhibit significant correlation with color intensity of cooked quinoa
however the varieties with red or dark colors (lsquoPeruvian Redrsquo lsquoBolivian Redrsquo and lsquoBlackrsquo)
were more highly accepted by consumers compared to samples with light color (lsquoTiticacarsquo
lsquoBolivian Whitersquo lsquoQQ74rsquo) In sum consumers preferred cooked quinoa with grassy aroma firm
and crunchy texture and lack of woody aroma and low cohesive pasty or adhesive texture
162
The variety lsquoBlackrsquo was accepted at a similar level as commercial samples in aroma
tasteflavor texture and overall evaluation With a closer examination of the consumer
demographic consumers who were more familiar with quinoa rated the lsquoBlackrsquo quinoa variety
with higher scores (average of 7) compared to those panelists less familiar with quinoa who
assigned lower average scores (59) (Figure 1S) This tricolor quinoa (browndark mixture) is not
as common as red and yellowwhite quinoa in the US market However the potential of tricolor
quinoa may be great due to the relative high consumer acceptance as well as high gain yield in
the field
Instrumental Texture Profile Analysis (TPA)
The physical properties of cooked quinoa were determined using the texture analyzer
(Table 6) Samples differed in all six texture parameters lsquoNL-6rsquo lsquoPeruvian Redrsquo lsquoBolivian Redrsquo
and lsquoCalifornia Tricolorrsquo exhibited the hardest texture while lsquoTemukorsquo lsquoQQ74rsquo lsquoIslugarsquo
lsquoLinaresrsquo and lsquoCO407Daversquo displayed the lowest hardness values Consistent with trained panel
evaluation lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Daversquo were more adhesive than all other varieties
lsquoTiticacarsquo was the springiest variety while lsquoKaslaearsquo and lsquoQuF9P1-20rsquo were the least springy
varieties The commercial samples with the exception of lsquoPeruvian Whitersquo exhibited a more
gummy texture lsquoTiticacarsquo and lsquoBolivian Whitersquo were the chewiest samples In contrast varieties
of lsquoTemukorsquo lsquoQQ74rsquo lsquoIslugarsquo lsquoLinaresrsquo lsquoQuF9P1-20rsquo and lsquoCO407Daversquo showed the least
gummy and chewy texture The result was comparable to an earlier study (Wu et al 2014)
Similarly quinoa varieties with darker color (orangeredbrowndark) tended to yield harder
texture compared to the varieties with light color (whiteyellow) which is caused by the thicker
seed coat in dark colored quinoa In this study adhesive quinoa varieties lsquoQQ74rsquo lsquoLinaresrsquo and
163
lsquoCO407Daversquo were found to have higher adhesiveness values (-17 kgs to -13 kgs) compared
to other varieties previously reported (-029 kgs to 0) (Wu et al 2014)
Correlations of instrumental tests and trained panel evaluations of texture were
significant for hardness and adhesiveness (r = 070 and -063 respectively) (Table 7) Since
adhesiveness was calculated from the first negative peak area of the TPA graph a negative
correlation coefficient was observed but still indicating a high level of agreement between
instrumental and panel tests Springiness tested by TPA was not correlated with texture
attributes
Cohesiveness from the instrumental test was negatively correlated with cohesiveness
from the trained panel texture evaluation (r = -066) Instrumental cohesiveness also exhibited
positive correlations with the trained panel evaluation of firmness and crunchiness (r = 080 and
076 respectively) and negative correlations with pastiness adhesiveness moistness (r = -072
-075 and -082 respectively) Upon a closer examination of the definitions in the instrumental
test cohesiveness was defined as lsquohow well the product withstands a second deformation relative
to its resistance under the first deformationrsquo and is calculated as the ratio of second peak area to
first peak area (Wiles et al 2004) In the sensory lexicon cohesiveness was defined as lsquodegree
to which a substance is compressed between the teeth before it breaksrsquo (Szczesniak 2002) These
differential definitions or explanations of these attributes may have caused the different results
Additionally the gumminess and chewiness from the instrumental evaluation were not
significantly correlated with their counterpart notes from the trained panel evaluations but
correlated with other sensory attributes evaluated by the trained panel Instrumental gumminess
164
was positively correlated with firm and crunchy textures(r = 079 and 078 respectively) but
negatively correlated with cohesive pasty adhesive and moist (r = -067 -068 -075 and -
078 respectively) Additionally a positive correlation was found between instrumental
chewiness and firmness from the panel evaluation (r = 057) whereas negative correlations were
found between instrumental chewiness and panel evaluated cohesiveness pastiness
adhesiveness and moistness (r = -043 -045 -055 and -052 respectively) In the instrumental
texture profile gumminess is calculated by hardness multiplied by cohesiveness and chewiness
is calculated by gumminess multiplied by springiness (Epstein et al 2002) Hence gumminess
was significantly correlated with hardness and cohesiveness and chewiness was significantly
correlated with gumminess In another study of Lyon et al (2000) pasty and adhesive were
expressed as lsquoinitial starchy coatingrsquo and lsquoself-adhesivenessrsquo respectively in cooked rice and
were both negatively correlated with instrumental hardness Generally the instrument test is
more accurate and stable but the parameter or sensory attributes were relatively limited Sensory
panels are able to use various vocabularies to describe the food however accuracy and precision
of panel evaluations were lower than for the instrument Consequently both tools can be
important in sensory evaluation depending on the objectives and resources availability
Future Studies
A lexicon of cooked quinoa was firstly developed in this paper Further discussion and
improvement of the lexicon are necessary and require cooperation with industry and chefs The
lexicon is not only useful in categorizing varieties but also can be used to evaluate post-harvest
practice cooking protocols and other quinoa foodsdishes Additionally quinoa seed quality
varies among years and locations and sensory properties also change over different
165
environments To validate the sensory profile of varieties especially adhesiveness evaluation
should be repeated on the samples from other years and locations Finally multiple dishes food
types should be included in future consumer evaluation studies to identify the best application of
different varieties
Conclusion
A lexicon of cooked quinoa was developed based on aroma tastefavor texture and
color Using the lexicon the trained panel conducted descriptive analysis evaluation on 16
quinoa varieties from field trials and 5 commercial samples Many sensory attributes exhibited
significant differences among quinoa samples especially texture attributes
Consumer evaluations (n = 102) were conducted on six selected samples with diverse
color texture and origin Commercial samples and the variety lsquoBlackrsquo were better accepted by
consumers The adhesive variety lsquoQQ74rsquo was the least accepted quinoa variety in the plain
cooked quinoa dish However because of its cohesive texture lsquoQQ74rsquo shows possible
application in other dishes and foods such as quinoa sushi and extruded snacks Furtherly Partial
Least Square Regression indicated the consumerrsquos preferred attributes were grassy aroma and
firm and crunchy texture while the attributes of pasty adhesive and cohesive were not liked by
consumers
Correlations of panel evaluation and instrumental test were observed in hardness and
adhesiveness However chewiness and gumminess were not significant correlated between panel
test and instrumental test Further training should be addressed to clarify the definitions of
sensory attributes With the assistance and calibration from instruments such as the texture
166
analyzer and electronic tongue panel training can be more efficient and panelists can be more
accurate at evaluation
Acknowledgements
The study was funded by the USDA Organic Research and Extension Initiative
(NIFAGRANT11083982) The authors acknowledge Washington State University Sensory
Facility and their technicians Beata Vixie and Karen Weller The authors also acknowledge
Sergio Nunez de Arco and Sarah Connolly to provide commercial samples Thanks to Raymond
Kinney Max Wood and Hanna Walters who managed the plants harvested the seeds and
collected the data of yield and 1000-seed weight on field trial quinoa varieties Thanks also go to
the USDA-ARS Western Wheat Quality Lab which provided equipment for protein and ash tests
and the texture analyzer
Author contributions
CF Ross and G Wu together designed the study G Wu conducted panel training
collected and processed data and drafted the manuscript KM Murphyrsquos research group provided
the quinoa samples and assisted cleaning process CF Ross CF Morris and KM Murphy edited
the manuscript
167
References
Abugoch LEJ 2009 Chapter 1 quinoa (Chenopodium quinoa Willd) Adv Food Nutr Res
581ndash31
Arco SND Quinoas Calling In Murphy KM Matanguihan J editors Quinoa improvement
and sustainable production Hoboken NJ John Wiley amp Sons Inc p 211
Casas Moreno MM Barreto-Palacios V Gonzalez-Carrascosa R Iborra-Bernad C Andres-Bello
A Martiacutenez-Monzoacute J Garciacutea-Segovia P 2015 Evaluation of textural and sensory properties
on typical spanish small cakes designed using alternative flours J Culinary Sci Technol 13
19-28
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(Waxy) genes J Cereal Sci 35 51-63
Foumlste M Nordlohne SD Elgeti D Linden MH Heinz V Jekle M Becker T Impact of quinoa
bran on gluten-free dough and bread characteristics Eur Food Res Technol 2014 239 767-
75
Furche C Salcedo S Krivonos E Rabczuk P Jara B Fernaacutendez D Correa F 2015 Chapter 41
International quinoa trade In Bazile D Bertero D Nieto C editors State of the art report
on quinoa in 2013 Rome FAO amp CIRAD p 317 ndash 20
Gerber NN1968 Geosmin from microorganisms is trans-1 10-dimethyl-trans-9-decalol
Tetrahedron Lett 9 2971-4
168
Koumlksel H Ryu GH Basman A Demiralp H Ng PK 2004 Effects of extrusion variables on the
properties of waxy hulless barley extrudates FoodNahrung 48 19-24
Kowalski RJ Morris CF Ganjyal GM 2015 Waxy soft white wheat extrusion characteristics
and thermal and rheological propertiesCereal Chem 92 145-53
Koziol MJ 1991 Afrosimetric estimation of threshold saponin concentration for bitterness in
quinoa (Chenopodium quinoa Willd) J Sci Food Agr 54 211-9
Limpawattana M Shewfelt R 2010 Flavor lexicon for sensory descriptive profiling of different
rice types J Food Sci 75 199-205
Lorenz K Coulter L Quinoa flour in baked products Plant Food Hum Nutr 1991 41 213-23
Lyon BG Champagne ET Vinyard BT Windham WR Barton FE Webb BD McKenzie KS
1999 Effects of degree of milling drying condition and final moisture content on sensory
texture of cooked rice Cereal Chem 76 56-62
Lyon BG Champagne ET Vinyard BT Windham WR 2000 Sensory and instrumental
relationships of texture of cooked rice from selected cultivars and postharvest handling
practices Cereal Chem 77 64-9
Meilgaad MC Civille GV Carr BT 2007 Chapter 11 The spectrum descriptive analysis
method In Meilgaad MC Civille GV Carr BT Sensory evaluation techniques Boca Raton
FL CRC Press p 225 ndash 32
169
Meullenet JF Marks BP Hankins JA Griffin VK Daniels MJ 2000 Sensory quality of cooked
long-grain rice as affected by rough rice moisture content storage temperature and storage
duration Cereal Chem 77 259 ndash 63
Mossman AP Fellers DA Suzuki H 1983 Rice stickiness I Determination of rice stickiness
with an Instron tester Cereal Chem 60 286ndash92
Muntildeoz AM 2003 Training time in descriptive analysis In Moskowitz HR Muntildeoz AM and
Gacula MC editors Viewpoints and controversies in sensory science and consumer product
testing Trumbull Food amp Nutrition Press Inc p 351 ndash 6
Peterson AJ Murphy KM 2015 Quinoa cultivation for temperate North America
considerations and areas for investigation In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 173-92
Palmer GH 1994 Chapter 5 Storage In Hoseney RC editor Cereal science and technology
2nd edition St Paul MN American Association of Cereal Chemisty Inc p 107
Pop A Muste S Man S Mureșan C 2014 Improvement of tagliatelle quality by addition of red
quinoa flour Bulletin UASVM Food Sci Tech 71 225-6
Pulvento C Riccardia M Biondib S Orsinic F Jacobsend SE Ragabe R DrsquoAndriaa R Lavinia
A 2015 Chapter 613 Quinoa in Italy research and perspectives In Bazile D Bertero D
Nieto C editors State of the art report on quinoa in 2013 Rome FAO amp CIRAD p 460
Quiroga C Escalera R Aroni G Bonifacio A Gonzaacutelez JA Villca M Saravia R Ruiz A 2015
Chapter 31 Traditional processes and technological innovations in quinoa harvesting
170
processing and industrialization In Bazile D Bertero D Nieto C editors State of the art
report of quinoa in the world in 2013 Rome FAO amp CIRAD p 231
Repo-Carrasco R Espinoza C Jacobsen SE 2003 Nutritional value and use of the Andean
crops quinoa (Chenopodium quinoa) and kantildeiwa (Chenopodium pallidicaule) Food Rev Int
19 179-89
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile
D Bertero D Nieto C editors State of the art report on quinoa in 2013 Rome FAO amp
CIRAD p 67
Sowbhagya CM Ramesh BS Bhattacharya KR 1987 The relationship between cooked-rice
texture and physicochemical characteristics of rice J Cereal Sci 5 287ndash97
Suwannaporn P Linnemann A and Chaveesuk R 2008 Consumer preference mapping for rice
product concepts Brit Food J 110 595-606
Stikic R Glamoclija D Demin M Vucelic-Radovic B Jovanovic Z Milojkovic-Opsenica D
Milovanovic M 2012 Agronomical and nutritional evaluation of quinoa seeds
(Chenopodium quinoa Willd) as an ingredient in bread formulations J Cereal Sci 55 132-8
Szczesniak AS 2002 Texture is a sensory property Food Qual Prefer 13 215-25
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Belton PS JRN Taylor editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science Business Media p 108 ndash 10
171
Tomlins KI Manful JT Larwer P and Hammond L 2005 Urban consumer preferences and
sensory evaluation of locally produced and imported rice in West Africa Food Qual Prefer
16 79-89
Van Soest JJG De Wit D Vliegenthart JFG 1996 Mechanical properties of thermoplastic waxy
maize starch J Appl Polym Sci 61 1927-37
Wang S Opassathavorn A Zhu F 2015 Influence of quinoa flour on quality characteristics of
cookie bread and Chinese steamed bread J Texture Stud 46 281-92
Wiles JL Green BW Bryant R 2004 Texture profile analysis and composition of a minced
catfish product J Texture Stud 35 325-37
Wu G Morris C F Murphy K M 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79 2337-45
172
Table 1-Quinoa samples
Varietya Color Source
Titicaca Yellowwhite Denmark
Black Blackbrown mixture White Mountain Farm Colorado USA
KU-2 Yellowwhite Washington USA
Cahuil Brownorange mixture White Mountain Farm Colorado USA
Red Head Yellowwhite Wild Garden Seed Oregon USA
Cherry Vanilla Yellowwhite Wild Garden Seed Oregon USA
Temuko Yellowwhite Washington USA
QuF9P39-51 Yellowwhite Washington USA
Kaslaea Yellowwhite MN USA
QQ74 Yellowwhite Chile
Isluga Yellowwhite Chile
Linares Yellowwhite Washington USA
Puno Yellowwhite Denmark
QuF9P1-20 Yellowwhite Washington USA
NL-6 Yellowwhite Washington USA
CO407Dave Yellowwhite White Mountain Farm Colorado USA
Bolivian White White Bolivia
Bolivian Red Red Bolivia
California Tricolor
Blackbrown mixture California USA
Peruvian Red Red Peru
Peruvian White White Peru aThe first 16 varieties (Tititcaca ndash CO407Dave) were grown in Chimacum WA
173
Table 2-Lexicon of cooked quinoa as developed by the trained panelists (n = 9)
Attribute Intensitya Reference Definition
Aroma
Caramel 10 1 piece of caramel candy (Kraft) (81 g) in 100 mL water
Aromatics associated with caramel tastes
Grain-like 10 Cooked brown rice (15 g) (Great Value)
Rice like wheaty sorghum like
Bean-like 8 Cooked red bean (10 g) (Great Value)
Aromatics associated with cooked beans or bean protein
Nutty 10 Dry roasted peanuts (10 g) (Planters)c
Aromatics associated with roasted nuts
Buttery 10 Unsalted butter (1cm1cm01cm) (Tillamook)c
Aromatics associated with natural fresh butter
Starchy 10 Wheat flour water (11 ww) (Great Value)c
Aromatics associated with the starch
Grassygreen 9 Fresh cut grass collected 1 h before usingc
Aromatics associated with grass
Earthymusty 8 Sliced raw button mushrooms (fresh cut)c
Aromatic reminiscent of decaying vegetative matters and damp black soil root like
Woody 7 Toothpicks (20)c Aromatics reminiscent of dry cut wood cardboard
TasteFlavor
Sweet 3 9 2 and 5 (ww) sucrose solution (CampH pure cane sugar)b
Basic taste sensation elicited by sugar
Bitter 5 8 mgL quinine sulfate acid (Sigma)
Basic taste sensation elicited by caffeine
174
Grain-like 10 Cooked brown rice (Great Value)
Tasted associated with cooked grain such as rice
Bean-like 10 Cooked red beans (Great Value)
Beans bean protein
Nutty 10 Dry roasted peanut (Planters)c Taste associated with roasted nuts
Earthy 7 Sliced raw button mushrooms (fresh)
Taste associated with decaying vegetative matters and damp black soil
Toasted 10 Toasted English muffin (at 6 of a toaster) (Franze Original English Muffin)
Taste associated with toast
Texturee
Soft - Firm 3
7
Firm tofu (Azumaya)b
Brown rice (Great Value)
Force required to compress a substance between molar teeth (in the case of solids) or between tongue and palate (in the case of semi-solids)d
Separate - Cohesive
15
7
Cracker (Premium unsalted cracker)
Cake (Sponge cake Walmart Bakery)
Degree to which a substance is compressed between the teeth before it breaks
Pasty
10 Mashed potato (Great Value Mashed Potatoes powder)
Smooth creamy pulpy slippery
Adhesiveness sticky
10
3
Sticky rice (Koda Farms Premium Sweet Rice)
Brown rice (Great Value)
Force required to remove the material that adheres to the mouth (the palate and teeth) during the normal eating process
Crunchy 13 Thick cut potato chip (Tostitos Restaurant Style
Force with which a sample crumbles cracks or shatters
175
Tortilla Chips)b
Chewygummy
15
7
Gummy Bear (Haribo Gold-Bears mixed flavor)
Brown rice (Great Value)
Length of time (in sec) required to masticate the sample at a constant rate of force application to reduce it to a consistency suitable for swallowing
Astringent 12
6
Tannic acid (2gL)
Tannic acid (1gL) (Sigma)
Puckering or tingling sensation elicited by grape juice
Waterymoist 10
3
Salad tomato (Natural Sweet Cherubs)
Brown rice (Great Value)
Degree of wet or dry
Color
Red 4 9
N-W8M Board Walke
N-W16N Ballet Barree
Yellow 3 10
15B-2U Sandy Toese 15B-7
N Summer Harveste
Black 3 10
N-C32N Strong Influencee N-C4M Trench Coate
aReference intensities were based on a 15-cm scale with 0 = extremely low and 15 = extremely high bMeilgaad et al (2007) cLimpawattana and Shewfelt (2010) dTexture definitions in Szczesniak (2002) were used eAce Hardware color chip
176
Table 3-Significance and F-value of the effects of panelist replicate and quinoa variety on aroma flavor and texture of cooked quinoa as determined using a trained panel (n = 9)
Attribute Panelist Replicate Quinoa Variety PanelistVariety
Aroma
Caramel 26548 093 317 174
Grain-like 7338 000 125 151
Bean-like 7525 029 129 135
Nutty 6274 011 322 118
Buttery 21346 003 301 104
Starchy 12094 1102 094 135
Grassy 17058 379dagger 282 162
Earthy 12946 239 330 198
Woody 13178 039 269 131
TasteFlavor
Sweet 6745 430 220 137
Bitter 9368 1290 2059 236
Grain-like 7681 392 222 206
Bean-like 7039 122 142 141
Nutty 7209 007 169 153
Earthy 9313 131 330 177
Toasted 10975 015 373 184
Texture
Firm 1803 022 1587 141
Cohesive 14750 011 656 208
Pasty 3919 2620 1832 205
Adhesive 2439 287dagger 5740 183
177
Crunchy 13649 001 1871 167
Chewy 3170 870 150dagger 167
Astringent 10183 544 791 252
Waterymoist 10281 369dagger 1809 164
daggerP lt 010 P lt 005 P lt 001 P lt 0001
178
Table 4-Mean separation of significant tasteflavor attributes of cooked quinoa determined by the trained panel Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Sweet Bitter Grain-like Nutty Earthy Toasty
Titicaca 40cdef1 39bcde 73abc 51abcdef 44bcdef 47abcd
Black 36f 42bcd 69bcde 49def 52a 46abcd
KU2 41bcdef 38cde 73abc 52abcdef 40fg 44bcdefg
Cahuil 41abcdef 44b 70bcde 50abcdef 48abc 51a
Red Head 42abcd 43bc 72abcd 51abcdef 42defg 44bcdefg
Cherry Vanilla 40def 52a 66e 48ef 44bcdef 40fghi
Temuko 36ef 56a 68cde 47f 43cdef 40ghi
QuF9P39-51 47a 34e 73abc 48def 40efg 46abcde
Kaslaea 47ab 39bcde 70bcde 55ab 44bcdef 45bcdefg
QQ74 40def 38cde 66e 50abcdef 45bcde 42defghi
Isluga 41bcdef 41bcd 69cde 55a 46bcd 47abcd
Linares 39def 40bcd 65e 49cdef 43def 38i
Puno 44abcd 39bcde 72abcd 51abcdef 45bcde 43cdefghi
QuF9P1-20 42abcdef 43bc 69bcde 53abcd 45bcde 38i
NL-6 38def 37de 72abcd 55a 45bcd 44bcdefgh
CO 407 Dave 41bcdef 40bcd 67de 51abcdef 41defg 39hi
Bolivian White 47ab 22f 69bcde 50bcdef 42def 41efghi
Bolivian Red 42abcde 24f 72abcd 53abcdef 43cdef 46bcde
California Tricolor 40def 27f 74ab 53abcde 48ab 48ab
Peruvian Red 43abcd 25f 75a 48ef 45bcde 47abc
Peruvian White 46abc 26f 70bcde 55abc 37g 45bcdef
179
Table 5-Mean separation of consumer preference Different letters within a column indicate consumer evaluation scores were different among quinoa samples at P lt 005
Samples Aroma Color Appearance TasteFlavor Texture Overall
Black 56a 63b 61bc 61abc 65a 63ab
QQ74 61a 56c 53d 56c 53b 53c
Titicaca 60a 57bc 56cd 58bc 63a 59bc
Peruvian Red 60a 72a 70a 65a 68a 67a
Bolivian Red 60a 69a 66ab 64ab 67a 64ab
Bolivian White 57a 59bc 58c 62ab 63a 62ab
180
Table 6-Hardness adhesiveness cohesiveness springiness gumminess and chewiness of the cooked quinoa samples as determined using Texture Profile Analysis (TPA)
Variety Hardness
(kg)
Adhesiveness
(kgs)
Cohesiveness Springiness Gumminess
(kg)
Chewiness
(kg)
Titicaca 505abc1 -02ab 08abc 15a 384bc 599a
Black 545ab -01a 07bcd 10abc 404abc 404ab
KU-2 490abcd -01a 07bcd 09abc 363bcd 332abc
Cahuil 464bcde -01a 07bcd 08abc 344cd 281bc
Red Head 412defg -03ab 06ef 09abc 246ef 225bc
Cherry Vanilla 391efgh -02ab 05fgh 08abc 208fg 178bc
Temuko 328gh -09c 04hi 08abc 147g 120c
QuF9P39-51 451cde -02ab 07de 10abc 297de 272bc
Kaslaea 493abcd -02ab 07bcd 06c 359cd 227bc
QQ74 312h -17e 04i 09abc 132g 119c
Isluga 362fgh -05b 05ghi 08abc 171fg 137bc
Linares 337gh -16de 05ghi 09abc 159g 146bc
Puno 504abc -01a 06ef 10abc 301de 301bc
QuF9P1-20 438cdef -02ab 06fg 05c 242ef 137bc
NL-6 555a -01a 07cde 09abc 376bcd 350abc
CO407Dave 357fgh -13d 04hi 09abc 160g 141bc
Bolivian White 441cdef -01ab 05fg 14ab 242ef 340abc
Bolivian Red 572a -01ab 08ab 14ab 440ab 593a
California Tricolor
572a -01a 08a 08bc 477a 361abc
Peruvian Red 568a 00a 08ab 08abc 439ab 342abc
Peruvian White 459bcde -01a 08abc 11abc 347cd 394abc
181
Table 7-Correlation of trained panel texture evaluation data and instrumental TPA over the 21 quinoa varieties
Variables Hardness Adhesiveness Cohesiveness Gumminess Chewiness Firm 070 059 080 079 057 Cohesive -060 -051 -066 -067 -043 Pasty -060 -070 -072 -068 -045 Adhesive -067 -063 -075 -075 -055 Crunchy 072 054 076 078 055 Moist -066 -066 -082 -078 -052
daggerP lt 01 P lt 005 P lt 001 P lt 0001
182
Figure 1-Principal component Analysis (PCA) biplot of aroma evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil Red Head
Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white Kaslaea
QQ74
Isluga
Linares
Puno
QuF9P1-20 NL-6
CO 407 Dave
Bolivia white
Bolivia red California Tricolor
Caramel Grain-like
Bean-like Nutty
Buttery Starchy
Grassy
Earthy
Woody
-25
-2
-15
-1
-05
0
05
1
15
2
-3 -25 -2 -15 -1 -05 0 05 1 15 2 25 3 35 4
F2 (2
455
)
F1 (4234 )
183
Figure 2-Principal component Analysis (PCA) biplot of tasteflavor evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil
Red Head Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white
Kaslaea
QQ74 Isluga
Linares
Puno
QuF9P1-20
NL-6
CO 407 Dave
Bolivia white
Bolivia red
California Tricolor
Sweet
Bitter Grain-like
Bean-like
Nutty
Earthy
Toasted
-3
-2
-1
0
1
2
3
-4 -3 -2 -1 0 1 2 3 4 5
F2 (3
073
)
F1 (3391 )
184
Figure 3-Principal component Analysis (PCA) biplot of texturemouthfeel evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil
Red Head Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white
Kaslaea
QQ74 Isluga
Linares
Puno
QuF9P1-20
NL-6
CO 407 Dave
Bolivia white
Bolivia red California Tricolor
Firm Cohesive
Pasty
Adhesive
Crunchy
Chewy Astringent
Moist
-2
-15
-1
-05
0
05
1
15
2
25
-3 -25 -2 -15 -1 -05 0 05 1 15 2 25 3 35
F2 (2
212
)
F1 (5959 )
185
Figure 4-Partial Least Squares (PLS) biplot correlating aroma color appearance tasteflavor texture and overall attributes evaluated by the trained panel (n = 9) to the consumer panel (n = 102) for 6 cooked quinoa samples (Consumer acceptances are in bold italics)
Grainy aroma
Beany aroma
Nutty aroma
Buttery
Starchy
Grassy
Earthy
Woody
Sweet
Bitter grainy flavor
Beany flavor
Earthy flavor Nutty flavor
Toasty
Firm Cohesive
Pasty
Adhesive
Crunchy
Chewy
Astringent
Waterymoist
Aroma
Color Appearance TasteFlavor
Texture Overall
Black
Bolivia red
QQ74
Bolivia white
Commercial Red
Titicaca
-1
-075
-05
-025
0
025
05
075
1
-1 -075 -05 -025 0 025 05 075 1
t2
t1
186
Supplementary tables
Table 1S-Mean separation of significant aroma attributes of cooked quinoa determined by the trained panel (n = 9) Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Caramel Nutty Buttery Green Earthy Woody
Titicaca 59a1 60a 45abc 39fg 42defgh 37cdef
Black 46g 50efg 38ef 47abc 54a 46a
KU2 50efg 51defg 41cdef 40efg 38h 35ef
Cahuil 56abc 53bcdefg 43abcd 49a 48b 39bcde
Red Head 55abcd 60a 45abc 44bcde 46bcd 41bc
Cherry Vanilla 52cdef 54bcdef 43abcde 43bcdef 46bcdef 37bcdef
Temuko 55abcd 56abcde 44abc 40defg 41efgh 37bcdef
QuF9P39-51 58ab 60a 46ab 42bcdefg 44bcdefg 36def
Kaslaea 53bcde 55abcde 42abcde 41defg 40gh 37bcdef
QQ74 50efg 48fg 39def 42defg 45bcdef 38bcdef
Isluga 52cdef 57abc 43abcd 43bcdefg 46bcde 39bcde
Linares 52cdef 54bcdef 42bcde 38g 44bcdefg 37cdef
Puno 56abc 56abcde 46ab 42cdefg 46bcdef 38bcdef
QuF9P1-20 53bcdef 58ab 44abcd 42cdefg 44bcdefg 40bcd
NL-6 57abc 53bcdefg 44abcd 39fg 44bcdefg 35def
CO 407 Dave 51def 54abcde 46ab 40efg 42defgh 34f
Bolivian White 53bcde 57abcd 46ab 43bcdef 43cdefgh 39bcd
Bolivian Red 52cdef 51defg 42bcde 43bcdefg 44bcdefg 37bcdef
California Tricolor 54abcde 51cdefg 38ef 44abcd 48bc 41ab
Peruvian Red 48fg 48g 36f 47ab 46bcdef 38bcdef
Peruvian White 54abcde 60a 48a 45abcd 41fgh 40bc
187
Table 2S-Mean separation of significant texture attributes of cooked quinoa determined by the trained panel Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Firm Cohesive Pasty Adhesive Crunchy Astringent Moist
Titicaca 70ab 63efgh 37ghi 37ghi 56bc 47d 38hij
Black 71ab 63efgh 32i 38ghi 58b 55abc 35jk
KU2 66bcd 64efg 38fghi 37ghi 49de 46de 38hij
Cahuil 68abc 61fghi 37ghi 36hi 56bc 55ab 37ij
Red Head 57fgh 68bcde 46cde 49d 45ef 55ab 48de
Cherry Vanilla 56gh 65cdef 49c 44def 43fg 55ab 49de
Temuko 49ij 70abcd 56b 57c 39gh 59a 51cd
QuF9P39-51 61defg 65def 47cd 40efgh 48def 48cd 42fgh
Kaslaea 60defg 62fghi 40defgh 40fgh 51cd 51bcd 42gh
QQ74 44j 70abc 60ab 81ab 37hi 46def 57ab
Isluga 52hi 66cdef 43cdef 55c 44efg 50bcd 48de
Linares 45j 75a 65a 86a 33i 47d 61a
Puno 58efgh 60fghij 41defg 43efg 52cd 47d 47def
QuF9P1-20 52hi 65def 43cdefg 46de 44fg 55ab 47defg
NL-6 64cde 61fghi 40efgh 41efgh 51cd 46de 46efg
CO 407 Dave 45j 72ab 59ab 80b 35hi 47d 55bc
Bolivian White 56gh 61fghi 38fghi 41efgh 50de 34g 48de
Bolivian Red 62cdef 59hij 34hi 36hi 56bc 38g 42fgh
California Tricolor 68abc 56j 32i 33i 60ab 39efg 39hij
Peruvian Red 74a 57ij 35hi 33i 64a 39fg 31k
Peruvian White 60defg 59ghij 38fghi 37hi 48def 34g 40hi
188
Figure-1S Demographic influence on preference of variety lsquoBlackrsquo
75a
66ab 61bc
54c
61bc
0
1
2
3
4
5
6
7
8
75 50 25 None Other
Liking score of lsquoBlackrsquo
Proportion of organic food consumption
52b
64a 65a 69a 70a
57ab 59ab
0
1
2
3
4
5
6
7
8
Everyday 4-5 timesper week
2-3 timesper week
Once aweek
A fewtimes per
month
Aboutevery 6months
Other
Liking score of lsquoBlackrsquo
Frequency of rice consumption
189
Chapter 7 Conclusions
Quinoa quality is a complex topic with seed composition influencing sensory and
physical properties This dissertation evaluated the seed characteristics composition flour
properties and cooking quality of 13 quinoa samples Differences in seed morphology and
composition contributed to the texture of cooked quinoa The seeds with higher raw seed
hardness lower bulk density or higher seed coat proportion yielded a firmer gummier and
chewier texture after cooking Higher protein content correlated with harder more adhesive
more cohesive gummier and chewier texture of cooked quinoa Additionally flour peak
viscosity breakdown final viscosity and setback exhibited influence on different texture
parameters Cooking time and water uptake ratio also significantly influence the texture whereas
cooking loss did not show any correlation with texture Starch characteristics also significantly
differed among quinoa varieties (Chapter 3) Amylose content ranged from 27 to 169
among 13 quinoa samples The quinoa samples with higher amylose proportion or higher starch
enthalpy tended to yield harder stickier more cohesive and chewier quinoa These studies on
seed quality seed characteristics compositions and cooking quality provided useful information
to food industry professionals to use in the development of quinoa products using appropriate
quinoa varieties Indices such protein content and flour viscosity (RVA) can be quickly
determined and exhibited strong correlations with cooked quinoa texture Furthur study should
develop a prediction model using protein content or RVA parameters to predict the texture of
cooked quinoa In this way food manufactures can quickly predict the texture or functionality of
quinoa varieties and then determine their specific application Moreover many of the test
methods were using the methods used in rice such as kernel hardness texture of cooked quinoa
190
thermal properties (DSC) and cooking qualities Such methods should be standardized in near
future as those defined by AACC (American Association of Cereal Chemists) The development
of standard methods allows for easier comparisons among different studies In Chapter 4 the
seed quality response to soil salinity and fertilization was studied Quinoa protein content
increased under high Na2SO4 concentration (32 dS m-1) The variety lsquoQQ065rsquo maintained similar
levels of hardness and density under salinity stress and is considered to be the best adapted
variety among four varieties The variety can be applied in salinity affected areas Future studies
can be applied on salinity drought influence on quinoa amino acids profile starch composition
fiber content and saponins content
Sensory evaluation of cooked quinoa was further examined in Chapter 5 Using a trained
panel the lexicon for cooked quinoa was developed Using this lexicon the sensory profiles of
16 field trial varieties and 5 commercial quinoa samples were generated Varietal differences
were observed in the aromas of caramel nutty buttery grassy earthy and woody tasteflavor of
sweet bitter grain-like nutty earthy and toasty and texture of firm cohesive pasty adhesive
crunchy chewy astringent and moist Subsequent consumer evaluation on 6 selected quinoa
samples indicated lsquoPeruvian Redrsquo was the most accepted overall whereas a sticky variety lsquoQQ74rsquo
was the least accepted Partial least square analysis using trained panel data and consumer
acceptance data indicated that overall consumer liking was driven by grassy aroma and firm and
crunchy texture The lexicon and the attributes driving consumer-liking can be utilized by
breeders and farmers to evaluate their quinoa varieties and products The information is also
useful to the food industry to evaluate ingredients from different locations and years improve
processing procedures and develop products
191
Overall the dissertation provided significant information of quinoa seed quality and
sensory characteristics among different varieties including both commercialized samples and
field trial samples not yet available in market Several quinoa varieties increasingly grown in
US were included in the studies The variety lsquoCherry Vanillarsquo and lsquoTiticacarsquo are among the
varieties gaining the best yields in US Their seed characteristics and sensory attributes
described in this dissertation should be helpful for industry professionals in their research and
product development Varieties include lsquoTiticacarsquo lsquoCherry Vanillarsquo and lsquoBlackrsquo Additionally
important tools were developed in quinoa evaluation including texture analysis using TPA and
the lexicon of cooked quinoa
As with any set of studies other research questions arise to be addressed in future
research First saponins the compounds introducing bitter taste in quinoa require further study
Sweet quinoa varieties (saponins content lt 011) should be bred and adapted to the US
Although many consumers may like the bitter taste and especially the potential health benefits of
saponins it is important to provide consumers choices of both bitter and non-bitter quinoa types
To assist the breeding of sweet quinoa genetic markers can be developed and associated with the
phenotype of saponin content As for the methods testing saponin content the foam method is
quick but not accurate whereas the GC method is accurate but requires long sample preparation
time and high capital investment An accurate more affordable and more efficient method such
as one using a spectrophotometer should be developed
Second one important nutritional value of quinoa is the balanced essential amino acids
The essential amino acids profiles change according to environment (drought and saline soil)
quinoa variety and processing (cleaning milling and cooking) and these changes should be
192
further studied It is important to prove quinoa seed maintains the rich essential amino acids even
growing under marginal conditions or being subjected to cleaning processes such as abrasion
and washing
Third betalains are the compounds contributing to the color of quinoa seed and providing
potential health benefits Betalain content type (relate to diverse colors) and their genetic loci in
quinoa can be further investigated Color diversity is one of the attractive properties in quinoa
seeds However the commercialized quinoa samples are in white or red color while more quinoa
varieties present orange purple brown and gray colors More choices of quinoa colorstypes
may attract more consumers
Finally sensory evaluation of quinoa varieties should be applied to the samples from
multiple years and locations since environment can significantly influence the sensory attributes
Also in addition to plain cooked quinoa more quinoa dishes can be involved in consumer
acceptance studies as different quinoa varieties may be suitable for various dishes
v
variety among four varieties Finally sensory evaluation studies on cooked quinoa were
conducted A lexicon of cooked quinoa was developed including the sensory attributes of aroma
tasteflavor texture and color Results from the trained and consumer panel indicated that
consumer liking of quinoa was positively influenced by grassy aroma and firm and crunchy
texture These results represent valuable information to quinoa breeders in the determination of
seed quality of diverse quinoa varieties In the food industry the results of seed quality and
sensory studies (lexicon and consumer-liking) can be utilized to evaluate quinoa ingredients from
multiple locations or years determine the efficiency of post-harvest processing and develop
appropriate products according to the properties of the specific quinoa variety Overall this
dissertation contributed to the growing body of research describing the chemical physical and
sensory properties of quinoa
vi
TABLE OF CONTENTS
Page
ACKNOWLEDGMENTS iii
ABSTRACT iv-v
LIST OF TABLES ix-xi
LIST OF FIGURES xii-xiii
CHAPTERS
1 Introduction 1
References 6
2 Literature review 9
References 26
Tables 41
Figures44
3 Evaluation of texture differences among varieties of cooked quinoa 46
Abstract 46
Introduction 48
Materials and Methods 51
Results 54
Discussion 60
vii
Conclusion 63
References 65
Tables 71
Figures78
4 Quinoa starch characteristics and their correlation with
texture of cooked quinoa 80
Abstract 80
Introduction 81
Materials and Methods 82
Results 87
Discussion 95
Conclusion 102
References 103
Tables 109
5 Quinoa seed quality response to sodium chloride and
Sodium sulfate salinity 118
Abstract 118
Introduction 120
Materials and Methods 122
Results 125
Discussion 123
viii
Conclusion 132
References 134
Tables 139
Figure 145
6 Lexicon development and sensory attributes of cooked quinoa 146
Abstract 146
Introduction 148
Materials and Methods 150
Results and Discussion 155
Conclusion 165
References 167
Tables 172
Figures183
7 Conclusions 189
ix
LIST OF TABLES
Page
CHAPTER 2
Table 1 Essential amino acid of quinoa protein and FAOWHO suggested requirement (mgg
protein) 41
Table 2 Quinoa vitamin content (mg100g) 42
Table 3 Quinoa mineral content (mgmg ) 43
CHAPTER 3
Table 1 Varieties of quinoa used in the experimenthelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip71
Table 2 Seed characteristics and composition 72
Table 3 Texture profile analysis (TPA) of cooked quinoa 73
Table 4 Cooking quality of quinoa 74
Table 5 Pasting properties of quinoa flour by RVA 75
Table 6 Thermal properties of quinoa flour by Differential Scanning Calorimetry (DSC) 76
Table 7 Correlation coefficients between quinoa seed characteristics composition and
processing parameters and TPA texture of cooked quinoa 77
CHAPTER 4
Table 1 Quinoa varieties tested 109
Table 2 Starch content and composition 110
Table 3 Starch properties and α-amylase activity 111
Table 4 Texture of starch gel 112
Table 5 Thermal properties of starch 113
x
Table 6 Pasting properties of starch 114
Table 7 Correlation coefficients between starch properties and texture of cooked quinoa 115
Table 8 Correlations between starch properties and seed DSC RVA characteristics 116
CHAPTER 5
Table 1 Analysis of variance with F-values for protein content hardness and density of quinoa
seed 139
Table 2 Salinity variety and fertilization effects on quinoa seed protein content () 140
Table 3 Salinity variety and fertilization effects on quinoa seed hardness (kg) 141
Table 4 Salinity variety and fertilization effects on quinoa seed density (g cm3) 142
Table 5 Correlation coefficients of protein hardness and density of quinoa seed 143
Table 6 Correlation coefficients of quinoa seed quality and agronomic performance and seed
mineral content144
CHAPTER 6
Table 1 Quinoa samples 172
Table 2 Lexicon of cooked quinoa as developed by the trained panelists (n = 9) 173
Table 3 Significance and F-value of the effects of panelist replicate and quinoa variety on
aroma flavor and texture of cooked quinoa as determined using a trained panel (n = 9) 176
Table 4 Mean separation of significant tasteflavor attributes of cooked quinoa determined by
the trained panel Different letters within a column indicate attribute intensities were different
among quinoa samples at P lt 005 as determined using Fisherrsquos LSD 178
Table 5 Mean separation of consumer preference Different letters within a column indicate
consumer evaluation scores were different among quinoa samples at P lt 005 179
xi
Table 6 Hardness adhesiveness cohesiveness springiness gumminess and chewiness of the
cooked quinoa samples as determined using Texture Profile Analysis (TPA) Different letters
within a column indicate attribute intensities were different among quinoa samples at P lt 005
180
Table 7 Correlation of trained panel texture evaluation data and instrumental TPA over the 21
quinoa varieties 181
Table 1S Mean separation of significant aroma attributes of cooked quinoa determined by the
trained panel (n = 9) Different letters within a column indicate attribute intensities were different
among quinoa samples at P lt 005 as determined using Fisherrsquos LSD 186
Table 2S Mean separation of significant texture attributes of cooked quinoa determined by the
trained panel Different letters within a column indicate attribute intensities were different among
quinoa samples at P lt 005 as determined using Fisherrsquos LSD 187
xii
LIST OF FIGURES
Page
CHAPTER 2
Figure 1 Quinoa seed section and two-layered pericarp under perianth (Wu et al 2014) 44
Figure 2 Figure 2-Quinoa seed structure (Prego et al 1998) 45
CHAPTER 3
Figure 1 Rapid Visco Analyzer (RVA) graph of lsquoCherry Vanillarsquo and lsquoRed Commercialrsquo quinoa
flours 78
Figure 2 Seed coat image by SEM 79
CHAPTER 5
Figure 1 Protein content () of quinoa in response to combined fertility and
salinity treatments 145
CHAPTER 6
Figure 1 Principal component Analysis (PCA) biplot of aroma evaluations by the trained
sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 182
Figure 2 Principal component Analysis (PCA) biplot of tasteflavor evaluations by the trained
sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 183
xiii
Figure 3 Principal component Analysis (PCA) biplot of texturemouthfeel evaluations by the
trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 184
Figure 4 Partial Least Squares (PLS) biplot correlating aroma color appearance tasteflavor
texture and overall attributes evaluated by the trained panel (n = 9) to the consumer panel (n =
102) for 6 quinoa samples (Consumer acceptances are in bold italics) 185
Figure-1S Demographic influence on preference of variety lsquoBlackrsquo 188
xiv
Dedication
This dissertation is dedicated to those who are interested in quinoa
the beautiful small grain providing nutrition and fun
1
Chapter 1 Introduction
Quinoa is growing rapidly in the global market largely due to its high nutritional value
and potential application in a wide range of products Bolivia and Peru are the major producers
and exporters of quinoa In Peru production increased from 31824 MT (Metric Ton) in 2007 to
108000 MT in 2015 (USDA 2015) In 2013 organic quinoa from Bolivia and Peru were sold at
averages of $8000MT and $7000MT respectively (Nuntildeez de Acro 2015) Of all countries the
US and Canada import the most quinoa and comprise 53 and 15 of the global imports
respectively (Carimentrand et al 2015) Quinoa yield is on average 600 kgha with yield
varying greatly and among varieties and environments (Garcia et al 2004) The total production
cost is $720ha in the southern Altiplano region of Bolivia and the farm-gate price reached
$60kg in 2013 (Nuntildeez de Acro 2015) With 2600 kg annual quinoa yield in a small 3 ha farm
the revenue would be $15390 which could potentially raise a family out of poverty (Nuntildeez de
Acro 2015)
Quinoa possesses many sensory properties Food texture refers to those qualities of a
food that can be felt with the fingers tongue palate or teeth (Sahin and Sumnu 2006) Texture is
one of most significant properties of food products Quinoa has unique texture ndash creamy smooth
and a little crunchy (James 2009) The texture of cooked quinoa is not only influenced by seed
structure but also determined by compounds such as starch and protein However publications
describing the texture of cooked quinoa are limited
Seed characteristics and structure are important factors influencing the textual properties
of cooked quinoa seed Quinoa is a dicotyledonous plant species very different from
2
monocotyledonous cereal grains The majority of the seed is the middle perisperm of which cells
have very thin walls and angular-shaped starch grains (Prego et al 1998) The two-layer
endosperm of the quinoa seed consists of living thick-walled cells rich in proteins and lipids but
without starch The protein bodies found in the embryo and endosperm lack crystalloids and
contain one or more globoids of phytin (Prego 1998) Given the structure of quinoa the seed
properties such as seed size hardness and seed coat proportion may influence the texture of the
cooked quinoa Nevertheless correlations between seed characteristics seed structure and
texture of cooked quinoa have not been performed
Beside the physical properties of seed the seed composition will influence the texture as
well Protein and starch are the major components in quinoa while their correlation to texture
has not been studied Starch characteristics and structures significantly influence the texture of
the end product Starch granules of quinoa is very small (1-2μm) compared to that of rice and
barley (Tari et al 2003) Quinoa starch is lower in amylose content (11 of starch) (Ahamed
1996) which may yield the hard texture Chain length of amylopectin also influences hardness of
food product (Ong and Blanshard 1995) In sum the influence of quinoa seed composition and
characteristics on cooked product should be studied
In addition to seed quality and characteristics the sensory attributes of quinoa are also
significant as they influence consumer acceptance and the application of the quinoa variety
However there is a lack of lexicon to describe the sensory attributes of cooked quinoa Rice is
considered as a model when studying quinoa sensory attributes because they are cooked in
similar ways The lexicon of cooked rice were developed and defined in the study of Champagne
3
et al (2004) Sewer floral starchygrain hay-likemusty popcorn green beans sweet taste
sour and astringent were among those attributes
Consumer acceptance is of great interested to breeders farmers and the food industry
Acceptability of quinoa bread was studied by Rosell et al (2009) and Chlopicka et al (2012)
Gluten free quinoa spaghetti (Chillo et al 2008) and dark chocolate with 20 quinoa
(Schumacher et al 2010) were evaluated using a sensory panel However cooked quinoa the
most common way of consuming quinoa has not been studied for its sensory properties and
consumer preference Additionally consumer acceptance of quinoa may be influenced by the
panelistsrsquo demographic such as origin food culture familiarity with less common grains and
quinoa and opinion of a healthy diet Furthermore compared to instrumental tests sensory
evaluation tests are generally more expensive and time consuming hence correlations of sensory
panel and instrumental data are of interest If correlations exist instrumental analyses can be
used to substitute or complement sensory panel evaluation
Based on the above discussion this dissertation focused on the study of seed
characteristics quality and texture of cooked quinoa and starch characteristics among various
quinoa varieties Seed quality under saline soil conditions was also investigated To develop the
sensory profiles of cooked quinoa a trained panel developed and validated a lexicon for cooked
quinoa while a consumer panel evaluated their acceptance of different quinoa varieties From
these data the drivers of consumer liking were determined
The dissertation is divided into 7 chapters Chapter 1 is an introduction of the topic and
overall objectives of the studies Chapter 2 provides a literature review of recent progress in
4
quinoa studies including quinoa seed structure and compositions physical properties flour
properties health benefits and quinoa products Chapter 3 was published in Journal of Food
Science under the title of lsquoEvaluation of texture differences among varieties of cooked quinoarsquo
The objectives of Chapter 3 were to study the texture difference among varieties of cooked
quinoa and evaluate the correlation between the texture and the seed characters and
composition cooking process flour pasting properties and thermal properties
Chapter 4 includes the manuscript entitled lsquoQuinoa starch characteristics and their
correlation with texture of cooked quinoarsquo The objectives of Chapter 4 were to determine starch
characteristics of quinoa among different varieties and investigate the correlations between the
starch characteristics and cooking quality of quinoa
Chapter 5 has been submitted to Frontier in Plant Science under the title lsquoQuinoa seed
quality response to sodium chloride and sodium sulfate salinityrsquo In Chapter 5 quinoa seed
quality grown under salinity stress was assessed Four quinoa varieties were grown under six
salinity treatments and two levels of fertilization and then quinoa seed quality characteristics
such as protein content seed hardness and seed density were evaluated
Chapter 6 is the manuscript entitled lsquoLexicon development and sensory attributes of
cooked quinoarsquo In Chapter 6 a lexicon of cooked quinoa was developed using a trained panel
The lexicon provided descriptions of the sensory attributes of aroma tasteflavor texture and
color with references developed for each attribute The trained panel then applied this lexicon to
the evaluation of 16 field trial quinoa varieties from WSU and 5 commercial quinoa samples
from Bolivia and Peru A consumer panel also evaluated their acceptance of 6 selected quinoa
5
samples Using data from the trained panel and the consumer panel the key sensory attributes
driving consumer liking were determined Finally Chapter 7 presents the conclusions and
recommendations for future studies
6
References
Nuntildeez de Acro Chapter 12 Quinoarsquos calling In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 211 ndash 25
Ahamed NT Singhal RS Kulkarni PR Pal M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 31 99-103
Ando H Chen Y Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food Components in
Fractions of Quinoa Seed Food Sci Technol Res 8(1) 80-4
Carimentrand A Baudoin A Lacroix P Bazile D Chia E 2015 Chapter 41 International
quinoa trade In D Bazile D Bertero and C Nieto editors State of the Art Report of
Quinoa in the World in 2013 Rome FAO amp CIRAD p 316 ndash 29
Champagne ET Bett-Garber KL McClung AM Bergman C 2004 Sensory characteristics of
diverse rice cultivars as influenced by genetic and environmental factors Cereal Chem 81
237-43
Chillo S Civica V Iannetti M Mastromatteo M Suriano N Del Nobile M 2010 Influence of
repeated extrusions on some properties of non-conventional spaghetti J Food Eng 100 329-
35
Chlopicka J Pasko P Gorinstein S Jedryas A Zagrodzki P 2012 Total phenolic and total
flavonoid content antioxidant activity and sensory evaluation of pseudocereal breads LWT-
Food Sci Technol 46 548-55
7
Garcia M Raes D Allen R Herbas C 2004 Dynamics of reference evapotranspiration in the
Bolivian highlands (Altiplano) Agr Forest Meteorol 125(1) 67-82
James LEA 2009 Quinoa (Chenopodium quinoa Willd) composition chemistry nutritional
and functional properties Adv Food Nutr Res 58 1-31
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine structure of amylopectin J Cereal Sci 21 251-60
Perdon AA Siebenmorgen TJ Buescher RW Gbur EE 1999 Starch retrogradation and texture
of cooked milled rice during storage J Food Sci 64 828-32
Prego I Maldonado S Otegui M 1998 Seed structure and localization of reserves in
Chenopodium quinoa Ann Bot 82(4) 481-8
Ramesh M Ali SZ Bhattacharya KR1999 Structure of rice starch and its relation to cooked-
rice texture Carbohydr Polym 38 337-47
Rosell CM Cortez G Repo-Carrasco R 2009 Bread making use of Andean crops quinoa
kantildeiwa kiwicha and tarwi Cereal Chem 86 386-92
Sahin S Sumnu SG 2006 Physical properties of foods Springer Science amp Business Media
P39 ndash 109
Schumacher AB Brandelli A Macedo FC Pieta L Klug TV de Jong EV 2010 Chemical and
sensory evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J
Food Sci Technol 47 202-6
8
Tari TA Annapure US Singhal RS Kulkarni PR 2003 Starch-based spherical aggregates
screening of small granule sized starches for entrapment of a model flavouring compound
vanillin Carbohydr Polym 53 45-51
USDA US Department of Agriculture 2015a Peru Quinoa outlook Access from
httpwwwfasusdagovdataperu-quinoa-outlook
9
Chapter 2 Literature Review
Introduction
Quinoa (Chenopodium quinoa Willd) is a dicotyledonous pseudocereal from the Andean
region of South America The plant belongs to a complex of allotetraploid taxa (2n = 4x = 36)
which includes Chenopodium berlandieri subsp berlandieri Chenopodium berlandieri subsp
nuttalliae Chenopodium hircinum and Chenopodium quinoa (Gomez-Pando 2015 Matanguihan
et al 2015) Closely related species include the weed lambsquarter (Chenopodium album)
amaranth (Amaranth palmeri) sugar beet (Beta vulgaris L) and spinach (Spinacea oleracea L)
(Maughan et al 2004) Quinoa plant is C3 specie with 90 self-pollenating (Gonzalez et al
2011) Quinoa was domesticated approximately 5000 ndash 7000 years ago in the Lake Titicaca area
in Bolivia and Peru (Gonzalez et al 2015) Quinoa produces small oval-shaped seeds with a
diameter of 2 mm and a weight of 2 g ndash 46 g 1000-seed (Wu et al 2014) The seed color varies
and can be white yellow orange red purple brown or gray White and red quinoas are the most
common commercially available varietals in the US marketplace (Data from online resources
and local stores in Pullman WA) With such small seeds quinoa provides excellent nutritional
value such as high protein content balanced essential amino acids high proportion of
unsaturated fatty acids rich vitamin B complex vitamin E and minerals antioxidants such as
phenolics and betalains and rich dietary fibers (Wu 2015) For these reasons quinoa is
recognized as a ldquocompleterdquo food (Taverna et al 2012)
10
This chapter reviewed publications in quinoa varieties global development seed
structure and constituents quinoa health benefits physical properties and thermal properties
quinoa flour characteristics processing and quinoa products
Quinoa varieties
There are 16422 quinoa accessions or genetypes conserved worldwide 14502 of which
are conserved in genebanks from the Andean region (Rojas et al 2013) Bolivia and Peru
manage 13023 quinoa accessions (80 of world total accessions) in 140 genebanks (Rojas and
Pinto 2015)
Based on genetic diversity adaptation and morphological characteristics five ecotypes
of quinoa have been identified in the Andean region including valley quinoa Altiplano quinoa
salar quinoa sea level quinoa and subtropical quinoa (Tapia et al 1980) The sea-level ecotype
or Chilean lowland ecotype is the best adapted to temperate climate and high summer
temperature (Peterson and Murphy 2015a)
Adaptation
Quinoa has shown excellent adaptation to marginal or extreme environments and such
adaptation was summarized by Gonzalez et al (2015) Quinoa growing areas range from sea
level to 4200 masl (meters above sea level) with growing temperature rangeing from -4 to 38 ordmC
The plant has adapted to drought-stressed environments but can also grow in areas with
humidity ranging from 40 to 88 Quinoa can grow in marginal soil conditions such as dry
(Garcia et al 2003) infertile (Sanchez et al 2003) and with wide pH range from acidic to basic
(Jacobsen and Stolen 1993) Quinoa has also adapted to high salinity soil (equal to sea salt level
11
or 40 dSm) (Koyro and Eisa 2008 Hariadi et al 2011 Peterson and Murphy 2015b)
Furthermore quinoa has shown tolerance to frost at -8 to -4 ordmC (Jacobsen et al 2005)
Even though quinoa varieties are remarkably diverse and able to adapt to extreme
conditions time and resources are required to breed the high-yielding varieties that are adapted
to regional environments in North America Challenges to achieving strong performance include
yield waterlogging pre-harvest sprouting weed control and tolerance to disease insect pests
and animal stress (Peterson and Murphy 2015a) The breeding work not only needs the effort
from breeders and researchers but also demands the participation and collaboration of local
farmers
In addition to being widely grown in South America quinoa has also recently been
grown in North America Europe Australia Africa and Asia In US quinoa cultivation and
breeding started in the 1980s by the efforts from seed companies private individuals and
Colorado State University (Peterson and Murphy 2015a) Since 2010 Washington State
University has been breeding quinoa in the Pacific Northwest to suit the diverse environmental
conditions including rainfall and temperature Peterson and Murphy (2015a) found the major
challenges in North America included heat susceptibility downy mildew (Plasmopara viticola)
saponin removal weed stress and insect stress (such as aphids and Lygus sp)
With high nutritional value quinoa is recognized as significant in food security and
treating malnutrition issue in developing countries (Rojas 2011) Maliro and Guwela (2015)
reviewed quinoa breeding in Africa Initial experiments showed quinoa can grow well in Malawi
and Kenya in both warm and cool areas The quinoa grain yields in Malawi and Kenya are 3-4
12
tonha which are comparable to the yields in South America However the challenge remains to
adopt quinoa into the local diet and cultivate a quinoa consuming market
Physical Properties of Quinoa
Physical properties of seed refer to seed morphology size gravimetric properties
(weight density and porosity) aerodynamic properties and hardness which are critical to
technology and equipment designed for post-harvest process such as seed cleaning
classification aeration drying and storage (Vilche et al 2003)
The quinoa seed is oval-shaped with a diameter of approximately 18 to 22 mm (Bertero
et al 2004 Wu et al 2014) Mean 1000-seed weight of quinoa is around 27 g (Bhargava et al
2006) and a range of 15 g to 45 g has been observed among varieties (Wu et al 2014)
Commercial quinoa from Bolivia tends to have higher 1000-seed weight of 38 g to 45 g
Additionally bulk density ranges from 066 gmL to 075 gmL in most varieties (Wu et al
2014) Porosity refers to the fraction of space in bulk seed which is not occupied by the seed
(Thompson and Isaac 1976) The porosity of quinoa is 23 (Vilche et al 2003) while that of
rice is 50 to 60 (Kunze et al 2004)
Terminal velocity is the air velocity at which seeds remain in suspension This parameter
is important in cleaning quinoa to remove impurities such as dockage hollow and immature
kernels and mixed weed seeds Vilche et al (2003) reported the terminal velocity of 081 ms-1
while the value of rice was 6 ms-1 to 77 ms-1 (Razavi and Farahmandfar 2008)
Seed hardness or crushing strength is used as a rough estimation of moisture content in
rice (Kunze et al 2004) The hardness of quinoa seed can be tested using a texture analyzer (Wu
13
et al 2014) A stainless cylinder (10 mm in diameter) compressed one quinoa seed to 90 strain
at the rate of 5 mms Because of hardness variation among individual seeds at least six
measurements were required Among the thirteen quinoa samples that were tested hardness
ranged from 58 kg to 110 kg (Wu et al 2014)
Quinoa Seed Structure
Grain structure of quinoa was described in detail by Taylor and Parker (2002) On the
outside of grain is a perianth which can be easily removed during cleaning or rubbing
Sometimes betalain pigments concentrate on this perianth layer and the seed shows bright purple
or golden colors However this color will disappear with the removal of the perianth Inside the
perianth is two-layered pericarp with papillose surface (Figure 1) Beneath the pericarp a seed
coat or episperm is located The seed coat can be white yellow orange red brown or black
Red and white quinoa share the largest market share with consumers exhibiting increasing
interest in brownblack mixed products such as lsquoCalifornia Tricolorrsquo(data from Google
Shopping Amazon and local stores in Pullman WA)
The main seed is enveloped in outside layers and the structure was depicted by Prego et
al (1998) (Figure 2) The embryo (two cotyledons and radicle) coils around a center pericarp
which occupies ~40 of seed volume (Fleming and Galwey 1998) Protein and lipid bodies are
primarily present in the embryo whereas starch granules provide storage in the thin-walled
perisperm Minerals of phosphorus potassium and magnesium are concentrated in phytin
globoids located in the embryo and calcium is located in the pericarp (Konishi et al 2004)
Quinoa Seed Constituents
14
Quinoa is known as a lsquocomplete foodrsquo (James 2009) The seed composition was recently
reviewed by Wu (2015) and Maradini Filho et al (2015) In sum the high nutritional value of
quinoa arises from its high protein content complete and balanced essential amino acids high
proportion of unsaturated fatty acids high concentrations of vitamin B complex vitamin E and
minerals and high phenolic and betalain content
A protein range of 12 to 17 in quinoa has been reported by most studies (Rojas et al
2015) This protein content is higher than wheat (8 to 14 ww) (Halverson and Zeleny 1988)
and rice (4 - 105 ww) (Champagne et al 2004) Additionally quinoa contains all essential
amino acids at concentrations exceeding the suggested requirements from FAOWHO (Table 1)
Quinoa is also gluten-free because it is lacking in prolamins Prolamins are a group of
storage proteins that are rich in proline Prolamins can interact with water and form the gluten
structure which cannot be tolerated by those with celiac disease (Fasano et al 2003) Quinoa and
rice both contain low prolamins (72 and 89 of total protein respectively) and are
considered gluten-free crops Prolamins in wheat (called gliadin) comprise 285 of its total
protein and in maize this concentration of prolamin is 245 (Koziol 1992)
The protein quality of quinoa protein was reported by Ruales and Nair (1992) In raw
quinoa the net protein utilization (NPU) was 757 biological value (BV) was 826 and
digestibility (TD) was 917 all of which were slightly lower than those of casein The
digestibility of quinoa protein is comparable to that of other high quality food proteins such as
soy beans and skim milk (Taylor and Parker 2002) The Protein Efficiency Ratio (PER) in
quinoa ranges from 195 to 31 and is similar to that of casein (Gross et al 1989 Guzmaacuten-
15
Maldonado and Paredes-Lopez 2002) Regarding functional properties of quinoa protein isolates
Eugenia et al (2015) found Bolivian quinoa exhibited the highest thermal stability oil binding
capacity and water binding capacity at acidic pH The Peruvian samples showed the highest
water binding capacity at basic pH and the best foaming capacity at pH 5
Quinoa starch content ranges from 58 to 64 of the dry seed weight (Vega‐Gaacutelvez et
al 2010) Quinoa possesses a small granule size of 06 to 2 μm similar to that of amaranth (1 to
2 μm) and much smaller than those of other grains such as rice wheat oat barley and
buckwheat (2 to 36 μm) (Lindeboom et al 2004) The amylose content in quinoa starch tends to
be lower than found in common grains A range of 3 to 20 was reported by Lindeboom et al
(2005) whereas amylose content is around 25 in cereals As in most cereals quinoa starch is
type A in X-ray diffraction pattern (Ando et al 2002) Li et al (2016) found significant variation
among 26 commercial quinoa samples in the physicochemical properties of starch such as gel
texture thermal and pasting parameters which were strongly affected by apparent amylose
content
Quinoa lipids comprise 55 to 71 of dry seed weight in most reports (Maradini Filho
et al 2015) Ando et al (2002) found quinoa (cultivar Real TKW from Bolivia) perisperm and
embryo contained 50 and 102 total fatty acids respectively Among these fatty acids
unsaturated fatty acids such as oleic linoleic and linolenic comprised 875 Ogungbenle
(2003) reported the properties of quinoa lipids The values of acid iodine peroxide and
saponification were 05 54 24 and 192 respectively
16
Quinoa micronutrients of vitamins and minerals and the relative lsquoreference daily intakersquo
are summarized in Table 2 and 3 respectively Compared to Daily Intake References quinoa
provides a good source of Vitamin B1 B2 and B9 and Vitamin E as well as minerals such as
magnesium phosphorous iron and copper
Quinoa is one of the crops representing diversity in color including white vanilla
yellow orange red brown gray and dark Besides the anthocyannins in dark quinoa (Paśko et
al 2009) the major pigment in quinoa is betalain primarily presenting in seed coat and the
compounds can be subdivided into red-violet betacyannins and yellow-orange betaxanthins
(Tang et al 2015) Betalain is a water-soluble pigment which is permitted quantum satis as a
natural food colorant and applied in fruit yogurt ice cream jams chewing gum sauces and
soups (Esatbeyoglu et al 2015) Additionally betalain potentially offers health benefits such as
antioxidant activity anti-inflammation activity preventing low-density lipoprotein (LDL)
oxidation and DNA damage (Benavente-Garcia and Castillo 2008 Esatbeyoglu et al 2015)
Saponins
Saponins are compounds on the seed coat of quinoa that confer a bitter taste The
compounds are considered to be a defense system against herbivores and pathogens Regarding
chemical structure saponins are a group of glycosides consisting of a hydrophilic carbohydrate
chain (such as arabinose glucose galactose xylose and rhamnose) and a hydrophobic aglycone
(Kuljanabhagavad and Wink 2009) Chemical structures of aglycones were summarized by
Kuljanabhagavad and Wink (2009)
17
Saponins have been considered as anti-nutrient because of haemolytic activity which
refers to the breakdown of red blood cells (Khalil and El-Adawy 1994) However saponins
exhibited health benefit functions such as anti-inflammation (Yao et al 2009) antibacterial
antimicrobial activity (Killeen et al 1998) anti-tumor activity (Shao et al 1996) and
antioxidant activity (Guumllccedilin et al 2006) Furthermore saponins have medicinal use Sun et al
(2009) reported saponins can activate immune system and were used as vaccine adjuvants
Saponins also exhibited anti-cancer activity (Man et al 2010)
Even though saponins have potential health benefits their bitter taste is not pleasant to
consumers To address the bitterness found in bitter quinoa varieties (gt 011 saponin content)
sweet quinoa varieties were bred through conventional genetic selection to contain a lower
saponin content (lt 011 saponin content) For instance lsquoSajamarsquo lsquoKurmirsquo lsquoAynoqarsquo
lsquoKosunarsquo and lsquoBlanquitarsquo in Bolivia lsquoBlanca de Juninrsquo in Peru and lsquoTunkahuanrsquo in Ecuador are
considered sweet quinoa varieties (Quiroga et al 2015) Unfortunately varieties from Bolivia
Peru and Ecuador do not adapt to temperate climates such as those found in the Pacific
Northwest in US and Europe A sweet variety called lsquoJessiersquo exhibits acceptable yield in Pacific
Northwest and has a great market potential Further development of sweet quinoa varieties
adapted to local climate will happen in near future
To remove saponins both dry and wet processing methods have been developed The wet
method or moist method refers to washing quinoa while rubbing the grain with hands or by a
stone Repo-Carrasco et al (2003) suggested the best washing conditions of 20 min soaking 20
min stirring with a water temperature of 70 degC The wet method becomes costly due to the
required drying process Additionally quinoa grain may begin to germinate during wet cleaning
18
The dry method or abrasive dehulling uses mechanical abrasion to polish the grain and
remove the saponins A dehulling process was reported by Reichert et al (1986) using Tanential
Abrasive Dehulling Device (TADD) and removal of 6 - 15 of kernel was required to reduce
the saponins content to lower than 011 Additionally a TM-05 Taka-Yama testing mill was
used in the quinoa pearling process (to 20 - 30 pearling degree) (Goacutemez-Caravaca et al
2014) The dry method is relatively cheaper than wet method and does not generate saponin
waste water The saponin removal efficiency of the dry and washing methods were reported to be
87 and 72 respectively (Reichert et al 1986 Gee et al 1993) A combination of dry and wet
methods was recommended to obtain the efficient cleaning (Repo-Carrasco et al 2003)
Since quinoa is such an expensive crop a 25 to 30 weight lost during the cleaning
process represents a substantial loss on an industrial scale In addition mineral phenolic and
fiber content may dramatically decrease during processing resulting in a loss of nutritional
value Hence cleaning process should be further optimized to reach lower grain weight loss
while maintain an efficient saponins elimination
Removed saponins can be utilized as side products Since saponins also have excellent
foaming property they can be applied in cosmetics and foods as foam-stabilizing and
emulsifying agents (Yang et al 2010) detergents (Chen et al 2010) and preservatives
(Taormina et al 2006)
Saponin content is important to analyze since it highly influences the taste of quinoa
Traditionally the afrosimetric method or foam method was used to estimate saponins content In
this method saponon content is calculated from foam height after shaking quinoa and water
19
mixture for a specific time (Koziol 1991) This afrosimetric method is fast and affordable and
can be used by farmers as a quick estimation of saponin content however the method is not very
accurate The foam stability varies among samples A more accurate method was developed
using Gas Chromatography (GC) (Ridout et al 1991) Using this method quinoa flour was first
defatted using a Soxhlet extraction and then hydrolyzed in reflux for 3 h with a methanol
solution of HCl (2 N) The hydrolysis product sapogenins were extracted with ethyl acetate and
derivatized with bis-(trimethylsilyl) trifluoroacetamide (BSTFA) and dry pyridine and then
tested using GC Generally GC method is a more solid and accurate method compared to foam
method however GC also requires high capital investment as well as long and complex sample
preparation For quinoa farmers and food manufactures fast and affordable methods to test
saponins content in quinoa need to be developed
Saponins have been an important topic in quinoa research Future studies in this area can
include 1) breeding and commercialization of saponin-free or sweet quinoa varieties with high
yield and high agronomy performance (resistance to biotic and abiotic stresses) 2) development
of quick and low cost detection method of saponin content and 3) application of saponin in
medicine foods and cosmetics can be further explored
Health benefits
Simnadis et al (2015) performed a meta-analysis of 18 studies which used animal models
to assess the physiological effects associated with quinoa consumption From these studies
purported physiological effects of quinoa consumption included decreased weight gain
improved lipid profile (decrease LDL and cholesterol) and improved capacity to respond to
20
oxidative stress Simnadis et al (2015) pointed out that the presence of saponins protein and
20-hydroxyecdysone (affects energy homeostasis and intestinal fat absorption) contributed to
those benefit effects
Furthermore Ruales et al (2002) found increased plasma levels of IGF-1 (insulin-like
growth factor) in 50-65 month-old boys after consuming a quinoa infant food for 15 days This
result implicated the potential of quinoa to reduce childhood malnutrition In another study of 22
students (aged 18 to 45) the daily consumption of a quinoa cereal bar for 30 days significantly
decreased triglycerides cholesterol and LDL compared to those parameters prior to quinoa
consumption These results suggest that quinoa intake may reduce the risk of developing
cardiovascular disease (Farinazzi-Machado et al 2012) De Carvalho et al (2014) studied the
influence of quinoa on over-weight postmenopausal women Consumption of quinoa flakes (25
gd for 4 weeks) was found to reduce serum triglycerides and TBARS (thiobarbituric acid
reactive substances) and increase GSH (glutathione) and urinary excretion of enterolignans
compared to those indexes before consuming quinoa flakes
Quinoa flour properties
Functional properties of quinoa flour were determined by Ogungbenle (2003) Quinoa
flour has high water absorption capacity (147) and low foaming capacity (9) and stability
(2) Water absorption capacity was determined by the volume of water retained per gram of
quinoa flour during 30-min mixing at 24 ordmC (Beuchat 1977) The water absorption of quinoa was
higher than that of fluted pumpkin seed (85) soy flour (130) and pigeon pea flour (138)
which implies the potential use of quinoa flour in viscous foods such as soups doughs and
21
baked products Additionally foaming capacity was determined by the foam volumes before and
after whipping of 8 protein solution at pH 70 (Coffmann and Garciaj 1977) Then foam
samples were inverted and dripped though 2 mm wire screen in to beakers The foam stability
was determined by the weight of liquid released from foam after a specific time and the original
weight of foam (Coffmann and Garciaj 1977) Furthermore minimum protein solubility was
observed at pH 60 similar to that of pearl millet and higher than pigeon pea (pH 50) and fluted
pumpkin seed (pH 40) Relatively high solubility of quinoa protein in acidic condition implies
the potential application of quinoa protein in acidic food and carbonated beverages
Wu et al (2014) studied flour viscosity among 13 quinoa samples with large variations
reported among samples The ranges of peak viscosity final viscosity and setback were 59
RVU ndash 197 RVU 56 RVU ndash 203 RVU and -62 RVU ndash 73 RVU respectively which were
comparable to those of rice flour (Zhou et al 2003) Flour viscosity significantly influence
texture of quinoa and rice (Champagne et al 1998 Wu et al 2014)
Ruales et al (1993) studied processing influence on the physico-chemical characteristics
of quinoa flour The process included cooking and autoclaving of the seeds drum drying of
flour and extrusion of the grits Autoclaved quinoa samples exhibited the lowest degree of starch
gelatinization (325) whereas precookeddrum dried quinoa samples were 974 Higher
polymer degradation was found in the cooked samples compared to the autoclaved samples
Water solubility in cooked samples (54 to 156) and autoclaved samples (70 to 96) increased
with the processing time (30 to 60 min cooking and 10 to 30 min autoclaving)
Thermal Properties of quinoa
22
Thermal properties of quinoa flour (both starch and protein) have been determined using
Differential Scanning Calorimetry (DSC) (Abugoch et al 2009) A quinoa flour suspension was
prepared in 20 (ww) concentration The testing temperature was raised from 27 to 120 degC at a
rate of 10 degCmin Two peaks in the DSC graph referenced the starch gelatinization temperature
at 657 degC and protein denaturalization at 989 degC Enthalpy refers to the energy required to
complete starch gelatinization or protein denaturazition In the study of Abugoch et al (2009)
the enthalpy was 59 Jg for starch and 22 Jg for proteins in quinoa
Product development with quinoa
Quinoa has been used in different products such as spaghetti bread and cookies to
enhance nutritional value including a higher protein content and more balanced amino acid
profile Chillo et al (2008) evaluated the quality of spaghetti from amaranth and quinoa flour
Compared to durum semolina spaghetti the spaghetti with amaranth and quinoa flour exhibited
equal breakage susceptibility higher cooking loss and lower instrumental stickiness The
sensory acceptance scores were not different from the control The solid loss weight increase
volume increase adhesiveness and moisture of a corn and quinoa mixed spaghetti were 162thinspg
kgminus1 23 times 26 times 20907thinspg and 384thinspg kgminus1 respectively (Caperuto et al 2001)
Schoenlechner et al (2010) found the optimal combination of 60 buckwheat 20 amaranth
and 20 quinoa yielded an improved dough matrix compared to other flour combinations With
the addition of 6 egg white powder and 12 emulsifier (distilled monoglycerides) this gluten-
free pasta exhibited acceptable firmness and cooking quality compared to wheat pasta
23
Stikic et al (2012) added 20 quinoa seeds in bread formulations which resulted in the
similar dough development time and stability compared to those of wheat dough even though
the bread specific volume was lower (63 mLg) compared to wheat bread (67 mLg) The
protein content of bread increased by 2 (ww) and sensory characteristics were lsquoexcellentrsquo as
evaluated by five trained expert panelists Iglesias-Puig et al (2015) found 25g100 g quinoa
flour substitution in wheat bread showed small depreciation in bread quality in terms of loaf
volume crumb firmness and acceptability whereas the nutritional value increased in dietary
fiber minerals protein and healthy fats Rizzello et al (2016) selected strains (lactic acid
bacteria) to develop a quinoa sourdough A wheat bread with 20 (ww) quinoa sourdough
exhibited improved nutritional (such as protein digestibility and quality) textural and sensory
features Quinoa leaves were also applied to bread making (Świeca et al 2014) With the
replacement of wheat flour by 1 to 5 (ww) quinoa leaves the bread crumb exhibited increased
firmness cohesiveness and gumminess Antioxidant activity and phenolic contents both
significantly increased compared to wheat bread
Pagamunici et al (2014) developed three gluten-free cookies with rice and quinoa flour
with 15 26 and 36 (ww) quinoa flour proportions respectively The formulation with
36 quinoa flour had the highest alpha-linolenic acid and mineral content and the cookie
displayed excellent sensory characteristics as evaluated by 80 non-trained consumer panelists
Another study optimized a gluten-free quinoa formulation with 30 quinoa flour 25 quinoa
flakes and 45 corn starch (Brito et al 2015) The cookie was characterized as a product rich in
essential amino acids linolenic acid minerals and dietary fiber This cookie was among those
24
products using the highest quinoa flour content (55 ww) while still received acceptable
sensory scores
Repo-Carrasco-Valencia and Serna (2011) introduced an extrusion process in Peru
Quinoa flour was tempered to 12 moisture for extrusion During extrusion total and insoluble
dietary fiber decreased by 5 to 17 and 13 to 29 respectively whereas the soluble dietary
fiber significantly increased by 38 to 71 Additionally the radical scavenging activity was
also increased in extruded quinoa compared to raw quinoa
Schumacher et al (2010) developed a dark chocolate with addition of 20 quinoa An
improved nutritional value was observed in 9 (ww) increase in vitamin E 70 - 104
increases in amino acids of cysteine tyrosine and methionine This quinoa dark chocolate
received over 70 acceptance index from sensory panel
Gluten-free beer is of increasing interest in the market (Dezelak et al 2014) Ogungbenle
(2003) found quinoa has high D-xylose and maltose and low glucose and fructose content
suggesting its potential use in malted drink de Meo et al (2011) applied alkaline steeping to
pseudocereal and found its positive effects on pseudocereals malt production by increasing total
soluble nitrogen and free amino nitrogen Kamelgard (2012) patented a method to create a
quinoa-based beverage fermented by a yeast Saccharomyces cerevisiae The beverage can be
distilled and aged to form gluten-free liquor Dezelak et al (2014) processed a quinoa beer-like
beverage (fermented with Saccharomyces pastorianus TUM 3470) resulting in a product with a
nutty aroma low alcohol content and rich in minerals and amino acids However further
development of the brewing procedure was necessary since the beverage showed a less attractive
25
appearance (near to black color and greyish foam) and astringent mouthfeel Compared to barley
brewing attributes of quinoa exhibited lower malt extracts longer saccharification times higher
values in total protein fermentable amino nitrogen content and iodine test
Processing quinoa grain to dried edible product and sweet quinoa product were developed
by Scanlin and Burnett (2010) The edible quinoa product was processed through pre-
conditioning (abrasion and washing) moist heating (steam cooking and pressure cooking) dry
heating (baking toasting and dehydrating) and post-production treatment As for sweet quinoa
product germination and malting processing were applied Caceres et al (2014) patented a
process to extract peptides and maltodextrins from quinoa flour and the extracts were applied in
a gel-format food as a supplement during and after physical activity
26
References
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2013-20
Abugoch LE Romero N Tapia CA Silva J Rivera M 2008 Study of some physicochemical
and functional properties of quinoa (Chenopodium quinoa Willd) protein isolates J Agric
Food Chem 56(12) 4745-50
Ando H Chen Y Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food Components in
Fractions of Quinoa Seed Food Sci Technol Res 8(1) 80-4
Benavente-Garcia O Castillo J 2008 Update on uses and properties of citrus flavonoids new
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56(15) 6185-205
Bertero HD de la Vega AJ Correa G Jacobsen SE Mujica A 2004 Genotype and genotype-
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Crops Res 89(2ndash3) 299-318
Beuchat LR 1977 Functional and electrophoretic characteristics of succinylated peanut flour
protein J Agric Food Chem 25(2) 258-61
Bhargava A Shukla S Rajan S Ohri D 2006 Genetic diversity for morphological and quality
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167-73
27
Brito IL de Souza EL Felex SSS Madruga MS Yamashita F Magnani M 2015 Nutritional
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73
Caceres JIE Calderon PD Lira FO 2014 Method for the formulation of a gel-format foodstuff
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101
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
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Paul MN American Association of Cereal Chemists Inc p 88 ndash 9
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28
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101-7
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Deželak M Zarnkow M Becker T Košir IJ 2014 Processing of bottom-fermented gluten-free
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Farinazzi-Machado FMV Barbalho SM Oshiiwa M Goulart R Pessan Junior O 2012 Use of
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cardiovascular diseases Food Sci Technol(Campinas) 32(2) 239-44
Fasano A Berti I Gerarduzzi T Not T Colletti RB Drago S Hill ID 2003 Prevalence of celiac
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Fleming JE Galwey NW 1998 Quinoa (Chenopodium quinoa Willd) nutritional quality and
technological aspects as human food In Belton PS Taylor JRN editors Increasing the
29
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Friedman M Brandon DL 2001 Nutritional and health benefits of soy proteins J Agric Food
Chem 49(3)1069-86
Garcia M Raes D Jacobsen SE 2003 Evapotranspiration analysis and irrigation requirements
of quinoa (Chenopodium quinoa) in the Bolivian highlands Agr Water Manage 60(2) 119-
34
Gee JM Price KR Ridout CL Wortley GM Hurrell RF Johnson IT 1993 Saponins of quinoa
(Chenopodium quinoa) effects of processing on their abundance in quinoa products and their
biological effects on intestinal mucosal tissue J Sci Food Agric 63(2) 201-9
Goacutemez-Caravaca AM Iafelice G Verardo V Marconi E Caboni MF 2014 Influence of
pearling process on phenolic and saponin content in quinoa (Chenopodium quinoa Willd)
Food Chem 157 174-8
Gomez-Pando L 2015 Chapter 6 Quinoa breeding In Murphy KM Matanguihan J editors
Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p
87 ndash 97
Gonzaacutelez JA Bruno M Valoy M Prado FE 2011 Genotypic variation of gas exchange
parameters and leaf stable carbon and nitrogen isotopes in ten quinoa cultivars grown under
drought J Agron Crop Sci 197(2) 81-93
30
Gonzaacutelez JA Eisa SSS Hussin SAES and Prado FE 2015 Chapter 1 Quinoa An Incan Crop
to Face Global Changes in Agriculture In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 182-6
Graf BL Rojas-Silva P Rojo LE Delatorre-Herrera J Baldeoacuten ME Raskin I 2015 Innovations
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Comp Rev Food Sci Food Safety 14(4) 431-45
Gross R Koch F Malaga I de Miranda A Schoeneberger H Trugo L 1989 Chemical
composition and protein quality of some local Andean food sources Food Chem 34(1) 25-
34
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Guzmaacuten-Maldonado S Paredes-Lopez O 2002 Functional products of plants indigenous to
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Maguer ML editors Functional foods Biochemical and processing aspects CRC Press p
293-328
Halverson J Zeleny L 1988 Chapter 2 Criteria of wheat quality In Pomeranz Y editor
Wheat Chemistry and Technology 3rd edition St Paul MN American Association of
Cereal Chemists Inc p 25 ndash 6
31
Hariadi Y Marandon K Tian Y Jacobsen SE Shabala S 2011 Ionic and osmotic relations in
quinoa (Chenopodium quinoa Willd) plants grown at various salinity levels J Exp Bot
62(1) 185-93
Iglesias-Puig E Monedero V Haros M 2015 Bread with whole quinoa flour and bifidobacterial
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71-7
Jacobsen SE Monteros C Christiansen J Bravo L Corcuera L Mujica A 2005 Plant responses
of quinoa (Chenopodium quinoa Willd) to frost at various phenological stages Eur J Agron
22(2) 131-9
Jacobsen SE Stoslashlen O 1993 Quinoa-morphology phenology and prospects for its production as
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and functional properties Adv Food Nutr Res 58 1-31
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Google Patents
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for their in vivo impact J Agric Food Chem 46(8) 3178-86
32
Konishi Y Hirano S Tsuboi H Wada M 2004 Distribution of minerals in quinoa
(Chenopodium quinoa Willd) seeds Biotechnol Appl Biochem 68(1) 231-4
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of Chenopodium quinoa Willd Plant Soil 302(1-2) 79-90
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Chenopodium quinoa Willd Phytochem Rev 8(2) 473-90
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In Champagne ET editor Rice Chemistry and Technology 3rd edition St Paul MN
American Association of Cereal Chemists Inc p 193 ndash 211
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328-38
Lindeboom N Chang PR Falk KC Tyler RT 2005 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2) 216-22
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4) 89-99
Man S Gao W Zhang Y Huang L Liu C 2010 Chemical study and medical application of
saponins as anti-cancer agents Fitoterapia 81(7) 703-14
33
Maradini Filho AM Pirozi MR Da Silva Borges JT Pinheiro SantAna HM Paes Chaves JB
Dos Reis Coimbra JS 2015 Quinoa nutritional functional and antinutritional aspects Crit
Rev Food Sci Nutr (just-accepted)
Matanguihan JB Jellen EN and Kolano A 2015 Chapter 7 Quinoa cytogenetics molecular
genetics and diversity In Murphy KM Matanguihan J editors Quinoa Improvement and
Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 109-24
Maughan PJ Bonifacio A Jellen EN Stevens MR Coleman CE Ricks M Mason SL Jarvis
DE Gardunia BW Fairbanks DJ 2004 A genetic linkage map of quinoa (Chenopodium
quinoa) based on AFLP RAPD and SSR markers Theor Appl Genet 109(6) 1188-95
de Meo B Freeman G Marconi O Booer C Perretti G Fantozzi P 2011 Behaviour of Malted
Cereals and Pseudo-Cereals for Gluten-Free Beer Production J Inst Brew 117(4) 541-6
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quinoa) flour Int J Food Sci Nutr 54(2) 153-8
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quinoa) flour Int J Food Sci Nutr 54(2) 153-8
Quiroga C Escalera R Aroni G Bonifacio A Gonzaacutelez JA Villca M Saravia R Ruiz A 2015
Chapter 31 Traditional processes and Technological Innovations in Quinoa Harvesting
Processing and Industrialization In D Bazile D Bertero and C Nieto editors State of the
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34
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containing the whole flour of a new quinoa cultivar J Brazil Chem Soc 25 219-28
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Peterson AJ Murphy KM 2015a Chapter 10 Quinoa Cultivation for Temperate North America
Considerations and Areas for Investigation In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 182-6
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sodium sulfate salinity Crop Sci 55(1) 331-8
Prego I Maldonado S Otegui M 1998 Seed structure and localization of reserves in
Chenopodium quinoa Ann Bot 82(4) 481-8
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nutritional quality of quinoa Cereal Chem 70(3)303-5
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rice grains Int Agrophys 22(4) 353-9
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471-5
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Repo-Carrasco-Valencia RAM Serna LA 2011 Quinoa (Chenopodium quinoa Willd) as a
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225-30
Repo-Carrasco R Espinoza C Jacobsen SE 2003 Nutritional value and use of the Andean crops
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2) 179-89
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and preliminary investigations into the effects of reduction by processing J Sci Food Agric
54(2) 165-76
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enhancing the nutritional textural and sensory features of white bread Food Microbiol 56 1-
13
Rojas W 2011 Quinoa an ancient crop to contribute to world food security Santiago Chile
FAO Oficina Regional para America Latina y el Caribe
Rojas W Pinto M Alanoca C Goacutemez-Pando L Leoacuten-Lobos P Alercia A Diulgheroff S
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Murphy KM Matanguihan J editors Quinoa Improvement and Sustainable Production
Hoboken NJ John Wiley amp Sons Inc p 128-30
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
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of quinoa flour (Chenopodium quinoa Willd) Starch - Staumlrke 45(1)13-9
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37
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crude saponins obtained from asparagus Cancer Lett 104(1) 31-6
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Stikic R Glamoclija D Demin M Vucelic-Radovic B Jovanovic Z Milojkovic-Opsenica D
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(Chenopodium quinoa Willd) as an ingredient in bread formulations J Cereal Sci 55(2)
132-8
Sun HX Xie Y Ye YP 2009 Advances in saponin-based adjuvants Vaccine 27(12) 1787-96
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Pseudocereals and less common cereals grain properties and utilization potential Springer
Science amp Business Media p 96-9
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comparison pycnometer T ASAE 10(5) 693-6
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cooked quinoa J Food Sci 79(11) 2337-45
Wu G Chapter 11 Nutritional properties of quinoa In Murphy KM Matanguihan J editors
Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc
p193 ndash 205
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term preservative efficacy of the saponins from J Food Drug Anal 18(3) 4417-25
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(Chenopodium quinoa Willd) Seeds in lipopolysaccharide-stimulated raw 2647
Macrophages Cells J Food Sci 79(5) 1018-23
40
Zhou Z Robards K Helliwell S Blanchard C 2003 Effect of rice storage on pasting properties
of rice flour Food Res Int 36(6) 625-34
41
Table 1-Essential amino acid of quinoa protein and FAOWHO suggested requirement (mgg protein)
Essential amino acid Quinoa protein a FAOWHO suggested requirement b
Histidine 258 18
Isoleucine 433 25
Leucine 736 55
Lysine 525 51
Methionine amp Cysteine 273 25
Phenylalanine amp Tyrosine 803 47
Threonine 439 27
Tryptophan 385 7
Valine 506 32
a) Abugoch et al (2008) b) Friedman and Brandon (2001)
42
Table 2-Quinoa vitamins content (mg100g)
Quinoa a-d Reference Daily Intake
Thianmin (B1) 029-038 15
Riboflavin (B2) 030-039 17
Niacin (B3) 106-152 20
Pyridoxine (B6) 0487 20
Folate (B9) 0781 04
Ascorbic acid (C) 40 60
α-Tocopherol (VE) (IU) 537 30
Β-Carotene 039 NR
a (Koziol 1992) b (Ruales and Nair 1993) c (Ranhotra et al 1993) d (USDA 2015)
43
Table 3-Quinoa minerals content (mgmg )
Whole graina RDI b
K 8257 NR
Mg 4526 400
Ca 1213 1000
P 3595 1000
Fe 95 18
Mn 37 NR
Cu 07 2
Zn 08 15
Na 13 NR
(aAndo et al 2002 bUSDA 2015)
44
Figure 1-Quinoa seed section and two-layered pericarp under perianth (Wu et al 2014)
45
Figure 2-Quinoa seed structure (Prego et al 1998)
(PE pericarp SC seed coat C cotyledons SA shoot apex H hypocotylradicle axis R radicle F funicle EN endosperm P perisperm Bar = 500 μm)
46
Chapter 3 Evaluation of Texture Differences among Varieties of
Cooked Quinoa
Published manuscript
Wu G Morris C F amp Murphy K M (2014) Evaluation of texture differences among
varieties of cooked quinoa Journal of Food Science 79(11) S2337-S2345
ABSTRACT
Texture is one of the most significant factors for consumersrsquo experience of foods Texture
differences of cooked quinoa were studied among thirteen different varieties Correlations
between the texture parameters and seed composition seed characteristics cooking quality flour
pasting properties and flour thermal properties were determined The results showed that texture
of cooked quinoa was significantly differed among varieties lsquoBlackrsquo lsquoCahuilrsquo and lsquoRed
Commercialrsquo yielded harder texture while lsquo49ALCrsquo lsquo1ESPrsquo and lsquoCol6197rsquo showed softer
texture lsquo49ALCrsquo lsquo1ESPrsquo lsquoCol6197rsquo and lsquoQQ63rsquo were more adhesive while other varieties
were not sticky The texture profile correlated to physical-chemical properties in different ways
Protein content was positively correlated with all the texture profile analysis (TPA) parameters
Seed hardness was positively correlated with TPA hardness gumminess and chewiness at P le
009 Seed density was negatively correlated with TPA hardness cohesiveness gumminess and
chewiness whereas seed coat proportion was positively correlated with these TPA parameters
Increased cooking time of quinoa was correlated with increased hardness cohesiveness
gumminess and chewiness The water uptake ratio was inversely related to TPA hardness
47
gumminess and chewiness RVA peak viscosity was negatively correlated with the hardness
gumminess and chewiness (P lt 007) breakdown was also negatively correlated with those TPA
parameters (P lt 009) final viscosity and setback were negatively correlated with the hardness
cohesiveness gumminess and chewiness (P lt 005) setback was correlated with the
adhesiveness as well (r = -063 P = 002) Onset gelatinization temperature (To) was
significantly positively correlated with all the texture profile parameters and peak temperature
(Tp) was moderately correlated with cohesiveness whereas neither conclusion temperature (Tc)
nor enthalpy correlated with the texture of cooked quinoa This study provided information for
the breeders and food industry to select quinoa with specific properties for difference use
purposes
Keywords cooked quinoa variety texture profile analysis (TPA) RVA DSC
Practical Application The research described in this paper indicates that the texture of different
quinoa varieties varies significantly The results can be used by quinoa breeders and food
processors
48
Introduction
Quinoa (Chenopodium quinoa Willd) a pseudocereal (Lindeboom et al 2007) is known as
a complete food due to its high nutritional value (Jancurovaacute et al 2009) Protein content of dry
quinoa grain ranges from 8 to 22 (Jancurovaacute et al 2009) Quinoa protein is high in nutritive
quality with an excellent balance of essential amino acids (Abugoch et al 2008) Quinoa is also a
gluten-free crop (Alvarez-Jubete et al 2010) Quinoa consumption in the US and Europe has
increased dramatically over the past decade but these regions rely on imports primarily from
Bolivia and Peru (Food and Agriculture Organization of the United Nations FAO 2013) For
these reasons greater knowledge of quinoa grain quality is needed
Quinoa is traditionally cooked as a whole grain similar to rice or milled into flour and made
into pasta and breads (Food and Agriculture Organization of the United Nations FAO 2013)
Quinoa can also be processed by extrusion drum-drying and autoclaving (Ruales et al 1993)
Commercial quinoa products include pasta bread cookies muffins cereal snacks drinks
flakes baby food and diet supplements (Ruales et al 2002 Del Castillo et al 2009 Cortez et al
2009 Demirkesen et al 2010 Schumacher et al 2010)
Texture is one of most significant properties of food that affects the consuming experience
Food texture refers to those qualities of a food that can be felt with the fingers tongue palate or
teeth (Vaclavik and Christian 2003) Cooked quinoa has a unique texture described as creamy
smooth and slightly crunchy (Abugoch 2009) Texture can be influenced by the seed structure
composition cooking quality and thermal properties However we know of no report which
documents the texture of cooked quinoa and the factors that affect it
49
Quinoa has small seeds compared to most cereals and seed size may affect the texture of
cooked quinoa Seed characteristics and structure are the significant factors potentially affecting
the textural properties of processed food Rousset et al (1995) indicated that the length and
lengthwidth ratio of rice kernels was associated with a wide range of texture attributes including
crunchy brittle elastic juicy pasty sticky and mealy which were determined by a sensory
panel The correlation between quinoa seed characteristics and cooked quinoa texture has not
been studied
Quinoa is consumed as whole grain without removing the bran unlike most rice and wheat
The insoluble fiber and non-starch polysaccharides in the seed coat can affect mouth feel and
texture Hence seed coat proportion may contribute to the texture of cooked quinoa Mohapatra
and Bal (2006) reported that the milling degree of rice positively influenced cohesiveness and
adhesiveness of cooked rice but was negatively correlated to hardness
Quinoa seed qualities such as the size hardness weight density and seed coat proportion
may influence the water binding capacity of seed during thermal processing thereby affecting
the texture of the cooked cereal (Fitzgerald et al 2003) Nevertheless correlations between seed
characteristics and texture of cooked quinoa have not been previously described
Seed composition may influence texture as well Higher protein content was reported to
cause reduced stickiness and harder texture of cooked rice (Ramesh et al 2000) Quinoa seeds
contain approximately 60 starch (Ando et al 2002) Starch granules are particularly small (05
- 3μm) Amylose content of quinoa is as low as 11 (Ahamed et al 1996) while the amylose
proportion in most cereals such as wheat is around 25 (Zeng et al 1997 BeMiller and Huber
50
2008) Amylose content of starch correlated positively with the hardness of cooked rice and
cooked white salted noodles (Ong and Blanshard 1995 Epstein et al 2002 Baik and Lee 2003)
Flour pasting properties can greatly influence the texture of cooked products Their
correlation has not been illustrated in quinoa while some research have been conducted on
cooked rice A lower peak viscosity and positive setback are associated with a harder texture
while a higher peak viscosity breakdown and lower setback are associated with a sticky texture
in cooked rice (Limpisut and Jindal 2002) Champagne et al (1999) indicated that adhesiveness
had strong correlations with Rapid Visco Analyzer (RVA) measurements Ramesh et al (2000)
reported that harder cooked rice texture was associated with a lower peak viscosity and positive
setback while sticky rice had a higher peak viscosity higher breakdown and lower setback
The gelatinization temperature of quinoa starch ranges from 54ordmC to 71ordmC (Ando et al
2002) lower than that of rice barley and wheat starches (Marshall 1994 Tang 2004 Tang et al
2005) Gelatinization temperature likely plays an important role in waxy rice quality (Perdon and
Juliano 1975 Juliano et al 1987) but was not correlated to the eating quality of normal rice
(Ramesh et al 2000) Despite a considerable amount of work having been conducted on the
thermal properties of cereal starch little is known about the relationship between quinoa flour
thermal properties and cooked quinoa texture
The correlation of quinoa cooking quality and texture has not been previously reported In
rice cooking quality exhibited strong correlations to the texture profile analysis (TPA) Cooking
time has been reported to correlate positively with hardness and negatively with adhesiveness of
cooked rice (Mohapatra and Bal 2006) Higher water uptake ratio and volume expansion ratio
were associated with softer more adhesive and more cohesive texture of cooked rice
51
(Mohapatra and Bal 2006) Cooking loss has been reported to improve firmness but decrease
juiciness (Rousset et al 1995)
There is a need to further study the texture of cooked quinoa and its determining factors
The objective of this paper is to study the texture difference among varieties of cooked quinoa
and evaluate the correlation between the texture and the seed characters and composition
cooking process flour pasting properties and thermal properties
Materials and Methods
Seed characteristics
Eleven varieties and two commercial lots of quinoa are listed in Table 1 The two grain
lots were referred as lsquoYellow Commercialrsquo and lsquoRed Commercialrsquo according to the seed color
Seed size (diameter) was determined by lining up and measuring the length of 20 seeds Average
seed diameter was calculated from three repeated measurements Bulk density of seed was
measured by the weightvolume method Seed weight was determined gravimetrically Seed
hardness was determined using the texture analyzer TAndashXT2i (Texture Technology Corp
Scarsdale NY USA) A cylinder of 10 mm in diameter compressed one seed to 90 strain at
the rate of 5 mms The force (kg) was recorded as the seed hardness Seed coat proportions were
determined by a Scanning Electron Microscope (SEM) FEI Quanta 200F (FEI Corp Hillsboro
OR USA) The seed was cross-sectioned and the SEM image was captured under 800times
magnification The seed coat proportions were measured using the software ruler in micrometers
Chemical compositions
Whole quinoa flour was prepared using a cyclone sample mill (UDY Corporation Fort
Collins CO USA) equipped with a 05 mm screen and was used for compositional analysis
52
pasting viscosity and thermal properties Ash and moisture content of quinoa flour were tested
according to the Approved Method 08-0101 and 44-1502 respectively (AACCI 2012) Protein
content was determined by a nitrogen analyzer coupled with a thermo-conductivity detector
(LECO Corporation Joseph MI USA) The factor of 625 was used to calculate the protein
content from the nitrogen content (Approved Method 46-3001 AACCI 2012) Protein and ash
were calculated on a dry weight basis
Cooking protocol
The cooking protocol of quinoa was modified from a rice cooking method (Champagne
et al 1998) Five grams of quinoa seed were soaked for 20 min in 10 mL deionized water in a
flask Soaking is required to remove the bitter saponins (Pappier et al 2008) and enhance
cooking quality (Mohapatra and Bal 2006) The mixture was then boiled for 2 min and the flask
was set in boiling water for 18 min The flask was covered to prevent water loss
Cooking quality
Two grams of quinoa seed were cooked in 20 mL deionized water for 20 min and extra
water was removed Cooking time was determined when the middle white part of the seed
completely disappeared (Mohapatra and Bal 2006) The water uptake ratio was calculated from
the seed weight ratio before and after cooking Cooking volume was the seed volume after
cooking Cooking loss was the total of soluble and insoluble matter in the cooking water
(Rousset et al 1995) Three mL of cooking water of each sample was placed on an aluminum
pan and dried at 130 ordmC overnight The weight of dry solids in the pan was used to calculate the
cooking loss
Texture profile analysis (TPA)
53
Texture profile analysis (TPA) was used to determine the texture of cooked quinoa
according to a modified method for cooked rice texture (Champagne et al 1999) Two grams of
cooked quinoa were arranged on the texture analyzer platform as close to one layer as possible
A stainless steel plate (50 mm times 40 mm times 10 mm) compressed the cooked quinoa from 5 mm to
01 mm at 5 mmsec The compression was conducted twice The texture analyzer generated a
graph with time as the x-axis and force as the y-axis Six parameters were calculated from the
graph (Epstein et al 2002) Hardness is the height of the first peak adhesiveness is the area 3
cohesiveness is area 2 divided by area 1 springiness is distance 1 divided by distance 2
gumminess is hardness multiplied by cohesiveness chewiness is gumminess multiplied by
springiness In the present study no significant differences or correlations were obtained for
springiness As such this parameter will not be included except to describe the overall result (see
below)
Flour viscosity
Quinoa flour pasting viscosity was determined using the Rapid Visco Analyzer (RVA)
RVA-4 (Newport Scientific Pty Ltd Narrabeen Australia) Quinoa flour (43 g) was added to
25 mL deionized water in an aluminum cylinder container The contents were immediately
mixed and heated following the instrument program The temperature was increased from 50 ordmC
to 93 ordmC in 8 min at a constant rate was held at 95 ordmC from 8 to 24 min cooled to 50 ordmC from 24
to 28 min and held at 50 ordmC from 29 to 40 min The program generated a graph with time against
shear force (Figure 1) expressed in RVU (cP = RVU times 12)
Two peaks representing peak viscosity and final viscosity are normally included in the
RVA graph Peak time was the time to reach the first peak Holding strength or trough is the
54
minimum viscosity after the first peak Breakdown is the viscosity difference between peak and
minimum viscosity Setback is the viscosity difference between final and minimum viscosity
Pasting temperature and the time to reach the peak were also recorded
Thermal properties using Differential Scanning Calorimetry (DSC)
Thermal properties of quinoa flour were determined by Differential Scanning
Calorimetry (DSC) Tzero Q2000 (TA instruments New Castle DE USA) The protocol was a
modification of the method of Abugoch et al (2009) Quinoa flour (02 g) was added to 200 μL
deionized water and mixed on a vortex mixer for 10 s to form a slurry Ten to twelve milligrams
of slurry was added to an aluminum pan by pipette The pan was sealed and placed at the center
of DSC platform An empty pan was used as reference The temperature was increased from 25
ordmC to 120 ordmC at 10 ordmCmin then equilibrated to 25 ordmC Gelatinization temperature and enthalpy
were determined from the graph
Statistical analysis
All experiments were repeated three times The hypothesis tests of normality and equal
variance multiple comparisons (Fisherrsquos LSD) and correlation studies were conducted by SAS
92 (SAS Institute Cary NC) A P-value of 005 is considered as the level of statistical
significance unless otherwise specified
Results
Seed characteristics and flour composition
Quinoa seed characteristics and composition are shown in Table 2 Quinoa seeds were
small compared to cereals such as rice wheat and maize Diameters of quinoa seed mostly
ranged between 19 to 22 mm except for lsquoJapanese Strainrsquo which was significantly smaller (15
55
mm) Seed hardness was significantly different among varieties ranging from 583 k g in
lsquoCol6197rsquo to 1096 kg in lsquoOro de Vallersquo Bulk seed density of quinoa varied from 063 kgL in
lsquoBlancarsquo to 081 kgL in lsquoJapanese Strainrsquo Varieties from White Mountain farm and the WSU
Organic Farm were lower in bulk density most of which were below 07 kgL The commercial
and Port Townsend samples were higher in density most of which were around 075 kgL
Thousand-seed weights of quinoa were particularly low ranging from 18 g in lsquoJapanese Strainrsquo
to 41g in lsquoRed Commercialrsquo Seed coat proportion was also significantly different among
varieties Three layers are shown in the seed coat (Figure 2) The varieties lsquoBlackrsquo and lsquoBlancarsquo
had the thickest seed coat (38 and 97 μm respectively) with coat proportions of 40 and 45
respectively lsquoYellow Commercialrsquo and lsquo1ESPrsquo had the thinnest seed coats (15 and 16 μm
respectively) with the coat proportion of 07 and 05 respectively The difference was
almost ten-fold among the varieties
Protein and ash content of quinoa flour
Protein content varied from 113 in lsquo1ESPrsquo to 170 in lsquoCahuilrsquo lsquoCherry Vanillarsquo and
lsquoOro de Vallersquo also had high protein contents of 160 and 156 respectively Ash content
ranged from 12 in the Commercial Yellow seed to 40 in lsquoQQ63rsquo comparable to that in rice
flour (Champagne 2004)
Texture of cooked quinoa
The hardness of cooked quinoa ranged from 20 g for lsquo49ALCrsquo and lsquoCol6197rsquo to 347
kg for lsquoBlackrsquo (Table 3) lsquoOro de Vallersquo and lsquoBlancarsquo were relatively hard varieties with TPA
hardness of 285 kg and 306 kg respectively whereas lsquo1ESPrsquo lsquoJapanese Strainrsquo and lsquoQQ63rsquo
were softer with a hardness of 245 kg 293 kg and 297 kg respectively
56
Adhesiveness is the extent to which seeds stick to each other the probe and the stage
lsquo49ALCrsquo lsquo1ESPrsquo lsquoCol6197rsquo and lsquoQQ63rsquo were significantly stickier with adhesiveness value
of -029 kgs -027 kgs -023 kgs and -020 kgs respectively All other varieties exhibited
lower adhesiveness with values less than 010 kgs Visual examination of the cooked samples
showed that with the more adhesive varieties the seeds stuck together as with sticky rice while
for other varieties the grains were separated
Cohesiveness of cooked lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo was
significantly higher with values from 068 to 071 respectively while those of lsquo49ALCrsquo lsquo1ESPrsquo
and lsquoCol6197rsquo were lower at 054 056 and 053 respectively Springiness is the recovery
from crushing or the elastic recovery (Tsuji 1981 Seguchi et al 1998) Cooked quinoa of all
varieties exhibited excellent elastic recovery properties with springiness values approximating
10
Gumminess is the combination of hardness and cohesiveness Chewiness is gumminess
multiplied by springiness As springiness values were all close to 10 gumminess and chewiness
of cooked quinoa were very similar in value lsquoBlackrsquo lsquoBlancarsquo and lsquoCahuilrsquo were highest in
gumminess and chewiness 24 kg 22 kg and 23 kg respectively while lsquo1ESPrsquo lsquo49ALCrsquo and
lsquoCol6197rsquo were lowest at 14 kg 11 kg and 11 kg respectively The difference among varieties
was greater than three-fold
Cooking quality
Cooking quality of quinoa is shown in Table 4 Cooking time varied from 119 min in
lsquoCol6197rsquo to 192 min in lsquoBlackrsquo cultivar and was significantly correlated with all TPA texture
parameters Longer cooking time also correlated with higher protein content (r = 052 P = 007)
57
Water uptake ratio varied from 25 to 4 fold in lsquoQQ63rsquo and lsquoCol6197rsquo respectively Water
uptake ratio was negatively correlated to seed hardness (r = 052 P = 004) Harder seeds tended
to absorb less water during cooking Cooking volume ranged from 107 mL to 137 mL and did
not significantly correlate with other properties Cooking loss ranged from 035 to 176 and
differed among varieties but was not correlated with water uptake ratio cooking time or cooking
volume
Quinoa flour pasting properties by RVA
Pasting viscosity of quinoa whole seed flour was determined using the Rapid Visco
Analyzer (RVA) The results are shown in Table 5 Peak viscosity differed among varieties
Varieties could be categorized into three groups based on peak viscosity The peak viscosity of
lsquoQQ63rsquo lsquoCol6197rsquo lsquo1ESPrsquo lsquoJapanese Strainrsquo lsquoYellow Commercialrsquo lsquoCopacabanarsquo and lsquoRed
Commercialrsquo varied from 144 to 197 RVU The peak viscosity of lsquoBlancarsquo lsquoBlackrsquo lsquo49ALCrsquo
and lsquoCahuilrsquo ranged from 98 to 116 RVU while those of lsquoOro de Vallersquo and lsquoCherry Vanillarsquo
were 59 and 66 RVU respectively
Trough viscosity namely the minimum viscosity after the first peak showed more than a
three-fold difference among varieties As in the case of peak viscosity the trough of different
varieties can be categorized into the same three groups
Breakdown is the difference between the peak and minimum viscosity lsquoQQ63rsquo lsquo1ESPrsquo
and lsquoJapanese Strainrsquo showed large breakdowns of 51 51 and 62 RVU respectively
Breakdown of lsquoCherry Vanillarsquo lsquoOro de Vallersquo and the Commercial Yellow seed were lower at
12 10 and 11 RVU respectively Breakdown of the other varieties ranged from 18 to 36 RVU
58
The final viscosity of the Commercial Yellow seed was 203 RVU the highest among all
varieties Final viscosity of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo
ranged from 56 to 82 RVU and was lower than that of other varieties which ranged from 106 to
190 RVU
Setback is the difference between final and trough viscosity Setback of lsquoRed
Commercialrsquo lsquoCahuilrsquo and lsquoBlackrsquo were all negative -62 -11 and -6 RVU respectively which
indicated that the final viscosity of these cultivars was lower than their trough viscosity Setback
of lsquoBlancarsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo were slightly positive at 2 2 and 6 RVU
respectively while those of other cultivars were much greater between 42 and 73 RVU Peak
time which is the time to reach the first peak ranged from 93 to 115 min The pasting
temperature was 93 ordmC and not different among the varieties
Thermal properties of quinoa flour using DSC
Thermal properties of quinoa flour were determined using DSC Gelatinization
temperatures (To onset temperature Tp peak temperature Tc conclusion temperature) and
gelatinization enthalpies are shown in Table 6 To of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry
Vanillarsquo and lsquoJapanese Strainrsquo were not different from each other and ranged from 645 ordmC to
659 ordmC To of lsquoOro de Vallersquo lsquoCopacabanarsquo lsquoCol6197rsquo and lsquoQQ63rsquo ranged from 605 ordmC to
631 ordmC while other varieties were lower and ranged from 544 ordmC to 589 ordmC Tp ranged from
675 ordmC in the Commercial Yellow seed to 752 ordmC in lsquoCahuilrsquo Tc ranged from 780 ordmC in lsquoRed
Commercialrsquo to 850ordmC in the lsquoJapanese Strainrsquo Enthalpy of quinoa flour differed among
varieties The range was from 11 Jg in lsquoYellow Commercialrsquo to 18 Jg in lsquoBlancarsquo
Correlations between physical-chemical properties and cooked quinoa texture
59
A summary of correlation coefficients between quinoa physical-chemical properties and
TPA texture profile parameters of cooked quinoa are shown in Table 7 Seed hardness was found
to be positively related to the TPA hardness gumminess and chewiness of cooked quinoa (P lt
009) Seed bulk density was negatively correlated to hardness cohesiveness gumminess and
chewiness while seed coat proportion was positively correlated to those parameters Protein
content of quinoa exhibited a positive relationship with TPA hardness (P = 008) and
adhesiveness cohesiveness gumminess and chewiness No significant correlation was observed
between the seed size 1000 seed weight ash content and the texture properties of cooked
quinoa
Cooking time of quinoa was highly positively correlated with all of the TPA texture
profile parameters Water uptake ratio during cooking was found to be significantly associated
with hardness gumminess and chewiness of cooked quinoa while cooking volume also showed
a modest correlation to hardness (r = -047 P = 010) Cooking loss was not correlated with any
texture parameter
Flour pasting viscosity was significantly correlated with texture of cooked quinoa Peak
viscosity and breakdown exhibited negative correlations with the hardness gumminess and
chewiness of cooked quinoa (P lt 010) Breakdown was also negatively associated with the
cohesiveness (r = -051 P lt 010) Final viscosity and setback were found to be negatively
correlated to hardness cohesiveness gumminess and chewiness while setback also exhibited a
significant correlation to adhesiveness (r = -064 P = 002)
60
Considering thermal properties To exhibited strong positive correlations with all texture
parameters Tp was found to be moderately related to cohesiveness (r = 050 P = 008) Neither
Tc nor enthalpy was significantly correlated to the TPA parameters of cooked quinoa
Discussion
Seed characteristics
Harder seed yielded harder gummier and chewier TPA texture after cooking The
varieties with lower seed bulk density or thicker seed coat yielded a firmer more cohesive
gummier and chewier texture Likely the condensed cells and non-starch polysaccharides of the
seed coat are a barrier between starch granules in the middle perisperm and water molecules
outside the seed
Seed composition
Higher protein appeared to contribute to a firmer more adhesive gummier and chewier
texture of cooked quinoa as evidenced by the TPA parameters Protein has been reported to play
a significant role in the texture of cooked rice and noodles (Ramesh et al 2000 Martin and
Fitzgerald 2002 Saleh and Meullenet 2007 Xie et al 2008 Hou et al 2013) According to the
previous studies proteins affect the food texture through three major routes (1) binding of water
(Saleh and Meullenet 2007) (2) interacting reversibly with starch bodies (Chrastil 1993) and (3)
forming networks via disulphide bonds which restrict starch granule swelling and water
hydration (Saleh and Meullenet 2007)
Cooking quality
Cooking time was found to be a key factor for cooked quinoa texture as it was closely
associated with most texture attributes Other cooking qualities such as the water uptake ratio
61
cooking volume and cooking loss were not significantly correlated to texture In the study of
rice the cooking time of rice positively correlated with hardness negatively with cohesiveness
and not significantly with adhesiveness (Mohapatra and Bal 2006) The higher water uptake ratio
and volume expansion ratio were negatively associated with softer more adhesive and more
cohesive texture This result agrees with the study on cooked rice Rousset et al (1995) study
indicated that longer cooking time greater water uptake and cooking loss related to the softer
less crunchy and more pasty texture
Flour pasting properties
The varieties with a higher peak viscosity in flour had a softer less gummy and less
chewy texture after cooking The cultivars with higher final peak viscosity yielded a softer less
cohesive less gummy and chewy texture The varieties with a greater breakdown such as
lsquoQQ63rsquo lsquo1ESPrsquo and lsquoJapanese Strainrsquo were softer in TPA parameter Breakdown has been
reported to negatively correlate with the proportion of long chain amylopectin (Han and
Hamaker 2001) Long chain amylopectin may form intra- or inter-molecular interactions with
protein and lipids and result in a firmer or harder texture (Ong and Blanshard 1995)
Quinoa varieties with a lower setback were harder after cooking compared to those with a
higher setback In rice conversely setback was positively correlated with amylose content
(Varavinit et al 2003) which would positively influence the hardness of cooked rice (Ong and
Blanshard 1995 Champagne et al 1999) Unlike rice and many other cereals where the amylose
content is approximately 25-29 the amylose proportion in quinoa starch is lower on the order
of 11 (Ahamed et al 1996) Amylose may play a different role in cooked quinoa hardness
compared to other cereals
62
Starch viscosity has been reported to significantly affect the texture of cooked rice
Champagne et al (1999) used the RVA measurements to predict TPA of cooked rice and found
that adhesiveness strongly correlated to RVA parameters Harder rice was correlated with lower
peak viscosity and positive setback while stickier rice had a higher peak viscosity breakdown
and lower setback (Ramesh et al 2000) The difference between quinoa and rice seed structure
and starch composition and the difference of texture determining methods may contribute to the
different trends in correlation
Thermal properties
The gelatinization temperature of quinoa flour ranged from 55 ordmC to 85 ordmC lower than
that of whole rice flour which was 70 ordmC to 103 ordmC (Marshall 1994) This result agrees with the
previous study on quinoa flour (Ando et al 2002) The quinoa varieties with higher To exhibited
a firmer more adhesive more cohesive gummier and chewier texture Higher Tp was associated
with increased cohesiveness The enthalpy of quinoa flour ranged from 11 to 18 Jg about one-
tenth that of whole rice flour (141 ndash 151 Jg) (Marshall 1994) indicating that it takes less
energy to cook quinoa than cook rice
Thermal properties of quinoa flour were generally correlated with flour pasting
properties Higher To and Tp were correlated with lower flour peak viscosity and lower trough
The result is comparable to the previous study of Sandhu and Singh (2007) who found that
gelatinization temperature and enthalpy of corn starch strongly influenced the peak breakdown
final and setback viscosity The thermal properties of quinoa flour were not correlated with
breakdown and setback likely was due to other composition factors in the flour such as protein
and fiber
63
Conclusions
The texture of cooked quinoa varied markedly among the different varieties indicating
that genetics management or geographic origin may all be important considerations for quinoa
quality As such differences in seed morphology and chemical composition appear to contribute
to quinoa processing parameters and cooked texture Harder seed yielded a firmer gummier and
chewier texture both lower seed density and high seed coat proportion related to a firmer more
cohesive gummier and chewier texture Seed size and weight appeared to be largely unrelated to
the texture of the cooked quinoa Protein content was a key factor apparently influencing texture
Higher protein content was related to harder more adhesive and cohesive gummier and chewier
texture Cooking time and water uptake ratio significantly affected the texture of cooked quinoa
whereas cooking volume moderately affected the hardness cooking loss was not correlated with
texture RVA peak viscosity was negatively correlated with the hardness gumminess and
chewiness breakdown was also negatively correlated with those TPA parameters Final viscosity
and setback were negatively correlated with the hardness cohesiveness gumminess and
chewiness Setback was correlated with the adhesiveness as well Gelatinization temperature To
affected all the texture profile parameters positively Tp slightly related to the cohesiveness
while Tc and enthalpy were not correlated with the texture
Acknowledgements
This project was supported by funding from the USDA Organic Research and Extension
Initiative project number NIFA GRANT11083982 The authors acknowledge Stacey Sykes and
Alecia Kiszonas for editing support
Author Contributions
64
G Wu and CF Morris designed the study together G Wu collected test data and drafted the
manuscript CF Morris and KM Murphy edited the manuscript KM Murphy provided
samples and project oversight
65
References
AACC International 2012 Approved Methods of Analysis Method 08-0101 Ash - Basic
method Approved April 13 1961 Method 44-1502 Moisture ndash Air-Oven Methods (130ordmC)
Approved October 30 1975 Method 46-3001 Crude protein ndash Combustion method
Approved November 8 1995 Reapproved November 3 1999 Available online only
AACCI St Paul MN
Abugoch LE Romero N Tapia CA Silva J Rivera M 2008 Study of some physicochemical
and functional properties of quinoa (Chenopodium quinoa Willd) protein isolates J Agric
Food Chem 564745-50
Abugoch LEJ 2009 Chapter 1 Quinoa (Chenopodium quinoa Willd) Adv Food Nutr Res
581-31
Abugoch L Castro E Tapia C Antildeoacuten MC Gajardo P Villarroel A 2009 Stability of quinoa
flour proteins (Chenopodium quinoa Willd) during storage Int J Food Sci Tech 442013-20
Ahamed NT Singhal RS Kulkami PR Palb M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 3199-103
Alvarez-Jubete L Arendt EK Gallagher E 2010 Nutritive value of pseudocereals and their
increasing use as functional gluten-free ingredients Trends in Food Sci Tech 21(2)106-13
Ando H Chen YC Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food components in
fractions of quinoa seed Food Sci Technol Res 8(1)80-4
66
Baik BK Lee MR 2003 Effects of starch amylose content of wheat on textural properties of
white salted noodles Cereal Chem 80304-9
BeMiller JN Huber KC 2008 Carbohydrates In Damdaran S Parkin KL Fennema OR editors
Food chemistry Boca Raton CRC Press p 121
Champagne ET Lyon BG Min BK Vinyard BT Bett KL Barton IIFE Webb BD Kohlwey DE
1998 Effects of postharvest processing on texture profile analysis of cooked rice Cereal
Chem 75(2)181-6
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5)764-71
Champagne ET 2004 The rice grain and its gross composition In Champagne ET editor Rice
chemistry and technology St Paul Minn American Association of Cereal Chemists p 88
Chrastil J 1993 Enzyme activities in preharvest rice grains J Agric Food Chem 41(12)2245-8
Cortez G Repo-Carrasco R Rosell CM 2009 Breadmaking use of andean crops quinoa kantildeiwa
kiwicha and tarwi Cereal Chem 86(4)386-92
Del Castillo V Lescano G Armada M 2009 Foods formulation for people with celiac disease
based on quinoa (Chenopodium quinoa) cereal flours and starches mixtures Archivos
Latinoamericanos De Nutricion 59(3)332-36
67
Demirkesen I Mert B Sumnu G Sahin S 2010 Rheological properties of gluten-free bread
formulations J Food Eng 96(2)295-303
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(Waxy) genes J Cereal Sci 3551-63
Fitzgerald MA Martin M Ward RM Park WD Shead HJ 2003 Viscosity of rice flour a
rheological and biological study J Agric Food Chem 51(8) 2295-9
Food and Agriculture Organization of the United Nations (FAO) 2013 The international year of
quinoa Available from httpwwwfaoorgquinoa-2013en Accessed 2013 February 20
Han XZ Hamaker BR 2001 Amylopectin fine structure and rice starch paste breakdown J
Cereal Sci 34(3)279-84
Hou GG Saini R Ng PKW 2013 Relationship between physicochemical properties of wheat
flour wheat protein composition and textural properties of cooked chinese white salted
noodles Cereal Chem 90(5)419-29
Jancurovaacute M Minarovicova L Dandar A 2009 Quinoa ndash a review Czech J Food Sci 27(2)71-9
Juliano BO Villareal RM Bantildeos L 1987 Varietal differences in physicochemical properties of
waxy rice starch Starch - Staumlrke 39(9)298-301
68
Limpisut P Jindal VK 2002 Comparison of rice flour pasting properties using brabender
viscoamylograph and rapid visco analyser for evaluating cooked rice texture Starch - Staumlrke
54(8)350-7
Lindeboom N Chang PR Falk KC Tyler RT 2007 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2)216-22
Marshall WE 1994 Starch gelatinization in brown and milled rice a study using differential
scanning calorimetry In Marshall WE Wadsworth IJ editors Rice science and technology
New York NY Marcel Dekker Inc p 222
Martin M Fitzgerald MA 2002 Proteins in rice grains influence cooking properties J Cereal Sci
36(3)285-94
Mohapatra D Bal S 2006 Cooking quality and instrumental textural attributes of cooked rice
for different milling fractions J Food Eng 73(3)253-9
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine stucture of amylopectin J Cereal Sci 21(3)251-60
Pappier U Fernandez Pinto V Larumbe G Vaamonde G 2008 Effect of processing for saponin
removal on fungal contamination of quinoa seeds (Chenopodium quinoa Willd) Int J Food
Microbiol 125(2)153-7
Perdon AA Juliano BO 1975 Gel and molecular properties of waxy rice starch Starch - Staumlrke
27(3)69-71
69
Ramesh M Bhattacharya KR Mitchell JR 2000 Developments in understanding the basis of
cooked-rice texture Crit Rev Food Sci Nutr 40(6)449-60
Rousset S Pons B Pilandon C 1995 Sensory texture profile grain physico-chemical
characteristics and instrumental measurements of cooked rice J Texture Stud 26(2)119-35
Ruales J Valencia S Nair B 1993 Effect of processing on the physico-chemical characteristics
of quinoa flour (Chenopodium quinoa Willd) Starch - Staumlrke 45(1)13-9
Ruales J de Grijalva Y Lopez-Jaramillo P Nair BM 2002 The nutritional quality of an infant
food from quinoa and its effect on the plasma level of insulin-like growth factor-1 (IGF-1) in
undernourished children Int J Food Sci Nutr 53(2)143-54
Saleh MI Meullenet JF 2007 Effect of protein disruption using proteolytic treatment on cooked
rice texture properties J Texture Stud 38(4)423-37
Sandhu KS Singh N 2007 Some properties of corn starches II Physicochemical gelatinization
retrogradation pasting and gel textural properties Food Chem 101(4)1499-507
Schumacher A Brandelli A Macedo F Pieta L Klug T Jong E 2010 Chemical and sensory
evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J Food
Sci Tech 47(2)202-6
Seguchi M Hayashi M Kanenaga K Ishihara C Noguchi S1998 Springiness of pancake and
its relation to binding of prime starch to tailings in stored wheat flour Cereal Chem
75(1)37-42
70
Tang H 2004 Relationship between functionality and structure in barley starches Carbohydr
Polym 57(2)145-52
Tang H Mitsunaga T Kawamura Y 2005 Functionality of starch granules in milling fractions
of normal wheat grain Carbohyd Polym 59(1)11-7
Tsuji S 1981 Texture measurement of cooked rice kernels using the multiple-point mensuration
method 1 J Texture Stud 12(2)93-105
Vaclavik VA Christian EW 2003 Evaluation of food quality In Vaclavik V Christian EW
editors Essentials of food science New York NY Kluwer AcademicPlnum Publishers p 4
Varavinit S Shobsngob S Varanyanond W Chinachoti P Naivikul O 2003 Effect of amylose
content on gelatinization retrogradation and pasting properties of flours from different
cultivars of thai rice Starch - Staumlrke 55(9)410-5
Xie L Chen N Duan B Zhu Z Liao X 2008 Impact of proteins on pasting and cooking
properties of waxy and non-waxy rice J Cereal Sci 47(2)372-9
Zeng M Morris CF Batey IL Wrigley CW 1997 Sources of variation for starch gelatinization
pasting and gelation properties in wheat Cereal Chem 7463-71
71
Table 1-Varieties of quinoa used in the experiment
Variety Original Seed Source Location
Black White Mountain Farm White Mountain Farm Colorado US
Blanca White Mountain Farm White Mountain Farm Colorado US
Cahuil White Mountain Farm White Mountain Farm Colorado US
Cherry Vanilla Wild Garden Seeds Philomath Oregon WSUa Organic Farm Pullman Washington US
Oro de Valle Wild Garden Seeds Philomath Oregon WSUa Organic Farm Pullman Washington US
49ALC USDA Port Townsend Washington US
1ESP USDA Port Townsend Washington US
Copacabana USDA Port Townsend Washington US
Col6197 USDA Port Townsend Washington US
Japanese Strain USDA Port Townsend Washington US
QQ63 USDA Port Townsend Washington US
Yellow Commercial Multi Organics company Bolivia
Red Commercial Multi Organics company Bolivia a WSU - Washington State University
72
Table 2-Seed characteristics and compositiona
Variety Diameter (mm)
Hardness (kg)
Bulk Density (gmL)
Seed Coat Proportion ()
Protein ()
Ash ()
Black 21bc 994b 0584d 37bc 143d 215hi
Blanca 22ab 608l 0672c 89a 135e 284ef
Cahuil 21abc 772e 0757a 49b 170a 260fg
Cherry Vanilla 19e 850d 0717b 41b 160b 239gh
Oro de Valle 19e 1096a 0715b 43b 156b 305de
49ALC 19de 935c 0669c 26cd 127g 348bc
1ESP 19e 664h 0672c 10f 113i 248gh
Copacabana 20cd 643i 0671c 44b 129g 361b
Col6197 19e 583m 0657c 24de 118h 291ef
Japanese Strain 15f 618k 0610d 21def 148cd 324cd
QQ63 19e 672g 0661c 45b 135f 401a
Yellow Commercial
21abc 622j 0663c 14ef 146c 198i
Red Commercial 22a 706f 0730ab 26cd 145cd 226hi a Mean values with different letters within a column are significantly different (P lt 005)
73
Table 3-Texture profile analysis (TPA)a of cooked quinoa
Variety Hardness (kg)
Adhesiveness (kgs)
Cohesiveness Gumminess (kg)
Chewiness (kg)
Black 347a -004a 069ab 24a 24a
Blanca 306bcd -003a 071a 22abc 22abc
Cahuil 327abc -003a 071a 23ab 23ab
Cherry Vanilla 278de -002a 071a 20cd 20cd
Oro de Valle 285d -001a 068ab 19cd 19cd
49ALC 209f -029c 054d 11ef 11ef
1ESP 245e -027bc 056d 14e 14e
Copacabana 305bcd -010a 068ab 21bcd 21bcd
Col6197 202f -023bc 053d 11ef 11ef
Japanese Strain 293d -008a 066bc 19cd 19cd
QQ63 297cd -020b 062c 19d 19d
Yellow Commercial 306bcd -003a 069ab 21abc 21bc
Red Commercial 338ab -005a 068ab 23ab 23ab a Mean values with different letters within a column are significantly different (P lt 005)
74
Table 4-Cooking qualitya of quinoa
Variety Optimal Cooking Time (min)
Water uptake ()
Cooking Volume (mL)
Cooking Loss ()
Black 192a 297c 109c 065f
Blanca 183abc 344b 130ab 067f
Cahuil 169de 357ab 137a 102c
Cherry Vanilla 165ef 291c 107c 102c
Oro de Valle 173cde 238d 109c 102c
49ALC 136h 359ab 126b 043g
1ESP 153g 373ab 132ab 035h
Copacabana 157fg 379ab 127b 175a
Col6197 119i 397a 126b 176a
Japanese Strain 166def 371ab 116c 106b
QQ63 177bc 244d 126b 067f
Yellow Commercial 187ab 372ab 129ab 076d
Red Commercial 155fg 276cd 132ab 071e a Mean values with different letters within a column are significantly different (P lt 005)
75
Table 5-Pasting properties of quinoa flour by RVAa
Variety Peak Viscosity (RVU)
Trough
(RVU)
Breakdown
(RVU)
Final Viscosity (RVU)
Setback (RVU)
Peak Time (min)
Black 102g 81e 21e 75g -6f 102e
Blanca 98g 80e 18e 82g 2e 99f
Cahuil 116f 85e 31d 74g -11f 104de
Cherry Vanilla
66h 54g 12f 57h 2e 97fg
Oro de Valle
59h 50g 10f 56h 6e 93h
49ALC 107fg 71f 36c 132e 62b 97fg
1ESP 161cd 110c 51b 174c 64b 98fg
Copacabana 175b 141b 34cd 190b 49c 106cd
Col6197 155de 133b 22e 177bc 44cd 108bc
Japanese Strain
172bc 109c 62a 159d 50c 96gh
QQ63 144e 94d 51b 167cd 73a 97fg
Yellow Commercial
172bc 162a 11f 203a 41d 109b
Red Commercial
197a 168a 29d 106f -62g 115a
a Mean values with different letters within a column are significantly different (P lt 005)
76
Table 6-Thermal properties of quinoa flour by Differential Scanning Calorimetry (DSC)a
Gelatinization Temperature (ordmC)
Variety To Tp Tc Enthalpy (Jg)
Black 656a 725c 818abcd 15abc
Blanca 658a 743ab 819abcd 18a
Cahuil 659a 752a 839ab 16ab
Cherry Vanilla 649ab 741ab 823abc 12c
Oro de Valle 631bc 719cd 809abcde 12bc
49ALC 579e 714d 810bcde 15abc
1ESP 544f 690f 785de 15abc
Copacabana 630c 715cd 802cde 14abc
Col6197 605d 689f 785de 15abc
Japanese Strain 645abc 740b 850a 12c
QQ63 630c 702e 784de 13bc
Yellow Commercial 570e 676g 790cde 11c
Red Commercial 589de 693ef 780e 12c a Mean values with different letters within a column are significantly different (P lt 005)
77
Table 7-Correlation coefficients between quinoa seed characteristics composition and processing parameters and TPA texture of cooked quinoaa
Hardness Adhesiveness Cohesiveness Gumminess Chewiness
Seed Hardness 051 002ns 028ns 049 049
Bulk Density -055 -044ns -063 -060 -060
Seed Coat Proportion 074 038ns 055 072 072
Protein 050 077 075 057 057
Cooking Time 077 062 074 076 076
Water Uptake Ratio -058 -025ns -046ns -056 -056
Cooking Volume -048 -014ns -032ns -046ns -046ns
Peak Viscosity -051 -014ns -041ns -053 -054
Breakdown -048 -047ns -051 -053 -053
Final Viscosity -069 -043ns -060 -070 -070
Setback -058 -064 -059 -060 -060
To 059 054 061 061 061
Tp 042ns 041ns 050 045ns 046ns a ns non-significant difference P lt 010 P lt 005 P lt 001
78
Figure 1-Rapid Visco Analyzer (RVA) graph of lsquoCherry Vanillarsquo and lsquoRed Commercialrsquo
quinoa flours ( lsquoCherry Vanillarsquo lsquoRed Commercialrsquo Temperature)
Time (min)
0 10 20 30 40
Vis
cosi
ty (R
VU
)
0
50
100
150
200
250
Tem
pera
ture
(degC
)
50
100
150
200
79
Figure 2-Seed coat image by SEM
(1 whole seed section P-perisperm C-cotyledon 2 three layers of quinoa seed coat
3 seed coat of lsquoCherry Vanillarsquo 382 microm 4 seed coat of lsquo1ESPrsquo 95microm)
4 3
2 1
P
C C
80
Chapter 4 Quinoa Starch Characteristics and Their Correlation with
Texture of Cooked Quinoa
ABSTRACT
Starch composition and physical properties strongly influence the functionality and end-
quality of cereals Here correlations between starch characteristics and seed quality cooking
properties and texture were investigated Starch characteristics differed among the eleven
experimental varieties and two commercial quinoa tested The total starch content of seed ranged
from 532 to 751 g 100 g Total starch amylose content ranged from 27 to 169 and the
degree of amylose-lipid complex ranged from 34 to 433 The quinoa samples with higher
amylose tended to yield harder stickier more cohesive more gummy and more chewy texture
after cooking With higher degree of amylose-lipid complex or amylose leaching the cooked
quinoa tended to be softer and less chewy Higher starch enthalpy correlated with firmer more
adhesive more cohesive and more chewy texture Indicating that varieties with different starch
properties should be utilized in different end-products
Keywords quinoa starch texture cooked quinoa
Practical Application The research provided the starch characteristics of different quinoa
varieties showing correlations between starch and cooked quinoa texture These results can help
breeders and food manufacturers to better understand quinoa starch properties and the use of
cultivars for different food product applications
81
Introduction
Quinoa (Chenopodium quinoa Willd) is a pseudocereal from the Andean mountains in
South America Quinoa is garnering greater attention worldwide because of its high protein
content and balanced essential amino acids As in other crops starch is one of the major
components of quinoa seed Starch content structure molecular composition pasting thermal
properties and other characteristics may influence the cooking quality and texture of cooked
quinoa
The total starch content of quinoa seed has been reported to range from 32 to 69
(Abugoch 2009) Starch granules are small (1-2μm) compared to those of rice and barley (Tari et
al 2003) Amylose content of quinoa starch was reported to range from 35 to 225 (Abugoch
2009) generally lower than that of other crops Amylose content exhibited significant influence
on the texture of cooked quinoa (Ong and Blanshard 1995) Similarly cooked rice texture was
correlated to starch amylose and chain length (Ong and Blanshard 1995 Ramesh et al 1999)
and leaching of amylose and amylopectin during cooking (Patindol et al 2010) However
amylose-lipid complex and amylose leaching properties have not been studied in quinoa cultivars
with diverse genetic backgrounds Perdon et al (1999) indicated that starch retrogradation was
positively correlated with firmness and stickiness of cooked milled rice during storage and
similar correlations would be anticipated for quinoa
Starch swelling power and water solubility influenced wheat and rice noodle quality and
texture (Crosbie 1991 McCormick et al 1991 Konik et al 1993 Ross et al 1997 Bhattacharya
et al 1999) whereas the role of starch swelling powerwater solubility in the texture of cooked
quinoa has not been reported
82
The texture of rice starch gels has been studied Gel texture was influenced by treatment
temperature incorporation of glucomannan and sugar concentration (Charoenrein et al 2011
Jiang et al 2011 Sun et al 2014) The texture of quinoa starch gel however has not been
reported
Gelatinization temperature enthalpy and pasting properties of starch were correlated
with the texture of cooked rice (Ong and Blanshard 1995 Champagne et al 1999 Limpisut and
Jindal 2002) The correlations between starch thermal properties pasting properties and cooked
quinoa texture however have also not been reported
Starch is an important component of grains and exhibits significant influence on the
texture of cooked rice noodles and other foods The texture of cooked quinoa has been studied
previously (Wu et al 2014) however the correlation of starch and cooked quinoa texture
nevertheless remained unclear The objectives of the present study were to understand 1) the
starch characteristics of different quinoa varieties and 2) the correlations between the starch
characteristics and the texture of cooked quinoa
Materials and Methods
Starch isolation
Eleven varieties and two commercial quinoa samples were included in this study (Table
1) Quinoa starch was isolated using a method modified from Lindeboom et al (2005) and Qian
et al (1999) Two hundred grams of seed were steeped in 1000 mL NaOH (03 wv) overnight
at 4 degC and rinsed with distilled water three times to remove the saponins The rinsed quinoa
was ground in a Waring blender (Conair Corp Stamford CT USA) for 15 min The slurry
was screened through a series of sieves US No 40 100 and 200 mesh sieves with openings of
83
425 150 and 74 μm respectively Distilled water was added and stirred to speed up the
filtration Filter residue was discarded whereas the filtrate was centrifuged under 2000 times g for 20
min The supernatant was decanted and the top brown layer of sediment (protein and lipids) was
gently scraped loose and discarded The remaining pellet was resuspended in distilled water and
centrifuged again This resuspension-centrifuge process was repeated three times or until the
brown topmost layer was all removed The white starch pellet was then dispersed in 95 ethanol
and centrifuged under 2000 times g for 10 min The supernatant was discarded and the starch pellet
was air-dried and gently ground using a mortar and pestle
α-amylase activity
The activity of α-amylase was determined using a Megazyme Kit (Megazyme
International Ireland Co Wicklow Ireland)
Apparent total amylose content degree of amylose-lipid complex
Apparent amylose content was determined using a cold NaOH method (Mahmood et al
2007) with modification Sample of 10 mg was weighed into a 20 mL microcentrifuge tube To
the sample was added 150 μL of 95 ethanol and 900 μL of 1M NaOH mixed vigorously and
kept on a shaker overnight at room temperature The starch solution of 200 μL was removed and
combined with 1 mL of 005 M citric acid 800 μL iodine solution (02 g I2 2 g KI in 250 mL
distilled water) and 10 mL distilled water reaching a final volume of 12 mL The solution was
chilled in a refrigerator for 20 min The absorbance at 620nm was determined using a
spectrophotometer (Shimadzu Biospec-1601 DNAProteinEnzyme Analyzer Shimadzu corp
Kyoto Japan) A standard curve was created using a dilution series of amylose amylopectin
84
proportions of 010 19 28 37 46 and 55 respectively (Sigma-Aldrich Co LLC St Louis
MO USA)
Total amylose content was determined using the same method for apparent amylose
except that lipids in the starch samples were removed in advance The starch was defatted using
hexane and ultrasonic treatment as follows One gram of starch was dissolved in 15 mL hexane
and set in an ultrasonic water bath for 2 hours The suspension was then centrifuged at 1000 times g
for 1 min The supernatant was discarded and the procedure was repeated a second time The
sample was then dried in a fume hood overnight
Degree of amylose-lipid complex = [total amylose ndash apparent amylose] total amylose times 100
Amylose leaching properties
Amylose leaching was determined using the modified method of Hoover and Ratnayake
(2002) Starch (025 g) was mixed with 5 mL distilled water and heated at 60 degC for 30 min
then cooled in ice water and centrifuged at 2000 times g for 10 min Supernatant of 1 mL was added
to 800 μL iodine solution and 102 mL distilled water to achieve the same volume of 12 mL as
in the apparent amylose test The solution was chilled in a refrigerator for 20 min and the
absorbance at 620 nm was determined The amylose leaching was expressed as mg of amylose
leached from 100 g of starch
Starch pasting properties
Starch pasting properties were determined using the Rapid Visco Analyzer RVA-4
(Newport Scientific Pty Ltd Narrabeen Australia) Starch (3 g) was added to 25 mL distilled
water mixed and heated in the RVA using the following procedure The initial temperature was
50 ordmC and increased to 93 ordmC within 8 min at a constant rate held at 95 ordmC from 8 min to 24 min
85
cooled to 50 ordmC from 24 min to 28 min and held at 50 ordmC from 29 min to 40 min The result was
expressed in RVU units (RVU = cP12)
Starch gel texture
Starch gel texture was determined using a TA-XT2i Texture Analyzer (Texture
Technologies Corp Hamilton MA USA) The starch gels were prepared in the RVA using the
same procedure as for pasting properties Then the starch gels were stored at 4 degC for 24 hours
The testing procedure followed the method of Jiang et al (2011) with modification The gel
cylinder (3 cm high and 35 cm diameter) was compressed using a TA-25 cylinder probe at the
speed of pre-test 20 mms test 05 mms and post-test 05 mms to 10 mm deformation Two
compressions were conducted with an interval time of 20 s Hardness springiness and
cohesiveness were obtained from the TPA (Texture Profile Analysis) graph (x-axis distance and
y-axis force) Hardness (g) was expressed by the maximum force of the first peak springiness
was the ratio of distance (time) to peak 2 to distance to peak 1 cohesiveness was the ratio of the
second positive area under the compression curve to that of the first positive area
Freeze-thaw stability
Freeze-thaw stability was determined using the modified method from Lindeboom et al
(2005) and Charoenrein et al (2005) Starch slurry was cooked using the RVA with 125 g
starch and 25 mL distilled water The starch suspensions were heated at 60 degC from 0 ndash 2 min
the temperature was increased to 105 degC from 3 ndash 8 min with a constant rate and held at 105 degC
from 9 - 11 min The cooked samples were stored at -18 degC for 20 hours and then kept at room
temperature for 4 hours Water was decanted and the weight difference was determined The
86
freeze-thaw cycle was repeated five times The freeze-thaw stability was expressed as water loss
after each freeze-thaw cycle
Starch thermal properties
Thermal properties of starch were determined using Differential Scanning Calorimetry
(DSC) (Lindeboom et al 2005) Starch samples of 10 mg were weighed into aluminum pans
(Perkin-Elmer Kit No 219-0062) with 20 μL distilled water The pans were sealed and the
suspensions were incubated at room temperature (25 degC) for 2 hours to achieve equilibrium The
pans were then scanned at 10 degCmin from 25 degC to 120 degC The onset temperature (To) peak
temperature (Tp) and completion temperature (Tc) were the temperature to start the peak reach
the peak and complete the peak respectively Additionally enthalpy of gelatinization was
determined by the area under the peak
Swelling power and solubility
Swelling power and water solubility of starch were obtained at 93 degC (Vandeputte et al
2003) Starch samples of 05 g were added to 12 mL distilled water and mixed vigorously The
suspensions were immediately set in a water bath with a rotating rack at 93 degC for 30 min The
suspensions were then cooled in ice water for 2 min and centrifuged at 3000 g for 15 min The
supernatant was carefully removed with a pipette and the weight of wet sediment was recorded
The removed supernatants were dried in a 105 degC oven over night The weight of dry sediment
was recorded The swelling power and water solubility were expressed using the following
equations
Swelling power = wet sediment weight [dry sample weight times (1 ndash water solubility))
Water solubility = dry sediment weight dry sample weight times 100
87
Swelling power is expressed as a unitless ratio
Statistical analysis
All experiments were repeated three times Multiple comparisons were conducted using
Fisherrsquos LSD in SAS 92 (SAS Inst Cary NC USA) Correlations were calculated using
PROC CORR code in SAS 92 A P value of 005 was considered as the level of significance
unless otherwise specified
Results
Starch content and composition
Total starch content of quinoa seeds on a dry basis ranged from 532 g 100 g in the
variety lsquoBlackrsquo to 751 g 100 g in a commercial sample named lsquoYellow Commercialrsquo (Table 2)
Varieties lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo were lower in total
starch content all below 60 g100 g The Port Townsend seeds and commercial seeds contained
higher levels of starch mostly over 70 g100 g
Apparent amylose contents ranged from 27 in lsquo49ALCrsquo to 169 in lsquoCahuilrsquo all
lower than the corn starch standard which was 264 Varieties lsquoCahuilrsquo lsquoBlackrsquo and lsquoYellow
Commercialrsquo contained higher apparent amylose 147 to 169 It is worth noting that
lsquo49ALCrsquo contained the lowest apparent and total amylose contents 27 and 47 respectively
Total amylose of the other varieties ranged from 111 in lsquoQQ63rsquo to 173 in lsquoCahuilrsquo
The degree of amylose-lipid complex differed among the samples ranging from 34 in
lsquoCahuilrsquo to 43 in lsquo49ALCrsquo and lsquoCol6197rsquo Statistically however only lsquo49ALCrsquo and
lsquoCol6197rsquo were significantly higher than lsquoCahuilrsquo in degree of amylose-lipid complex
Starch properties
88
Amylose leaching property exhibited great differences among samples (Table 3)
lsquo49ALCrsquo and lsquo1ESPrsquo showed the highest amylose leaching at 862 and 716 mg 100 g starch
respectively lsquoCahuilrsquo lsquoJapanese Stainrsquo and lsquoRed Commercialrsquo were the lowest with amylose
leaching less than 100 mg 100 g starch lsquoBlackrsquo and lsquoBlancarsquo were relatively low as well with
210 and 171 mg amylose leaching 100 g starch The other varieties were intermediate and
ranged from 349 to 552 mg 100 g starch
Water solubility of quinoa starch ranged from 07 to 45 all lower than that of corn
starch which was 79 lsquoJapanese Strainrsquo lsquoQQ63rsquo lsquoCommercial Yellowrsquo and lsquoPeruvian Redrsquo
were the highest in water solubility 26 to 45 The starch water solubility in the other varieties
was between 10 and 19
Swelling power of quinoa starch ranged from 170 to 282 all higher than that of corn
starch (89) lsquo49ALCrsquo and lsquo1ESPrsquo showed the highest swelling powers 282 and 276
respectively lsquoYellow Commercialrsquo and lsquoRed Commercialrsquo showed relatively lower swelling
power 188 and 196 respectively The remaining varieties did not exhibit differences in
swelling power with values between 253 and 263
α-Amylase activity
Activity of α-amylase in quinoa flour separated the samples to three groups (Table 3)
lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo showed high α-amylase activity from
086 CU to 116 CU (Ceralpha Unit) lsquoBlackrsquo lsquo49ALCrsquo and lsquoCopacabanarsquo were lower in α-
amylase activity 043 031 and 020 CU respectively The other varieties and commercial
samples exhibited particularly low α-amylase activities with the values lower than 01 CU
Starch gel texture
89
Texture of starch gels included hardness springiness and cohesiveness (Table 4)
Hardness of starch gel of lsquoCahuilrsquo and lsquoJapanese Strainrsquo represented the highest and the lowest
values 900 and 201 g respectively Hardness of the other varieties ranged from 333 g in
lsquo49ALCrsquo to 725 g in lsquoBlackrsquo
lsquoJapanese Strainrsquo and lsquoYellow Commercialrsquo exhibited the highest and lowest springiness
values of the starch gels 092 and 071 respectively Springiness of other starch samples ranged
from 075 to 085 and were not significantly different from each other
Cohesiveness of starch gels ranged from 053 to 089 The starch gels of lsquoJapanese
Strainrsquo lsquoCol6197rsquo and lsquoCopacabanarsquo were more cohesive at 089 083 and 078 respectively
The starch gels of lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquo1ESPrsquo were moderately cohesive
with the cohesiveness of 072 ndash 073 Other varieties exhibited less cohesive starch gels lsquoQQ63rsquo
and commercial samples showed the least cohesive starch gels 053 ndash 057 For comparison the
hardness springiness and cohesiveness of the corn starch gel was 721 084 and 073
respectively These values were among the upper-to-middle range of those counterpart values of
the texture of quinoa starch gels
Starch thermal properties
Thermal properties of quinoa starch include gelatinization temperature and enthalpy
(Table 5) Onset temperature To of quinoa starch ranged from 515 ordmC in lsquoYellow Commercialrsquo to
586 ordmC in lsquoBlancarsquo Peak temperature Tp ranged from 595 ordmC in lsquoRed Commercialrsquo to 654 ordmC
in lsquoJapanese Strainrsquo Conclusion temperature ranged from 697 ordmC in lsquoCol6197rsquo to 788 ordmC in
lsquoJapanese Strainrsquo The commercial samples exhibited lower gelatinization temperatures To Tp
90
and Tc of the corn starch were 560 626 and 743 ordmC respectively They were within the ranges
of those values of the quinoa starches
Enthalpy refers to the energy required during starch gelatinization The enthalpy of
quinoa starch ranged from 99 to 116 Jg Starch from lsquoCahuilrsquo exhibited the highest enthalpy
116 Jg higher than that of lsquo49ALCrsquo and lsquoQQ63rsquo However enthalpies of other samples were
not significantly different Corn starch enthalpy was 105 Jg comparable to those of quinoa
starches
Starch pasting properties
Starch viscosity was investigated using the RVA (Table 6) Peak viscosity of quinoa
starches ranged from 193 to 344 RVU Varieties lsquoBlancarsquo and lsquoCahuilrsquo showed the highest peak
viscosities 344 and 342 RVU respectively lsquoJapanese Strainrsquo and lsquoQQ63rsquo were lowest in starch
peak viscosity 193 and 213 RVU respectively The peak viscosity of corn starch was 255 RVU
falling within the middle range of quinoa peak viscosities
The tough is the minimum viscosity after the first peak The trrough of quinoa starch
ranged from 137 to 301 RVU The starches of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and
lsquoOro de Vallersquo showed highest trough values from 252 to 301 RVU lsquo49ALCrsquo lsquo1ESPrsquo
lsquoCopacabanarsquo lsquoJapanese Strainrsquo and lsquoQQ63rsquo were lowest in trough ranging from 137 to 186
RVU The trough of corn starch was 131 RVU lower than that of all quinoa starches
Starch breakdown of lsquo49ALCrsquo was 119 RVU higher than that of other samples except
corn starch which was 124 RVU lsquoJapanese Strainrsquo and lsquoOro de Vallersquo showed the lowest
breakdowns 12 and 17 RVU respectively Breakdown of the other samples ranged from 39 to
97 RVU
91
Final viscosity of lsquoCahuilrsquo starch was 405 RVU significantly higher than that of other
varieties At the other extreme final viscosity of lsquo49ALCrsquo starch was 225 RVU significantly
lower than that of the other varieties The final viscosity of corn starch was 283 RVU close to
that of lsquoJapanese Strainrsquo and lsquoQQ63rsquo but lower than that of the other quinoa samples
The highest setback was observed with lsquo1ESPrsquo starch (140 RVU) At the other extreme
the setback of lsquoOro de Vallersquo was 53 RVU which was lower than the other quinoa samples
Additionally setbacks of lsquoBlancarsquo lsquo49ALCrsquo and lsquoJapanese stainrsquo starches were also among the
lower range varying from 82 RVU to 88 RVU The remaining varieties exhibited higher setback
from 101 RVA to 127 RVU Setback of corn starch was 152 RVU significantly higher than all
the other quinoa starches
RVA peak times of quinoa starches varied significantly among the samples lsquoJapanese
Strainrsquo lsquoBlancarsquo lsquoCahuilrsquo and lsquoOro de Vallersquo required longer time to reach the peak viscosity
with peak times of 105 to 113 min Other varieties showed shorter peak times between 79 to
99 min The starch of lsquo49ALCrsquo however only needed 64 min to reach peak viscosity shorter
than those of other quinoa samples The peak time of corn starch was 73 min shorter than those
of quinoa starches except lsquo49ALCrsquo
Freeze-thaw stability of starch
Freeze-thaw stability of starches was expressed as the water loss () of each freeze-thaw
cycle Quinoa starch samples and corn starch showed similar trends in freeze-thaw stability
Most water loss occurred after cycles 1 and 2 Starch gels on average (excluding lsquo49ALCrsquo) lost a
cumulative total of 522 ndash 689 of water after cycle 2 and a total of 745 ndash 823 after cycle 5
Furthermore the starch gels of lsquoQQ63rsquo and lsquo1ESPrsquo lost the least water indicating higher freeze-
92
thaw stability Conversely the starch gel of lsquoJapanese Strainrsquo lost the most water in every cycle
indicating the lowest degree of freeze-thaw stability
lsquo49ALCrsquo and lsquo1ESPrsquo starches exhibited freeze-thaw behavior that was different
compared to the other samples After freezing the samples of lsquo49ALCrsquo and lsquo1ESPrsquo produced
gels that were less rigid more viscous than the other samples Further they did not lose as much
water after the first cycle The sample of lsquo1ESPrsquo however turned into a solid gel from cycle 2 to
5 And the water loss of the lsquo1ESPrsquo gel was close to that of other samples during cycles 2 and 5
Correlations between starch properties and the texture of cooked quinoa
Correlations between starch properties and texture of cooked quinoa were examined
(Table 7) using texture profile analysis (TPA) of cooked quinoa of Wu et al (2014) Total starch
content was moderately correlated with adhesiveness of cooked quinoa (r = -048 P = 009) but
was not significantly correlated with any of the other texture parameters Conversely apparent
amylose content was highly correlated with all texture parameters (067 le r le 072) Total
amylose content also exhibited significant correlations with all texture parameters (056 le r le
061) Furthermore the degree of amylose-lipid complex was negatively correlated with all
texture parameters (-070 le r le -060) and amylose leaching proportion was highly correlated
with the texture of cooked quinoa (-084 le r le -074)
Water solubility and swelling power of starch were not observed to correlate well with
any of the texture parameters Higher α-amylase activity tended to yield more adhesive (r = 055)
and more cohesive (r = 051 P = 007) texture However α-amylase activity was not correlated
with the hardness gumminess or chewiness of cooked quinoa
93
Some texture parameters of starch gels were associated with the texture parameters of
cooked quinoa The hardness of starch gels was not correlated with the hardness of cooked
quinoa but was weakly correlated with adhesiveness (r = 059) Weakly positive correlations
were found between starch gel hardness and cooked quinoa cohesiveness gumminess and
chewiness (049 le r le 051 P le 010) Springiness and cohesiveness of starch gels were not
correlated with the measured textural properties of cooked quinoa
Onset gelatinization temperature (To) of starch exhibited weak correlations with
adhesiveness (r = 049 P = 009) and cohesiveness (r = 051 P = 007) but was not correlated
with the other texture parameters Peak gelatinization temperature (Tp) of starch was correlated
with cohesiveness (r = 056) and hardness adhesiveness gumminess and chewiness (047 le r le
056 P le 010) No correlation was found with conclusion temperature (Tc) and texture Starch
enthalpy did correlate with the texture parameters (r = 064 in hardness 069 le r le 072 in other
texture parameters)
Starch viscosity measurements were variably correlated with the texture of cooked
quinoa Peak viscosity correlated adhesiveness (r = 054 P = 006) and cohesiveness (r = 047 P
= 010) but not with the other texture parameters Trough was more highly correlated with
adhesiveness cohesiveness gumminess and chewiness (r = 077 in adhesiveness 055 le r le
063 in other texture parameters)
It is interesting to note that starch breakdown only correlated with adhesiveness of
cooked quinoa (r = -060) and not with any other texture parameter Setback was not correlated
with any texture parameter These two RVA parameters breakdown and setback are usually
considered to be important indexes of end-use quality In quinoa however breakdown and
94
setback of starch apparently are not predictive of cooked quinoa texture In addition final
viscosity was also correlated with adhesiveness (r = 068) and cohesiveness (r = 058) and
correlated moderately with gumminess and chewiness (r = 053 P = 006) Peak time was
correlated with adhesiveness (r = 077) cohesiveness (r = 068) gumminess (r = 060) and
chewiness (r = 060) and to a lesser extent with hardness (r = 053 P = 006)
Correlations between starch properties and seed DSC RVA characteristics
Total starch content correlated with seed hardness (r = -073) seed coat proportion (r = -
071) and starch viscosities (peak viscosity trough and final viscosity) (-068 lt r lt -060) and
also to a lesser extent with seed density (r = 054 P = 006) and starch thermal properties (To
Tp and enthalpy) (-051 lt r lt -049 008 lt P lt009) (Table 8)
Water solubility of starch was correlated with starch viscosity such as peak viscosity (r =
-049 P = 009) and breakdown (r = -048 P = 010) Swelling power was only correlated with
peak time (r = -054 P = 006) (data not shown)
Apparent amylose content was correlated with protein content (r = 058) and optimal
cooking time (r = 056) but total amylose content did not show either of these correlations Both
apparent and total amylose contents were correlated with starch gel hardness starch enthalpy
and starch viscosity such as trough breakdown final viscosity and peak time
The degree of amylose-lipid complex exhibited negative correlations with seed protein
content (r = -07) and optimal cooking time of quinoa seed (r = -067) Moreover amylose
leaching was negatively correlated with protein content (r = -062) starch gel hardness (r = --
064) starch Tp (r = -058) and enthalpy (r = -064) optimal cooking time (r = -055) and starch
viscosities such as breakdown (r = 062) and peak time (r = -081) Additionally α-amylase
95
activity was correlated with protein content (r = 066) seed density (r = -072) seed coat
proportion (r = 055) starch To (r = 061) and starch viscosities such as peak viscosity (r =
070) trough (r = 072) and final viscosity (r = 061)
Discussion
Starch content and composition
Total starch content does influence the functional and processing properties of cereals
The total starch content of quinoa was reported to be between 32 and 69 (Abugoch 2009)
Among our varieties most of the Port Townsend varieties and commercial quinoa contained
more than 69 starch It is interesting to note that the Port Townsend samples lsquo49ALCrsquo lsquo1ESPrsquo
lsquoCol6197rsquo and lsquoQQ63rsquo were also more sticky or more adhesive after cooking than other
varieties These varieties may exhibit better performance in extrusion products or in beverages
which require high viscosity
Amylose content affects texture and gelation properties The proportion of amylose and
amylopectin impacts the functionality of cereals in this study both apparent and total amylose
contents were determined Total amylose includes those amylose molecules that are complexed
with lipids
Amylose content of quinoa was reported to range from 35 to 225 dry basis
(Abugoch 2009) generally lower than that of common cereals which is around 25 Overall
both apparent and total amylose contents of the quinoa in the present study fell within the range
which has been reported lsquo49ALCrsquo was an exception showing significantly lower apparent and
total amylose contents of 27 and 47 respectively Thus this variety is close to be being a
lsquowaxyrsquo which refers to the cereal starches that are comprised of mostly amylopectin (99) and
96
little amylose (~1) As the waxy wheat showed an excellent expansion during extrusion
(Kowalski et al 2014) lsquo49ALCrsquo is a promising variety to produce breakfast cereal or extruded
snacks
The degree of amylose-lipid complex showed great variability among the samples 34 ndash
433 whereas the value in wheat flour was reported to be 32 (Bhatnagar and Hanna 1994) or
13 to 23 (Zeng et al 1997) Degree of amylose-lipid complex showed significant and
negative correlations with all texture parameters such as hardness adhesiveness cohesiveness
gumminess and chewiness
The effect of amylose-lipid complex on product texture has been reported in previous
studies The degree of amylose-lipid complex correlated with the texture (hardness and
crispness) and quality (radial expansion) of corn-based snack (Thachil et al 2014) Wokadala et
al (2012) indicated that amylose-lipid complexes played a significant role in starch biphasic
pasting
Starch properties
Amylose leaching was also highly variable among the quinoa varieties 35 ndash 862 mg
100g starch Vandeputte et al (2003) studied amylose leaching of waxy and normal rice
starches The amylose leaching values at 65 ordmC were below 1 of starch comparable with those
in quinoa starch Pronounced increase of amylose leaching was observed at the temperatures
higher than 95 ordmC Patindol et al (2010) found that both amylose and amylopectin leached out
during cooking rice The proportion of the leached amylose and amylopectin influenced the
texture of cooked rice We found similar results indicating correlations between amylose
leaching and texture of cooked quinoa
97
Water solubility of quinoa starch was significantly lower than that of corn starch whereas
swelling power of quinoa starch was higher than that of corn starch Both water solubility and
swelling power were determined at 95 ordmC Lindeboom et al (2005) determined swelling power
and solubility of quinoa starch among eight varieties at 65 75 85 and 95 ordmC The water
solubility at 95 ordmC ranged from 01 to 47 which was lower than the corn starch standard of
100 The swelling power at 95 ordmC ranged from 164 to 526 lower than the corn starch
standard of 549 The quinoa starch in this study showed a narrower range of swelling power
170 to 282
α-Amylase activity
The quinoa in this study had significantly different α-amylase activity (003 ndash 116 CU)
Previous studies reported low α-amylase activity in quinoa compared to oat (Maumlkinen et al
2013) and traditional malting cereals (Hager et al 2014) Moreover the activity of α-amylase
indicates the degree of seed germination and the availability of sugars for fermentation In the
study of Hager et al (2014) α-amylase activity increased from 0 to 35 CU during 72 h
germination
Texture of starch gel
Starch gel texture has been previously studied on corn and rice starches but not on
quinoa starch Hardness of rice starch gel was reported to be 339 g by Charoenrein et al (2011)
and 116 g by Jiang et al (2011) Hardness of corn starch was reported to be around 100 g in the
study of Sun et al (2014) much lower than the standard corn starch hardness in this study 721
g Compared to those of rice and corn starch quinoa starch gel exhibited harder texture which
may be caused by either genetic variation or different processing procedures to form the gel
98
Additionally springiness and cohesiveness of rice starch gel were reported as 085 and 055
respectively (Jiang et al 2011) Quinoa starch gel exhibited comparable springiness and higher
cohesiveness than those of rice starch gel
Thermal properties of quinoa starch
The thermal properties of quinoa starch in this study were comparable to those of rice
starch (Cai et al 2014) The study of Lindeboom et al (2005) however found lower
gelatinization temperatures and higher enthalpies compared to the present study which may be
due to varietal difference
Furthermore correlation between thermal properties of quinoa starch and flour (Wu et al
2014) was investigated Gelatinization temperatures To Tp and Tc of starch and whole seed
flour were highly correlated especially To and Tp exhibited high r of 088 The enthalpy of
starch and flour however was not significantly correlated In this case quinoa flour can be used
to estimate quinoa starch gelatinization temperatures but not the enthalpy Additionally since
flour is easier to prepare compared to starch further studies can be conducted with a larger
number of quinoa samples to model the prediction of starch thermal properties using flour
thermal properties
Starch pasting properties
Viscosity and pasting properties of starch play a significant role in the functionality of
cereals Jane et al (1999) studied the pasting properties of starch from cereals such as maize
rice wheat barley amaranth and millet The peak viscosities ranged from 58 RVU in barley to
219 RVU in sweet rice lower than those of most quinoa starches except lsquoJapanese Strainrsquo and
lsquoQQ63rsquo Final viscosities ranged from 54 RVU in barley to 208 RVU in cattail millet all lower
99
than those of the quinoa starches in the present study Setback of cereal starches mostly ranged
from 6 RVU in waxy amaranth to 74 RVU in non-waxy maize lower than those of most quinoa
starches except lsquoOre de Vallersquo Cattail millet starch exhibited the setback of 208 RVU higher
than those of quinoa starches
The relationships between RVA pasting parameters of quinoa starch and flour were
studied by Wu et al (2014) Final viscosity of starch and flour was correlated negatively (r = -
063 P = 002) The other RVA parameters did not exhibit significant correlation between starch
and flour RVA In other words RVA of quinoa flour cannot be used to predict RVA of quinoa
starch In addition to starch the fiber and protein in whole quinoa flour may influence the
viscosity As quinoa is normally utilized as whole grain or whole grain flour instead of refined
flour the flour RVA should be a better indication on the end-use functionality
Freeze-thaw stability of starch
Quinoa starches in the present study did not show high stability during freeze and thaw
cycles Praznik et al (1999) studied freeze-thaw stability of various cereal starches Similar to
the present study Praznik et al concluded quinoa starches exhibited low freeze-thaw stability
Conversely Ahamed et al (1996) found quinoa starch exhibited excellent freeze-thaw stability
Unfortunately the variety was not indicated Overall it is reasonable to assert that for some
quinoa cultivars the starch may have better freeze-thaw stability than in other cultivars
However most quinoa varieties in published studies did not show good freeze-thaw stability
Correlations between starch characteristics and texture of cooked quinoa
The quinoa starch characteristics correlated with the texture of cooked quinoa in some
aspects Total starch content however did not show any strong correlations with TPA
100
parameters as was initially expected Since quinoa is consumed as whole grain or whole flour
fiber and bran may exhibit more influence on the texture than anticipated from the impact of
starch alone
The quinoa varieties with higher apparent and total amylose contents tended to yield a
harder stickier more cohesive more gummy and chewy texture Similar correlations are found
with cooked rice noodle and corn-based extrusion snacks The hardness of cooked rice was
positively correlated with amylose content and negatively correlated with adhesiveness (Yu et al
2009) Epstein et al (2002) reported that full waxy noodles were softer thicker less adhesive
and chewy and more cohesive and springy compared to normal noodles and partial waxy
noodles Increased amylose content in a corn-based extrusion snack resulted in higher amylose-
lipid formation and softer texture (Thachil et al 2014)
Higher levels of amylose-lipid complex in starch were associated with softer less
adhesive less cohesive and less gummy and less chewy cooked quinoa The correlation between
the degree of amylose-lipid complex and texture of cooked rice or quinoa has not been
previously reported Kaur and Singh (2000) however found that amylose-lipid complex
increased with longer cooking time of rice flour Additionally cooking time is a key factor to
determine texture ndash the longer a cereal is cooked the softer less sticky less cohesive and less
gummy and chewy the texture
Correlations were found between amylose leaching and cooked quinoa TPA parameters
especially hardness gumminess and chewiness with r of -082 Increased amylose leaching
yielded a softer gel made from potato starch (Hoover et al 1994) However the correlations of
101
amylose leaching and α-amylase activity with texture of end product for quinoa have not been
reported previously
Swelling power and water solubility were reported to influence the texture of wheat and
rice noodle (Crosbie 1991 McCormick et al 1991 Konik et al 1993 Ross et al 1997
Bhattacharya et al 1999) However in the present report no correlation was found between
swelling power water solubility and the texture of cooked quinoa Additionally the study of
Ong and Blanshard (1995) indicated a positive correlation between enthalpy and the texture of
cooked rice Similar results were found in this study
RVA is a fast and reliable way to predict flour functionality and end-use properties
Pasting properties of rice flour have been used to predict texture of cooked rice (Champagne et
al 1999 Limpisut and Jindal 2002) In our previous study cooked quinoa texture correlated
negatively with the final viscosity and setback of quinoa flour (Wu et al 2014) In this study
texture correlated with trough breakdown final viscosity and peak time of quinoa starch
However RVA of quinoa flour and starch did not correlate with each other Flour RVA might be
a convenient way to predict cooked quinoa texture
Correlations between starch properties and seed DSC RVA characteristics
Quinoa with higher total starch tended to have a thinner seed coat This makes sense
because starch protein lipids and fiber are the major components of seed An increase in one
component will result in a proportional decrease in the other component contents
Additionally the starch RVA parameters (except peak viscosity) can be used to estimate
apparent or total amylose content based on their correlations Further studies should be
conducted with a larger sample size of quinoa and a more accurate prediction model can be built
102
The samples with lower protein or those requiring shorter cooking time tended to contain
higher levels of amylose-lipid complex Additionally amylose-lipid complex was reported to
influence the texture of extrusion products (Bhatnagar and Hanna 1994 Thachil et al 2014) For
this reason protein and optimal cooking time are promising indicators of the behavior of quinoa
during extrusion
Conclusions
In summary starch content composition and characteristics were significantly different
among quinoa varieties Amylose content degree of amylose-lipid complex and amylose
leaching property of quinoa starch exhibited great variances and strong correlations with texture
of cooked quinoa Additionally starch gel texture pasting properties and thermal properties
were different among varieties and different from those of rice and corn starches Enthalpy
RVA trough final viscosity and peak time exhibited significant correlations with cooked quinoa
texture Overall starch characteristics greatly influenced the texture of cooked quinoa
Acknowledgments
This project was supported by the USDA Organic Research and Extension Initiative
(NIFAGRANT11083982) The authors acknowledge Girish Ganjyal and Shyam Sablani for
using the Differential Scanning Calorimetry (DSC) thanks to Stacey Sykes for editing support
Author Contributions
G Wu and CF Morris designed the study together and established the starch isolation
protocol G Wu collected test data and drafted the manuscript CF Morris and KM Murphy
edited the manuscript KM Murphy provided quinoa samples
103
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581-31
Ahamed NT Singhal RS Kulkarni PR Pal M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 31(1)99-103
Araujo-Farro PC Podadera G Sobral PJA Menegalli FC 2010 Development of films based on
quinoa (Chenopodium quinoa Willd) starch Carbohydr Polym 81(4)839-48
Bhatnagar S Hanna MA 1994 Amylose-lipid complex formation during single-screw extrusion
of various corn starches Cereal Chem 71(6)582-6
Bhattacharya M Zee SY Corke H 1999 Physicochemical properties related to quality of rice
noodles Cereal Chem 76(6)861-7
Cai J Yang Y Man J Huang J Wang Z Zhang C Gu M Liu Q Wei C 2014 Structural and
functional properties of alkali-treated high-amylose rice starch Food Chem 145245-53
Champagne ET 2004 The rice grain and its gross composition In Champagne ET editor Rice
chemistry and technology St Paul Minn American Association of Cereal Chemists p 88
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5)764-71
104
Charoenrein S Tatirat O Rengsutthi K Thongngam M 2011 Effect of konjac glucomannan on
syneresis textural properties and the microstructure of frozen rice starch gels Carbohydr
Polym 83(1)291-6
Crosbie GB 1991 The relationship between starch swelling properties paste viscosity and
boiled noodle quality in wheat flours J Cereal Sci 13(2)145-50
De Pilli T Derossi A Talja R Jouppila K Severini C 2012 Starchndashlipid complex formation
during extrusion-cooking of model system (rice starch and oleic acid) and real food (rice
starch and pistachio nut flour) Eur Food Res Technol 234(3)517-25
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(waxy) genes J Cereal Sci 35(1) 51-63
Hager AS Maumlkinen OE Arendt EK 2014 Amylolytic activities and starch reserve mobilization
during the germination of quinoa Eur Food Res Technol 239(4)621-7
Hoover R Ratnayake WS 2002 Starch characteristics of black bean chick pea lentil navy bean
and pinto bean cultivars grown in Canada Food Chem 78(4)489-98
Hoover R Vasanthan T Senanayake NJ Martin AM 1994 The effects of defatting and heat-
moisture treatment on the retrogradation of starch gels from wheat oat potato and lentil
Carbohydr Res 261(1)13-24
105
Jane J Chen Y Lee L McPherson A Wong K Radosavljevic M Kasemsuwan T 1999 Effects
of amylopectin branch chain length and amylose content on the gelatinization and pasting
properties of starch 1 Cereal Chem 76(5)629-37
Jiang Q Xu X Jin Z Tian Y Hu X Bai Y 2011 Physico-chemical properties of rice starch
gels Effect of different heat treatments J Food Eng 107(3)353-7
Kaur K Singh N 2000 Amylose-lipid complex formation during cooking of rice flour Food
Chem 71(4)511-7
Konik CM Miskelly DM Gras PW 1993 Starch swelling power grain hardness and protein
relationship to sensory properties of japanese noodles Starch - Staumlrke 45(4)139-44
Kowalski R Morris C Ganjyal G 2015 Extrusion characteristics thermal and rheological
properties of soft white wheat flour in comparison with regular wheat flour Cereal Chem
92(2)145-53
Limpisut P Jindal VK 2002 Comparison of rice flour pasting properties using Brabender
Viscoamylograph and Rapid Visco Analyser for evaluating cooked rice texture Starch‐
Staumlrke 54(8)350-7
Lindeboom N Chang PR Falk KC Tyler RT 2005 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2)216-22
Mahmood T Turner MA Stoddard FL 2007 Comparison of methods for colorimetric amylose
determination in cereal grains Starch‐Staumlrke 59(8)357-65
106
Maumlkinen OE Zannini E Arendt EK 2013 Germination of oat and quinoa and evaluation of the
malts as gluten free baking ingredients Plant Foods Hum Nutr 68(1)90-5
Matos M Timgren A Sjoo M Dejmek P Rayner M 2013 Preparation and encapsulation
properties of double Pickering emulsions stabilized by quinoa starch granules Colloids and
Surfaces A 423147-53
McCormick K Panozzo J Hong S 1991 A swelling power test for selecting potential noodle
quality wheats Aust J Agric Res 42(3)317-23
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine structure of amylopectin J Cereal Sci 21(3)251-60
Ong MH Blanshard JMV 1995 Texture determinants of cooked parboiled rice II
Physicochemical properties and leaching behaviour of rice J Cereal Sci 21(3)261-9
Pagno CH Costa TMH de Menezes EW Benvenutti EV Hertz PF Matte CR Tosati JV
Monteiro AR Rios AO Flores SH 2015 Development of active biofilms of quinoa
(Chenopodium quinoa W) starch containing gold nanoparticles and evaluation of
antimicrobial activity Food Chem 173755-62
Patindol J Gu X Wang YJ 2010 Chemometric analysis of cooked rice texture in relation to
starch fine structure and leaching characteristics Starch - Staumlrke 62(3-4)188-97
Perdon AA Siebenmorgen TJ Buescher RW Gbur EE 1999 Starch retrogradation and texture
of cooked milled rice during storage J Food Sci 64(5)828-32
107
Praznik W Mundigler N Kogler A Pelzl B Huber A Wollendorfer M 1999 Molecular
background of technological properties of selected starches Starch‐Staumlrke 51(6) 197-211
Qian J Kuhn M 1999 Characterization of Amaranthus cruentus and Chenopodium quinoa
starch Starch‐Staumlrke 51(4)116-20
Ramesh M Zakiuddin Ali S Bhattacharya KR 1999 Structure of rice starch and its relation to
cooked-rice texture Carbohydr Polym 38(4)337-47
Rayner M Sjoumlouml M Timgren A Dejmek P 2012 Quinoa starch granules as stabilizing particles
for production of Pickering emulsions Faraday Discuss 158(1)139-55
Ross AS Quail KJ Crosbie GB 1997 Physicochemical properties of Australian flours
influencing the texture of yellow alkaline noodles Cereal Chem 74(6)814-20
Sun Q Xing Y Qiu C Xiong L 2014 The pasting and gel textural properties of corn starch in
glucose fructose and maltose syrup PloS one 9(4)e95862
Thachil MT Chouksey MK Gudipati V 2014 Amylose-lipid complex formation during
extrusion cooking effect of added lipid type and amylose level on corn-based puffed snacks
Int J Food Sci Tech 49(2)309-16
Vandeputte GE Derycke V Geeroms J Delcour JA 2003 Rice starches II Structural aspects
provide insight into swelling and pasting properties J Cereal Sci 38(1)53-9
Wokadala OC Ray SS Emmambux MN 2012 Occurrence of amylosendashlipid complexes in teff
and maize starch biphasic pastes Carbohydr Polym 90(1)616-22
108
Wu G Morris C F Murphy K M 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79(11)2337-45
Yu S Ma Y Sun DW 2009 Impact of amylose content on starch retrogradation and texture of
cooked milled rice during storage J Cereal Sci 50(2)139-44
Zeng M Morris CF Batey IL Wrigley CW 1997 Sources of variation for starch gelatinization
pasting and gelation properties in wheat Cereal Chem 74(1)63-71
109
Table 1-Quinoa varieties tested
Variety Original Seed Source Location
Black White Mountain Farm White Mountain Farm Colo USA
Blanca White Mountain Farm White Mountain Farm Colo USA
Cahuil White Mountain Farm White Mountain Farm Colo USA
Cherry Vanilla Wild Garden Seeds Philomath Oregon
WSUa Organic Farm Pullman Wash USA
Oro de Valle Wild Garden Seeds Philomath Oregon
WSUa Organic Farm Pullman Wash USA
49ALC USDA Port Townsend Wash USA
1ESP USDA Port Townsend Wash USA
Copacabana USDA Port Townsend Wash USA
Col6197 USDA Port Townsend Wash USA
Japanese Strain USDA Port Townsend Wash USA
QQ63 USDA Port Townsend Wash USA
Yellow Commercial Multi Organics company Bolivia
Red Commercial Multi Organics company Bolivia a WSU Washington State Univ
110
Table 2-Starch content and composition
Variety Total starch
(g 100 g)
Apparent amylose
()
Total
amylose ()
Degree of amylose
lipid complex ()
Black 532f 153a 159ab 96bc
Blanca 595de 102cd 163a 361ab
Cahuil 622d 169a 173a 34c
Cherry Vanilla
590de 105cd 116bc 164abc
Oro de Valle 573ef 114bcd 166a 300abc
49ALC 674c 27e 47d 426a
1ESP 705bc 86d 152abc 389ab
Copacabana 734ab 120bc 153abc 222abc
Col6197 725ab 102cd 140abc 433a
Japanese Strain
723ab 116bcd 165ab 305abc
QQ63 713abc 84d 111c 241abc
Yellow Commercial
751a 147ab 150abc 118abc
Red Commercial
691bc 100cd 164a 375ab
Corn starch - 264 - -
111
Table 3-Starch properties and α-amylase activity
Variety Amylose leaching (mg 100 g starch)
Water solubility ()
Swelling power
α-Amylase activity (CU)
Black 210ef 16de 260bcd 043d
Blanca 171efg 10de 260bcd 086c
Cahuil 97fg 16cde 253cd 106b
Cherry Vanilla 394d 15de 253cd 116a
Oro de Valle 420d 16de 245d 103b
49ALC 862a 07e 282a 031e
1ESP 716b 13de 276ab 003g
Copacabana 438cd 14de 263bc 020f
Col6197 552c 19cd 257cd 009g
Japanese Strain 31fg 45a 170f 005g
QQ63 315de 26bc 262bc 008g
Yellow Commercial
349d 32b 188e 005g
Red Commercial 35g 26bc 196e 003g
Corn starch - 79 89 -
112
Table 4-Texture of starch gel
Variety Hardness (g) Springiness Cohesiveness
Black 725ab 082ab 064cd
Blanca 649abc 083ab 072bc
Cahuil 900a 085ab 072bc
Cherry Vanilla 607abc 078bc 072bc
Oro de Valle 448abc 078bc 064cd
49ALC 333bc 081bc 061cd
1ESP 341bc 081bc 073bc
Copacabana 402bc 084ab 078ab
Col6197 534abc 083ab 083ab
Japanese Strain 765ab 092a 089a
QQ63 201c 078bc 053d
Yellow Commercial 436bc 071c 057d
Red Commercial 519abc 075bc 055d
Corn starch 721 084 073
113
Table 5-Thermal properties of starch
Variety Gelatinization temperature Enthalpy (Jg)
To (ordmC) Tp (ordmC) Tc (ordmC)
Black 560b 639bc 761bc 112abc
Blanca 586a 652ab 754bcd 113abc
Cahuil 582a 648ab 755bcd 116a
Cherry Vanilla 563b 627cd 747bcd 111abc
Oro de Valle 562b 623d 739cd 106abc
49ALC 524ef 598f 747bcd 101bc
1ESP 530de 608ef 738cd 103abc
Copacabana 565b 622d 731de 106abc
Col6197 540cd 598f 697f 105abc
Japanese Strain 579a 654a 788a 104abc
QQ63 545c 616de 766ab 99c
Yellow Commercial 515f 599f 708ef 107abc
Red Commercial 520ef 595f 700 f 116ab
Corn starch 560 626 743 105
114
Table 6-Pasting properties of starch
Variety Peak viscosity
(RVU)a
Trough
(RVU)
Breakdown
(RVU)
Final viscosity
(RVU)
Setback
(RVU)
Peak time
(min)
Black 293abc 252abc 41efg 363ab 111abcd 92e
Blanca 344a 301a 42defg 384ab 82de 111ab
Cahuil 342ab 297a 45def 405a 108abcd 106bc
Cherry Vanilla 313abc 263abc 50de 369ab 106abcd 99d
Oro de Valle 294abc 277ab 17fg 330abc 53e 105c
49ALC 256cde 137f 119a 225d 88cde 64i
1ESP 269bcd 172ef 97ab 313bc 140a 79h
Copacabana 258cde 186def 72bcd 308bc 122abc 81gh
Col6197 270bcd 231bcd 39efg 347ab 116abcd 86fg
Japanese Strain 193e 181def 12g 264cd 83de 113a
QQ63 213de 152f 60cde 254cd 101bcd 88ef
Yellow Commercial
290abc 223cde 67bcde 350ab 127ab 93de
Red Commercial 327abc 242bc 85bc 366ab 125ab 92ef
Corn 255 131 124 283 152 73 aRVU = cP12
115
Table 7-Correlation coefficients between starch properties and texture of cooked quinoaa
Hardness Adhesiveness Cohesiveness Gumminess Chewiness
Total starch content
-032ns -048 -043ns -039ns -039ns
Apparent amylose content
069 072 069 072 072
Actual amylose content
061 062 056 061 061
Degree of amylose-lipid complex
-065 -060 -070 -070 -070
Amylose leaching
-082 -075 -074 -082 -082
α-Amylase activity
018ns 055 051 032ns 032ns
Starch gel hardness
042ns 059 051 049 049
DSC
To 034ns 049 051 041ns 041ns
Tp 047 052 056 052 052
ΔH 064 072 069 070 070
RVA
Peak viscosity 031ns 054 047 041ns 041ns
Trough 044ns 077 063 055 055
Breakdown -034ns -060 -044ns -038ns -038ns
Final viscosity 045ns 068 058 053 053
Peak time 053 077 068 060 060
ns non-significant difference P lt 010 P lt 005 P lt 001 aTPA is the Texture Profile Analysis of cooked quinoa data were presented in Wu et al (2014)
116
Table 8-Correlations between starch properties and seed DSC RVA characteristicsa
Total
starch content
Water solubility
Apparent amylose content
Total amylose content
Degree of amylose-lipid complex
Amylose leaching
α-Amylase activity
Protein -047ns 023ns 058 031ns -069 -062 066
Seed hardness
-073 -041ns -003ns -021ns -020ns 019ns 053
Bulk density
054 049 -020ns -015ns 031ns 019ns -072
Seed coat proportion
-071 -041ns 027ns 021ns -028ns -038ns 055
Starch gel hardness
-045ns 017 ns 065 053 -044ns -064 046ns
Starch DSC
To -049 -004ns 041ns 043ns -033ns -049 061
Tp -050 010ns 047ns 045ns -042ns -058 052
Enthalpy -051 -011ns 059 055 -041ns -064 049
Starch viscosity
Peak viscosity
-066 -049 028ns 027ns -020ns -023ns 070
Trough -068 -017ns 056 057 -031ns -052 072
Breakdown
022ns -048 -061 -067 027ns 062 -025ns
Final viscosity
-060 -022ns 063 060 -037ns -046ns 061
Peak time -032ns 045ns 058 072 -029ns -081 043ns
117
Cooking quality
Optimal cooking time
-043ns 019ns 056 040ns -067 -055 029ns
ns non-significant difference P lt 010 P lt 005 P lt 001 aSeed characteristics data were presented in Wu et al (2014)
118
Chapter 5 Quinoa Seed Quality Response to Sodium Chloride and
Sodium Sulfate Salinity
Submitted to the Frontiers in Plant Science
Research Topic Protein crops Food and feed for the future
Abstract
Quinoa (Chenopodium quinoa Willd) is an Andean grain with an edible seed that both contains
high protein content and provides high quality protein with a balanced amino acid profile
Quinoa is a halophyte adapted to harsh environments with highly saline soil In this study four
quinoa varieties were grown under six salinity treatments and two levels of fertilization and then
evaluated for quinoa seed quality characteristics including protein content seed hardness and
seed density Concentrations of 8 16 and 32 dS m-1 of NaCl and Na2SO4 as well as a no-salt
control were applied to the soil medium across low (1 g N 029 g P 029 g K per pot) and high
(3 g N 085 g P 086 g K per pot) fertilizer treatments Seed protein content differed across soil
salinity treatments varieties and fertilization levels Protein content of quinoa grown under
salinized soil ranged from 130 to 167 comparable to that from normal conditions NaCl
and Na2SO4 exhibited different impacts on protein content Whereas the different concentrations
of NaCl did not show differential effects on protein content the seed from 32 dS m-1 Na2SO4
contained the highest protein content Seed hardness differed among varieties and was
moderately influenced by salinity level (P = 009) Seed density was affected significantly by
119
variety and Na2SO4 concentration but was unaffected by NaCl concentration The plants from 8
dS m-1 Na2SO4 soil had lower density (066 gcm3) than those from 16 dS m-1 and 32 dS m-1
Na2SO4 074 and 072gcm3 respectively This paper identifies changes in critical seed quality
traits of quinoa as influenced by soil salinity and fertility and offers insights into variety
response and choice across different abiotic stresses in the field environment
Key words quinoa soil salinity protein content hardness density
120
Introduction
Quinoa (Chenopodium quinoa Willd) has garnered much attention in recent years
because it is an excellent source of plant-based protein and is highly tolerance of soil salinity
Because soil salinity affects between 20 to 50 of irrigated arable land worldwide (Pitman and
Lauchli 2002) the question of how salinity affects seed quality in a halophytic crop like quinoa
needs to be addressed Protein content in most quinoa accessions has been reported to range from
12 to 17 depending on variety environment and inputs (Rojas et al 2015) This range
tends to be higher than the protein content of wheat barley and rice which were reported to be
105- 14 8-14 and 6-7 respectively (Shih 2006 Orth and Shellenberger1988 Cai et
al 2013) Additionally quinoa has a well-balanced complement of essential amino acids
Specifically quinoa is rich in lysine which is considered the first limiting essential amino acid in
cereals (Taylor and Parker 2002) Protein quality such as Protein Efficiency Ratio is similar to
that of casein (Ranhotra et al 1993) Furthermore with a lack of gluten protein quinoa can be
safely consumed by gluten sensitiveintolerant population (Zevallos et al 2014)
Quinoa shows exceptional adaption to harsh environments such as drought and salinity
(Gonzaacutelez et al 2015) Soil salinity reduces crop yields and is a worldwide problem In the
United States approximately 54 million acres of cropland in forty-eight States were occupied by
saline soils while another 762 million acres are at risk of becoming saline (USDA 2011) The
salinity issue leads producers to grow more salt-tolerant crops such as quinoa
Many studies have focused on quinoarsquos tolerance to soil salinity with a particular
emphasis on plant physiology (Ruiz-Carrasco et al 2011 Adolf et al 2012 Cocozza et al
121
2013 Shabala et al 2013) and agronomic characteristics such as germination rate plant height
and yield (Prado et al 2000 Chilo et al 2009 Peterson and Murphy 2015 Razzaghi et al
2012) For instance Razzaghi et al (2012) showed that the seed number per m2 and seed yield
did not decrease as salinity increased from 20 to 40 dS m-1 in the variety Titicaca Ruiz-Carrasco
et al (2011) reported that under 300 mM NaCl germination and shoot length were significantly
reduced whereas root length was inhibited in variety BO78 variety PRJ biomass was less
affected and exhibited the greatest increase in proline concentration Jacobsen et al (2000)
suggested that stomatal conductance leaf area and plant height were the characters in quinoa
most sensitive to salinity Wilson et al (2002) examined salinity stress of salt mixtures of
MgSO4 Na2SO4 NaCl and CaCl2 (3 ndash 19 dS m-1) No significant reduction in plant height and
fresh weight were observed In a comparison of the effects of NaCl and Na2SO4 on seed yield
quinoa exhibited greater tolerance to Na2SO4 than to NaCl (Peterson and Murphy 2015)
Few studies have focused on the influence of salinity on seed quality in quinoa Karyotis
et al (2003) conducted a field experiment in Greece (80 m above sea level latitude 397degN)
With the exception of Chilean variety lsquoNo 407rsquo seven other varieties exhibited significant
increases in protein (13 to 33) under saline-sodic soil with electrical conductivity (EC) of
65 dS m-1 Mineral contents of phosphorous iron copper and boron did not decrease under
saline conditions Koyro and Eisa (2008) found a significant increase in protein and a decrease in
total carbohydrates under high salinity (500 mM) Pulvento et al (2012) indicated that fiber and
saponin contents increased under saline conditions with well watersea water ratio of 11
compared to those under normal soil
122
Protein is one of the most important nutritional components of quinoa seed The content
and quality of protein contribute to the nutritional value of quinoa Additionally seed hardness is
an important trait in crops such as wheat and soybeans For instance kernel hardness highly
influences wheat end-use quality (Morris 2002) and correlates with other seed quality
parameters such as ash content semolina yield and flour protein content (Hruškovaacute and Švec
2009) Hardness of soybean influenced water absorption seed coat permeability cookability
and overall texture (Zhang et al 2008) Quinoa seed hardness was correlated with the texture of
cooked quinoa influencing hardness chewiness and gumminess and potentially consumer
experience (Wu et al 2014) Furthermore seed density is also a quality index and is negatively
correlated with the texture of cooked quinoa such as hardness cohesiveness chewiness and
gumminess (Wu et al 2014)
Chilean lowland varieties have been shown to be the most well-adapted to temperate
latitudes (Bertero 2003) and therefore they have been extensively utilized in quinoa breeding
programs in both Colorado State University and Washington State University (Peterson and
Murphy 2015) For these reasons Chilean lowland varieties were evaluated in the present study
The objectives of this study were to 1) examine the effect of soil salinity on the protein content
seed hardness and density of quinoa varieties 2) determine the effect of different levels of two
agronomically important soil salts NaCl and Na2SO4 on seed quality and 3) test the influence
of fertilization levels on salinity tolerance of quinoa The present study illustrates the different
influence of NaCl and Na2SO4 on quinoa seed quality and provides better guidance for variety
selection and agronomic planning in highly saline environments
Materials and Methods
123
Genetic material
Quinoa germplasms were obtained from Dr David Brenner at the USDA-ARS North
Central Regional Plant Introduction Station in Ames Iowa The four quinoa varieties CO407D
(PI 596293) UDEC-1 (PI 634923) Baer (PI 634918) and QQ065 (PI 614880) were originally
sourced from lowland Chile CO407D was released by Colorado State University in 1987
UDEC-1 Baer and QQ065 were varieties from northern central and southern locations in Chile
with latitudes of 3463deg S 3870deg S and 4250deg S respectively
Experimental design
A controlled environment greenhouse study was conducted using a split-split-plot
randomized complete block design with three replicates per treatment Factors included four
quinoa varieties two fertility levels and seven salinity treatments (three concentration levels
each of NaCl and Na2SO4) Three subsamples each representing a single plant were evaluated
for each treatment combination Quinoa variety was treated as the main plot salinity level as the
sub-plot and fertilization as the sub-sub-plot Salinity levels included 8 16 and 32 dS m-1 of
NaCl and Na2SO4 The details of controlling salinity levels were described by Peterson and
Murphy (2015) In brief fertilization was provided by a mixture of alfalfa meal
monoammonium phosphate and feather meal Low fertilization level referred to 1 g of N 029 g
of P and 029 g of K in each pot and high fertilization level referred to 3 g of N 086 g of P and
086 g of K in each pot Each pot contained about 1 L of Sunshine Mix 1 (Sun Gro Horticulture
Bellevue WA) (dry density of 100 gL water holding capacity of ca 480 gL potting mix) The
124
entire experiment was conducted twice with the planting dates of September 10th 2011 and
October 7th 2011
Seed quality tests
Protein content of quinoa was determined using the Dumas combustion nitrogen method
(LECO Corp Joseph Mich USA) (AACCI Method 46-3001) A factor of 625 was used to
convert nitrogen to protein Seed hardness was determined using the Texture Analyzer (TA-
XT2i) (Texture Technologies Corp Scarsdale NY) and a modified rice kernel hardness method
(Krishnamurthy and Giroux 2001) A single quinoa kernel was compressed until the point of
fracture using a 1 cm2 cylinder probe traveling at 5 mms Repeat measurements were taken on 9
random kernels The seed hardness was recorded as the average peak force (Kg) of the repeated
measures
Seed density was determined using a pycnometer (Pentapyc 5200e Quantachrome
Instruments Boynton Beach FL) Quinoa seed was placed in a closed micro container and
compressed nitrogen was suffused in the container Pressure in the container was recorded both
with and without nitrogen The volume of the quinoa sample was calculated by comparing the
standard pressure obtained with a stainless steel ball Density was the seed weight divided by the
displaced volume Seed density was collected on only the second greenhouse experiment
Statistical analysis
Data were analyzed using the PROC GLM procedure in SAS (SAS Institute Cary NC)
Greenhouse experiment repetition was treated as a random factor in protein content and seed
hardness analysis Variety salinity and fertilization were treated as fixed factors Fisherrsquos LSD
125
Test was used to access multiple comparisons Pearson correlation coefficients between protein
hardness and density were obtained via PROC CORR procedure in SAS using the treatment
means
Results
Protein
Variety salinity and fertilization all exhibited highly significant effects on protein
content (P lt 0001) (Table 1) The greatest contribution to variation in seed protein was due to
fertilization (F = 40247) In contrast salinity alone had a relatively minor effect and the
varieties responded similarly to salinity as evidenced by a non-significant interaction The
interactions however were found in variety x fertilization as well as in salinity x fertilization
both of which were addressed in later paragraphs It is worth noting that the two experiments
produced different seed protein contents (F = 4809 P lt0001) experiment x variety interaction
was observed (F = 1494 P lt0001) (data not shown) Upon closer examination this interaction
was caused by variety QQ065 which produced an overall mean protein content of 129 in
experiment 1 and 149 in experiment 2 Protein contents of the other three varieties were
essentially consistent across the two experiments
Across all salinity and fertilization treatments the variety protein means ranged from
130 to 167 (data not shown) As expected high fertilization resulted in an increase in
protein content across all varieties The mean protein contents under high and low fertilization
were 158 and 136 respectively (Table 2) The means of Baer and CO407D were the
126
highest 151 and 149 respectively QQ065 contained 141 protein significantly lower
than the other varieties
Even though salinity effects were relatively smaller than fertilization and variety effects
salinity still had a significant effect on protein content (Table 1) The two types of salt exhibited
different impacts on protein (Table 2) Protein content did not differ according to different
concentrations of NaCl with means (across varieties and fertilization levels) from 147 to
149 Seed from 32 dS m-1 Na2SO4 however contained higher protein (152) than that from
8 dS m-1 and 16 dS m-1 Na2SO4 (144 and 142 respectively)
A significant interaction of salinity x fertilization was detected indicating that salinity
differentially impacted seed protein content under high and low fertilization level (Figure 1)
Within the high fertilizer treatment protein content in the seed from 32dS m-1 Na2SO4 was
significantly higher (167) than all other samples which did not differ from each other (~13)
Within the low fertilizer treatment protein content of seeds from 8 dS m-1 and 16 dS m-1
Na2SO4 were significantly lower than those from the NaCl treatments and 32dS m-1 Na2SO4
The significant interaction between variety and fertilization (Table 1) was due to the
different response of QQ065 Protein mean of QQ065 from high fertilization was 144 lower
than the other varieties CO407D UDEC-1 and Baer exhibited a decline of 16 - 18 in
protein under low fertilization while QQ065 dropped only 5
Hardness
Variety exhibited the greatest influence on seed hardness (F = 21059 P lt0001)
whereas fertilization did not show any significant effect (Table 1) Salinity exhibited a moderate
127
effect (F = 200 P = 009) Varieties responded consistently to salinity under various fertilization
levels since neither variety x salinity nor salinity x fertilization interaction was significant
However a variety x fertilization interaction was observed which will be discussed in a later
paragraph Similar to the situation in protein content experiment repetition exhibited a
significant influence on seed hardness Whereas the hardness of CO407D was consistent across
the two greenhouse experiments the hardness of other three varieties all decreased by 8 to 9
Mean hardness was significantly different among varieties CO407D had the hardest
seeds with hardness mean of 100 kg (Table 3) UDEC-1 was softer at 94 kg whereas Baer and
QQ065 were the softest and with similar hardness means of 77 kg and 74 kg respectively
Salinity exhibited a moderate impact on seed hardness (P = 009) The highest hardness
mean was observed under 16 dS m-1 Na2SO4 whereas the lowest was under 8 dS m-1 NaCl with
means of 89 and 83 kg respectively
A significant fertilization x variety interaction was found for seed hardness The hardness
of UDEC-1 and Baer did not differ across fertilization level whereas CO407D was harder under
low fertilization and QQ065 was harder under high fertilization
Seed density
Variety and salinity both significantly affected seed density whereas fertilization did not
show a significant influence (Table 1) The greatest contribution to variation in seed density was
due to variety (F = 2282) Salinity exhibited a relatively smaller effect yet still significant (F =
282 P lt005) Neither variety x salinity interaction nor salinity x fertilization interaction was
observed which indicated that varieties similarly responded to salinity under high and low
128
fertilization levels An interaction of variety x fertilization was found and the details were
presented later
Across all salinity and fertilization treatments CO407D had the highest mean density
080 gcm3 followed by Baer with 069 gcm3 (Table 4) UDEC-1 and QQ065 had the lowest and
similar densities (~065 gcm3)
With regard to salinity effect the Na2SO4 treatments exhibited differential influence on
seed density Density means did not significantly change due to the increased concentration of
NaCl ranging from 068 to 071 gcm3 (Table 4) The samples from 8 dS m-1 Na2SO4 soil had
lower density (066 gcm3) than those from 16 dS m-1 and 32 dS m-1 Na2SO4 074 and
072gcm3 respectively
A significant variety x fertilization interaction was found With closer examination
UDEC-1 and Baer yielded higher density seeds under high fertilization whereas CO407D and
QQ065 did not differ in density between fertilization treatments
Correlations of protein hardness and density
Correlation coefficients among seed protein content hardness and density are shown in
Table 5 No significant correlation was detected between protein content and seed hardness
However both protein content and hardness were correlated with seed density The overall
correlation coefficient was low (r = 019 P = 003) between density and protein A marginally
significant correlation was found between density and protein content of the seeds from NaCl
salinized soil under low fertilization No correlation was found between density and protein
content of the seeds from NaCl salinized soil under high fertilization or Na2SO4 salinized soil
129
The overall correlation coefficient was 038 (P lt 00001) between density and hardness
The low fertilization samples from both NaCl and Na2SO4 soil showed significant correlations
between density and hardness with coefficients of 051 and 047 (both P lt 0005) The high
fertility quinoa did not exhibit any correlation between density and hardness
Correlation with yield leaf greenness index plant height and seed minerals contents
Correlation between seed quality and yield leaf greenness index plant height and seed
mineral concentration were obtained using data from Peterson and Murphy (2015) (Table 6)
Seed hardness significantly correlated with yield and plant height (r = 035 and 031
respectively) Protein content and density however did not correlate with yield leaf greenness
or plant height Correlations were found between quality indices and the concentration of
different minerals Protein was negatively correlated with Cu and Mg (r = -052 and -050
respectively) Hardness was negatively correlated with Cu P and Zn (r = -037 -056 -029
respectively) but was positively correlated with Mn (r = 057) Density was negatively
correlated with Cu (r = -035)
Discussion
Protein
Although salinity exhibited a significant effect on seed protein content the impact was
relatively minor compared to fertilization and variety effects In another words over a wide
range of saline soil quinoa can grow and yield seeds with stable protein content
130
Protein content of quinoa growing under salinized soil ranged from 127 to 167 (data
not shown) within the general range of protein content under non-saline conditions which was
12 to 17 (Rojas et al 2015) Saline soil did not cause a significant decrease in seed protein
It is interesting to notice that the samples from 32 dS m-1 Na2SO4 tended to contain the highest
protein especially in variety QQ065 The studies of Koyro and Eisa (2008) and Karyotis et al
(2003) also indicated that protein content significantly increased under high salinity (NaCl)
whereas total carbohydrates decreased In contrast Ruffino et al (2009) found that quinoa
protein decreased under 250 mM NaCl salinity in a growth chamber experiment It is reasonable
to conclude that salinity exhibits contrasting effects on different quinoa genotypes QQ065 and
CO407D both significantly increased in protein under 32 dS m-1 Na2SO4 however the yield
decline was 519 and 245 respectively (Peterson and Murphy 2015) This result indicted
that CO407D was the variety most optimally adapted to severe sodic saline soil tested in this
study
Na2SO4 level exhibited a significant influence on protein content whereas NaCl level did
not In the study of Koyro and Eisa (2008) however seed protein of the quinoa variety Hualhuas
(origin from Peru) increased under the highest salinity level of 500 mM NaCl compared to lower
NaCl levels (0 ndash 400 mM) This disagreement of NaCl influence may be due to diversity of
genotypes It is worth noting that quinoa protein contents in this paper were primarily above 13
based on wet weight (as-is-moisture of approximately ~8 -10) even under saline soil and low
fertilization level This protein content is generally equal to or higher than that of other crops
such as barley and rice (Wu 2015) In conclusion quinoa maintained high and stable protein
content under salinity stress
131
Hardness
Quinoa seed hardness was only moderately affected by salinity (P = 009) indicating that
quinoa primarily maintained seed texture when growing under a wide range of saline soil
CO407D exhibited the hardest seed (100 kg) whereas Baer and QQ065 were relatively soft (74
ndash 77 kg) A previous study indicated a hardness range of 58 ndash 109 kg among 11 quinoa
varieties and 2 commercial samples (Wu et al 2014) The commercial samples had hardness
values of 62 kg and 71 kg Since commercial samples generally maintain stable quality and
indicate an acceptable level for consumers seed hardness around 7 kg as in Baer and QQ065
should be considered as acceptable quality The hardness of CO407D was close to that of the
colored variety lsquoBlackrsquo (100 kg) which had a thicker seed coat than that of the yellow seeded
varieties It was reported that a thicker seed coat is related to harder texture (Fraczek et al 2005)
Even though the greenhouse is a highly controlled environment and the two experiments
were conducted in similar seasons (planted in September and October respectively) seed protein
and hardness were still different across the two experiments However ANOVA indicated
modest-to-no significant interactions with salinity and fertilization such that responses to salinity
and fertilization were consistent with little or no change in rank order Even though experiment x
variety was significant the F-values were relatively low compared to the major effects such as
variety and fertilization and neither of them was crossing interaction This is a particularly
noteworthy result for breeders farmers and processors
Density
132
The range of seed density under salinity 055 ndash 089 gcm3 was comparable to the
density range of 13 quinoa samples (058 ndash 076 gcm3 ) (Wu et al 2014) Generally CO407D
had higher seed density (071 ndash 089 gcm3) which indicated that seed density in this variety was
affected by salinity stress In contrast the density of QQ065 did not change according to salinity
type or concentration which indicated a stable quality under saline soil
Correlations
The correlation between seed hardness and density was only significant under low fertilization
but not under high fertilization The high fertilization level in the greenhouse experiment
exceeded the amount of fertilizer that would normally be applied in field environments whereas
the low fertilization level is closer to the field situation Therefore correlation between hardness
and density may still exist in field trials
Conclusions
Under saline soil conditions quinoa did not show any marked decrease in seed quality
such as protein content hardness and density Protein content even increased under high Na2SO4
concentration (32 dS m-1) Varieties exhibited great differential reactions to fertilization and
salinity levels QQ065 maintained a similar level of hardness and density whereas seed of
CO407D was both harder and higher density under salinity stress If only seed quality is
considered then QQ065 is the most well-adapted variety in this study
The influences of NaCl and Na2SO4 were different The higher concentration of Na2SO4
tended to increase protein content and seed density whereas NaCl concentration did not exhibit
any significant difference on those quality indexes
133
Acknowledgement
The research was funded by USDA Organic Research and Extension Initiative project
number NIFAGRANT11083982 The authors acknowledge Alecia Kiszonas for assisting in the
data analysis
Author contributions
Peterson AJ set up the experiment design in the greenhouse and grew harvested and
processed quinoa samples Wu G collected seed quality data such as protein content seed
hardness and density Peterson AJ and Wu G together processed the data Wu G also drafted the
manuscript Murphy KM and Morris CF edited the manuscript
Conflict of interest statement
The authors declared to have no conflict of interest
134
References
AACC International Approved Methods of Analysis Method 46-3001 Crude protein ndash
Combustion method Approved November 8 1995 Reapproved November 3 1999
Availablenline only AACCI St Paul MN
Adolf VI Shabala S Andersen MN Razzaghi F Jacobsen SE 2012 Varietal differences of
quinoas tolerance to saline conditions Plant Soil 357 117ndash29
Bertero HD 2003 Response of developmental processes to temperature and photoperiod in
quinoa (Chenopodium quinoa Willd) Food Rev Int 19 87ndash97
Cai S Yu G Chen X Huang Y Jiang X Zhang G Jin X 2013 Grain protein content variation
and its association analysis in barley BMC Plant Boil 13 35
Chilo G Molina MV Carabajal R Ochoa M 2009 Temperature and salinity effects on
germination and seedling growth on two varieties of Chenopodium quinoa Agri-Scientia 26
15ndash22
Cocozza C Pulvento C Lavini A Riccardi M dAndria R Tognetti R 2013 Effects of
increasing salinity stress and decreasing water availability on ecophysiological traits of
quinoa (Chenopodium quinoa Willd) grown in a mediterranean-type agroecosystem J Agron
Crop Sci 199 229ndash40
Fraczek J Hebda T Slipek Z Kurpaska S 2005 Effect of seed coat thickness on seed hardness
Can Biosyst Eng 47 41ndash5
135
Gonzaacutelez JA Eisa SSS Hussin SAES Prado FE 2015 Quinoa an Incan crop to face global
changes in agriculture In Murphy KM Matanguihan J editors Quinoa Improvement and
Sustainable Production Hoboken NJ John Wiley Sons p 7ndash11
Hruškovaacute M Švec I 2009 Wheat hardness in relation to other quality factors Czech J Food Sci
27 240ndash8
Jacobsen S Quispe H Mujica A 2000 Quinoa an alternative crop for saline soils in the Andes
in Scientist and Farmer Partners in Research for the 21st Century (Program Report 1999-
2000) ed International Potato Center (Peru) 403ndash8
Jancurovaacute M Minarovicovaacute L Dandar A 2009 Quinoandasha review Czech J Food Sci 27 71ndash9
Karyotis T Iliadis C Noulas C Mitsibonas T 2003 Preliminary research on seed production
and nutrient content for certain quinoa varieties in a salinendashsodic soil J Agron Crop Sci 189
402ndash8
Koyro HW Eisa S 2008 Effect of salinity on composition viability and germination of seeds of
Chenopodium quinoa Willd Plant Soil 302 79-90
Krishnamurthy K Giroux MJ 2001 Expression of wheat puroindoline genes in transgenic rice
enhances grain softness Nat Biotechnol 19 162ndash6
Morris CF 2002 Puroindolines the molecular genetic basis of wheat grain hardness Plant mol
Biol 48 633ndash47
136
Orth RA Shellenberger JA 1988 Chapter 1 Origin production and utilization of wheat In
Pomeranz Y editor Wheat Chemistry and Technology 3th edition St Paul MN American
Association of Cereal Chemists Inc p 11ndash2
Peterson A Murphy K 2015 Tolerance of lowland quinoa cultivars to sodium chloride and
sodium sulfate salinity Crop Sci 55 331ndash8
Pitman MG Laumluchli A 2002 Global impact of salinity and agricultural ecosystems In Laumluchli
A Luumlttge U editors Netherlands Springer p 3ndash20
Prado FE Boero C Gallardo M Gonzaacutelez JA 2000 Effect of NaCl on germination growth and
soluble sugar content in Chenopodium quinoa Willd seeds Bot Bull Acad Sinica 41 27ndash34
Pulvento C Riccardi M Lavini A Iafelice G Marconi E dAndria R 2012 Yield and quality
characteristics of quinoa grown in open field under different saline and non-saline irrigation
regimes J Agron Crop Sci 198 254ndash63
Ranhotra G Gelroth J Glaser B Lorenz K Johnson D 1993 Composition and protein
nutritional quality of quinoa Cereal Chem 70 303ndash5
Razzaghi F Ahmadi SH Jacobsen SE Jensen CR Andersen MN 2012 Effects of salinity and
soilndashdrying on radiation use efficiency water productivity and yield of quinoa (Chenopodium
quinoa Willd) J Agron Crop Sci 198 173ndash84
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile D
137
Bertero D Nieto C editors State of the Art Report of Quinoa in the World in 2013 Rome
FAO amp CIRAD p 67-8
Ruffino A Rosa M Hilal M Gonzaacutelez J Prado F 2010 The role of cotyledon metabolism in the
establishment of quinoa (Chenopodium quinoa)seedlings growing under salinity Plant Soil
326 213ndash24
Ruiz-Carrasco K Antognoni F Coulibaly A K Lizardi S Covarrubias A Martiacutenez E A
Shabala S Hariadi Y Jacobsen SE 2013 Genotypic difference in salinity tolerance in quinoa is
determined by differential control of xylem Na+ loading and stomatal density J Plant Physiol
170 906ndash14
Shih FF 2006 Chapter 6 Rice protein In Champagne ET editor Rice Chemistry and
Technology 3rd edition St Paul MN American Association of Cereal Chemists Inc p
143-4
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Taylor JRN Parker ML editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science amp Business Media p 96-101
USDA (United States Department of Agriculture) 2011 Soil and water resources conservation
act (RCA) P 31 Access from
httpwwwnrcsusdagovInternetFSE_DOCUMENTSstelprdb1044939pdf
Wilson C Read J Abo-Kassem E 2002 Effect of mixed-salt salinity on growth and ion
relations of a quinoa and a wheat variety J Plant Nutri 25 2689ndash704
138
Wu G Morris CF Murphy KM 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79 2337ndash45
Wu G 2015 Chapter 11 Nutritional properties of quinoa In Murphy KM Matanguihan J
editors Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp
Sons Inc p 193-205
Zhang B Chen P Chen CY Wang D Shi A Hou A Ishibashi T 2008 Quantitative trait loci
mapping of seed hardness in soybean Crop Sci 48 1341ndash9
Zevallos VF Herencia LI Chang F Donnelly S Ellis HJ Ciclitira PJ 2014 Gastrointestinal
effects of eating quinoa (Chenopodium quinoa Willd) in celiac patients Am J Gastroenterol
109 270ndash8
Zurita-Silva A 2011 Variation in salinity tolerance of four lowland genotypes of quinoa
(Chenopodium quinoa Willd) as assessed by growth physiological traits and sodium
transporter gene expression Plant Physiol Bioch 49 1333ndash41
139
Table 1-Analysis of variance with F-values for protein content hardness and density of quinoa seed
Effect F-values
Protein Hardness Density
Model 524 360 245
Variety 2463 21059 2282
Salinity 975 200dagger 282
Fertilization 40247 107 260
Variety x Salinity 096 098 036
Variety x Fertilization 2062 1094 460
Salinity x Fertilization 339 139 071
Variety x Salinity x Fertilization 083 161dagger 155
dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the 001 probability level Significant at the lt0001 probability level
140
Table 2-Salinity variety and fertilization effects on quinoa seed protein content ()
Salinity Protein content ()
Variety Protein content ()
Fertilization Protein content ()
8 dS m-1 NaCl 147bc1 CO407D 149ab High 158a
16 dS m-1 NaCl 148ab UDEC-1 147b Low 136b
32 dS m-1 NaCl 149ab Baer 151a
8 dS m-1 Na2SO4 144cd QQ065 141c
16 dS m-1 Na2SO4 142d
32 dS m-1 Na2SO4 152a 1Different letters in a given column indicate significant differences (P lt 005)
141
Table 3-Salinity variety and fertilization effects on quinoa seed hardness (kg)
Salinity Hardness (kg)1 Variety Hardness (kg)
8 dS m-1 NaCl 83 CO407D 100a2
16 dS m-1 NaCl 87 UDEC-1 94b
32 dS m-1 NaCl 85 Baer 77c
8 dS m-1 Na2SO4 87 QQ065 74c
16 dS m-1 Na2SO4 89
32 dS m-1 Na2SO4 88 1Hardness was significant at the 009 probability level 2Different letters in a given column indicate significant differences (P lt 005)
142
Table 4-Salinity variety and fertilization effects on quinoa seed density (g cm3)
Salinity density (g cm3) Variety density (g cm3)
8 dS m-1 NaCl 069bc1 CO407D 080a
16 dS m-1 NaCl 068bc UDEC-1 066bc
32 dS m-1 NaCl 071abc Baer 069b
8 dS m-1 Na2SO4 066c QQ065 065c
16 dS m-1 Na2SO4 074a
32 dS m-1 Na2SO4 072ab 1Different letters in a given column indicate significant differences (P lt 005)
143
Table 5-Correlation coefficients of protein hardness and density of quinoa seed
Correlation All NaCl Na2SO4
High fertilization
Low fertilization
High fertilization
Low fertilization
Protein -Density 019 013ns 029dagger 026ns 019ns
Hardness - Density 038 027ns 051 022ns 047
ns Not significant dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the lt0001 probability level
144
Table 6-Correlation coefficients of quinoa seed quality and agronomic performance and seed mineral content
Protein Hardness Density
Yield 004 035 006
Plant Height -004 031 011
Cu -052 -037 -035
Mg -050 004 0
Mn -006 057 025dagger
P -001 -056 -015
Zn -004 -029 -028dagger
dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the 001 probability level Significant at the lt0001 probability level
145
Figure 1-Protein content () of quinoa in response to combined fertility and salinity treatments
146
Chapter 6 Lexicon development and consumer acceptance
of cooked quinoa
ABSTRACT
Quinoa is becoming increasingly popular with an expanding number of varieties being
commercially available In order to compare the sensory properties of these quinoa varieties a
common sensory lexicon needs to be developed Thus the objective of this study was to develop
a lexicon of cooked quinoa and examine consumer acceptance of various varieties A trained
panel (n = 9) developed appropriate aroma tasteflavor texture and color descriptors to describe
cooked quinoa and evaluated 21 quinoa varieties Additionally texture of the cooked quinoa was
determined using a texture analyzer Results indicated panelists using this developed lexicon
could distinguish among these quinoa varieties showing significant differences in aromas
tasteflavors and textures Specifically quinoa variety effects were observed for the aromas of
caramel nutty buttery grassy earthy and woody tasteflavor of sweet bitter grain-like nutty
earthy and toasty and texture of firm cohesive pasty adhesive crunchy chewy astringent and
moist The varieties lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Drsquo exhibited adhesive texture that has not
been seen in any commercialized quinoa Subsequent consumer evaluation (n = 102) on 6
selected samples found that the lsquoPeruvian Redrsquo was the most accepted overall while the least
accepted was lsquoQQ74rsquo Partial least squares analysis on the consumer and trained panel data
indicated that overall consumer liking was driven by higher intensities of grassy aroma and firm
and crunchy texture The attributes of pasty moist and adhesive were less accepted by
consumers This overall liking was highly correlated with consumer liking of texture (r = 096)
147
tasteflavor (r = 095) and appearance (r = 091) of cooked quinoa From the present study the
quinoa lexicon and key drivers of consumer acceptance can be utilized in the industry to evaluate
quinoa product quality and processing procedures
Keywords quinoa lexicon sensory evaluation
Practical application The lexicon of cooked quinoa can be used by breeders to screen quinoa
varieties Furthermore the lexicon will useful in the food industry to evaluate quinoa ingredients
from multiple farms harvest years processing procedures and product development
148
Introduction
Quinoa is classified as a pseudocereal like amaranth and buckwheat With its high
protein content and balanced essential amino acid profile quinoa is becoming popular
worldwide From 1992 to 2012 quinoa exports increased dramatically from 600 tons to 37000
tons (Furche et al 2015) Quinoa price in retail stores increased from $9kg in 2013 to $13kg -
$20kg in 2015 (Arco 2015) Quinoa has been incorporated into numerous products including
bread cookies pasta cakes and chocolates (Pop et al 2014 Alencar et al 2015 Casas Moreno
et al 2015 Wang et al 2015) Some of these products are gluten-free foods thus targeting the
gluten-sensitive market segment (Wang et al 2015)
Popularity of quinoa inspired US researchers to breed varieties that are compatible with
local weather and soil conditions which greatly differ from quinoarsquos original land the Andean
mountain region Since 2010 Washington State University has been breeding quinoa in the
Pacific Northwest region of United States Of the quinoa varieties evaluated in the breeding
program agronomic attributes of interest include high yield consistent performance over years
and tolerance to drought salinity heat and diseases (Peterson and Murphy 2013 Peterson
2013) However beyond agronomic attributes the grain sensory profiles of these quinoa
varieties are also important to assist in breeding decisions as well as screening
genotypescultivars for various food applications
In order to provide a complete descriptive profile of the cooked quinoa a trained sensory
evaluation should be used along with a complete lexicon of the sensory attributes of importance
Currently no quinoa lexicon is available and descriptions of quinoa sensory properties are
149
limited From currently published research papers attributes describing quinoa taste have been
limited to bitter sweet earthy and nutty (Koziol 1991 Lorenz and Coulter 1991 Repo-Carrasco
et al 2003 Stikic et al 2012 Foumlste M et al 2014) and texture of cooked quinoa has been
described as creamy smooth and crunchy (Abugoch 2009) Thus to address the lack of quinoa
lexicon one objective of this study is to develop a lexicon describing the sensory properties of
quinoa
Beyond developing a lexicon to describe quinoa consumer preference of the different
quinoa varieties is also of great interest Most previous sensory studies in quinoa focused on
acceptance of quinoa-containing products while consumer acceptance on plain grain of quinoa
varieties has not been studied Because of the lack of cooked quinoa studies with consumers rice
may be considered as a model to study quinoa because of their similar cooking process Tomlins
et al (2005) found consumer preference of rice was driven by the attributes of uniform clean
bright translucent and cream with consumers not liking the brown color of cooked rice and
unshelled paddy in raw rice In another study Suwannaporn et al (2008) found consumer
acceptance of rice products was significantly influenced by convenience grain variety and
traditionnaturalness
This study presenting a quinoa lexicon along with consumer acceptance of quinoa
varieties provides critical information for both the breeding programs and food industry
researchers Given the predicted importance of texture in consumer acceptance of quinoa texture
analysis was conducted to evaluate the parameters of hardness adhesiveness cohesiveness
chewiness and gumminess in quinoa samples
150
This lexicon describing the sensory attributes of cooked quinoa will be a useful tool to
evaluate quinoa varieties compare samples from different farms harvest years seed quality and
cleaning processing procedures Finally the sensory attributes driving consumersrsquo liking can be
utilized to evaluate optimal quinoa quality and target different consumers based on preference
Materials and methods
Quinoa samples
The present study included twenty-one quinoa samples harvested in 2014 which included
sixteen varieties from Finnriver Organic Farm (Finnriver WA) and five commercial samples
from Bolivia and Peru (Table 1)
Quinoa preparation
Following harvest the samples from Finnriver Farm were cleaned in a Clipper Office
Tester (Seedburo Des Plainies IL USA) to separate mixed weed seeds and threshed materials
Furthermore the samples were soaked for 30 min rubbed manually under running water and
dried at 43 ordmC until the moisture reached lt 11 Generally a moisture of 12 - 14 is
considered safe for grain storage (Hoseney 1989)
To prepare quinoa samples for sensory evaluation samples were soaked for 30 min and
mixed with water at a 12 ratio These mixtures were brought to a boil and simmered for 20 min
Following cooking the quinoa was cooled to room temperature Samples of cooked quinoa (10
g) were served in 30 mL plastic containers with lids (SOLO Lakeforest IL USA) Quinoa
151
samples were cooked and placed in covered cups within 2 h before evaluation Unsalted
crackers plastic cups used as cuspidors and napkins were provided to each panelist
Trained sensory evaluation panel
This project was approved by the Institutional Review Board of Washington State
University Sensory panelists (n = 9) were recruited via email announcements Panelists were
selected based on their interest in quinoa and availability All participants signed the Informed
Consent Form They received non-monetary incentives for each training session and a large non-
monetary reward at the completion of the formal evaluation
Demographic information was collected using a questionnaire Panelists included 4
females and 5 males ranging in age from 21 to 60 (mean age of 35) Regarding quinoa
consumption frequency four panelists frequently consumed quinoa (few times per month to
everyday) whereas five panelists rarely consumed quinoa As quinoa is a novel crop to most of
the world this was expected Since rice is a comparable model of quinoa frequency of rice
consumption was also considered with all panelists being frequent rice consumers
Sensory training and lexicon development
The training consisted of 12 sessions of 15 hours totaling 18 hours In the early stages
of the panel training attribute terms and references were discussed Panelists were first presented
with samples in covered plastic containers The samples widely varied in their sensory attributes
and included the varieties of lsquoBlackrsquo lsquoBolivian Redrsquo and lsquoBolivian Whitersquo The panelists
developed terms to describe the appearance aroma flavor taste and texture of the samples
Additionally the same samples were evaluated by an experienced sensory evaluation panel with
152
terms collected from this set of evaluators Terms were collected from panelists professionals
and literature describing rice (Meilgaard et al 2007 Limpawattana and Shewfelt 2010) The
term list was presented and discussed with panelist consensus being used to determine which
sensory terms appeared in the final lexicon
The final lexicon and associated definitions are presented in Table 2 This lexicon
included the sensory attributes of color (black red yellow) aroma (caramel grain-like bean-
like nutty buttery starchy grassygreen earthymusty woody) tasteflavor (sweet bitter grain-
like bean-like nutty earthy and toasted) and texture (soft-firm separate-cohesive pasty
adhesivenesssticky crunchycrumblycrisp chewygummy astringent and waterymoist)
References standards for each attribute were introduced The references were discussed and
modified until the panelists were in agreement Panelists reviewed the reference standards at the
beginning of each training session Since aroma varies over time all aroma references were
prepared 1-2 h before training During training three to four quinoa samples were evaluated and
discussed in each session The ability to detect attribute differences and the reproducibility of
panelists were both monitored and visualized using spider graphs and line graphs Using this
feedback panelists were calibrated paying extra attention to those attributes that were outside of
the panel standard deviation Practice sessions were continued until the panelists accurately and
consistently assessed varietal differences of quinoa
The protocols applied to evaluate samples and references were consistent among
panelists At the start of the evaluation the sample cup was shaken to allow the aroma to
accumulate in the headspace Panelists then lifted the cover and immediately took three short
sharp sniffs to evaluate the aroma Panelists then determined the color and its intensity Finally
153
panelists used the spoon to place the sample in-mouth and evaluate the tasteflavor and texture
Between each sample panelists rinsed their palate using water and unsalted crackers A 15-cm
line scale with 15-cm indentations on each end was used to determine the intensity of attributes
The values of 15 and 135 represented the extremely low and high intensity respectively Using
the lexicon panelists were trained to sense and quantify the attributes of cooked quinoa on
aroma color tasteflavor and texture
Following the development of the lexicon formal evaluations were conducted in the
sensory booths under white lights Compusensereg Five (Guelph Ontario Canada) provided scales
and programs for evaluation and collected results Panelists followed the protocol and used the
lexicon and 15-cm scales to evaluate the sensory attributes of the cooked quinoa samples
Twenty-one quinoa samples were tested in duplicate Panelists attended one session per day and
four sessions in total During each session panelists evaluated 10 or 11 samples with a 30 s
break after each sample and a 10 min break after the fifth sample Each variety was assigned
with a random three-digit code and the serving order was randomized
Consumer acceptance panel
From the 21 samples evaluated by the trained panelists six were selected for consumer
evaluation These six samples selected were diverse in color tasteflavor and texture as defined
by the trained panel results Consumers (n = 102) were recruited from Pullman WA Of the
consumers 49 were male and 52 were female with age ranging from 19 to 64 (mean age of 33)
The consumers showed different familiarity with quinoa with 29 indicating that they were
154
familiar with quinoa 40 having tried quinoa a few times and 32 having never tried quinoa
before All consumers had consumed rice before
The project was approved by the Institutional Review Board of Washington State
University Each consumer signed an Informed Consent Form and received a non-monetary
incentive at the end of evaluation The evaluation was conducted in the sensory booths under
white light Six quinoa samples were assigned with three-digit code and randomly presented to
each consumer using monadic presentation Quinoa samples were cooked and distributed in
evaluation cups and lidded (~10 gcup) the day before stored at 4 degC overnight and placed at
room temperature (25 degC) for 1 h prior to evaluation
During evaluation consumers followed the protocol instructions and indicated the degree
of acceptance of aroma color appearance tasteflavor texture and overall liking using a 7-point
hedonic scale (1 = dislike extremely 7 = like extremely) provided by Compusensereg Five
(Guelph Ontario Canada) A comments section was provided at the end of each sample
evaluation to gather additional opinions and information Between samples panelists took a 30 s
break and cleansed their palates using unsalted crackers and water
Texture Profile Analysis by instrument (TPA)
The texture of 21 cooked quinoa samples were conducted using a TA-XT2i Texture
Analyzer (Texture Technologies Corp Hamilton MA USA) (Wu et al 2014) Samples were
cooked using the same procedure as in the trained panel evaluation and cooled to room
temperature prior to evaluation
Statistical analysis
155
Sample characteristics and trained panel results were analyzed using three-way ANOVA
and mean separation (Fisherrsquos LSD) PCA was performed on the trained panel data Using
trained panel data and consumer evaluation data partial least square regression analysis was
performed Additionally correlations between instrument tests and panel evaluation on texture
and tasteflavor were determined XLSTAT 2013 (Addinsoft Paris France) was used for all data
analysis
Results and Discussion
Lexicon Development
A lexicon was created to describe the sensory attributes of cooked quinoa (Table 2) A
total of 27 attributes were included in the lexicon based on color (black red yellow) aroma
(caramel grain-like bean-like nutty buttery starchy grassygreen earthymusty and woody)
tasteflavor (sweet bitter grain-like bean-like nutty earthy and toasted) and texture (firm
cohesive pasty adhesivenesssticky crunchy chewygummy astringent and waterymoist)
Rice is considered as a good model of quinoa lexicon developments since both products
have common preparation methods The lexicon for cooked rice has been developed for the
aroma tasteflavor and texture properties of rice (Lyon et al 1999 Meullenet et al 2000
Limpawattana and Shewfelt 2010) Many attributes from these previously developed rice
lexicons can be applied to cooked quinoa For instance rice aroma and flavor notes such as
starchy woody grain nutty buttery earthy sweet bitter and astringent are also present in
quinoa Hence those notes were also included in the lexicon of cooked quinoa in present study
with quinoa varieties showing differences in these attributes
156
This present lexicon presents some sensory attributes not found to be significantly
different among the quinoa varieties These attributes include grain-like bean-like and starchy
aroma bean-like flavor and chewy texture Even though the trained panel did not detect
differences in this study future studies may find differences among other quinoa varieties for
these attributes so they were kept in the lexicon For instance the flavoraroma notes of
lsquorancidoxidizedrsquo lsquosourrsquo lsquometallicrsquo may also be present in other quinoa varieties or have these
attributes develop during storage as has been shown in rice (Meullenet et al 2000)
The lexicon also expanded the vocabularies to describe quinoa This lexicon is a
valuable tool with multiple practical applications such as describing and screening quinoa
varieties in breeding and evaluating post-harvest process and cooking methods
Lexicon Application Evaluation of the 21 quinoa samples
The effects of panelist replicate and quinoa variety on aroma tasteflavor and texture of
cooked quinoa were evaluated (n = 9) (Table 3) The quinoa variety exhibited significant
influences on most attributes listed in the lexicon (P lt 005) except for grain-like bean-like and
starchy aroma and bean-like flavor Generally quinoa variety effects were greater in the
perceived texture of cooked quinoa than in the aroma and flavor attributes however bitterness
was also highly significant among varieties Although panelists were trained over 18 h and
references were used for calibration significant panelist effects were still observed Based on the
inherent variation of human subjects such panelist effects commonly occur in sensory evaluation
of a complex product (Muntildeoz 2003) In future studies increased training and practice to further
clarify attribute definitions may reduce panelist effects (Muntildeoz 2003)
157
Examining the details of aroma attributes quinoa variety effect significantly influenced
the aroma attributes of caramel nutty buttery grassy earthy and woody (Figure 1) Principal
Components Analysis (PCA) was performed in order to visualize differences among the
varieties For aroma the first two components described 669 of the variation among quinoa
samples PC1 was primarily defined by the grassy and woody aromas while PC2 was primarily
described by more starchy and grain-like aromas The proximity of the attributes to a specific
quinoa sample reflected its degree of association For instance lsquoCalifornia Tricolorrsquo was most
commonly described by earthy woody grassy bean-like and nutty aroma lsquoTemukorsquo exhibited
sweet and grain-like aroma Yellowwhite quinoa such as lsquoTiticacarsquo lsquoRed Headrsquo lsquoQuF9P39-51rsquo
and lsquoPeruvian Whitersquo showed significantly more nutty (6) aroma compared to brown and red
quinoa varieties (48 ndash 51) (Table 1S) lsquoBlackrsquo lsquoCahuilrsquo and lsquoPeruvian Redrsquo exhibited more
grassy aroma (47 ndash 49) compared to lsquoTiticacarsquo lsquoLinaresrsquo and lsquoNL-6rsquo (38 ndash 39) lsquoBlackrsquo
showed the most earthy aroma (54) among all varieties
PCA was also performed to show how the varieties differed in their flavortaste
properties (Figure 2) The first two components described 646 of the varietal differences The
lsquoBlackrsquo variety was found to have more bitter and earthy flavors lsquoPeruvian Whitersquo was most
commonly described by sweet and nutty flavor and lack of earthy flavors lsquoTemukorsquo was mostly
defined by its bitter taste and lack of sweetness nutty grain-like and toasty flavors Overall
sweet and bitter taste and grain-like nutty earthy and toasty flavor exhibited significant
difference among quinoa varieties (plt005) The lsquoQuF9P39-51rsquo lsquoKaslaearsquo lsquoBolivian Whitersquo
and lsquoPeruvian Whitersquo were assigned the highest values in sweet taste (46 ndash 47) significantly
sweeter than lsquoBlackrsquo lsquoCherry Vanillarsquo lsquoTemukorsquo lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCalifornia Tricolorrsquo
158
(36 ndash 40)(Table 4) lsquoTemukorsquo and lsquoCherry Vanillarsquo were the most bitter samples (56 and 52
respectively) It is worth noting that the commercial samples were assigned the lowest bitterness
scores ranging from 22 ndash 27 significantly lower than the field trial varieties (34 ndash 56) Similar
to earthy aroma lsquoBlackrsquo also exhibited the earthiest flavor (52) Additionally lsquoCahuilrsquo and
lsquoCalifornia Tricolorrsquo showed high scores in earthy flavor (both 48) Toasty flavor varied from
38 in lsquoLinaresrsquo and lsquoQuF9P1-20rsquo to 51 in lsquoCahuilrsquo
Quinoa bitterness is caused by saponin compounds present on the seed coat It has been
reported that saponin can be removed by abrasion pearling and rinsing (Taylor and Parker
2002) However in the present study despite two cleaning process steps (airscreen and rinsing)
there was still bitter flavor remained Besides processing genetic background can also affect
saponin content Some sweet quinoa varieties (lsquoSajamarsquo lsquoKurmirsquo lsquoAynoqrsquoarsquo lsquoKrsquoosuntildearsquo and
lsquoBlanquitarsquo in Bolivia and lsquoBlancade Juninrsquo in Peru) have been developed with total seed
saponin content lower than 110 mg100 g (Quiroga et al 2015) However these varieties are not
adapted to the growing conditions in the Pacific Northwest (Peterson and Murphy 2015) The
quinoa varieties in WSU breeding program are primarily from Chilean lowland and those
varieties are more highly adapted to temperate areas In this case sweet quinoa varieties from
Bolivia and Peru were not included in this study However in 2015 a saponin-free quinoa
variety lsquoJessiersquo was grown in different locations of Washington State with a comparable yield
to bitter varieties The sensory evaluation of this new variety lsquoJessiersquo would be meaningful
Earthy which may be referred to as moldy and musty is caused by geosmin (a bicyclic
alcohol with formula C12H22O) which produced by actinobacteria (Gerber 1968) Samples with a
dark color (lsquoBlackrsquo lsquoCalifornia Tricolorrsquo and lsquoCahuilrsquo) tended to exhibit more earthy aroma and
159
flavor Possibly the pericarpseed coat composition of dark quinoa favors the actinobacteria-
producing geosmin
Overall texture attributes of cooked quinoa exhibited greater differences in values
(Figure 3) Among commercial quinoa varieties the red quinoa was firmer more gummy and
more chewy in texture compared to the yellowwhite commercial quinoa Several WSU field trial
varieties (lsquoQQ74rsquo lsquoLinaresrsquo and CO407D) exhibited greater variation in adhesiveness The first
two PCA factors explained 817 of the variation among samples lsquoPeruvian Redrsquo was most
accurately described by firm and crunchy texture and a lack of pasty sticky and cohesive
texture In contrast lsquoLinaresrsquo lsquoCO407Daversquo and lsquoQQ74rsquo were mostly described as pasty sticky
and cohesive yet lacking in firmness and crunchiness Mixed color or red color samples
(lsquoPeruvian Redrsquo lsquoBlackrsquo lsquoCahuilrsquo and lsquoCalifornia Tricolorrsquo) tended to be both firmer and
crunchier compared to the samples with light color However some yellow samples such as
lsquoTiticacarsquo and lsquoKU-2rsquo also had hard texture The varieties lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Daversquo
had the softest texture and also exhibited the least crunchy but the most pasty sticky and moist
texture Additionally compared to field trial varieties commercial samples tended to be lower in
intensity for the attributes of cohesiveness pastiness adhesiveness and astringency Moreover
astringent is the dry and puckering mouth feeling which is caused by the combination of tannins
and salivary proteins The differences found in this study among quinoa varieties may be caused
by processing protocols (removal of tannins to various degrees) or diverse genetic backgrounds
Consumer acceptance
160
Consumers evaluated six selected quinoa samples including the field trial varieties of
lsquoBlackrsquo lsquoTiticacarsquo lsquoQQ74rsquo and the commercial samples of lsquoPeruvian Redrsquo lsquoBolivian Redrsquo and
lsquoBolivian Whitersquo The selected samples were diverse in color texture and included both WSU
field trial varieties and commercial quinoa Among the field trial varieties the lsquoBlackrsquo variety
exhibited more grassy aroma earthy flavor and chewy texture lsquoTiticacarsquo had more caramel
aroma and lsquoQQ74rsquo was more adhesive than the other samples
The quinoa varieties varied significantly in consumer acceptance of color appearance
taste flavor texture and overall acceptance (P lt 0001) (Table 5) Overall lsquoPeruvian Redrsquo was
more accepted by consumers compared to lsquoTiticacarsquo and lsquoQQ74rsquo lsquoBlackrsquo received a similar
level of acceptance with all the commercial samples and the acceptance of lsquoTiticacarsquo did not
differ from lsquoBolivian Redrsquo and lsquoBolivian Whitersquo In aroma acceptance no significant difference
was found among the varieties In color lsquoPeruvian Redrsquo and lsquoBolivian Redrsquo received
significantly higher scores In appearance lsquoPeruvian Redrsquo was rated higher than all other
varieties except lsquoBolivian Redrsquo while lsquoQQ74rsquo gained the lowest rate Additionally lsquoQQ74rsquo was
less accepted in tasteflavor than all commercial samples but did not differ from other field trial
varieties lsquoBlackrsquo and lsquoTiticacarsquo Furthermore the texture of lsquoQQ74rsquo was the least accepted and
other varieties did not show any significant differences
However low acceptance in adhesive texture of cooked quinoa does not indicate the
adhesive quinoa varieties will not have market potential Adhesiveness in cooked rice is
correlated with high amylopectin and low amylose (Mossman et al 1983 Sowbhagya et al
1987) Hence adhesive quinoa may also contain low amylose Additionally previous studies
found waxy cereal or starch (0 amylose and 100 amylopectin) exhibited excellent
161
performance in extrusion Kowalski et al (2014) found that waxy wheat extrudates exhibited
nearly twice the expansion ratio as that of normal wheat Koumlksel et al (2004) found hulless waxy
barley to be promising for extrusion using low shear screw configuration Van Soest et al (1996)
reported high elongation (500) in extruded maize starch Consequently the adhesive quinoa
varieties have great potential to apply in extruded or other puffed foods
Consumer preference of the sensory attributes was analyzed using Partial Least Square
Regression (PLS) (Figure 4) The attributes presented by lsquoPeruvian Redrsquo including lsquograssyrsquo
aroma lsquograinyrsquo flavors and lsquofirmrsquo and lsquocrunchyrsquo textures were preferred among consumers The
less preferred attributes included lsquopastyrsquo lsquowaterymoistrsquo lsquoadhesiversquo and lsquocohesiversquo all attributes
used to describe the lsquoQQ74rsquo variety Overall acceptance was driven by crunchy texture (r =
090) but negatively correlated with lsquocohesiversquo lsquopastyrsquo and lsquoadhesiversquo texture (r = -096 -087
and -089 respectively) Specifically aroma acceptance of cooked quinoa was negatively
correlated with lsquowoodyrsquo (r = -083) Texture acceptance was positively correlated with lsquofirmrsquo(r =
084) and lsquocrunchyrsquo (r = 094) but was negatively correlated with lsquocohesiversquo (r = -096) lsquopastyrsquo
(r = -095) lsquoadhesiversquo (r = -096) and lsquomoistrsquo (r = -085) Even though lsquoearthyrsquo is a common
attribute in foods such as mushroom and beets this study on quinoa indicated that earthy aroma
and flavor were not the attributes driving consumersrsquo liking of cooked quinoa Color and
appearance did not exhibit significant correlation with color intensity of cooked quinoa
however the varieties with red or dark colors (lsquoPeruvian Redrsquo lsquoBolivian Redrsquo and lsquoBlackrsquo)
were more highly accepted by consumers compared to samples with light color (lsquoTiticacarsquo
lsquoBolivian Whitersquo lsquoQQ74rsquo) In sum consumers preferred cooked quinoa with grassy aroma firm
and crunchy texture and lack of woody aroma and low cohesive pasty or adhesive texture
162
The variety lsquoBlackrsquo was accepted at a similar level as commercial samples in aroma
tasteflavor texture and overall evaluation With a closer examination of the consumer
demographic consumers who were more familiar with quinoa rated the lsquoBlackrsquo quinoa variety
with higher scores (average of 7) compared to those panelists less familiar with quinoa who
assigned lower average scores (59) (Figure 1S) This tricolor quinoa (browndark mixture) is not
as common as red and yellowwhite quinoa in the US market However the potential of tricolor
quinoa may be great due to the relative high consumer acceptance as well as high gain yield in
the field
Instrumental Texture Profile Analysis (TPA)
The physical properties of cooked quinoa were determined using the texture analyzer
(Table 6) Samples differed in all six texture parameters lsquoNL-6rsquo lsquoPeruvian Redrsquo lsquoBolivian Redrsquo
and lsquoCalifornia Tricolorrsquo exhibited the hardest texture while lsquoTemukorsquo lsquoQQ74rsquo lsquoIslugarsquo
lsquoLinaresrsquo and lsquoCO407Daversquo displayed the lowest hardness values Consistent with trained panel
evaluation lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Daversquo were more adhesive than all other varieties
lsquoTiticacarsquo was the springiest variety while lsquoKaslaearsquo and lsquoQuF9P1-20rsquo were the least springy
varieties The commercial samples with the exception of lsquoPeruvian Whitersquo exhibited a more
gummy texture lsquoTiticacarsquo and lsquoBolivian Whitersquo were the chewiest samples In contrast varieties
of lsquoTemukorsquo lsquoQQ74rsquo lsquoIslugarsquo lsquoLinaresrsquo lsquoQuF9P1-20rsquo and lsquoCO407Daversquo showed the least
gummy and chewy texture The result was comparable to an earlier study (Wu et al 2014)
Similarly quinoa varieties with darker color (orangeredbrowndark) tended to yield harder
texture compared to the varieties with light color (whiteyellow) which is caused by the thicker
seed coat in dark colored quinoa In this study adhesive quinoa varieties lsquoQQ74rsquo lsquoLinaresrsquo and
163
lsquoCO407Daversquo were found to have higher adhesiveness values (-17 kgs to -13 kgs) compared
to other varieties previously reported (-029 kgs to 0) (Wu et al 2014)
Correlations of instrumental tests and trained panel evaluations of texture were
significant for hardness and adhesiveness (r = 070 and -063 respectively) (Table 7) Since
adhesiveness was calculated from the first negative peak area of the TPA graph a negative
correlation coefficient was observed but still indicating a high level of agreement between
instrumental and panel tests Springiness tested by TPA was not correlated with texture
attributes
Cohesiveness from the instrumental test was negatively correlated with cohesiveness
from the trained panel texture evaluation (r = -066) Instrumental cohesiveness also exhibited
positive correlations with the trained panel evaluation of firmness and crunchiness (r = 080 and
076 respectively) and negative correlations with pastiness adhesiveness moistness (r = -072
-075 and -082 respectively) Upon a closer examination of the definitions in the instrumental
test cohesiveness was defined as lsquohow well the product withstands a second deformation relative
to its resistance under the first deformationrsquo and is calculated as the ratio of second peak area to
first peak area (Wiles et al 2004) In the sensory lexicon cohesiveness was defined as lsquodegree
to which a substance is compressed between the teeth before it breaksrsquo (Szczesniak 2002) These
differential definitions or explanations of these attributes may have caused the different results
Additionally the gumminess and chewiness from the instrumental evaluation were not
significantly correlated with their counterpart notes from the trained panel evaluations but
correlated with other sensory attributes evaluated by the trained panel Instrumental gumminess
164
was positively correlated with firm and crunchy textures(r = 079 and 078 respectively) but
negatively correlated with cohesive pasty adhesive and moist (r = -067 -068 -075 and -
078 respectively) Additionally a positive correlation was found between instrumental
chewiness and firmness from the panel evaluation (r = 057) whereas negative correlations were
found between instrumental chewiness and panel evaluated cohesiveness pastiness
adhesiveness and moistness (r = -043 -045 -055 and -052 respectively) In the instrumental
texture profile gumminess is calculated by hardness multiplied by cohesiveness and chewiness
is calculated by gumminess multiplied by springiness (Epstein et al 2002) Hence gumminess
was significantly correlated with hardness and cohesiveness and chewiness was significantly
correlated with gumminess In another study of Lyon et al (2000) pasty and adhesive were
expressed as lsquoinitial starchy coatingrsquo and lsquoself-adhesivenessrsquo respectively in cooked rice and
were both negatively correlated with instrumental hardness Generally the instrument test is
more accurate and stable but the parameter or sensory attributes were relatively limited Sensory
panels are able to use various vocabularies to describe the food however accuracy and precision
of panel evaluations were lower than for the instrument Consequently both tools can be
important in sensory evaluation depending on the objectives and resources availability
Future Studies
A lexicon of cooked quinoa was firstly developed in this paper Further discussion and
improvement of the lexicon are necessary and require cooperation with industry and chefs The
lexicon is not only useful in categorizing varieties but also can be used to evaluate post-harvest
practice cooking protocols and other quinoa foodsdishes Additionally quinoa seed quality
varies among years and locations and sensory properties also change over different
165
environments To validate the sensory profile of varieties especially adhesiveness evaluation
should be repeated on the samples from other years and locations Finally multiple dishes food
types should be included in future consumer evaluation studies to identify the best application of
different varieties
Conclusion
A lexicon of cooked quinoa was developed based on aroma tastefavor texture and
color Using the lexicon the trained panel conducted descriptive analysis evaluation on 16
quinoa varieties from field trials and 5 commercial samples Many sensory attributes exhibited
significant differences among quinoa samples especially texture attributes
Consumer evaluations (n = 102) were conducted on six selected samples with diverse
color texture and origin Commercial samples and the variety lsquoBlackrsquo were better accepted by
consumers The adhesive variety lsquoQQ74rsquo was the least accepted quinoa variety in the plain
cooked quinoa dish However because of its cohesive texture lsquoQQ74rsquo shows possible
application in other dishes and foods such as quinoa sushi and extruded snacks Furtherly Partial
Least Square Regression indicated the consumerrsquos preferred attributes were grassy aroma and
firm and crunchy texture while the attributes of pasty adhesive and cohesive were not liked by
consumers
Correlations of panel evaluation and instrumental test were observed in hardness and
adhesiveness However chewiness and gumminess were not significant correlated between panel
test and instrumental test Further training should be addressed to clarify the definitions of
sensory attributes With the assistance and calibration from instruments such as the texture
166
analyzer and electronic tongue panel training can be more efficient and panelists can be more
accurate at evaluation
Acknowledgements
The study was funded by the USDA Organic Research and Extension Initiative
(NIFAGRANT11083982) The authors acknowledge Washington State University Sensory
Facility and their technicians Beata Vixie and Karen Weller The authors also acknowledge
Sergio Nunez de Arco and Sarah Connolly to provide commercial samples Thanks to Raymond
Kinney Max Wood and Hanna Walters who managed the plants harvested the seeds and
collected the data of yield and 1000-seed weight on field trial quinoa varieties Thanks also go to
the USDA-ARS Western Wheat Quality Lab which provided equipment for protein and ash tests
and the texture analyzer
Author contributions
CF Ross and G Wu together designed the study G Wu conducted panel training
collected and processed data and drafted the manuscript KM Murphyrsquos research group provided
the quinoa samples and assisted cleaning process CF Ross CF Morris and KM Murphy edited
the manuscript
167
References
Abugoch LEJ 2009 Chapter 1 quinoa (Chenopodium quinoa Willd) Adv Food Nutr Res
581ndash31
Arco SND Quinoas Calling In Murphy KM Matanguihan J editors Quinoa improvement
and sustainable production Hoboken NJ John Wiley amp Sons Inc p 211
Casas Moreno MM Barreto-Palacios V Gonzalez-Carrascosa R Iborra-Bernad C Andres-Bello
A Martiacutenez-Monzoacute J Garciacutea-Segovia P 2015 Evaluation of textural and sensory properties
on typical spanish small cakes designed using alternative flours J Culinary Sci Technol 13
19-28
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(Waxy) genes J Cereal Sci 35 51-63
Foumlste M Nordlohne SD Elgeti D Linden MH Heinz V Jekle M Becker T Impact of quinoa
bran on gluten-free dough and bread characteristics Eur Food Res Technol 2014 239 767-
75
Furche C Salcedo S Krivonos E Rabczuk P Jara B Fernaacutendez D Correa F 2015 Chapter 41
International quinoa trade In Bazile D Bertero D Nieto C editors State of the art report
on quinoa in 2013 Rome FAO amp CIRAD p 317 ndash 20
Gerber NN1968 Geosmin from microorganisms is trans-1 10-dimethyl-trans-9-decalol
Tetrahedron Lett 9 2971-4
168
Koumlksel H Ryu GH Basman A Demiralp H Ng PK 2004 Effects of extrusion variables on the
properties of waxy hulless barley extrudates FoodNahrung 48 19-24
Kowalski RJ Morris CF Ganjyal GM 2015 Waxy soft white wheat extrusion characteristics
and thermal and rheological propertiesCereal Chem 92 145-53
Koziol MJ 1991 Afrosimetric estimation of threshold saponin concentration for bitterness in
quinoa (Chenopodium quinoa Willd) J Sci Food Agr 54 211-9
Limpawattana M Shewfelt R 2010 Flavor lexicon for sensory descriptive profiling of different
rice types J Food Sci 75 199-205
Lorenz K Coulter L Quinoa flour in baked products Plant Food Hum Nutr 1991 41 213-23
Lyon BG Champagne ET Vinyard BT Windham WR Barton FE Webb BD McKenzie KS
1999 Effects of degree of milling drying condition and final moisture content on sensory
texture of cooked rice Cereal Chem 76 56-62
Lyon BG Champagne ET Vinyard BT Windham WR 2000 Sensory and instrumental
relationships of texture of cooked rice from selected cultivars and postharvest handling
practices Cereal Chem 77 64-9
Meilgaad MC Civille GV Carr BT 2007 Chapter 11 The spectrum descriptive analysis
method In Meilgaad MC Civille GV Carr BT Sensory evaluation techniques Boca Raton
FL CRC Press p 225 ndash 32
169
Meullenet JF Marks BP Hankins JA Griffin VK Daniels MJ 2000 Sensory quality of cooked
long-grain rice as affected by rough rice moisture content storage temperature and storage
duration Cereal Chem 77 259 ndash 63
Mossman AP Fellers DA Suzuki H 1983 Rice stickiness I Determination of rice stickiness
with an Instron tester Cereal Chem 60 286ndash92
Muntildeoz AM 2003 Training time in descriptive analysis In Moskowitz HR Muntildeoz AM and
Gacula MC editors Viewpoints and controversies in sensory science and consumer product
testing Trumbull Food amp Nutrition Press Inc p 351 ndash 6
Peterson AJ Murphy KM 2015 Quinoa cultivation for temperate North America
considerations and areas for investigation In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 173-92
Palmer GH 1994 Chapter 5 Storage In Hoseney RC editor Cereal science and technology
2nd edition St Paul MN American Association of Cereal Chemisty Inc p 107
Pop A Muste S Man S Mureșan C 2014 Improvement of tagliatelle quality by addition of red
quinoa flour Bulletin UASVM Food Sci Tech 71 225-6
Pulvento C Riccardia M Biondib S Orsinic F Jacobsend SE Ragabe R DrsquoAndriaa R Lavinia
A 2015 Chapter 613 Quinoa in Italy research and perspectives In Bazile D Bertero D
Nieto C editors State of the art report on quinoa in 2013 Rome FAO amp CIRAD p 460
Quiroga C Escalera R Aroni G Bonifacio A Gonzaacutelez JA Villca M Saravia R Ruiz A 2015
Chapter 31 Traditional processes and technological innovations in quinoa harvesting
170
processing and industrialization In Bazile D Bertero D Nieto C editors State of the art
report of quinoa in the world in 2013 Rome FAO amp CIRAD p 231
Repo-Carrasco R Espinoza C Jacobsen SE 2003 Nutritional value and use of the Andean
crops quinoa (Chenopodium quinoa) and kantildeiwa (Chenopodium pallidicaule) Food Rev Int
19 179-89
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile
D Bertero D Nieto C editors State of the art report on quinoa in 2013 Rome FAO amp
CIRAD p 67
Sowbhagya CM Ramesh BS Bhattacharya KR 1987 The relationship between cooked-rice
texture and physicochemical characteristics of rice J Cereal Sci 5 287ndash97
Suwannaporn P Linnemann A and Chaveesuk R 2008 Consumer preference mapping for rice
product concepts Brit Food J 110 595-606
Stikic R Glamoclija D Demin M Vucelic-Radovic B Jovanovic Z Milojkovic-Opsenica D
Milovanovic M 2012 Agronomical and nutritional evaluation of quinoa seeds
(Chenopodium quinoa Willd) as an ingredient in bread formulations J Cereal Sci 55 132-8
Szczesniak AS 2002 Texture is a sensory property Food Qual Prefer 13 215-25
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Belton PS JRN Taylor editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science Business Media p 108 ndash 10
171
Tomlins KI Manful JT Larwer P and Hammond L 2005 Urban consumer preferences and
sensory evaluation of locally produced and imported rice in West Africa Food Qual Prefer
16 79-89
Van Soest JJG De Wit D Vliegenthart JFG 1996 Mechanical properties of thermoplastic waxy
maize starch J Appl Polym Sci 61 1927-37
Wang S Opassathavorn A Zhu F 2015 Influence of quinoa flour on quality characteristics of
cookie bread and Chinese steamed bread J Texture Stud 46 281-92
Wiles JL Green BW Bryant R 2004 Texture profile analysis and composition of a minced
catfish product J Texture Stud 35 325-37
Wu G Morris C F Murphy K M 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79 2337-45
172
Table 1-Quinoa samples
Varietya Color Source
Titicaca Yellowwhite Denmark
Black Blackbrown mixture White Mountain Farm Colorado USA
KU-2 Yellowwhite Washington USA
Cahuil Brownorange mixture White Mountain Farm Colorado USA
Red Head Yellowwhite Wild Garden Seed Oregon USA
Cherry Vanilla Yellowwhite Wild Garden Seed Oregon USA
Temuko Yellowwhite Washington USA
QuF9P39-51 Yellowwhite Washington USA
Kaslaea Yellowwhite MN USA
QQ74 Yellowwhite Chile
Isluga Yellowwhite Chile
Linares Yellowwhite Washington USA
Puno Yellowwhite Denmark
QuF9P1-20 Yellowwhite Washington USA
NL-6 Yellowwhite Washington USA
CO407Dave Yellowwhite White Mountain Farm Colorado USA
Bolivian White White Bolivia
Bolivian Red Red Bolivia
California Tricolor
Blackbrown mixture California USA
Peruvian Red Red Peru
Peruvian White White Peru aThe first 16 varieties (Tititcaca ndash CO407Dave) were grown in Chimacum WA
173
Table 2-Lexicon of cooked quinoa as developed by the trained panelists (n = 9)
Attribute Intensitya Reference Definition
Aroma
Caramel 10 1 piece of caramel candy (Kraft) (81 g) in 100 mL water
Aromatics associated with caramel tastes
Grain-like 10 Cooked brown rice (15 g) (Great Value)
Rice like wheaty sorghum like
Bean-like 8 Cooked red bean (10 g) (Great Value)
Aromatics associated with cooked beans or bean protein
Nutty 10 Dry roasted peanuts (10 g) (Planters)c
Aromatics associated with roasted nuts
Buttery 10 Unsalted butter (1cm1cm01cm) (Tillamook)c
Aromatics associated with natural fresh butter
Starchy 10 Wheat flour water (11 ww) (Great Value)c
Aromatics associated with the starch
Grassygreen 9 Fresh cut grass collected 1 h before usingc
Aromatics associated with grass
Earthymusty 8 Sliced raw button mushrooms (fresh cut)c
Aromatic reminiscent of decaying vegetative matters and damp black soil root like
Woody 7 Toothpicks (20)c Aromatics reminiscent of dry cut wood cardboard
TasteFlavor
Sweet 3 9 2 and 5 (ww) sucrose solution (CampH pure cane sugar)b
Basic taste sensation elicited by sugar
Bitter 5 8 mgL quinine sulfate acid (Sigma)
Basic taste sensation elicited by caffeine
174
Grain-like 10 Cooked brown rice (Great Value)
Tasted associated with cooked grain such as rice
Bean-like 10 Cooked red beans (Great Value)
Beans bean protein
Nutty 10 Dry roasted peanut (Planters)c Taste associated with roasted nuts
Earthy 7 Sliced raw button mushrooms (fresh)
Taste associated with decaying vegetative matters and damp black soil
Toasted 10 Toasted English muffin (at 6 of a toaster) (Franze Original English Muffin)
Taste associated with toast
Texturee
Soft - Firm 3
7
Firm tofu (Azumaya)b
Brown rice (Great Value)
Force required to compress a substance between molar teeth (in the case of solids) or between tongue and palate (in the case of semi-solids)d
Separate - Cohesive
15
7
Cracker (Premium unsalted cracker)
Cake (Sponge cake Walmart Bakery)
Degree to which a substance is compressed between the teeth before it breaks
Pasty
10 Mashed potato (Great Value Mashed Potatoes powder)
Smooth creamy pulpy slippery
Adhesiveness sticky
10
3
Sticky rice (Koda Farms Premium Sweet Rice)
Brown rice (Great Value)
Force required to remove the material that adheres to the mouth (the palate and teeth) during the normal eating process
Crunchy 13 Thick cut potato chip (Tostitos Restaurant Style
Force with which a sample crumbles cracks or shatters
175
Tortilla Chips)b
Chewygummy
15
7
Gummy Bear (Haribo Gold-Bears mixed flavor)
Brown rice (Great Value)
Length of time (in sec) required to masticate the sample at a constant rate of force application to reduce it to a consistency suitable for swallowing
Astringent 12
6
Tannic acid (2gL)
Tannic acid (1gL) (Sigma)
Puckering or tingling sensation elicited by grape juice
Waterymoist 10
3
Salad tomato (Natural Sweet Cherubs)
Brown rice (Great Value)
Degree of wet or dry
Color
Red 4 9
N-W8M Board Walke
N-W16N Ballet Barree
Yellow 3 10
15B-2U Sandy Toese 15B-7
N Summer Harveste
Black 3 10
N-C32N Strong Influencee N-C4M Trench Coate
aReference intensities were based on a 15-cm scale with 0 = extremely low and 15 = extremely high bMeilgaad et al (2007) cLimpawattana and Shewfelt (2010) dTexture definitions in Szczesniak (2002) were used eAce Hardware color chip
176
Table 3-Significance and F-value of the effects of panelist replicate and quinoa variety on aroma flavor and texture of cooked quinoa as determined using a trained panel (n = 9)
Attribute Panelist Replicate Quinoa Variety PanelistVariety
Aroma
Caramel 26548 093 317 174
Grain-like 7338 000 125 151
Bean-like 7525 029 129 135
Nutty 6274 011 322 118
Buttery 21346 003 301 104
Starchy 12094 1102 094 135
Grassy 17058 379dagger 282 162
Earthy 12946 239 330 198
Woody 13178 039 269 131
TasteFlavor
Sweet 6745 430 220 137
Bitter 9368 1290 2059 236
Grain-like 7681 392 222 206
Bean-like 7039 122 142 141
Nutty 7209 007 169 153
Earthy 9313 131 330 177
Toasted 10975 015 373 184
Texture
Firm 1803 022 1587 141
Cohesive 14750 011 656 208
Pasty 3919 2620 1832 205
Adhesive 2439 287dagger 5740 183
177
Crunchy 13649 001 1871 167
Chewy 3170 870 150dagger 167
Astringent 10183 544 791 252
Waterymoist 10281 369dagger 1809 164
daggerP lt 010 P lt 005 P lt 001 P lt 0001
178
Table 4-Mean separation of significant tasteflavor attributes of cooked quinoa determined by the trained panel Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Sweet Bitter Grain-like Nutty Earthy Toasty
Titicaca 40cdef1 39bcde 73abc 51abcdef 44bcdef 47abcd
Black 36f 42bcd 69bcde 49def 52a 46abcd
KU2 41bcdef 38cde 73abc 52abcdef 40fg 44bcdefg
Cahuil 41abcdef 44b 70bcde 50abcdef 48abc 51a
Red Head 42abcd 43bc 72abcd 51abcdef 42defg 44bcdefg
Cherry Vanilla 40def 52a 66e 48ef 44bcdef 40fghi
Temuko 36ef 56a 68cde 47f 43cdef 40ghi
QuF9P39-51 47a 34e 73abc 48def 40efg 46abcde
Kaslaea 47ab 39bcde 70bcde 55ab 44bcdef 45bcdefg
QQ74 40def 38cde 66e 50abcdef 45bcde 42defghi
Isluga 41bcdef 41bcd 69cde 55a 46bcd 47abcd
Linares 39def 40bcd 65e 49cdef 43def 38i
Puno 44abcd 39bcde 72abcd 51abcdef 45bcde 43cdefghi
QuF9P1-20 42abcdef 43bc 69bcde 53abcd 45bcde 38i
NL-6 38def 37de 72abcd 55a 45bcd 44bcdefgh
CO 407 Dave 41bcdef 40bcd 67de 51abcdef 41defg 39hi
Bolivian White 47ab 22f 69bcde 50bcdef 42def 41efghi
Bolivian Red 42abcde 24f 72abcd 53abcdef 43cdef 46bcde
California Tricolor 40def 27f 74ab 53abcde 48ab 48ab
Peruvian Red 43abcd 25f 75a 48ef 45bcde 47abc
Peruvian White 46abc 26f 70bcde 55abc 37g 45bcdef
179
Table 5-Mean separation of consumer preference Different letters within a column indicate consumer evaluation scores were different among quinoa samples at P lt 005
Samples Aroma Color Appearance TasteFlavor Texture Overall
Black 56a 63b 61bc 61abc 65a 63ab
QQ74 61a 56c 53d 56c 53b 53c
Titicaca 60a 57bc 56cd 58bc 63a 59bc
Peruvian Red 60a 72a 70a 65a 68a 67a
Bolivian Red 60a 69a 66ab 64ab 67a 64ab
Bolivian White 57a 59bc 58c 62ab 63a 62ab
180
Table 6-Hardness adhesiveness cohesiveness springiness gumminess and chewiness of the cooked quinoa samples as determined using Texture Profile Analysis (TPA)
Variety Hardness
(kg)
Adhesiveness
(kgs)
Cohesiveness Springiness Gumminess
(kg)
Chewiness
(kg)
Titicaca 505abc1 -02ab 08abc 15a 384bc 599a
Black 545ab -01a 07bcd 10abc 404abc 404ab
KU-2 490abcd -01a 07bcd 09abc 363bcd 332abc
Cahuil 464bcde -01a 07bcd 08abc 344cd 281bc
Red Head 412defg -03ab 06ef 09abc 246ef 225bc
Cherry Vanilla 391efgh -02ab 05fgh 08abc 208fg 178bc
Temuko 328gh -09c 04hi 08abc 147g 120c
QuF9P39-51 451cde -02ab 07de 10abc 297de 272bc
Kaslaea 493abcd -02ab 07bcd 06c 359cd 227bc
QQ74 312h -17e 04i 09abc 132g 119c
Isluga 362fgh -05b 05ghi 08abc 171fg 137bc
Linares 337gh -16de 05ghi 09abc 159g 146bc
Puno 504abc -01a 06ef 10abc 301de 301bc
QuF9P1-20 438cdef -02ab 06fg 05c 242ef 137bc
NL-6 555a -01a 07cde 09abc 376bcd 350abc
CO407Dave 357fgh -13d 04hi 09abc 160g 141bc
Bolivian White 441cdef -01ab 05fg 14ab 242ef 340abc
Bolivian Red 572a -01ab 08ab 14ab 440ab 593a
California Tricolor
572a -01a 08a 08bc 477a 361abc
Peruvian Red 568a 00a 08ab 08abc 439ab 342abc
Peruvian White 459bcde -01a 08abc 11abc 347cd 394abc
181
Table 7-Correlation of trained panel texture evaluation data and instrumental TPA over the 21 quinoa varieties
Variables Hardness Adhesiveness Cohesiveness Gumminess Chewiness Firm 070 059 080 079 057 Cohesive -060 -051 -066 -067 -043 Pasty -060 -070 -072 -068 -045 Adhesive -067 -063 -075 -075 -055 Crunchy 072 054 076 078 055 Moist -066 -066 -082 -078 -052
daggerP lt 01 P lt 005 P lt 001 P lt 0001
182
Figure 1-Principal component Analysis (PCA) biplot of aroma evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil Red Head
Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white Kaslaea
QQ74
Isluga
Linares
Puno
QuF9P1-20 NL-6
CO 407 Dave
Bolivia white
Bolivia red California Tricolor
Caramel Grain-like
Bean-like Nutty
Buttery Starchy
Grassy
Earthy
Woody
-25
-2
-15
-1
-05
0
05
1
15
2
-3 -25 -2 -15 -1 -05 0 05 1 15 2 25 3 35 4
F2 (2
455
)
F1 (4234 )
183
Figure 2-Principal component Analysis (PCA) biplot of tasteflavor evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil
Red Head Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white
Kaslaea
QQ74 Isluga
Linares
Puno
QuF9P1-20
NL-6
CO 407 Dave
Bolivia white
Bolivia red
California Tricolor
Sweet
Bitter Grain-like
Bean-like
Nutty
Earthy
Toasted
-3
-2
-1
0
1
2
3
-4 -3 -2 -1 0 1 2 3 4 5
F2 (3
073
)
F1 (3391 )
184
Figure 3-Principal component Analysis (PCA) biplot of texturemouthfeel evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil
Red Head Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white
Kaslaea
QQ74 Isluga
Linares
Puno
QuF9P1-20
NL-6
CO 407 Dave
Bolivia white
Bolivia red California Tricolor
Firm Cohesive
Pasty
Adhesive
Crunchy
Chewy Astringent
Moist
-2
-15
-1
-05
0
05
1
15
2
25
-3 -25 -2 -15 -1 -05 0 05 1 15 2 25 3 35
F2 (2
212
)
F1 (5959 )
185
Figure 4-Partial Least Squares (PLS) biplot correlating aroma color appearance tasteflavor texture and overall attributes evaluated by the trained panel (n = 9) to the consumer panel (n = 102) for 6 cooked quinoa samples (Consumer acceptances are in bold italics)
Grainy aroma
Beany aroma
Nutty aroma
Buttery
Starchy
Grassy
Earthy
Woody
Sweet
Bitter grainy flavor
Beany flavor
Earthy flavor Nutty flavor
Toasty
Firm Cohesive
Pasty
Adhesive
Crunchy
Chewy
Astringent
Waterymoist
Aroma
Color Appearance TasteFlavor
Texture Overall
Black
Bolivia red
QQ74
Bolivia white
Commercial Red
Titicaca
-1
-075
-05
-025
0
025
05
075
1
-1 -075 -05 -025 0 025 05 075 1
t2
t1
186
Supplementary tables
Table 1S-Mean separation of significant aroma attributes of cooked quinoa determined by the trained panel (n = 9) Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Caramel Nutty Buttery Green Earthy Woody
Titicaca 59a1 60a 45abc 39fg 42defgh 37cdef
Black 46g 50efg 38ef 47abc 54a 46a
KU2 50efg 51defg 41cdef 40efg 38h 35ef
Cahuil 56abc 53bcdefg 43abcd 49a 48b 39bcde
Red Head 55abcd 60a 45abc 44bcde 46bcd 41bc
Cherry Vanilla 52cdef 54bcdef 43abcde 43bcdef 46bcdef 37bcdef
Temuko 55abcd 56abcde 44abc 40defg 41efgh 37bcdef
QuF9P39-51 58ab 60a 46ab 42bcdefg 44bcdefg 36def
Kaslaea 53bcde 55abcde 42abcde 41defg 40gh 37bcdef
QQ74 50efg 48fg 39def 42defg 45bcdef 38bcdef
Isluga 52cdef 57abc 43abcd 43bcdefg 46bcde 39bcde
Linares 52cdef 54bcdef 42bcde 38g 44bcdefg 37cdef
Puno 56abc 56abcde 46ab 42cdefg 46bcdef 38bcdef
QuF9P1-20 53bcdef 58ab 44abcd 42cdefg 44bcdefg 40bcd
NL-6 57abc 53bcdefg 44abcd 39fg 44bcdefg 35def
CO 407 Dave 51def 54abcde 46ab 40efg 42defgh 34f
Bolivian White 53bcde 57abcd 46ab 43bcdef 43cdefgh 39bcd
Bolivian Red 52cdef 51defg 42bcde 43bcdefg 44bcdefg 37bcdef
California Tricolor 54abcde 51cdefg 38ef 44abcd 48bc 41ab
Peruvian Red 48fg 48g 36f 47ab 46bcdef 38bcdef
Peruvian White 54abcde 60a 48a 45abcd 41fgh 40bc
187
Table 2S-Mean separation of significant texture attributes of cooked quinoa determined by the trained panel Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Firm Cohesive Pasty Adhesive Crunchy Astringent Moist
Titicaca 70ab 63efgh 37ghi 37ghi 56bc 47d 38hij
Black 71ab 63efgh 32i 38ghi 58b 55abc 35jk
KU2 66bcd 64efg 38fghi 37ghi 49de 46de 38hij
Cahuil 68abc 61fghi 37ghi 36hi 56bc 55ab 37ij
Red Head 57fgh 68bcde 46cde 49d 45ef 55ab 48de
Cherry Vanilla 56gh 65cdef 49c 44def 43fg 55ab 49de
Temuko 49ij 70abcd 56b 57c 39gh 59a 51cd
QuF9P39-51 61defg 65def 47cd 40efgh 48def 48cd 42fgh
Kaslaea 60defg 62fghi 40defgh 40fgh 51cd 51bcd 42gh
QQ74 44j 70abc 60ab 81ab 37hi 46def 57ab
Isluga 52hi 66cdef 43cdef 55c 44efg 50bcd 48de
Linares 45j 75a 65a 86a 33i 47d 61a
Puno 58efgh 60fghij 41defg 43efg 52cd 47d 47def
QuF9P1-20 52hi 65def 43cdefg 46de 44fg 55ab 47defg
NL-6 64cde 61fghi 40efgh 41efgh 51cd 46de 46efg
CO 407 Dave 45j 72ab 59ab 80b 35hi 47d 55bc
Bolivian White 56gh 61fghi 38fghi 41efgh 50de 34g 48de
Bolivian Red 62cdef 59hij 34hi 36hi 56bc 38g 42fgh
California Tricolor 68abc 56j 32i 33i 60ab 39efg 39hij
Peruvian Red 74a 57ij 35hi 33i 64a 39fg 31k
Peruvian White 60defg 59ghij 38fghi 37hi 48def 34g 40hi
188
Figure-1S Demographic influence on preference of variety lsquoBlackrsquo
75a
66ab 61bc
54c
61bc
0
1
2
3
4
5
6
7
8
75 50 25 None Other
Liking score of lsquoBlackrsquo
Proportion of organic food consumption
52b
64a 65a 69a 70a
57ab 59ab
0
1
2
3
4
5
6
7
8
Everyday 4-5 timesper week
2-3 timesper week
Once aweek
A fewtimes per
month
Aboutevery 6months
Other
Liking score of lsquoBlackrsquo
Frequency of rice consumption
189
Chapter 7 Conclusions
Quinoa quality is a complex topic with seed composition influencing sensory and
physical properties This dissertation evaluated the seed characteristics composition flour
properties and cooking quality of 13 quinoa samples Differences in seed morphology and
composition contributed to the texture of cooked quinoa The seeds with higher raw seed
hardness lower bulk density or higher seed coat proportion yielded a firmer gummier and
chewier texture after cooking Higher protein content correlated with harder more adhesive
more cohesive gummier and chewier texture of cooked quinoa Additionally flour peak
viscosity breakdown final viscosity and setback exhibited influence on different texture
parameters Cooking time and water uptake ratio also significantly influence the texture whereas
cooking loss did not show any correlation with texture Starch characteristics also significantly
differed among quinoa varieties (Chapter 3) Amylose content ranged from 27 to 169
among 13 quinoa samples The quinoa samples with higher amylose proportion or higher starch
enthalpy tended to yield harder stickier more cohesive and chewier quinoa These studies on
seed quality seed characteristics compositions and cooking quality provided useful information
to food industry professionals to use in the development of quinoa products using appropriate
quinoa varieties Indices such protein content and flour viscosity (RVA) can be quickly
determined and exhibited strong correlations with cooked quinoa texture Furthur study should
develop a prediction model using protein content or RVA parameters to predict the texture of
cooked quinoa In this way food manufactures can quickly predict the texture or functionality of
quinoa varieties and then determine their specific application Moreover many of the test
methods were using the methods used in rice such as kernel hardness texture of cooked quinoa
190
thermal properties (DSC) and cooking qualities Such methods should be standardized in near
future as those defined by AACC (American Association of Cereal Chemists) The development
of standard methods allows for easier comparisons among different studies In Chapter 4 the
seed quality response to soil salinity and fertilization was studied Quinoa protein content
increased under high Na2SO4 concentration (32 dS m-1) The variety lsquoQQ065rsquo maintained similar
levels of hardness and density under salinity stress and is considered to be the best adapted
variety among four varieties The variety can be applied in salinity affected areas Future studies
can be applied on salinity drought influence on quinoa amino acids profile starch composition
fiber content and saponins content
Sensory evaluation of cooked quinoa was further examined in Chapter 5 Using a trained
panel the lexicon for cooked quinoa was developed Using this lexicon the sensory profiles of
16 field trial varieties and 5 commercial quinoa samples were generated Varietal differences
were observed in the aromas of caramel nutty buttery grassy earthy and woody tasteflavor of
sweet bitter grain-like nutty earthy and toasty and texture of firm cohesive pasty adhesive
crunchy chewy astringent and moist Subsequent consumer evaluation on 6 selected quinoa
samples indicated lsquoPeruvian Redrsquo was the most accepted overall whereas a sticky variety lsquoQQ74rsquo
was the least accepted Partial least square analysis using trained panel data and consumer
acceptance data indicated that overall consumer liking was driven by grassy aroma and firm and
crunchy texture The lexicon and the attributes driving consumer-liking can be utilized by
breeders and farmers to evaluate their quinoa varieties and products The information is also
useful to the food industry to evaluate ingredients from different locations and years improve
processing procedures and develop products
191
Overall the dissertation provided significant information of quinoa seed quality and
sensory characteristics among different varieties including both commercialized samples and
field trial samples not yet available in market Several quinoa varieties increasingly grown in
US were included in the studies The variety lsquoCherry Vanillarsquo and lsquoTiticacarsquo are among the
varieties gaining the best yields in US Their seed characteristics and sensory attributes
described in this dissertation should be helpful for industry professionals in their research and
product development Varieties include lsquoTiticacarsquo lsquoCherry Vanillarsquo and lsquoBlackrsquo Additionally
important tools were developed in quinoa evaluation including texture analysis using TPA and
the lexicon of cooked quinoa
As with any set of studies other research questions arise to be addressed in future
research First saponins the compounds introducing bitter taste in quinoa require further study
Sweet quinoa varieties (saponins content lt 011) should be bred and adapted to the US
Although many consumers may like the bitter taste and especially the potential health benefits of
saponins it is important to provide consumers choices of both bitter and non-bitter quinoa types
To assist the breeding of sweet quinoa genetic markers can be developed and associated with the
phenotype of saponin content As for the methods testing saponin content the foam method is
quick but not accurate whereas the GC method is accurate but requires long sample preparation
time and high capital investment An accurate more affordable and more efficient method such
as one using a spectrophotometer should be developed
Second one important nutritional value of quinoa is the balanced essential amino acids
The essential amino acids profiles change according to environment (drought and saline soil)
quinoa variety and processing (cleaning milling and cooking) and these changes should be
192
further studied It is important to prove quinoa seed maintains the rich essential amino acids even
growing under marginal conditions or being subjected to cleaning processes such as abrasion
and washing
Third betalains are the compounds contributing to the color of quinoa seed and providing
potential health benefits Betalain content type (relate to diverse colors) and their genetic loci in
quinoa can be further investigated Color diversity is one of the attractive properties in quinoa
seeds However the commercialized quinoa samples are in white or red color while more quinoa
varieties present orange purple brown and gray colors More choices of quinoa colorstypes
may attract more consumers
Finally sensory evaluation of quinoa varieties should be applied to the samples from
multiple years and locations since environment can significantly influence the sensory attributes
Also in addition to plain cooked quinoa more quinoa dishes can be involved in consumer
acceptance studies as different quinoa varieties may be suitable for various dishes
vi
TABLE OF CONTENTS
Page
ACKNOWLEDGMENTS iii
ABSTRACT iv-v
LIST OF TABLES ix-xi
LIST OF FIGURES xii-xiii
CHAPTERS
1 Introduction 1
References 6
2 Literature review 9
References 26
Tables 41
Figures44
3 Evaluation of texture differences among varieties of cooked quinoa 46
Abstract 46
Introduction 48
Materials and Methods 51
Results 54
Discussion 60
vii
Conclusion 63
References 65
Tables 71
Figures78
4 Quinoa starch characteristics and their correlation with
texture of cooked quinoa 80
Abstract 80
Introduction 81
Materials and Methods 82
Results 87
Discussion 95
Conclusion 102
References 103
Tables 109
5 Quinoa seed quality response to sodium chloride and
Sodium sulfate salinity 118
Abstract 118
Introduction 120
Materials and Methods 122
Results 125
Discussion 123
viii
Conclusion 132
References 134
Tables 139
Figure 145
6 Lexicon development and sensory attributes of cooked quinoa 146
Abstract 146
Introduction 148
Materials and Methods 150
Results and Discussion 155
Conclusion 165
References 167
Tables 172
Figures183
7 Conclusions 189
ix
LIST OF TABLES
Page
CHAPTER 2
Table 1 Essential amino acid of quinoa protein and FAOWHO suggested requirement (mgg
protein) 41
Table 2 Quinoa vitamin content (mg100g) 42
Table 3 Quinoa mineral content (mgmg ) 43
CHAPTER 3
Table 1 Varieties of quinoa used in the experimenthelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip71
Table 2 Seed characteristics and composition 72
Table 3 Texture profile analysis (TPA) of cooked quinoa 73
Table 4 Cooking quality of quinoa 74
Table 5 Pasting properties of quinoa flour by RVA 75
Table 6 Thermal properties of quinoa flour by Differential Scanning Calorimetry (DSC) 76
Table 7 Correlation coefficients between quinoa seed characteristics composition and
processing parameters and TPA texture of cooked quinoa 77
CHAPTER 4
Table 1 Quinoa varieties tested 109
Table 2 Starch content and composition 110
Table 3 Starch properties and α-amylase activity 111
Table 4 Texture of starch gel 112
Table 5 Thermal properties of starch 113
x
Table 6 Pasting properties of starch 114
Table 7 Correlation coefficients between starch properties and texture of cooked quinoa 115
Table 8 Correlations between starch properties and seed DSC RVA characteristics 116
CHAPTER 5
Table 1 Analysis of variance with F-values for protein content hardness and density of quinoa
seed 139
Table 2 Salinity variety and fertilization effects on quinoa seed protein content () 140
Table 3 Salinity variety and fertilization effects on quinoa seed hardness (kg) 141
Table 4 Salinity variety and fertilization effects on quinoa seed density (g cm3) 142
Table 5 Correlation coefficients of protein hardness and density of quinoa seed 143
Table 6 Correlation coefficients of quinoa seed quality and agronomic performance and seed
mineral content144
CHAPTER 6
Table 1 Quinoa samples 172
Table 2 Lexicon of cooked quinoa as developed by the trained panelists (n = 9) 173
Table 3 Significance and F-value of the effects of panelist replicate and quinoa variety on
aroma flavor and texture of cooked quinoa as determined using a trained panel (n = 9) 176
Table 4 Mean separation of significant tasteflavor attributes of cooked quinoa determined by
the trained panel Different letters within a column indicate attribute intensities were different
among quinoa samples at P lt 005 as determined using Fisherrsquos LSD 178
Table 5 Mean separation of consumer preference Different letters within a column indicate
consumer evaluation scores were different among quinoa samples at P lt 005 179
xi
Table 6 Hardness adhesiveness cohesiveness springiness gumminess and chewiness of the
cooked quinoa samples as determined using Texture Profile Analysis (TPA) Different letters
within a column indicate attribute intensities were different among quinoa samples at P lt 005
180
Table 7 Correlation of trained panel texture evaluation data and instrumental TPA over the 21
quinoa varieties 181
Table 1S Mean separation of significant aroma attributes of cooked quinoa determined by the
trained panel (n = 9) Different letters within a column indicate attribute intensities were different
among quinoa samples at P lt 005 as determined using Fisherrsquos LSD 186
Table 2S Mean separation of significant texture attributes of cooked quinoa determined by the
trained panel Different letters within a column indicate attribute intensities were different among
quinoa samples at P lt 005 as determined using Fisherrsquos LSD 187
xii
LIST OF FIGURES
Page
CHAPTER 2
Figure 1 Quinoa seed section and two-layered pericarp under perianth (Wu et al 2014) 44
Figure 2 Figure 2-Quinoa seed structure (Prego et al 1998) 45
CHAPTER 3
Figure 1 Rapid Visco Analyzer (RVA) graph of lsquoCherry Vanillarsquo and lsquoRed Commercialrsquo quinoa
flours 78
Figure 2 Seed coat image by SEM 79
CHAPTER 5
Figure 1 Protein content () of quinoa in response to combined fertility and
salinity treatments 145
CHAPTER 6
Figure 1 Principal component Analysis (PCA) biplot of aroma evaluations by the trained
sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 182
Figure 2 Principal component Analysis (PCA) biplot of tasteflavor evaluations by the trained
sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 183
xiii
Figure 3 Principal component Analysis (PCA) biplot of texturemouthfeel evaluations by the
trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly
differed among samples 184
Figure 4 Partial Least Squares (PLS) biplot correlating aroma color appearance tasteflavor
texture and overall attributes evaluated by the trained panel (n = 9) to the consumer panel (n =
102) for 6 quinoa samples (Consumer acceptances are in bold italics) 185
Figure-1S Demographic influence on preference of variety lsquoBlackrsquo 188
xiv
Dedication
This dissertation is dedicated to those who are interested in quinoa
the beautiful small grain providing nutrition and fun
1
Chapter 1 Introduction
Quinoa is growing rapidly in the global market largely due to its high nutritional value
and potential application in a wide range of products Bolivia and Peru are the major producers
and exporters of quinoa In Peru production increased from 31824 MT (Metric Ton) in 2007 to
108000 MT in 2015 (USDA 2015) In 2013 organic quinoa from Bolivia and Peru were sold at
averages of $8000MT and $7000MT respectively (Nuntildeez de Acro 2015) Of all countries the
US and Canada import the most quinoa and comprise 53 and 15 of the global imports
respectively (Carimentrand et al 2015) Quinoa yield is on average 600 kgha with yield
varying greatly and among varieties and environments (Garcia et al 2004) The total production
cost is $720ha in the southern Altiplano region of Bolivia and the farm-gate price reached
$60kg in 2013 (Nuntildeez de Acro 2015) With 2600 kg annual quinoa yield in a small 3 ha farm
the revenue would be $15390 which could potentially raise a family out of poverty (Nuntildeez de
Acro 2015)
Quinoa possesses many sensory properties Food texture refers to those qualities of a
food that can be felt with the fingers tongue palate or teeth (Sahin and Sumnu 2006) Texture is
one of most significant properties of food products Quinoa has unique texture ndash creamy smooth
and a little crunchy (James 2009) The texture of cooked quinoa is not only influenced by seed
structure but also determined by compounds such as starch and protein However publications
describing the texture of cooked quinoa are limited
Seed characteristics and structure are important factors influencing the textual properties
of cooked quinoa seed Quinoa is a dicotyledonous plant species very different from
2
monocotyledonous cereal grains The majority of the seed is the middle perisperm of which cells
have very thin walls and angular-shaped starch grains (Prego et al 1998) The two-layer
endosperm of the quinoa seed consists of living thick-walled cells rich in proteins and lipids but
without starch The protein bodies found in the embryo and endosperm lack crystalloids and
contain one or more globoids of phytin (Prego 1998) Given the structure of quinoa the seed
properties such as seed size hardness and seed coat proportion may influence the texture of the
cooked quinoa Nevertheless correlations between seed characteristics seed structure and
texture of cooked quinoa have not been performed
Beside the physical properties of seed the seed composition will influence the texture as
well Protein and starch are the major components in quinoa while their correlation to texture
has not been studied Starch characteristics and structures significantly influence the texture of
the end product Starch granules of quinoa is very small (1-2μm) compared to that of rice and
barley (Tari et al 2003) Quinoa starch is lower in amylose content (11 of starch) (Ahamed
1996) which may yield the hard texture Chain length of amylopectin also influences hardness of
food product (Ong and Blanshard 1995) In sum the influence of quinoa seed composition and
characteristics on cooked product should be studied
In addition to seed quality and characteristics the sensory attributes of quinoa are also
significant as they influence consumer acceptance and the application of the quinoa variety
However there is a lack of lexicon to describe the sensory attributes of cooked quinoa Rice is
considered as a model when studying quinoa sensory attributes because they are cooked in
similar ways The lexicon of cooked rice were developed and defined in the study of Champagne
3
et al (2004) Sewer floral starchygrain hay-likemusty popcorn green beans sweet taste
sour and astringent were among those attributes
Consumer acceptance is of great interested to breeders farmers and the food industry
Acceptability of quinoa bread was studied by Rosell et al (2009) and Chlopicka et al (2012)
Gluten free quinoa spaghetti (Chillo et al 2008) and dark chocolate with 20 quinoa
(Schumacher et al 2010) were evaluated using a sensory panel However cooked quinoa the
most common way of consuming quinoa has not been studied for its sensory properties and
consumer preference Additionally consumer acceptance of quinoa may be influenced by the
panelistsrsquo demographic such as origin food culture familiarity with less common grains and
quinoa and opinion of a healthy diet Furthermore compared to instrumental tests sensory
evaluation tests are generally more expensive and time consuming hence correlations of sensory
panel and instrumental data are of interest If correlations exist instrumental analyses can be
used to substitute or complement sensory panel evaluation
Based on the above discussion this dissertation focused on the study of seed
characteristics quality and texture of cooked quinoa and starch characteristics among various
quinoa varieties Seed quality under saline soil conditions was also investigated To develop the
sensory profiles of cooked quinoa a trained panel developed and validated a lexicon for cooked
quinoa while a consumer panel evaluated their acceptance of different quinoa varieties From
these data the drivers of consumer liking were determined
The dissertation is divided into 7 chapters Chapter 1 is an introduction of the topic and
overall objectives of the studies Chapter 2 provides a literature review of recent progress in
4
quinoa studies including quinoa seed structure and compositions physical properties flour
properties health benefits and quinoa products Chapter 3 was published in Journal of Food
Science under the title of lsquoEvaluation of texture differences among varieties of cooked quinoarsquo
The objectives of Chapter 3 were to study the texture difference among varieties of cooked
quinoa and evaluate the correlation between the texture and the seed characters and
composition cooking process flour pasting properties and thermal properties
Chapter 4 includes the manuscript entitled lsquoQuinoa starch characteristics and their
correlation with texture of cooked quinoarsquo The objectives of Chapter 4 were to determine starch
characteristics of quinoa among different varieties and investigate the correlations between the
starch characteristics and cooking quality of quinoa
Chapter 5 has been submitted to Frontier in Plant Science under the title lsquoQuinoa seed
quality response to sodium chloride and sodium sulfate salinityrsquo In Chapter 5 quinoa seed
quality grown under salinity stress was assessed Four quinoa varieties were grown under six
salinity treatments and two levels of fertilization and then quinoa seed quality characteristics
such as protein content seed hardness and seed density were evaluated
Chapter 6 is the manuscript entitled lsquoLexicon development and sensory attributes of
cooked quinoarsquo In Chapter 6 a lexicon of cooked quinoa was developed using a trained panel
The lexicon provided descriptions of the sensory attributes of aroma tasteflavor texture and
color with references developed for each attribute The trained panel then applied this lexicon to
the evaluation of 16 field trial quinoa varieties from WSU and 5 commercial quinoa samples
from Bolivia and Peru A consumer panel also evaluated their acceptance of 6 selected quinoa
5
samples Using data from the trained panel and the consumer panel the key sensory attributes
driving consumer liking were determined Finally Chapter 7 presents the conclusions and
recommendations for future studies
6
References
Nuntildeez de Acro Chapter 12 Quinoarsquos calling In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 211 ndash 25
Ahamed NT Singhal RS Kulkarni PR Pal M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 31 99-103
Ando H Chen Y Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food Components in
Fractions of Quinoa Seed Food Sci Technol Res 8(1) 80-4
Carimentrand A Baudoin A Lacroix P Bazile D Chia E 2015 Chapter 41 International
quinoa trade In D Bazile D Bertero and C Nieto editors State of the Art Report of
Quinoa in the World in 2013 Rome FAO amp CIRAD p 316 ndash 29
Champagne ET Bett-Garber KL McClung AM Bergman C 2004 Sensory characteristics of
diverse rice cultivars as influenced by genetic and environmental factors Cereal Chem 81
237-43
Chillo S Civica V Iannetti M Mastromatteo M Suriano N Del Nobile M 2010 Influence of
repeated extrusions on some properties of non-conventional spaghetti J Food Eng 100 329-
35
Chlopicka J Pasko P Gorinstein S Jedryas A Zagrodzki P 2012 Total phenolic and total
flavonoid content antioxidant activity and sensory evaluation of pseudocereal breads LWT-
Food Sci Technol 46 548-55
7
Garcia M Raes D Allen R Herbas C 2004 Dynamics of reference evapotranspiration in the
Bolivian highlands (Altiplano) Agr Forest Meteorol 125(1) 67-82
James LEA 2009 Quinoa (Chenopodium quinoa Willd) composition chemistry nutritional
and functional properties Adv Food Nutr Res 58 1-31
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine structure of amylopectin J Cereal Sci 21 251-60
Perdon AA Siebenmorgen TJ Buescher RW Gbur EE 1999 Starch retrogradation and texture
of cooked milled rice during storage J Food Sci 64 828-32
Prego I Maldonado S Otegui M 1998 Seed structure and localization of reserves in
Chenopodium quinoa Ann Bot 82(4) 481-8
Ramesh M Ali SZ Bhattacharya KR1999 Structure of rice starch and its relation to cooked-
rice texture Carbohydr Polym 38 337-47
Rosell CM Cortez G Repo-Carrasco R 2009 Bread making use of Andean crops quinoa
kantildeiwa kiwicha and tarwi Cereal Chem 86 386-92
Sahin S Sumnu SG 2006 Physical properties of foods Springer Science amp Business Media
P39 ndash 109
Schumacher AB Brandelli A Macedo FC Pieta L Klug TV de Jong EV 2010 Chemical and
sensory evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J
Food Sci Technol 47 202-6
8
Tari TA Annapure US Singhal RS Kulkarni PR 2003 Starch-based spherical aggregates
screening of small granule sized starches for entrapment of a model flavouring compound
vanillin Carbohydr Polym 53 45-51
USDA US Department of Agriculture 2015a Peru Quinoa outlook Access from
httpwwwfasusdagovdataperu-quinoa-outlook
9
Chapter 2 Literature Review
Introduction
Quinoa (Chenopodium quinoa Willd) is a dicotyledonous pseudocereal from the Andean
region of South America The plant belongs to a complex of allotetraploid taxa (2n = 4x = 36)
which includes Chenopodium berlandieri subsp berlandieri Chenopodium berlandieri subsp
nuttalliae Chenopodium hircinum and Chenopodium quinoa (Gomez-Pando 2015 Matanguihan
et al 2015) Closely related species include the weed lambsquarter (Chenopodium album)
amaranth (Amaranth palmeri) sugar beet (Beta vulgaris L) and spinach (Spinacea oleracea L)
(Maughan et al 2004) Quinoa plant is C3 specie with 90 self-pollenating (Gonzalez et al
2011) Quinoa was domesticated approximately 5000 ndash 7000 years ago in the Lake Titicaca area
in Bolivia and Peru (Gonzalez et al 2015) Quinoa produces small oval-shaped seeds with a
diameter of 2 mm and a weight of 2 g ndash 46 g 1000-seed (Wu et al 2014) The seed color varies
and can be white yellow orange red purple brown or gray White and red quinoas are the most
common commercially available varietals in the US marketplace (Data from online resources
and local stores in Pullman WA) With such small seeds quinoa provides excellent nutritional
value such as high protein content balanced essential amino acids high proportion of
unsaturated fatty acids rich vitamin B complex vitamin E and minerals antioxidants such as
phenolics and betalains and rich dietary fibers (Wu 2015) For these reasons quinoa is
recognized as a ldquocompleterdquo food (Taverna et al 2012)
10
This chapter reviewed publications in quinoa varieties global development seed
structure and constituents quinoa health benefits physical properties and thermal properties
quinoa flour characteristics processing and quinoa products
Quinoa varieties
There are 16422 quinoa accessions or genetypes conserved worldwide 14502 of which
are conserved in genebanks from the Andean region (Rojas et al 2013) Bolivia and Peru
manage 13023 quinoa accessions (80 of world total accessions) in 140 genebanks (Rojas and
Pinto 2015)
Based on genetic diversity adaptation and morphological characteristics five ecotypes
of quinoa have been identified in the Andean region including valley quinoa Altiplano quinoa
salar quinoa sea level quinoa and subtropical quinoa (Tapia et al 1980) The sea-level ecotype
or Chilean lowland ecotype is the best adapted to temperate climate and high summer
temperature (Peterson and Murphy 2015a)
Adaptation
Quinoa has shown excellent adaptation to marginal or extreme environments and such
adaptation was summarized by Gonzalez et al (2015) Quinoa growing areas range from sea
level to 4200 masl (meters above sea level) with growing temperature rangeing from -4 to 38 ordmC
The plant has adapted to drought-stressed environments but can also grow in areas with
humidity ranging from 40 to 88 Quinoa can grow in marginal soil conditions such as dry
(Garcia et al 2003) infertile (Sanchez et al 2003) and with wide pH range from acidic to basic
(Jacobsen and Stolen 1993) Quinoa has also adapted to high salinity soil (equal to sea salt level
11
or 40 dSm) (Koyro and Eisa 2008 Hariadi et al 2011 Peterson and Murphy 2015b)
Furthermore quinoa has shown tolerance to frost at -8 to -4 ordmC (Jacobsen et al 2005)
Even though quinoa varieties are remarkably diverse and able to adapt to extreme
conditions time and resources are required to breed the high-yielding varieties that are adapted
to regional environments in North America Challenges to achieving strong performance include
yield waterlogging pre-harvest sprouting weed control and tolerance to disease insect pests
and animal stress (Peterson and Murphy 2015a) The breeding work not only needs the effort
from breeders and researchers but also demands the participation and collaboration of local
farmers
In addition to being widely grown in South America quinoa has also recently been
grown in North America Europe Australia Africa and Asia In US quinoa cultivation and
breeding started in the 1980s by the efforts from seed companies private individuals and
Colorado State University (Peterson and Murphy 2015a) Since 2010 Washington State
University has been breeding quinoa in the Pacific Northwest to suit the diverse environmental
conditions including rainfall and temperature Peterson and Murphy (2015a) found the major
challenges in North America included heat susceptibility downy mildew (Plasmopara viticola)
saponin removal weed stress and insect stress (such as aphids and Lygus sp)
With high nutritional value quinoa is recognized as significant in food security and
treating malnutrition issue in developing countries (Rojas 2011) Maliro and Guwela (2015)
reviewed quinoa breeding in Africa Initial experiments showed quinoa can grow well in Malawi
and Kenya in both warm and cool areas The quinoa grain yields in Malawi and Kenya are 3-4
12
tonha which are comparable to the yields in South America However the challenge remains to
adopt quinoa into the local diet and cultivate a quinoa consuming market
Physical Properties of Quinoa
Physical properties of seed refer to seed morphology size gravimetric properties
(weight density and porosity) aerodynamic properties and hardness which are critical to
technology and equipment designed for post-harvest process such as seed cleaning
classification aeration drying and storage (Vilche et al 2003)
The quinoa seed is oval-shaped with a diameter of approximately 18 to 22 mm (Bertero
et al 2004 Wu et al 2014) Mean 1000-seed weight of quinoa is around 27 g (Bhargava et al
2006) and a range of 15 g to 45 g has been observed among varieties (Wu et al 2014)
Commercial quinoa from Bolivia tends to have higher 1000-seed weight of 38 g to 45 g
Additionally bulk density ranges from 066 gmL to 075 gmL in most varieties (Wu et al
2014) Porosity refers to the fraction of space in bulk seed which is not occupied by the seed
(Thompson and Isaac 1976) The porosity of quinoa is 23 (Vilche et al 2003) while that of
rice is 50 to 60 (Kunze et al 2004)
Terminal velocity is the air velocity at which seeds remain in suspension This parameter
is important in cleaning quinoa to remove impurities such as dockage hollow and immature
kernels and mixed weed seeds Vilche et al (2003) reported the terminal velocity of 081 ms-1
while the value of rice was 6 ms-1 to 77 ms-1 (Razavi and Farahmandfar 2008)
Seed hardness or crushing strength is used as a rough estimation of moisture content in
rice (Kunze et al 2004) The hardness of quinoa seed can be tested using a texture analyzer (Wu
13
et al 2014) A stainless cylinder (10 mm in diameter) compressed one quinoa seed to 90 strain
at the rate of 5 mms Because of hardness variation among individual seeds at least six
measurements were required Among the thirteen quinoa samples that were tested hardness
ranged from 58 kg to 110 kg (Wu et al 2014)
Quinoa Seed Structure
Grain structure of quinoa was described in detail by Taylor and Parker (2002) On the
outside of grain is a perianth which can be easily removed during cleaning or rubbing
Sometimes betalain pigments concentrate on this perianth layer and the seed shows bright purple
or golden colors However this color will disappear with the removal of the perianth Inside the
perianth is two-layered pericarp with papillose surface (Figure 1) Beneath the pericarp a seed
coat or episperm is located The seed coat can be white yellow orange red brown or black
Red and white quinoa share the largest market share with consumers exhibiting increasing
interest in brownblack mixed products such as lsquoCalifornia Tricolorrsquo(data from Google
Shopping Amazon and local stores in Pullman WA)
The main seed is enveloped in outside layers and the structure was depicted by Prego et
al (1998) (Figure 2) The embryo (two cotyledons and radicle) coils around a center pericarp
which occupies ~40 of seed volume (Fleming and Galwey 1998) Protein and lipid bodies are
primarily present in the embryo whereas starch granules provide storage in the thin-walled
perisperm Minerals of phosphorus potassium and magnesium are concentrated in phytin
globoids located in the embryo and calcium is located in the pericarp (Konishi et al 2004)
Quinoa Seed Constituents
14
Quinoa is known as a lsquocomplete foodrsquo (James 2009) The seed composition was recently
reviewed by Wu (2015) and Maradini Filho et al (2015) In sum the high nutritional value of
quinoa arises from its high protein content complete and balanced essential amino acids high
proportion of unsaturated fatty acids high concentrations of vitamin B complex vitamin E and
minerals and high phenolic and betalain content
A protein range of 12 to 17 in quinoa has been reported by most studies (Rojas et al
2015) This protein content is higher than wheat (8 to 14 ww) (Halverson and Zeleny 1988)
and rice (4 - 105 ww) (Champagne et al 2004) Additionally quinoa contains all essential
amino acids at concentrations exceeding the suggested requirements from FAOWHO (Table 1)
Quinoa is also gluten-free because it is lacking in prolamins Prolamins are a group of
storage proteins that are rich in proline Prolamins can interact with water and form the gluten
structure which cannot be tolerated by those with celiac disease (Fasano et al 2003) Quinoa and
rice both contain low prolamins (72 and 89 of total protein respectively) and are
considered gluten-free crops Prolamins in wheat (called gliadin) comprise 285 of its total
protein and in maize this concentration of prolamin is 245 (Koziol 1992)
The protein quality of quinoa protein was reported by Ruales and Nair (1992) In raw
quinoa the net protein utilization (NPU) was 757 biological value (BV) was 826 and
digestibility (TD) was 917 all of which were slightly lower than those of casein The
digestibility of quinoa protein is comparable to that of other high quality food proteins such as
soy beans and skim milk (Taylor and Parker 2002) The Protein Efficiency Ratio (PER) in
quinoa ranges from 195 to 31 and is similar to that of casein (Gross et al 1989 Guzmaacuten-
15
Maldonado and Paredes-Lopez 2002) Regarding functional properties of quinoa protein isolates
Eugenia et al (2015) found Bolivian quinoa exhibited the highest thermal stability oil binding
capacity and water binding capacity at acidic pH The Peruvian samples showed the highest
water binding capacity at basic pH and the best foaming capacity at pH 5
Quinoa starch content ranges from 58 to 64 of the dry seed weight (Vega‐Gaacutelvez et
al 2010) Quinoa possesses a small granule size of 06 to 2 μm similar to that of amaranth (1 to
2 μm) and much smaller than those of other grains such as rice wheat oat barley and
buckwheat (2 to 36 μm) (Lindeboom et al 2004) The amylose content in quinoa starch tends to
be lower than found in common grains A range of 3 to 20 was reported by Lindeboom et al
(2005) whereas amylose content is around 25 in cereals As in most cereals quinoa starch is
type A in X-ray diffraction pattern (Ando et al 2002) Li et al (2016) found significant variation
among 26 commercial quinoa samples in the physicochemical properties of starch such as gel
texture thermal and pasting parameters which were strongly affected by apparent amylose
content
Quinoa lipids comprise 55 to 71 of dry seed weight in most reports (Maradini Filho
et al 2015) Ando et al (2002) found quinoa (cultivar Real TKW from Bolivia) perisperm and
embryo contained 50 and 102 total fatty acids respectively Among these fatty acids
unsaturated fatty acids such as oleic linoleic and linolenic comprised 875 Ogungbenle
(2003) reported the properties of quinoa lipids The values of acid iodine peroxide and
saponification were 05 54 24 and 192 respectively
16
Quinoa micronutrients of vitamins and minerals and the relative lsquoreference daily intakersquo
are summarized in Table 2 and 3 respectively Compared to Daily Intake References quinoa
provides a good source of Vitamin B1 B2 and B9 and Vitamin E as well as minerals such as
magnesium phosphorous iron and copper
Quinoa is one of the crops representing diversity in color including white vanilla
yellow orange red brown gray and dark Besides the anthocyannins in dark quinoa (Paśko et
al 2009) the major pigment in quinoa is betalain primarily presenting in seed coat and the
compounds can be subdivided into red-violet betacyannins and yellow-orange betaxanthins
(Tang et al 2015) Betalain is a water-soluble pigment which is permitted quantum satis as a
natural food colorant and applied in fruit yogurt ice cream jams chewing gum sauces and
soups (Esatbeyoglu et al 2015) Additionally betalain potentially offers health benefits such as
antioxidant activity anti-inflammation activity preventing low-density lipoprotein (LDL)
oxidation and DNA damage (Benavente-Garcia and Castillo 2008 Esatbeyoglu et al 2015)
Saponins
Saponins are compounds on the seed coat of quinoa that confer a bitter taste The
compounds are considered to be a defense system against herbivores and pathogens Regarding
chemical structure saponins are a group of glycosides consisting of a hydrophilic carbohydrate
chain (such as arabinose glucose galactose xylose and rhamnose) and a hydrophobic aglycone
(Kuljanabhagavad and Wink 2009) Chemical structures of aglycones were summarized by
Kuljanabhagavad and Wink (2009)
17
Saponins have been considered as anti-nutrient because of haemolytic activity which
refers to the breakdown of red blood cells (Khalil and El-Adawy 1994) However saponins
exhibited health benefit functions such as anti-inflammation (Yao et al 2009) antibacterial
antimicrobial activity (Killeen et al 1998) anti-tumor activity (Shao et al 1996) and
antioxidant activity (Guumllccedilin et al 2006) Furthermore saponins have medicinal use Sun et al
(2009) reported saponins can activate immune system and were used as vaccine adjuvants
Saponins also exhibited anti-cancer activity (Man et al 2010)
Even though saponins have potential health benefits their bitter taste is not pleasant to
consumers To address the bitterness found in bitter quinoa varieties (gt 011 saponin content)
sweet quinoa varieties were bred through conventional genetic selection to contain a lower
saponin content (lt 011 saponin content) For instance lsquoSajamarsquo lsquoKurmirsquo lsquoAynoqarsquo
lsquoKosunarsquo and lsquoBlanquitarsquo in Bolivia lsquoBlanca de Juninrsquo in Peru and lsquoTunkahuanrsquo in Ecuador are
considered sweet quinoa varieties (Quiroga et al 2015) Unfortunately varieties from Bolivia
Peru and Ecuador do not adapt to temperate climates such as those found in the Pacific
Northwest in US and Europe A sweet variety called lsquoJessiersquo exhibits acceptable yield in Pacific
Northwest and has a great market potential Further development of sweet quinoa varieties
adapted to local climate will happen in near future
To remove saponins both dry and wet processing methods have been developed The wet
method or moist method refers to washing quinoa while rubbing the grain with hands or by a
stone Repo-Carrasco et al (2003) suggested the best washing conditions of 20 min soaking 20
min stirring with a water temperature of 70 degC The wet method becomes costly due to the
required drying process Additionally quinoa grain may begin to germinate during wet cleaning
18
The dry method or abrasive dehulling uses mechanical abrasion to polish the grain and
remove the saponins A dehulling process was reported by Reichert et al (1986) using Tanential
Abrasive Dehulling Device (TADD) and removal of 6 - 15 of kernel was required to reduce
the saponins content to lower than 011 Additionally a TM-05 Taka-Yama testing mill was
used in the quinoa pearling process (to 20 - 30 pearling degree) (Goacutemez-Caravaca et al
2014) The dry method is relatively cheaper than wet method and does not generate saponin
waste water The saponin removal efficiency of the dry and washing methods were reported to be
87 and 72 respectively (Reichert et al 1986 Gee et al 1993) A combination of dry and wet
methods was recommended to obtain the efficient cleaning (Repo-Carrasco et al 2003)
Since quinoa is such an expensive crop a 25 to 30 weight lost during the cleaning
process represents a substantial loss on an industrial scale In addition mineral phenolic and
fiber content may dramatically decrease during processing resulting in a loss of nutritional
value Hence cleaning process should be further optimized to reach lower grain weight loss
while maintain an efficient saponins elimination
Removed saponins can be utilized as side products Since saponins also have excellent
foaming property they can be applied in cosmetics and foods as foam-stabilizing and
emulsifying agents (Yang et al 2010) detergents (Chen et al 2010) and preservatives
(Taormina et al 2006)
Saponin content is important to analyze since it highly influences the taste of quinoa
Traditionally the afrosimetric method or foam method was used to estimate saponins content In
this method saponon content is calculated from foam height after shaking quinoa and water
19
mixture for a specific time (Koziol 1991) This afrosimetric method is fast and affordable and
can be used by farmers as a quick estimation of saponin content however the method is not very
accurate The foam stability varies among samples A more accurate method was developed
using Gas Chromatography (GC) (Ridout et al 1991) Using this method quinoa flour was first
defatted using a Soxhlet extraction and then hydrolyzed in reflux for 3 h with a methanol
solution of HCl (2 N) The hydrolysis product sapogenins were extracted with ethyl acetate and
derivatized with bis-(trimethylsilyl) trifluoroacetamide (BSTFA) and dry pyridine and then
tested using GC Generally GC method is a more solid and accurate method compared to foam
method however GC also requires high capital investment as well as long and complex sample
preparation For quinoa farmers and food manufactures fast and affordable methods to test
saponins content in quinoa need to be developed
Saponins have been an important topic in quinoa research Future studies in this area can
include 1) breeding and commercialization of saponin-free or sweet quinoa varieties with high
yield and high agronomy performance (resistance to biotic and abiotic stresses) 2) development
of quick and low cost detection method of saponin content and 3) application of saponin in
medicine foods and cosmetics can be further explored
Health benefits
Simnadis et al (2015) performed a meta-analysis of 18 studies which used animal models
to assess the physiological effects associated with quinoa consumption From these studies
purported physiological effects of quinoa consumption included decreased weight gain
improved lipid profile (decrease LDL and cholesterol) and improved capacity to respond to
20
oxidative stress Simnadis et al (2015) pointed out that the presence of saponins protein and
20-hydroxyecdysone (affects energy homeostasis and intestinal fat absorption) contributed to
those benefit effects
Furthermore Ruales et al (2002) found increased plasma levels of IGF-1 (insulin-like
growth factor) in 50-65 month-old boys after consuming a quinoa infant food for 15 days This
result implicated the potential of quinoa to reduce childhood malnutrition In another study of 22
students (aged 18 to 45) the daily consumption of a quinoa cereal bar for 30 days significantly
decreased triglycerides cholesterol and LDL compared to those parameters prior to quinoa
consumption These results suggest that quinoa intake may reduce the risk of developing
cardiovascular disease (Farinazzi-Machado et al 2012) De Carvalho et al (2014) studied the
influence of quinoa on over-weight postmenopausal women Consumption of quinoa flakes (25
gd for 4 weeks) was found to reduce serum triglycerides and TBARS (thiobarbituric acid
reactive substances) and increase GSH (glutathione) and urinary excretion of enterolignans
compared to those indexes before consuming quinoa flakes
Quinoa flour properties
Functional properties of quinoa flour were determined by Ogungbenle (2003) Quinoa
flour has high water absorption capacity (147) and low foaming capacity (9) and stability
(2) Water absorption capacity was determined by the volume of water retained per gram of
quinoa flour during 30-min mixing at 24 ordmC (Beuchat 1977) The water absorption of quinoa was
higher than that of fluted pumpkin seed (85) soy flour (130) and pigeon pea flour (138)
which implies the potential use of quinoa flour in viscous foods such as soups doughs and
21
baked products Additionally foaming capacity was determined by the foam volumes before and
after whipping of 8 protein solution at pH 70 (Coffmann and Garciaj 1977) Then foam
samples were inverted and dripped though 2 mm wire screen in to beakers The foam stability
was determined by the weight of liquid released from foam after a specific time and the original
weight of foam (Coffmann and Garciaj 1977) Furthermore minimum protein solubility was
observed at pH 60 similar to that of pearl millet and higher than pigeon pea (pH 50) and fluted
pumpkin seed (pH 40) Relatively high solubility of quinoa protein in acidic condition implies
the potential application of quinoa protein in acidic food and carbonated beverages
Wu et al (2014) studied flour viscosity among 13 quinoa samples with large variations
reported among samples The ranges of peak viscosity final viscosity and setback were 59
RVU ndash 197 RVU 56 RVU ndash 203 RVU and -62 RVU ndash 73 RVU respectively which were
comparable to those of rice flour (Zhou et al 2003) Flour viscosity significantly influence
texture of quinoa and rice (Champagne et al 1998 Wu et al 2014)
Ruales et al (1993) studied processing influence on the physico-chemical characteristics
of quinoa flour The process included cooking and autoclaving of the seeds drum drying of
flour and extrusion of the grits Autoclaved quinoa samples exhibited the lowest degree of starch
gelatinization (325) whereas precookeddrum dried quinoa samples were 974 Higher
polymer degradation was found in the cooked samples compared to the autoclaved samples
Water solubility in cooked samples (54 to 156) and autoclaved samples (70 to 96) increased
with the processing time (30 to 60 min cooking and 10 to 30 min autoclaving)
Thermal Properties of quinoa
22
Thermal properties of quinoa flour (both starch and protein) have been determined using
Differential Scanning Calorimetry (DSC) (Abugoch et al 2009) A quinoa flour suspension was
prepared in 20 (ww) concentration The testing temperature was raised from 27 to 120 degC at a
rate of 10 degCmin Two peaks in the DSC graph referenced the starch gelatinization temperature
at 657 degC and protein denaturalization at 989 degC Enthalpy refers to the energy required to
complete starch gelatinization or protein denaturazition In the study of Abugoch et al (2009)
the enthalpy was 59 Jg for starch and 22 Jg for proteins in quinoa
Product development with quinoa
Quinoa has been used in different products such as spaghetti bread and cookies to
enhance nutritional value including a higher protein content and more balanced amino acid
profile Chillo et al (2008) evaluated the quality of spaghetti from amaranth and quinoa flour
Compared to durum semolina spaghetti the spaghetti with amaranth and quinoa flour exhibited
equal breakage susceptibility higher cooking loss and lower instrumental stickiness The
sensory acceptance scores were not different from the control The solid loss weight increase
volume increase adhesiveness and moisture of a corn and quinoa mixed spaghetti were 162thinspg
kgminus1 23 times 26 times 20907thinspg and 384thinspg kgminus1 respectively (Caperuto et al 2001)
Schoenlechner et al (2010) found the optimal combination of 60 buckwheat 20 amaranth
and 20 quinoa yielded an improved dough matrix compared to other flour combinations With
the addition of 6 egg white powder and 12 emulsifier (distilled monoglycerides) this gluten-
free pasta exhibited acceptable firmness and cooking quality compared to wheat pasta
23
Stikic et al (2012) added 20 quinoa seeds in bread formulations which resulted in the
similar dough development time and stability compared to those of wheat dough even though
the bread specific volume was lower (63 mLg) compared to wheat bread (67 mLg) The
protein content of bread increased by 2 (ww) and sensory characteristics were lsquoexcellentrsquo as
evaluated by five trained expert panelists Iglesias-Puig et al (2015) found 25g100 g quinoa
flour substitution in wheat bread showed small depreciation in bread quality in terms of loaf
volume crumb firmness and acceptability whereas the nutritional value increased in dietary
fiber minerals protein and healthy fats Rizzello et al (2016) selected strains (lactic acid
bacteria) to develop a quinoa sourdough A wheat bread with 20 (ww) quinoa sourdough
exhibited improved nutritional (such as protein digestibility and quality) textural and sensory
features Quinoa leaves were also applied to bread making (Świeca et al 2014) With the
replacement of wheat flour by 1 to 5 (ww) quinoa leaves the bread crumb exhibited increased
firmness cohesiveness and gumminess Antioxidant activity and phenolic contents both
significantly increased compared to wheat bread
Pagamunici et al (2014) developed three gluten-free cookies with rice and quinoa flour
with 15 26 and 36 (ww) quinoa flour proportions respectively The formulation with
36 quinoa flour had the highest alpha-linolenic acid and mineral content and the cookie
displayed excellent sensory characteristics as evaluated by 80 non-trained consumer panelists
Another study optimized a gluten-free quinoa formulation with 30 quinoa flour 25 quinoa
flakes and 45 corn starch (Brito et al 2015) The cookie was characterized as a product rich in
essential amino acids linolenic acid minerals and dietary fiber This cookie was among those
24
products using the highest quinoa flour content (55 ww) while still received acceptable
sensory scores
Repo-Carrasco-Valencia and Serna (2011) introduced an extrusion process in Peru
Quinoa flour was tempered to 12 moisture for extrusion During extrusion total and insoluble
dietary fiber decreased by 5 to 17 and 13 to 29 respectively whereas the soluble dietary
fiber significantly increased by 38 to 71 Additionally the radical scavenging activity was
also increased in extruded quinoa compared to raw quinoa
Schumacher et al (2010) developed a dark chocolate with addition of 20 quinoa An
improved nutritional value was observed in 9 (ww) increase in vitamin E 70 - 104
increases in amino acids of cysteine tyrosine and methionine This quinoa dark chocolate
received over 70 acceptance index from sensory panel
Gluten-free beer is of increasing interest in the market (Dezelak et al 2014) Ogungbenle
(2003) found quinoa has high D-xylose and maltose and low glucose and fructose content
suggesting its potential use in malted drink de Meo et al (2011) applied alkaline steeping to
pseudocereal and found its positive effects on pseudocereals malt production by increasing total
soluble nitrogen and free amino nitrogen Kamelgard (2012) patented a method to create a
quinoa-based beverage fermented by a yeast Saccharomyces cerevisiae The beverage can be
distilled and aged to form gluten-free liquor Dezelak et al (2014) processed a quinoa beer-like
beverage (fermented with Saccharomyces pastorianus TUM 3470) resulting in a product with a
nutty aroma low alcohol content and rich in minerals and amino acids However further
development of the brewing procedure was necessary since the beverage showed a less attractive
25
appearance (near to black color and greyish foam) and astringent mouthfeel Compared to barley
brewing attributes of quinoa exhibited lower malt extracts longer saccharification times higher
values in total protein fermentable amino nitrogen content and iodine test
Processing quinoa grain to dried edible product and sweet quinoa product were developed
by Scanlin and Burnett (2010) The edible quinoa product was processed through pre-
conditioning (abrasion and washing) moist heating (steam cooking and pressure cooking) dry
heating (baking toasting and dehydrating) and post-production treatment As for sweet quinoa
product germination and malting processing were applied Caceres et al (2014) patented a
process to extract peptides and maltodextrins from quinoa flour and the extracts were applied in
a gel-format food as a supplement during and after physical activity
26
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flour proteins (Chenopodium quinoa Willd) during storage Int J Food Sci Tech 44(10)
2013-20
Abugoch LE Romero N Tapia CA Silva J Rivera M 2008 Study of some physicochemical
and functional properties of quinoa (Chenopodium quinoa Willd) protein isolates J Agric
Food Chem 56(12) 4745-50
Ando H Chen Y Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food Components in
Fractions of Quinoa Seed Food Sci Technol Res 8(1) 80-4
Benavente-Garcia O Castillo J 2008 Update on uses and properties of citrus flavonoids new
findings in anticancer cardiovascular and anti-inflammatory activity J Agric Food Chem
56(15) 6185-205
Bertero HD de la Vega AJ Correa G Jacobsen SE Mujica A 2004 Genotype and genotype-
by-environment interaction effects for grain yield and grain size of quinoa (Chenopodium
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Crops Res 89(2ndash3) 299-318
Beuchat LR 1977 Functional and electrophoretic characteristics of succinylated peanut flour
protein J Agric Food Chem 25(2) 258-61
Bhargava A Shukla S Rajan S Ohri D 2006 Genetic diversity for morphological and quality
traits in quinoa (Chenopodium quinoa Willd) Germplasm Genet Resour Crop Evol 54(1)
167-73
27
Brito IL de Souza EL Felex SSS Madruga MS Yamashita F Magnani M 2015 Nutritional
and sensory characteristics of gluten-free quinoa (Chenopodium quinoa Willd)-based
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73
Caceres JIE Calderon PD Lira FO 2014 Method for the formulation of a gel-format foodstuff
for use as a nutritional foodstuff enriched with peptides and maltodextrins obtained from
quinoa flour Google Patents
Caperuto LC Amaya-Farfan J Camargo CRO 2001 Performance of quinoa (Chenopodium
quinoa Willd) flour in the manufacture of gluten-free spaghetti J Sci Food Agric 81(1) 95-
101
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5) 764-71
Champagne ET Wood DF Juliano BO Bechtel D 2004 Chapter 4 The rice grain and its gross
composition In Champagne ET editor Rice Chemistry and Technology 3rd edition St
Paul MN American Association of Cereal Chemists Inc p 88 ndash 9
Chen YF Yang CH Chang MS Ciou YP Huang YC 2010 Foam properties and detergent
abilities of the saponins from Camellia oleifera Int J Mol Sci11(11) 4417-25
28
Chillo S Laverse J Falcone PM Del Nobile MA 2008 Quality of spaghetti in base amaranthus
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101-7
Coffmann CW Garciaj VV 1977 Functional properties and amino acid content of a protein
isolate from mung bean flour Int J Food Sci Technol 12(5) 473-84
De Carvalho FG Oviacutedio PP Padovan GJ Jordao Junior AA Marchini JS Navarro AM 2014
Metabolic parameters of postmenopausal women after quinoa or corn flakes intakendasha
prospective and double-blind study Int J Food Sci Nutr 65(3) 380-5
Deželak M Zarnkow M Becker T Košir IJ 2014 Processing of bottom-fermented gluten-free
beer-like beverages based on buckwheat and quinoa malt with chemical and sensory
characterization J Inst Brew 120(4) 360-70
Farinazzi-Machado FMV Barbalho SM Oshiiwa M Goulart R Pessan Junior O 2012 Use of
cereal bars with quinoa (Chenopodium quinoa W) to reduce risk factors related to
cardiovascular diseases Food Sci Technol(Campinas) 32(2) 239-44
Fasano A Berti I Gerarduzzi T Not T Colletti RB Drago S Hill ID 2003 Prevalence of celiac
disease in at-risk and not-at-risk groups in the United States a large multicenter study Arch
Intern Med 163(3) 286-92
Fleming JE Galwey NW 1998 Quinoa (Chenopodium quinoa Willd) nutritional quality and
technological aspects as human food In Belton PS Taylor JRN editors Increasing the
29
utilisation of sorghum buckwheat grain amaranth and quinoa for improved nutrition
Norwich UK Institute of Food Research p 49-64
Friedman M Brandon DL 2001 Nutritional and health benefits of soy proteins J Agric Food
Chem 49(3)1069-86
Garcia M Raes D Jacobsen SE 2003 Evapotranspiration analysis and irrigation requirements
of quinoa (Chenopodium quinoa) in the Bolivian highlands Agr Water Manage 60(2) 119-
34
Gee JM Price KR Ridout CL Wortley GM Hurrell RF Johnson IT 1993 Saponins of quinoa
(Chenopodium quinoa) effects of processing on their abundance in quinoa products and their
biological effects on intestinal mucosal tissue J Sci Food Agric 63(2) 201-9
Goacutemez-Caravaca AM Iafelice G Verardo V Marconi E Caboni MF 2014 Influence of
pearling process on phenolic and saponin content in quinoa (Chenopodium quinoa Willd)
Food Chem 157 174-8
Gomez-Pando L 2015 Chapter 6 Quinoa breeding In Murphy KM Matanguihan J editors
Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p
87 ndash 97
Gonzaacutelez JA Bruno M Valoy M Prado FE 2011 Genotypic variation of gas exchange
parameters and leaf stable carbon and nitrogen isotopes in ten quinoa cultivars grown under
drought J Agron Crop Sci 197(2) 81-93
30
Gonzaacutelez JA Eisa SSS Hussin SAES and Prado FE 2015 Chapter 1 Quinoa An Incan Crop
to Face Global Changes in Agriculture In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 182-6
Graf BL Rojas-Silva P Rojo LE Delatorre-Herrera J Baldeoacuten ME Raskin I 2015 Innovations
in health value and functional food development of quinoa (Chenopodium quinoa Willd)
Comp Rev Food Sci Food Safety 14(4) 431-45
Gross R Koch F Malaga I de Miranda A Schoeneberger H Trugo L 1989 Chemical
composition and protein quality of some local Andean food sources Food Chem 34(1) 25-
34
Guumllccedilin İ Mshvildadze V Gepdiremen A Elias R 2006 The antioxidant activity of a
triterpenoid glycoside isolated from the berries of Hedera colchica 3-O-(β-d-
glucopyranosyl)-hederagenin Phytother Res 20(2) 130-4
Guzmaacuten-Maldonado S Paredes-Lopez O 2002 Functional products of plants indigenous to
Latin America amaranth quinoa common beans and botanicals In Shi J Mazza G
Maguer ML editors Functional foods Biochemical and processing aspects CRC Press p
293-328
Halverson J Zeleny L 1988 Chapter 2 Criteria of wheat quality In Pomeranz Y editor
Wheat Chemistry and Technology 3rd edition St Paul MN American Association of
Cereal Chemists Inc p 25 ndash 6
31
Hariadi Y Marandon K Tian Y Jacobsen SE Shabala S 2011 Ionic and osmotic relations in
quinoa (Chenopodium quinoa Willd) plants grown at various salinity levels J Exp Bot
62(1) 185-93
Iglesias-Puig E Monedero V Haros M 2015 Bread with whole quinoa flour and bifidobacterial
phytases increases dietary mineral intake and bioavailability LWT-Food Sci Technol 60(1)
71-7
Jacobsen SE Monteros C Christiansen J Bravo L Corcuera L Mujica A 2005 Plant responses
of quinoa (Chenopodium quinoa Willd) to frost at various phenological stages Eur J Agron
22(2) 131-9
Jacobsen SE Stoslashlen O 1993 Quinoa-morphology phenology and prospects for its production as
a new crop in Europe Eur J Agron 2(1) 19-29
James LEA 2009 Quinoa (Chenopodium quinoa Willd) composition chemistry nutritional
and functional properties Adv Food Nutr Res 58 1-31
Kamelgard JI 2012 Quinoa-based beverages and method of creating quinoa-based beverages
Google Patents
Khalil A El-Adawy T 1994 Isolation identification and toxicity of saponin from different
legumes Food Chem 50(2) 197-201
Killeen GF Madigan CA Connolly CR Walsh GA Clark C Hynes MJ Power RF 1998
Antimicrobial saponins of Yucca schidigera and the implications of their in vitro properties
for their in vivo impact J Agric Food Chem 46(8) 3178-86
32
Konishi Y Hirano S Tsuboi H Wada M 2004 Distribution of minerals in quinoa
(Chenopodium quinoa Willd) seeds Biotechnol Appl Biochem 68(1) 231-4
Koyro HW Eisa SS 2008 Effect of salinity on composition viability and germination of seeds
of Chenopodium quinoa Willd Plant Soil 302(1-2) 79-90
Kozioł M1992 Chemical composition and nutritional evaluation of quinoa (Chenopodium
quinoa Willd) J Food Compost Anal 5(1) 35-68
Kuljanabhagavad T Wink M 2009 Biological activities and chemistry of saponins from
Chenopodium quinoa Willd Phytochem Rev 8(2) 473-90
Kunze OR Lan Y and Wratten FT 2004 Chapter 8 Physical and mechanical properties of rice
In Champagne ET editor Rice Chemistry and Technology 3rd edition St Paul MN
American Association of Cereal Chemists Inc p 193 ndash 211
Li G Wang S Zhu F 2016 Physicochemical properties of quinoa starch Carbohydr Polym 137
328-38
Lindeboom N Chang PR Falk KC Tyler RT 2005 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2) 216-22
Lindeboom N Chang PR Tyler RT 2004 Analytical biochemical and physicochemical aspects
of starch granule size with emphasis on small granule starches a review Starch-Staumlrke 56(3-
4) 89-99
Man S Gao W Zhang Y Huang L Liu C 2010 Chemical study and medical application of
saponins as anti-cancer agents Fitoterapia 81(7) 703-14
33
Maradini Filho AM Pirozi MR Da Silva Borges JT Pinheiro SantAna HM Paes Chaves JB
Dos Reis Coimbra JS 2015 Quinoa nutritional functional and antinutritional aspects Crit
Rev Food Sci Nutr (just-accepted)
Matanguihan JB Jellen EN and Kolano A 2015 Chapter 7 Quinoa cytogenetics molecular
genetics and diversity In Murphy KM Matanguihan J editors Quinoa Improvement and
Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 109-24
Maughan PJ Bonifacio A Jellen EN Stevens MR Coleman CE Ricks M Mason SL Jarvis
DE Gardunia BW Fairbanks DJ 2004 A genetic linkage map of quinoa (Chenopodium
quinoa) based on AFLP RAPD and SSR markers Theor Appl Genet 109(6) 1188-95
de Meo B Freeman G Marconi O Booer C Perretti G Fantozzi P 2011 Behaviour of Malted
Cereals and Pseudo-Cereals for Gluten-Free Beer Production J Inst Brew 117(4) 541-6
Ogungbenle H 2003 Nutritional evaluation and functional properties of quinoa (Chenopodium
quinoa) flour Int J Food Sci Nutr 54(2) 153-8
Ogungbenle HN 2003 Nutritional evaluation and functional properties of quinoa (Chenopodium
quinoa) flour Int J Food Sci Nutr 54(2) 153-8
Quiroga C Escalera R Aroni G Bonifacio A Gonzaacutelez JA Villca M Saravia R Ruiz A 2015
Chapter 31 Traditional processes and Technological Innovations in Quinoa Harvesting
Processing and Industrialization In D Bazile D Bertero and C Nieto editors State of the
Art Report of Quinoa in the World in 2013 Rome FAO amp CIRAD p 213 - 4
34
Pagamunici LM Gohara AK Souza AHP Bittencourt PRS Torquato AS Batiston WP
Matsushita M 2014 Using chemometric techniques to characterize gluten-free cookies
containing the whole flour of a new quinoa cultivar J Brazil Chem Soc 25 219-28
Paśko P Bartoń H Zagrodzki P Gorinstein S Fołta M Zachwieja Z 2009 Anthocyanins total
polyphenols and antioxidant activity in amaranth and quinoa seeds and sprouts during their
growth Food Chem 115(3) 994-8
Peterson AJ Murphy KM 2015a Chapter 10 Quinoa Cultivation for Temperate North America
Considerations and Areas for Investigation In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 182-6
Peterson A Murphy K 2015b Tolerance of lowland quinoa cultivars to sodium chloride and
sodium sulfate salinity Crop Sci 55(1) 331-8
Prego I Maldonado S Otegui M 1998 Seed structure and localization of reserves in
Chenopodium quinoa Ann Bot 82(4) 481-8
Ranhotra GS Gelroth JA Glaser BK Lorenz KJ Johnson DL 1993 Composition and protein
nutritional quality of quinoa Cereal Chem 70(3)303-5
Razavi SMA Farahmandfar R 2008 Effect of hulling and milling on the physical properties of
rice grains Int Agrophys 22(4) 353-9
Reichert R Tatarynovich J Tyler R 1986 Abrasive dehulling of quinoa (Chenopodium quinoa)
effect on saponin content as determined by an adapted hemolytic assay Cereal Chem 63(6)
471-5
35
Repo-Carrasco-Valencia RAM Serna LA 2011 Quinoa (Chenopodium quinoa Willd) as a
source of dietary fiber and other functional components Food Sci Technol (Campinas) 31
225-30
Repo-Carrasco R Espinoza C Jacobsen SE 2003 Nutritional value and use of the Andean crops
quinoa (Chenopodium quinoa) and kantildeiwa (Chenopodium pallidicaule) Food Rev Int 19(1-
2) 179-89
Ridout CL Price KR Dupont MS Parker ML Fenwick GR 1991 Quinoa saponinsmdashanalysis
and preliminary investigations into the effects of reduction by processing J Sci Food Agric
54(2) 165-76
Rizzello CG Lorusso A Montemurro M Gobbetti M 2016 Use of sourdough made with
quinoa (Chenopodium quinoa) flour and autochthonous selected lactic acid bacteria for
enhancing the nutritional textural and sensory features of white bread Food Microbiol 56 1-
13
Rojas W 2011 Quinoa an ancient crop to contribute to world food security Santiago Chile
FAO Oficina Regional para America Latina y el Caribe
Rojas W Pinto M Alanoca C Goacutemez-Pando L Leoacuten-Lobos P Alercia A Diulgheroff S
Padulosi S Bazile D 2013 Estado de la conservacioacuten ex situ de los recursos geneacuteticos de
quinua In Didier B Daniel BH Carlos N editors Estado del arte de la quinua en el mundo
en Libro de resuacutemenes Santiago FAO p 20-21
36
Rojas W Pinto M 2015 Chapter 8 Ex situ conservation of quinoa the bolivian experience In
Murphy KM Matanguihan J editors Quinoa Improvement and Sustainable Production
Hoboken NJ John Wiley amp Sons Inc p 128-30
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile D
Bertero D Nieto C editors State of the Art Report of Quinoa in the World in 2013 Rome
FAO amp CIRAD p 67
Ruales J Nair BM 1992 Nutritional quality of the protein in quinoa (Chenopodium quinoa
Willd) seeds Plant Foods Hum Nutr 42(1) 1-11
Ruales J Nair BM 1993 Saponins phytic acid tannins and protease inhibitors in quinoa
(Chenopodium quinoa Willd) seeds Food Chem 48(2)137-43
Ruales J Valencia S Nair B 1993 Effect of processing on the physico-chemical characteristics
of quinoa flour (Chenopodium quinoa Willd) Starch - Staumlrke 45(1)13-9
Ruales J Grijalva YD Lopez-Jaramillo P Nair BM 2002 The nutritional quality of an infant
food from quinoa and its effect on the plasma level of insulin-like growth factor-1 (IGF-1) in
undernourished children Int J Food Sci Nutr 53(2) 143-54
Sanchez HB Lemeur R Damme PV Jacobsen SE 2003 Ecophysiological analysis of drought
and salinity stress of quinoa (Chenopodium quinoa Willd) Food Rev Int 19(1-2) 111-9
Scanlin LA Burnett C (2010) Quinoa grain processing and products Google Patents
37
Schoenlechner R Drausinger J Ottenschlaeger V Jurackova K Berghofer E 2010 Functional
Properties of Gluten-Free Pasta Produced from Amaranth Quinoa and Buckwheat Plant
Foods Hum Nutr 65(4) 339-49
Schumacher AB Brandelli A Macedo FC Pieta L Klug TV de Jong EV 2010 Chemical and
sensory evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J
Food Sci Technol 47(2) 202-6
Shao Y Chin CK Ho CT Ma W Garrison SA Huang MT 1996 Anti-tumor activity of the
crude saponins obtained from asparagus Cancer Lett 104(1) 31-6
Simnadis TG Tapsell LC Beck EJ 2015 Physiological Effects Associated with Quinoa
Consumption and Implications for Research Involving Humans a Review Plant Foods Hum
Nutr 70(3) 238-49
Steffolani ME Villacorta P Morales-Soriano E Repo-Carrasco R Leoacuten AE Perez GT 2015
Physico-chemical and functional characterization of protein isolated from different quinoa
varieties (Chenopodium quinoa Willd) Cereal Chem (Accepted for publication)
Stevens MR Coleman CE Parkinson SE Maughan PJ Zhang HB Balzotti MR Kooyman DL
Arumuganathan K Bonifacio A Fairbanks DJ Jellen EN Stevens JJ 2006 Construction of
a quinoa (Chenopodium quinoa Willd) BAC library and its use in identifying genes
encoding seed storage proteins Theor Appl Genet 112(8) 1593-600
Stikic R Glamoclija D Demin M Vucelic-Radovic B Jovanovic Z Milojkovic-Opsenica D
Jacobsen SE Milovanovic M 2012 Agronomical and nutritional evaluation of quinoa seeds
38
(Chenopodium quinoa Willd) as an ingredient in bread formulations J Cereal Sci 55(2)
132-8
Sun HX Xie Y Ye YP 2009 Advances in saponin-based adjuvants Vaccine 27(12) 1787-96
Świeca M Sęczyk Ł Gawlik-Dziki U Dziki D 2014 Bread enriched with quinoa leaves - The
influence of protein-phenolics interactions on the nutritional and antioxidant quality Food
Chem 162 54-62
Tang Y Li X Zhang B Chen PX Liu R Tsao R 2015 Characterisation of phenolics betanins
and antioxidant activities in seeds of three Chenopodium quinoa Willd genotypes Food
Chem 166 380-8
Taormina PJ Simpson PG Bertera EA Komitopoulou E 2006 Beverage preservatives Google
Patents
Tapia M Mujica A Canahua A 1980 Origen y distribucion geografica y sistemas de
produccion de la quinua (Chenopodium quinoa Wild) Publicacion Universidad Nacional
Tecnica del Altiplano
Taverna LG Leonel M Mischan MM 2012 Changes in physical properties of extruded sour
cassava starch and quinoa flour blend snacks Food Sci Technol (Campinas) 32 826-34
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Taylor JRN Parker ML editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science amp Business Media p 96-9
39
Thompson R Isaacs G 1967 Porosity determinations of grains and seeds with an air-
comparison pycnometer T ASAE 10(5) 693-6
Vega-Gaacutelvez A Miranda M Vergara J Uribe E Puente L Martiacutenez EA 2010 Nutrition facts
and functional potential of quinoa (Chenopodium quinoa willd) an ancient Andean grain a
review J Sci Food Agric 90(15) 2541-7
USDA US Department of Agriculture Agricultrual Research Service 2015 USDA national
nutrient database for standard reference Release 18 Nutrient Data Laboratory Home Page
Available from httpwwwarsusdagovServicesdocshtmdocid=8964
Vilche C Gely M Santalla E 2003 Physical Properties of Quinoa Seeds Biosyst Eng 86(1) 59-
65
Wu G Morris CF Murphy KM 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79(11) 2337-45
Wu G Chapter 11 Nutritional properties of quinoa In Murphy KM Matanguihan J editors
Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc
p193 ndash 205
Yang CH Huang YC Chen YF Chang MH 2010 Foam properties detergent abilities and long-
term preservative efficacy of the saponins from J Food Drug Anal 18(3) 4417-25
Yao Y Yang X Shi Z Ren G 2014 Anti-inflammatory activity of saponins from quinoa
(Chenopodium quinoa Willd) Seeds in lipopolysaccharide-stimulated raw 2647
Macrophages Cells J Food Sci 79(5) 1018-23
40
Zhou Z Robards K Helliwell S Blanchard C 2003 Effect of rice storage on pasting properties
of rice flour Food Res Int 36(6) 625-34
41
Table 1-Essential amino acid of quinoa protein and FAOWHO suggested requirement (mgg protein)
Essential amino acid Quinoa protein a FAOWHO suggested requirement b
Histidine 258 18
Isoleucine 433 25
Leucine 736 55
Lysine 525 51
Methionine amp Cysteine 273 25
Phenylalanine amp Tyrosine 803 47
Threonine 439 27
Tryptophan 385 7
Valine 506 32
a) Abugoch et al (2008) b) Friedman and Brandon (2001)
42
Table 2-Quinoa vitamins content (mg100g)
Quinoa a-d Reference Daily Intake
Thianmin (B1) 029-038 15
Riboflavin (B2) 030-039 17
Niacin (B3) 106-152 20
Pyridoxine (B6) 0487 20
Folate (B9) 0781 04
Ascorbic acid (C) 40 60
α-Tocopherol (VE) (IU) 537 30
Β-Carotene 039 NR
a (Koziol 1992) b (Ruales and Nair 1993) c (Ranhotra et al 1993) d (USDA 2015)
43
Table 3-Quinoa minerals content (mgmg )
Whole graina RDI b
K 8257 NR
Mg 4526 400
Ca 1213 1000
P 3595 1000
Fe 95 18
Mn 37 NR
Cu 07 2
Zn 08 15
Na 13 NR
(aAndo et al 2002 bUSDA 2015)
44
Figure 1-Quinoa seed section and two-layered pericarp under perianth (Wu et al 2014)
45
Figure 2-Quinoa seed structure (Prego et al 1998)
(PE pericarp SC seed coat C cotyledons SA shoot apex H hypocotylradicle axis R radicle F funicle EN endosperm P perisperm Bar = 500 μm)
46
Chapter 3 Evaluation of Texture Differences among Varieties of
Cooked Quinoa
Published manuscript
Wu G Morris C F amp Murphy K M (2014) Evaluation of texture differences among
varieties of cooked quinoa Journal of Food Science 79(11) S2337-S2345
ABSTRACT
Texture is one of the most significant factors for consumersrsquo experience of foods Texture
differences of cooked quinoa were studied among thirteen different varieties Correlations
between the texture parameters and seed composition seed characteristics cooking quality flour
pasting properties and flour thermal properties were determined The results showed that texture
of cooked quinoa was significantly differed among varieties lsquoBlackrsquo lsquoCahuilrsquo and lsquoRed
Commercialrsquo yielded harder texture while lsquo49ALCrsquo lsquo1ESPrsquo and lsquoCol6197rsquo showed softer
texture lsquo49ALCrsquo lsquo1ESPrsquo lsquoCol6197rsquo and lsquoQQ63rsquo were more adhesive while other varieties
were not sticky The texture profile correlated to physical-chemical properties in different ways
Protein content was positively correlated with all the texture profile analysis (TPA) parameters
Seed hardness was positively correlated with TPA hardness gumminess and chewiness at P le
009 Seed density was negatively correlated with TPA hardness cohesiveness gumminess and
chewiness whereas seed coat proportion was positively correlated with these TPA parameters
Increased cooking time of quinoa was correlated with increased hardness cohesiveness
gumminess and chewiness The water uptake ratio was inversely related to TPA hardness
47
gumminess and chewiness RVA peak viscosity was negatively correlated with the hardness
gumminess and chewiness (P lt 007) breakdown was also negatively correlated with those TPA
parameters (P lt 009) final viscosity and setback were negatively correlated with the hardness
cohesiveness gumminess and chewiness (P lt 005) setback was correlated with the
adhesiveness as well (r = -063 P = 002) Onset gelatinization temperature (To) was
significantly positively correlated with all the texture profile parameters and peak temperature
(Tp) was moderately correlated with cohesiveness whereas neither conclusion temperature (Tc)
nor enthalpy correlated with the texture of cooked quinoa This study provided information for
the breeders and food industry to select quinoa with specific properties for difference use
purposes
Keywords cooked quinoa variety texture profile analysis (TPA) RVA DSC
Practical Application The research described in this paper indicates that the texture of different
quinoa varieties varies significantly The results can be used by quinoa breeders and food
processors
48
Introduction
Quinoa (Chenopodium quinoa Willd) a pseudocereal (Lindeboom et al 2007) is known as
a complete food due to its high nutritional value (Jancurovaacute et al 2009) Protein content of dry
quinoa grain ranges from 8 to 22 (Jancurovaacute et al 2009) Quinoa protein is high in nutritive
quality with an excellent balance of essential amino acids (Abugoch et al 2008) Quinoa is also a
gluten-free crop (Alvarez-Jubete et al 2010) Quinoa consumption in the US and Europe has
increased dramatically over the past decade but these regions rely on imports primarily from
Bolivia and Peru (Food and Agriculture Organization of the United Nations FAO 2013) For
these reasons greater knowledge of quinoa grain quality is needed
Quinoa is traditionally cooked as a whole grain similar to rice or milled into flour and made
into pasta and breads (Food and Agriculture Organization of the United Nations FAO 2013)
Quinoa can also be processed by extrusion drum-drying and autoclaving (Ruales et al 1993)
Commercial quinoa products include pasta bread cookies muffins cereal snacks drinks
flakes baby food and diet supplements (Ruales et al 2002 Del Castillo et al 2009 Cortez et al
2009 Demirkesen et al 2010 Schumacher et al 2010)
Texture is one of most significant properties of food that affects the consuming experience
Food texture refers to those qualities of a food that can be felt with the fingers tongue palate or
teeth (Vaclavik and Christian 2003) Cooked quinoa has a unique texture described as creamy
smooth and slightly crunchy (Abugoch 2009) Texture can be influenced by the seed structure
composition cooking quality and thermal properties However we know of no report which
documents the texture of cooked quinoa and the factors that affect it
49
Quinoa has small seeds compared to most cereals and seed size may affect the texture of
cooked quinoa Seed characteristics and structure are the significant factors potentially affecting
the textural properties of processed food Rousset et al (1995) indicated that the length and
lengthwidth ratio of rice kernels was associated with a wide range of texture attributes including
crunchy brittle elastic juicy pasty sticky and mealy which were determined by a sensory
panel The correlation between quinoa seed characteristics and cooked quinoa texture has not
been studied
Quinoa is consumed as whole grain without removing the bran unlike most rice and wheat
The insoluble fiber and non-starch polysaccharides in the seed coat can affect mouth feel and
texture Hence seed coat proportion may contribute to the texture of cooked quinoa Mohapatra
and Bal (2006) reported that the milling degree of rice positively influenced cohesiveness and
adhesiveness of cooked rice but was negatively correlated to hardness
Quinoa seed qualities such as the size hardness weight density and seed coat proportion
may influence the water binding capacity of seed during thermal processing thereby affecting
the texture of the cooked cereal (Fitzgerald et al 2003) Nevertheless correlations between seed
characteristics and texture of cooked quinoa have not been previously described
Seed composition may influence texture as well Higher protein content was reported to
cause reduced stickiness and harder texture of cooked rice (Ramesh et al 2000) Quinoa seeds
contain approximately 60 starch (Ando et al 2002) Starch granules are particularly small (05
- 3μm) Amylose content of quinoa is as low as 11 (Ahamed et al 1996) while the amylose
proportion in most cereals such as wheat is around 25 (Zeng et al 1997 BeMiller and Huber
50
2008) Amylose content of starch correlated positively with the hardness of cooked rice and
cooked white salted noodles (Ong and Blanshard 1995 Epstein et al 2002 Baik and Lee 2003)
Flour pasting properties can greatly influence the texture of cooked products Their
correlation has not been illustrated in quinoa while some research have been conducted on
cooked rice A lower peak viscosity and positive setback are associated with a harder texture
while a higher peak viscosity breakdown and lower setback are associated with a sticky texture
in cooked rice (Limpisut and Jindal 2002) Champagne et al (1999) indicated that adhesiveness
had strong correlations with Rapid Visco Analyzer (RVA) measurements Ramesh et al (2000)
reported that harder cooked rice texture was associated with a lower peak viscosity and positive
setback while sticky rice had a higher peak viscosity higher breakdown and lower setback
The gelatinization temperature of quinoa starch ranges from 54ordmC to 71ordmC (Ando et al
2002) lower than that of rice barley and wheat starches (Marshall 1994 Tang 2004 Tang et al
2005) Gelatinization temperature likely plays an important role in waxy rice quality (Perdon and
Juliano 1975 Juliano et al 1987) but was not correlated to the eating quality of normal rice
(Ramesh et al 2000) Despite a considerable amount of work having been conducted on the
thermal properties of cereal starch little is known about the relationship between quinoa flour
thermal properties and cooked quinoa texture
The correlation of quinoa cooking quality and texture has not been previously reported In
rice cooking quality exhibited strong correlations to the texture profile analysis (TPA) Cooking
time has been reported to correlate positively with hardness and negatively with adhesiveness of
cooked rice (Mohapatra and Bal 2006) Higher water uptake ratio and volume expansion ratio
were associated with softer more adhesive and more cohesive texture of cooked rice
51
(Mohapatra and Bal 2006) Cooking loss has been reported to improve firmness but decrease
juiciness (Rousset et al 1995)
There is a need to further study the texture of cooked quinoa and its determining factors
The objective of this paper is to study the texture difference among varieties of cooked quinoa
and evaluate the correlation between the texture and the seed characters and composition
cooking process flour pasting properties and thermal properties
Materials and Methods
Seed characteristics
Eleven varieties and two commercial lots of quinoa are listed in Table 1 The two grain
lots were referred as lsquoYellow Commercialrsquo and lsquoRed Commercialrsquo according to the seed color
Seed size (diameter) was determined by lining up and measuring the length of 20 seeds Average
seed diameter was calculated from three repeated measurements Bulk density of seed was
measured by the weightvolume method Seed weight was determined gravimetrically Seed
hardness was determined using the texture analyzer TAndashXT2i (Texture Technology Corp
Scarsdale NY USA) A cylinder of 10 mm in diameter compressed one seed to 90 strain at
the rate of 5 mms The force (kg) was recorded as the seed hardness Seed coat proportions were
determined by a Scanning Electron Microscope (SEM) FEI Quanta 200F (FEI Corp Hillsboro
OR USA) The seed was cross-sectioned and the SEM image was captured under 800times
magnification The seed coat proportions were measured using the software ruler in micrometers
Chemical compositions
Whole quinoa flour was prepared using a cyclone sample mill (UDY Corporation Fort
Collins CO USA) equipped with a 05 mm screen and was used for compositional analysis
52
pasting viscosity and thermal properties Ash and moisture content of quinoa flour were tested
according to the Approved Method 08-0101 and 44-1502 respectively (AACCI 2012) Protein
content was determined by a nitrogen analyzer coupled with a thermo-conductivity detector
(LECO Corporation Joseph MI USA) The factor of 625 was used to calculate the protein
content from the nitrogen content (Approved Method 46-3001 AACCI 2012) Protein and ash
were calculated on a dry weight basis
Cooking protocol
The cooking protocol of quinoa was modified from a rice cooking method (Champagne
et al 1998) Five grams of quinoa seed were soaked for 20 min in 10 mL deionized water in a
flask Soaking is required to remove the bitter saponins (Pappier et al 2008) and enhance
cooking quality (Mohapatra and Bal 2006) The mixture was then boiled for 2 min and the flask
was set in boiling water for 18 min The flask was covered to prevent water loss
Cooking quality
Two grams of quinoa seed were cooked in 20 mL deionized water for 20 min and extra
water was removed Cooking time was determined when the middle white part of the seed
completely disappeared (Mohapatra and Bal 2006) The water uptake ratio was calculated from
the seed weight ratio before and after cooking Cooking volume was the seed volume after
cooking Cooking loss was the total of soluble and insoluble matter in the cooking water
(Rousset et al 1995) Three mL of cooking water of each sample was placed on an aluminum
pan and dried at 130 ordmC overnight The weight of dry solids in the pan was used to calculate the
cooking loss
Texture profile analysis (TPA)
53
Texture profile analysis (TPA) was used to determine the texture of cooked quinoa
according to a modified method for cooked rice texture (Champagne et al 1999) Two grams of
cooked quinoa were arranged on the texture analyzer platform as close to one layer as possible
A stainless steel plate (50 mm times 40 mm times 10 mm) compressed the cooked quinoa from 5 mm to
01 mm at 5 mmsec The compression was conducted twice The texture analyzer generated a
graph with time as the x-axis and force as the y-axis Six parameters were calculated from the
graph (Epstein et al 2002) Hardness is the height of the first peak adhesiveness is the area 3
cohesiveness is area 2 divided by area 1 springiness is distance 1 divided by distance 2
gumminess is hardness multiplied by cohesiveness chewiness is gumminess multiplied by
springiness In the present study no significant differences or correlations were obtained for
springiness As such this parameter will not be included except to describe the overall result (see
below)
Flour viscosity
Quinoa flour pasting viscosity was determined using the Rapid Visco Analyzer (RVA)
RVA-4 (Newport Scientific Pty Ltd Narrabeen Australia) Quinoa flour (43 g) was added to
25 mL deionized water in an aluminum cylinder container The contents were immediately
mixed and heated following the instrument program The temperature was increased from 50 ordmC
to 93 ordmC in 8 min at a constant rate was held at 95 ordmC from 8 to 24 min cooled to 50 ordmC from 24
to 28 min and held at 50 ordmC from 29 to 40 min The program generated a graph with time against
shear force (Figure 1) expressed in RVU (cP = RVU times 12)
Two peaks representing peak viscosity and final viscosity are normally included in the
RVA graph Peak time was the time to reach the first peak Holding strength or trough is the
54
minimum viscosity after the first peak Breakdown is the viscosity difference between peak and
minimum viscosity Setback is the viscosity difference between final and minimum viscosity
Pasting temperature and the time to reach the peak were also recorded
Thermal properties using Differential Scanning Calorimetry (DSC)
Thermal properties of quinoa flour were determined by Differential Scanning
Calorimetry (DSC) Tzero Q2000 (TA instruments New Castle DE USA) The protocol was a
modification of the method of Abugoch et al (2009) Quinoa flour (02 g) was added to 200 μL
deionized water and mixed on a vortex mixer for 10 s to form a slurry Ten to twelve milligrams
of slurry was added to an aluminum pan by pipette The pan was sealed and placed at the center
of DSC platform An empty pan was used as reference The temperature was increased from 25
ordmC to 120 ordmC at 10 ordmCmin then equilibrated to 25 ordmC Gelatinization temperature and enthalpy
were determined from the graph
Statistical analysis
All experiments were repeated three times The hypothesis tests of normality and equal
variance multiple comparisons (Fisherrsquos LSD) and correlation studies were conducted by SAS
92 (SAS Institute Cary NC) A P-value of 005 is considered as the level of statistical
significance unless otherwise specified
Results
Seed characteristics and flour composition
Quinoa seed characteristics and composition are shown in Table 2 Quinoa seeds were
small compared to cereals such as rice wheat and maize Diameters of quinoa seed mostly
ranged between 19 to 22 mm except for lsquoJapanese Strainrsquo which was significantly smaller (15
55
mm) Seed hardness was significantly different among varieties ranging from 583 k g in
lsquoCol6197rsquo to 1096 kg in lsquoOro de Vallersquo Bulk seed density of quinoa varied from 063 kgL in
lsquoBlancarsquo to 081 kgL in lsquoJapanese Strainrsquo Varieties from White Mountain farm and the WSU
Organic Farm were lower in bulk density most of which were below 07 kgL The commercial
and Port Townsend samples were higher in density most of which were around 075 kgL
Thousand-seed weights of quinoa were particularly low ranging from 18 g in lsquoJapanese Strainrsquo
to 41g in lsquoRed Commercialrsquo Seed coat proportion was also significantly different among
varieties Three layers are shown in the seed coat (Figure 2) The varieties lsquoBlackrsquo and lsquoBlancarsquo
had the thickest seed coat (38 and 97 μm respectively) with coat proportions of 40 and 45
respectively lsquoYellow Commercialrsquo and lsquo1ESPrsquo had the thinnest seed coats (15 and 16 μm
respectively) with the coat proportion of 07 and 05 respectively The difference was
almost ten-fold among the varieties
Protein and ash content of quinoa flour
Protein content varied from 113 in lsquo1ESPrsquo to 170 in lsquoCahuilrsquo lsquoCherry Vanillarsquo and
lsquoOro de Vallersquo also had high protein contents of 160 and 156 respectively Ash content
ranged from 12 in the Commercial Yellow seed to 40 in lsquoQQ63rsquo comparable to that in rice
flour (Champagne 2004)
Texture of cooked quinoa
The hardness of cooked quinoa ranged from 20 g for lsquo49ALCrsquo and lsquoCol6197rsquo to 347
kg for lsquoBlackrsquo (Table 3) lsquoOro de Vallersquo and lsquoBlancarsquo were relatively hard varieties with TPA
hardness of 285 kg and 306 kg respectively whereas lsquo1ESPrsquo lsquoJapanese Strainrsquo and lsquoQQ63rsquo
were softer with a hardness of 245 kg 293 kg and 297 kg respectively
56
Adhesiveness is the extent to which seeds stick to each other the probe and the stage
lsquo49ALCrsquo lsquo1ESPrsquo lsquoCol6197rsquo and lsquoQQ63rsquo were significantly stickier with adhesiveness value
of -029 kgs -027 kgs -023 kgs and -020 kgs respectively All other varieties exhibited
lower adhesiveness with values less than 010 kgs Visual examination of the cooked samples
showed that with the more adhesive varieties the seeds stuck together as with sticky rice while
for other varieties the grains were separated
Cohesiveness of cooked lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo was
significantly higher with values from 068 to 071 respectively while those of lsquo49ALCrsquo lsquo1ESPrsquo
and lsquoCol6197rsquo were lower at 054 056 and 053 respectively Springiness is the recovery
from crushing or the elastic recovery (Tsuji 1981 Seguchi et al 1998) Cooked quinoa of all
varieties exhibited excellent elastic recovery properties with springiness values approximating
10
Gumminess is the combination of hardness and cohesiveness Chewiness is gumminess
multiplied by springiness As springiness values were all close to 10 gumminess and chewiness
of cooked quinoa were very similar in value lsquoBlackrsquo lsquoBlancarsquo and lsquoCahuilrsquo were highest in
gumminess and chewiness 24 kg 22 kg and 23 kg respectively while lsquo1ESPrsquo lsquo49ALCrsquo and
lsquoCol6197rsquo were lowest at 14 kg 11 kg and 11 kg respectively The difference among varieties
was greater than three-fold
Cooking quality
Cooking quality of quinoa is shown in Table 4 Cooking time varied from 119 min in
lsquoCol6197rsquo to 192 min in lsquoBlackrsquo cultivar and was significantly correlated with all TPA texture
parameters Longer cooking time also correlated with higher protein content (r = 052 P = 007)
57
Water uptake ratio varied from 25 to 4 fold in lsquoQQ63rsquo and lsquoCol6197rsquo respectively Water
uptake ratio was negatively correlated to seed hardness (r = 052 P = 004) Harder seeds tended
to absorb less water during cooking Cooking volume ranged from 107 mL to 137 mL and did
not significantly correlate with other properties Cooking loss ranged from 035 to 176 and
differed among varieties but was not correlated with water uptake ratio cooking time or cooking
volume
Quinoa flour pasting properties by RVA
Pasting viscosity of quinoa whole seed flour was determined using the Rapid Visco
Analyzer (RVA) The results are shown in Table 5 Peak viscosity differed among varieties
Varieties could be categorized into three groups based on peak viscosity The peak viscosity of
lsquoQQ63rsquo lsquoCol6197rsquo lsquo1ESPrsquo lsquoJapanese Strainrsquo lsquoYellow Commercialrsquo lsquoCopacabanarsquo and lsquoRed
Commercialrsquo varied from 144 to 197 RVU The peak viscosity of lsquoBlancarsquo lsquoBlackrsquo lsquo49ALCrsquo
and lsquoCahuilrsquo ranged from 98 to 116 RVU while those of lsquoOro de Vallersquo and lsquoCherry Vanillarsquo
were 59 and 66 RVU respectively
Trough viscosity namely the minimum viscosity after the first peak showed more than a
three-fold difference among varieties As in the case of peak viscosity the trough of different
varieties can be categorized into the same three groups
Breakdown is the difference between the peak and minimum viscosity lsquoQQ63rsquo lsquo1ESPrsquo
and lsquoJapanese Strainrsquo showed large breakdowns of 51 51 and 62 RVU respectively
Breakdown of lsquoCherry Vanillarsquo lsquoOro de Vallersquo and the Commercial Yellow seed were lower at
12 10 and 11 RVU respectively Breakdown of the other varieties ranged from 18 to 36 RVU
58
The final viscosity of the Commercial Yellow seed was 203 RVU the highest among all
varieties Final viscosity of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo
ranged from 56 to 82 RVU and was lower than that of other varieties which ranged from 106 to
190 RVU
Setback is the difference between final and trough viscosity Setback of lsquoRed
Commercialrsquo lsquoCahuilrsquo and lsquoBlackrsquo were all negative -62 -11 and -6 RVU respectively which
indicated that the final viscosity of these cultivars was lower than their trough viscosity Setback
of lsquoBlancarsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo were slightly positive at 2 2 and 6 RVU
respectively while those of other cultivars were much greater between 42 and 73 RVU Peak
time which is the time to reach the first peak ranged from 93 to 115 min The pasting
temperature was 93 ordmC and not different among the varieties
Thermal properties of quinoa flour using DSC
Thermal properties of quinoa flour were determined using DSC Gelatinization
temperatures (To onset temperature Tp peak temperature Tc conclusion temperature) and
gelatinization enthalpies are shown in Table 6 To of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry
Vanillarsquo and lsquoJapanese Strainrsquo were not different from each other and ranged from 645 ordmC to
659 ordmC To of lsquoOro de Vallersquo lsquoCopacabanarsquo lsquoCol6197rsquo and lsquoQQ63rsquo ranged from 605 ordmC to
631 ordmC while other varieties were lower and ranged from 544 ordmC to 589 ordmC Tp ranged from
675 ordmC in the Commercial Yellow seed to 752 ordmC in lsquoCahuilrsquo Tc ranged from 780 ordmC in lsquoRed
Commercialrsquo to 850ordmC in the lsquoJapanese Strainrsquo Enthalpy of quinoa flour differed among
varieties The range was from 11 Jg in lsquoYellow Commercialrsquo to 18 Jg in lsquoBlancarsquo
Correlations between physical-chemical properties and cooked quinoa texture
59
A summary of correlation coefficients between quinoa physical-chemical properties and
TPA texture profile parameters of cooked quinoa are shown in Table 7 Seed hardness was found
to be positively related to the TPA hardness gumminess and chewiness of cooked quinoa (P lt
009) Seed bulk density was negatively correlated to hardness cohesiveness gumminess and
chewiness while seed coat proportion was positively correlated to those parameters Protein
content of quinoa exhibited a positive relationship with TPA hardness (P = 008) and
adhesiveness cohesiveness gumminess and chewiness No significant correlation was observed
between the seed size 1000 seed weight ash content and the texture properties of cooked
quinoa
Cooking time of quinoa was highly positively correlated with all of the TPA texture
profile parameters Water uptake ratio during cooking was found to be significantly associated
with hardness gumminess and chewiness of cooked quinoa while cooking volume also showed
a modest correlation to hardness (r = -047 P = 010) Cooking loss was not correlated with any
texture parameter
Flour pasting viscosity was significantly correlated with texture of cooked quinoa Peak
viscosity and breakdown exhibited negative correlations with the hardness gumminess and
chewiness of cooked quinoa (P lt 010) Breakdown was also negatively associated with the
cohesiveness (r = -051 P lt 010) Final viscosity and setback were found to be negatively
correlated to hardness cohesiveness gumminess and chewiness while setback also exhibited a
significant correlation to adhesiveness (r = -064 P = 002)
60
Considering thermal properties To exhibited strong positive correlations with all texture
parameters Tp was found to be moderately related to cohesiveness (r = 050 P = 008) Neither
Tc nor enthalpy was significantly correlated to the TPA parameters of cooked quinoa
Discussion
Seed characteristics
Harder seed yielded harder gummier and chewier TPA texture after cooking The
varieties with lower seed bulk density or thicker seed coat yielded a firmer more cohesive
gummier and chewier texture Likely the condensed cells and non-starch polysaccharides of the
seed coat are a barrier between starch granules in the middle perisperm and water molecules
outside the seed
Seed composition
Higher protein appeared to contribute to a firmer more adhesive gummier and chewier
texture of cooked quinoa as evidenced by the TPA parameters Protein has been reported to play
a significant role in the texture of cooked rice and noodles (Ramesh et al 2000 Martin and
Fitzgerald 2002 Saleh and Meullenet 2007 Xie et al 2008 Hou et al 2013) According to the
previous studies proteins affect the food texture through three major routes (1) binding of water
(Saleh and Meullenet 2007) (2) interacting reversibly with starch bodies (Chrastil 1993) and (3)
forming networks via disulphide bonds which restrict starch granule swelling and water
hydration (Saleh and Meullenet 2007)
Cooking quality
Cooking time was found to be a key factor for cooked quinoa texture as it was closely
associated with most texture attributes Other cooking qualities such as the water uptake ratio
61
cooking volume and cooking loss were not significantly correlated to texture In the study of
rice the cooking time of rice positively correlated with hardness negatively with cohesiveness
and not significantly with adhesiveness (Mohapatra and Bal 2006) The higher water uptake ratio
and volume expansion ratio were negatively associated with softer more adhesive and more
cohesive texture This result agrees with the study on cooked rice Rousset et al (1995) study
indicated that longer cooking time greater water uptake and cooking loss related to the softer
less crunchy and more pasty texture
Flour pasting properties
The varieties with a higher peak viscosity in flour had a softer less gummy and less
chewy texture after cooking The cultivars with higher final peak viscosity yielded a softer less
cohesive less gummy and chewy texture The varieties with a greater breakdown such as
lsquoQQ63rsquo lsquo1ESPrsquo and lsquoJapanese Strainrsquo were softer in TPA parameter Breakdown has been
reported to negatively correlate with the proportion of long chain amylopectin (Han and
Hamaker 2001) Long chain amylopectin may form intra- or inter-molecular interactions with
protein and lipids and result in a firmer or harder texture (Ong and Blanshard 1995)
Quinoa varieties with a lower setback were harder after cooking compared to those with a
higher setback In rice conversely setback was positively correlated with amylose content
(Varavinit et al 2003) which would positively influence the hardness of cooked rice (Ong and
Blanshard 1995 Champagne et al 1999) Unlike rice and many other cereals where the amylose
content is approximately 25-29 the amylose proportion in quinoa starch is lower on the order
of 11 (Ahamed et al 1996) Amylose may play a different role in cooked quinoa hardness
compared to other cereals
62
Starch viscosity has been reported to significantly affect the texture of cooked rice
Champagne et al (1999) used the RVA measurements to predict TPA of cooked rice and found
that adhesiveness strongly correlated to RVA parameters Harder rice was correlated with lower
peak viscosity and positive setback while stickier rice had a higher peak viscosity breakdown
and lower setback (Ramesh et al 2000) The difference between quinoa and rice seed structure
and starch composition and the difference of texture determining methods may contribute to the
different trends in correlation
Thermal properties
The gelatinization temperature of quinoa flour ranged from 55 ordmC to 85 ordmC lower than
that of whole rice flour which was 70 ordmC to 103 ordmC (Marshall 1994) This result agrees with the
previous study on quinoa flour (Ando et al 2002) The quinoa varieties with higher To exhibited
a firmer more adhesive more cohesive gummier and chewier texture Higher Tp was associated
with increased cohesiveness The enthalpy of quinoa flour ranged from 11 to 18 Jg about one-
tenth that of whole rice flour (141 ndash 151 Jg) (Marshall 1994) indicating that it takes less
energy to cook quinoa than cook rice
Thermal properties of quinoa flour were generally correlated with flour pasting
properties Higher To and Tp were correlated with lower flour peak viscosity and lower trough
The result is comparable to the previous study of Sandhu and Singh (2007) who found that
gelatinization temperature and enthalpy of corn starch strongly influenced the peak breakdown
final and setback viscosity The thermal properties of quinoa flour were not correlated with
breakdown and setback likely was due to other composition factors in the flour such as protein
and fiber
63
Conclusions
The texture of cooked quinoa varied markedly among the different varieties indicating
that genetics management or geographic origin may all be important considerations for quinoa
quality As such differences in seed morphology and chemical composition appear to contribute
to quinoa processing parameters and cooked texture Harder seed yielded a firmer gummier and
chewier texture both lower seed density and high seed coat proportion related to a firmer more
cohesive gummier and chewier texture Seed size and weight appeared to be largely unrelated to
the texture of the cooked quinoa Protein content was a key factor apparently influencing texture
Higher protein content was related to harder more adhesive and cohesive gummier and chewier
texture Cooking time and water uptake ratio significantly affected the texture of cooked quinoa
whereas cooking volume moderately affected the hardness cooking loss was not correlated with
texture RVA peak viscosity was negatively correlated with the hardness gumminess and
chewiness breakdown was also negatively correlated with those TPA parameters Final viscosity
and setback were negatively correlated with the hardness cohesiveness gumminess and
chewiness Setback was correlated with the adhesiveness as well Gelatinization temperature To
affected all the texture profile parameters positively Tp slightly related to the cohesiveness
while Tc and enthalpy were not correlated with the texture
Acknowledgements
This project was supported by funding from the USDA Organic Research and Extension
Initiative project number NIFA GRANT11083982 The authors acknowledge Stacey Sykes and
Alecia Kiszonas for editing support
Author Contributions
64
G Wu and CF Morris designed the study together G Wu collected test data and drafted the
manuscript CF Morris and KM Murphy edited the manuscript KM Murphy provided
samples and project oversight
65
References
AACC International 2012 Approved Methods of Analysis Method 08-0101 Ash - Basic
method Approved April 13 1961 Method 44-1502 Moisture ndash Air-Oven Methods (130ordmC)
Approved October 30 1975 Method 46-3001 Crude protein ndash Combustion method
Approved November 8 1995 Reapproved November 3 1999 Available online only
AACCI St Paul MN
Abugoch LE Romero N Tapia CA Silva J Rivera M 2008 Study of some physicochemical
and functional properties of quinoa (Chenopodium quinoa Willd) protein isolates J Agric
Food Chem 564745-50
Abugoch LEJ 2009 Chapter 1 Quinoa (Chenopodium quinoa Willd) Adv Food Nutr Res
581-31
Abugoch L Castro E Tapia C Antildeoacuten MC Gajardo P Villarroel A 2009 Stability of quinoa
flour proteins (Chenopodium quinoa Willd) during storage Int J Food Sci Tech 442013-20
Ahamed NT Singhal RS Kulkami PR Palb M 1996 Physicochemical and functional properties
of Chenopodium quinoa starch Carbohydr Polym 3199-103
Alvarez-Jubete L Arendt EK Gallagher E 2010 Nutritive value of pseudocereals and their
increasing use as functional gluten-free ingredients Trends in Food Sci Tech 21(2)106-13
Ando H Chen YC Tang H Shimizu M Watanabe K Mitsunaga T 2002 Food components in
fractions of quinoa seed Food Sci Technol Res 8(1)80-4
66
Baik BK Lee MR 2003 Effects of starch amylose content of wheat on textural properties of
white salted noodles Cereal Chem 80304-9
BeMiller JN Huber KC 2008 Carbohydrates In Damdaran S Parkin KL Fennema OR editors
Food chemistry Boca Raton CRC Press p 121
Champagne ET Lyon BG Min BK Vinyard BT Bett KL Barton IIFE Webb BD Kohlwey DE
1998 Effects of postharvest processing on texture profile analysis of cooked rice Cereal
Chem 75(2)181-6
Champagne ET Bett KL Vinyard BT McClung AM Barton FE Moldenhauer K Linscombe S
McKenzie K 1999 Correlation between cooked rice texture and rapid visco analyser
measurements Cereal Chem 76(5)764-71
Champagne ET 2004 The rice grain and its gross composition In Champagne ET editor Rice
chemistry and technology St Paul Minn American Association of Cereal Chemists p 88
Chrastil J 1993 Enzyme activities in preharvest rice grains J Agric Food Chem 41(12)2245-8
Cortez G Repo-Carrasco R Rosell CM 2009 Breadmaking use of andean crops quinoa kantildeiwa
kiwicha and tarwi Cereal Chem 86(4)386-92
Del Castillo V Lescano G Armada M 2009 Foods formulation for people with celiac disease
based on quinoa (Chenopodium quinoa) cereal flours and starches mixtures Archivos
Latinoamericanos De Nutricion 59(3)332-36
67
Demirkesen I Mert B Sumnu G Sahin S 2010 Rheological properties of gluten-free bread
formulations J Food Eng 96(2)295-303
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(Waxy) genes J Cereal Sci 3551-63
Fitzgerald MA Martin M Ward RM Park WD Shead HJ 2003 Viscosity of rice flour a
rheological and biological study J Agric Food Chem 51(8) 2295-9
Food and Agriculture Organization of the United Nations (FAO) 2013 The international year of
quinoa Available from httpwwwfaoorgquinoa-2013en Accessed 2013 February 20
Han XZ Hamaker BR 2001 Amylopectin fine structure and rice starch paste breakdown J
Cereal Sci 34(3)279-84
Hou GG Saini R Ng PKW 2013 Relationship between physicochemical properties of wheat
flour wheat protein composition and textural properties of cooked chinese white salted
noodles Cereal Chem 90(5)419-29
Jancurovaacute M Minarovicova L Dandar A 2009 Quinoa ndash a review Czech J Food Sci 27(2)71-9
Juliano BO Villareal RM Bantildeos L 1987 Varietal differences in physicochemical properties of
waxy rice starch Starch - Staumlrke 39(9)298-301
68
Limpisut P Jindal VK 2002 Comparison of rice flour pasting properties using brabender
viscoamylograph and rapid visco analyser for evaluating cooked rice texture Starch - Staumlrke
54(8)350-7
Lindeboom N Chang PR Falk KC Tyler RT 2007 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2)216-22
Marshall WE 1994 Starch gelatinization in brown and milled rice a study using differential
scanning calorimetry In Marshall WE Wadsworth IJ editors Rice science and technology
New York NY Marcel Dekker Inc p 222
Martin M Fitzgerald MA 2002 Proteins in rice grains influence cooking properties J Cereal Sci
36(3)285-94
Mohapatra D Bal S 2006 Cooking quality and instrumental textural attributes of cooked rice
for different milling fractions J Food Eng 73(3)253-9
Ong MH Blanshard JMV 1995 Texture determinants in cooked parboiled rice I Rice starch
amylose and the fine stucture of amylopectin J Cereal Sci 21(3)251-60
Pappier U Fernandez Pinto V Larumbe G Vaamonde G 2008 Effect of processing for saponin
removal on fungal contamination of quinoa seeds (Chenopodium quinoa Willd) Int J Food
Microbiol 125(2)153-7
Perdon AA Juliano BO 1975 Gel and molecular properties of waxy rice starch Starch - Staumlrke
27(3)69-71
69
Ramesh M Bhattacharya KR Mitchell JR 2000 Developments in understanding the basis of
cooked-rice texture Crit Rev Food Sci Nutr 40(6)449-60
Rousset S Pons B Pilandon C 1995 Sensory texture profile grain physico-chemical
characteristics and instrumental measurements of cooked rice J Texture Stud 26(2)119-35
Ruales J Valencia S Nair B 1993 Effect of processing on the physico-chemical characteristics
of quinoa flour (Chenopodium quinoa Willd) Starch - Staumlrke 45(1)13-9
Ruales J de Grijalva Y Lopez-Jaramillo P Nair BM 2002 The nutritional quality of an infant
food from quinoa and its effect on the plasma level of insulin-like growth factor-1 (IGF-1) in
undernourished children Int J Food Sci Nutr 53(2)143-54
Saleh MI Meullenet JF 2007 Effect of protein disruption using proteolytic treatment on cooked
rice texture properties J Texture Stud 38(4)423-37
Sandhu KS Singh N 2007 Some properties of corn starches II Physicochemical gelatinization
retrogradation pasting and gel textural properties Food Chem 101(4)1499-507
Schumacher A Brandelli A Macedo F Pieta L Klug T Jong E 2010 Chemical and sensory
evaluation of dark chocolate with addition of quinoa (Chenopodium quinoa Willd) J Food
Sci Tech 47(2)202-6
Seguchi M Hayashi M Kanenaga K Ishihara C Noguchi S1998 Springiness of pancake and
its relation to binding of prime starch to tailings in stored wheat flour Cereal Chem
75(1)37-42
70
Tang H 2004 Relationship between functionality and structure in barley starches Carbohydr
Polym 57(2)145-52
Tang H Mitsunaga T Kawamura Y 2005 Functionality of starch granules in milling fractions
of normal wheat grain Carbohyd Polym 59(1)11-7
Tsuji S 1981 Texture measurement of cooked rice kernels using the multiple-point mensuration
method 1 J Texture Stud 12(2)93-105
Vaclavik VA Christian EW 2003 Evaluation of food quality In Vaclavik V Christian EW
editors Essentials of food science New York NY Kluwer AcademicPlnum Publishers p 4
Varavinit S Shobsngob S Varanyanond W Chinachoti P Naivikul O 2003 Effect of amylose
content on gelatinization retrogradation and pasting properties of flours from different
cultivars of thai rice Starch - Staumlrke 55(9)410-5
Xie L Chen N Duan B Zhu Z Liao X 2008 Impact of proteins on pasting and cooking
properties of waxy and non-waxy rice J Cereal Sci 47(2)372-9
Zeng M Morris CF Batey IL Wrigley CW 1997 Sources of variation for starch gelatinization
pasting and gelation properties in wheat Cereal Chem 7463-71
71
Table 1-Varieties of quinoa used in the experiment
Variety Original Seed Source Location
Black White Mountain Farm White Mountain Farm Colorado US
Blanca White Mountain Farm White Mountain Farm Colorado US
Cahuil White Mountain Farm White Mountain Farm Colorado US
Cherry Vanilla Wild Garden Seeds Philomath Oregon WSUa Organic Farm Pullman Washington US
Oro de Valle Wild Garden Seeds Philomath Oregon WSUa Organic Farm Pullman Washington US
49ALC USDA Port Townsend Washington US
1ESP USDA Port Townsend Washington US
Copacabana USDA Port Townsend Washington US
Col6197 USDA Port Townsend Washington US
Japanese Strain USDA Port Townsend Washington US
QQ63 USDA Port Townsend Washington US
Yellow Commercial Multi Organics company Bolivia
Red Commercial Multi Organics company Bolivia a WSU - Washington State University
72
Table 2-Seed characteristics and compositiona
Variety Diameter (mm)
Hardness (kg)
Bulk Density (gmL)
Seed Coat Proportion ()
Protein ()
Ash ()
Black 21bc 994b 0584d 37bc 143d 215hi
Blanca 22ab 608l 0672c 89a 135e 284ef
Cahuil 21abc 772e 0757a 49b 170a 260fg
Cherry Vanilla 19e 850d 0717b 41b 160b 239gh
Oro de Valle 19e 1096a 0715b 43b 156b 305de
49ALC 19de 935c 0669c 26cd 127g 348bc
1ESP 19e 664h 0672c 10f 113i 248gh
Copacabana 20cd 643i 0671c 44b 129g 361b
Col6197 19e 583m 0657c 24de 118h 291ef
Japanese Strain 15f 618k 0610d 21def 148cd 324cd
QQ63 19e 672g 0661c 45b 135f 401a
Yellow Commercial
21abc 622j 0663c 14ef 146c 198i
Red Commercial 22a 706f 0730ab 26cd 145cd 226hi a Mean values with different letters within a column are significantly different (P lt 005)
73
Table 3-Texture profile analysis (TPA)a of cooked quinoa
Variety Hardness (kg)
Adhesiveness (kgs)
Cohesiveness Gumminess (kg)
Chewiness (kg)
Black 347a -004a 069ab 24a 24a
Blanca 306bcd -003a 071a 22abc 22abc
Cahuil 327abc -003a 071a 23ab 23ab
Cherry Vanilla 278de -002a 071a 20cd 20cd
Oro de Valle 285d -001a 068ab 19cd 19cd
49ALC 209f -029c 054d 11ef 11ef
1ESP 245e -027bc 056d 14e 14e
Copacabana 305bcd -010a 068ab 21bcd 21bcd
Col6197 202f -023bc 053d 11ef 11ef
Japanese Strain 293d -008a 066bc 19cd 19cd
QQ63 297cd -020b 062c 19d 19d
Yellow Commercial 306bcd -003a 069ab 21abc 21bc
Red Commercial 338ab -005a 068ab 23ab 23ab a Mean values with different letters within a column are significantly different (P lt 005)
74
Table 4-Cooking qualitya of quinoa
Variety Optimal Cooking Time (min)
Water uptake ()
Cooking Volume (mL)
Cooking Loss ()
Black 192a 297c 109c 065f
Blanca 183abc 344b 130ab 067f
Cahuil 169de 357ab 137a 102c
Cherry Vanilla 165ef 291c 107c 102c
Oro de Valle 173cde 238d 109c 102c
49ALC 136h 359ab 126b 043g
1ESP 153g 373ab 132ab 035h
Copacabana 157fg 379ab 127b 175a
Col6197 119i 397a 126b 176a
Japanese Strain 166def 371ab 116c 106b
QQ63 177bc 244d 126b 067f
Yellow Commercial 187ab 372ab 129ab 076d
Red Commercial 155fg 276cd 132ab 071e a Mean values with different letters within a column are significantly different (P lt 005)
75
Table 5-Pasting properties of quinoa flour by RVAa
Variety Peak Viscosity (RVU)
Trough
(RVU)
Breakdown
(RVU)
Final Viscosity (RVU)
Setback (RVU)
Peak Time (min)
Black 102g 81e 21e 75g -6f 102e
Blanca 98g 80e 18e 82g 2e 99f
Cahuil 116f 85e 31d 74g -11f 104de
Cherry Vanilla
66h 54g 12f 57h 2e 97fg
Oro de Valle
59h 50g 10f 56h 6e 93h
49ALC 107fg 71f 36c 132e 62b 97fg
1ESP 161cd 110c 51b 174c 64b 98fg
Copacabana 175b 141b 34cd 190b 49c 106cd
Col6197 155de 133b 22e 177bc 44cd 108bc
Japanese Strain
172bc 109c 62a 159d 50c 96gh
QQ63 144e 94d 51b 167cd 73a 97fg
Yellow Commercial
172bc 162a 11f 203a 41d 109b
Red Commercial
197a 168a 29d 106f -62g 115a
a Mean values with different letters within a column are significantly different (P lt 005)
76
Table 6-Thermal properties of quinoa flour by Differential Scanning Calorimetry (DSC)a
Gelatinization Temperature (ordmC)
Variety To Tp Tc Enthalpy (Jg)
Black 656a 725c 818abcd 15abc
Blanca 658a 743ab 819abcd 18a
Cahuil 659a 752a 839ab 16ab
Cherry Vanilla 649ab 741ab 823abc 12c
Oro de Valle 631bc 719cd 809abcde 12bc
49ALC 579e 714d 810bcde 15abc
1ESP 544f 690f 785de 15abc
Copacabana 630c 715cd 802cde 14abc
Col6197 605d 689f 785de 15abc
Japanese Strain 645abc 740b 850a 12c
QQ63 630c 702e 784de 13bc
Yellow Commercial 570e 676g 790cde 11c
Red Commercial 589de 693ef 780e 12c a Mean values with different letters within a column are significantly different (P lt 005)
77
Table 7-Correlation coefficients between quinoa seed characteristics composition and processing parameters and TPA texture of cooked quinoaa
Hardness Adhesiveness Cohesiveness Gumminess Chewiness
Seed Hardness 051 002ns 028ns 049 049
Bulk Density -055 -044ns -063 -060 -060
Seed Coat Proportion 074 038ns 055 072 072
Protein 050 077 075 057 057
Cooking Time 077 062 074 076 076
Water Uptake Ratio -058 -025ns -046ns -056 -056
Cooking Volume -048 -014ns -032ns -046ns -046ns
Peak Viscosity -051 -014ns -041ns -053 -054
Breakdown -048 -047ns -051 -053 -053
Final Viscosity -069 -043ns -060 -070 -070
Setback -058 -064 -059 -060 -060
To 059 054 061 061 061
Tp 042ns 041ns 050 045ns 046ns a ns non-significant difference P lt 010 P lt 005 P lt 001
78
Figure 1-Rapid Visco Analyzer (RVA) graph of lsquoCherry Vanillarsquo and lsquoRed Commercialrsquo
quinoa flours ( lsquoCherry Vanillarsquo lsquoRed Commercialrsquo Temperature)
Time (min)
0 10 20 30 40
Vis
cosi
ty (R
VU
)
0
50
100
150
200
250
Tem
pera
ture
(degC
)
50
100
150
200
79
Figure 2-Seed coat image by SEM
(1 whole seed section P-perisperm C-cotyledon 2 three layers of quinoa seed coat
3 seed coat of lsquoCherry Vanillarsquo 382 microm 4 seed coat of lsquo1ESPrsquo 95microm)
4 3
2 1
P
C C
80
Chapter 4 Quinoa Starch Characteristics and Their Correlation with
Texture of Cooked Quinoa
ABSTRACT
Starch composition and physical properties strongly influence the functionality and end-
quality of cereals Here correlations between starch characteristics and seed quality cooking
properties and texture were investigated Starch characteristics differed among the eleven
experimental varieties and two commercial quinoa tested The total starch content of seed ranged
from 532 to 751 g 100 g Total starch amylose content ranged from 27 to 169 and the
degree of amylose-lipid complex ranged from 34 to 433 The quinoa samples with higher
amylose tended to yield harder stickier more cohesive more gummy and more chewy texture
after cooking With higher degree of amylose-lipid complex or amylose leaching the cooked
quinoa tended to be softer and less chewy Higher starch enthalpy correlated with firmer more
adhesive more cohesive and more chewy texture Indicating that varieties with different starch
properties should be utilized in different end-products
Keywords quinoa starch texture cooked quinoa
Practical Application The research provided the starch characteristics of different quinoa
varieties showing correlations between starch and cooked quinoa texture These results can help
breeders and food manufacturers to better understand quinoa starch properties and the use of
cultivars for different food product applications
81
Introduction
Quinoa (Chenopodium quinoa Willd) is a pseudocereal from the Andean mountains in
South America Quinoa is garnering greater attention worldwide because of its high protein
content and balanced essential amino acids As in other crops starch is one of the major
components of quinoa seed Starch content structure molecular composition pasting thermal
properties and other characteristics may influence the cooking quality and texture of cooked
quinoa
The total starch content of quinoa seed has been reported to range from 32 to 69
(Abugoch 2009) Starch granules are small (1-2μm) compared to those of rice and barley (Tari et
al 2003) Amylose content of quinoa starch was reported to range from 35 to 225 (Abugoch
2009) generally lower than that of other crops Amylose content exhibited significant influence
on the texture of cooked quinoa (Ong and Blanshard 1995) Similarly cooked rice texture was
correlated to starch amylose and chain length (Ong and Blanshard 1995 Ramesh et al 1999)
and leaching of amylose and amylopectin during cooking (Patindol et al 2010) However
amylose-lipid complex and amylose leaching properties have not been studied in quinoa cultivars
with diverse genetic backgrounds Perdon et al (1999) indicated that starch retrogradation was
positively correlated with firmness and stickiness of cooked milled rice during storage and
similar correlations would be anticipated for quinoa
Starch swelling power and water solubility influenced wheat and rice noodle quality and
texture (Crosbie 1991 McCormick et al 1991 Konik et al 1993 Ross et al 1997 Bhattacharya
et al 1999) whereas the role of starch swelling powerwater solubility in the texture of cooked
quinoa has not been reported
82
The texture of rice starch gels has been studied Gel texture was influenced by treatment
temperature incorporation of glucomannan and sugar concentration (Charoenrein et al 2011
Jiang et al 2011 Sun et al 2014) The texture of quinoa starch gel however has not been
reported
Gelatinization temperature enthalpy and pasting properties of starch were correlated
with the texture of cooked rice (Ong and Blanshard 1995 Champagne et al 1999 Limpisut and
Jindal 2002) The correlations between starch thermal properties pasting properties and cooked
quinoa texture however have also not been reported
Starch is an important component of grains and exhibits significant influence on the
texture of cooked rice noodles and other foods The texture of cooked quinoa has been studied
previously (Wu et al 2014) however the correlation of starch and cooked quinoa texture
nevertheless remained unclear The objectives of the present study were to understand 1) the
starch characteristics of different quinoa varieties and 2) the correlations between the starch
characteristics and the texture of cooked quinoa
Materials and Methods
Starch isolation
Eleven varieties and two commercial quinoa samples were included in this study (Table
1) Quinoa starch was isolated using a method modified from Lindeboom et al (2005) and Qian
et al (1999) Two hundred grams of seed were steeped in 1000 mL NaOH (03 wv) overnight
at 4 degC and rinsed with distilled water three times to remove the saponins The rinsed quinoa
was ground in a Waring blender (Conair Corp Stamford CT USA) for 15 min The slurry
was screened through a series of sieves US No 40 100 and 200 mesh sieves with openings of
83
425 150 and 74 μm respectively Distilled water was added and stirred to speed up the
filtration Filter residue was discarded whereas the filtrate was centrifuged under 2000 times g for 20
min The supernatant was decanted and the top brown layer of sediment (protein and lipids) was
gently scraped loose and discarded The remaining pellet was resuspended in distilled water and
centrifuged again This resuspension-centrifuge process was repeated three times or until the
brown topmost layer was all removed The white starch pellet was then dispersed in 95 ethanol
and centrifuged under 2000 times g for 10 min The supernatant was discarded and the starch pellet
was air-dried and gently ground using a mortar and pestle
α-amylase activity
The activity of α-amylase was determined using a Megazyme Kit (Megazyme
International Ireland Co Wicklow Ireland)
Apparent total amylose content degree of amylose-lipid complex
Apparent amylose content was determined using a cold NaOH method (Mahmood et al
2007) with modification Sample of 10 mg was weighed into a 20 mL microcentrifuge tube To
the sample was added 150 μL of 95 ethanol and 900 μL of 1M NaOH mixed vigorously and
kept on a shaker overnight at room temperature The starch solution of 200 μL was removed and
combined with 1 mL of 005 M citric acid 800 μL iodine solution (02 g I2 2 g KI in 250 mL
distilled water) and 10 mL distilled water reaching a final volume of 12 mL The solution was
chilled in a refrigerator for 20 min The absorbance at 620nm was determined using a
spectrophotometer (Shimadzu Biospec-1601 DNAProteinEnzyme Analyzer Shimadzu corp
Kyoto Japan) A standard curve was created using a dilution series of amylose amylopectin
84
proportions of 010 19 28 37 46 and 55 respectively (Sigma-Aldrich Co LLC St Louis
MO USA)
Total amylose content was determined using the same method for apparent amylose
except that lipids in the starch samples were removed in advance The starch was defatted using
hexane and ultrasonic treatment as follows One gram of starch was dissolved in 15 mL hexane
and set in an ultrasonic water bath for 2 hours The suspension was then centrifuged at 1000 times g
for 1 min The supernatant was discarded and the procedure was repeated a second time The
sample was then dried in a fume hood overnight
Degree of amylose-lipid complex = [total amylose ndash apparent amylose] total amylose times 100
Amylose leaching properties
Amylose leaching was determined using the modified method of Hoover and Ratnayake
(2002) Starch (025 g) was mixed with 5 mL distilled water and heated at 60 degC for 30 min
then cooled in ice water and centrifuged at 2000 times g for 10 min Supernatant of 1 mL was added
to 800 μL iodine solution and 102 mL distilled water to achieve the same volume of 12 mL as
in the apparent amylose test The solution was chilled in a refrigerator for 20 min and the
absorbance at 620 nm was determined The amylose leaching was expressed as mg of amylose
leached from 100 g of starch
Starch pasting properties
Starch pasting properties were determined using the Rapid Visco Analyzer RVA-4
(Newport Scientific Pty Ltd Narrabeen Australia) Starch (3 g) was added to 25 mL distilled
water mixed and heated in the RVA using the following procedure The initial temperature was
50 ordmC and increased to 93 ordmC within 8 min at a constant rate held at 95 ordmC from 8 min to 24 min
85
cooled to 50 ordmC from 24 min to 28 min and held at 50 ordmC from 29 min to 40 min The result was
expressed in RVU units (RVU = cP12)
Starch gel texture
Starch gel texture was determined using a TA-XT2i Texture Analyzer (Texture
Technologies Corp Hamilton MA USA) The starch gels were prepared in the RVA using the
same procedure as for pasting properties Then the starch gels were stored at 4 degC for 24 hours
The testing procedure followed the method of Jiang et al (2011) with modification The gel
cylinder (3 cm high and 35 cm diameter) was compressed using a TA-25 cylinder probe at the
speed of pre-test 20 mms test 05 mms and post-test 05 mms to 10 mm deformation Two
compressions were conducted with an interval time of 20 s Hardness springiness and
cohesiveness were obtained from the TPA (Texture Profile Analysis) graph (x-axis distance and
y-axis force) Hardness (g) was expressed by the maximum force of the first peak springiness
was the ratio of distance (time) to peak 2 to distance to peak 1 cohesiveness was the ratio of the
second positive area under the compression curve to that of the first positive area
Freeze-thaw stability
Freeze-thaw stability was determined using the modified method from Lindeboom et al
(2005) and Charoenrein et al (2005) Starch slurry was cooked using the RVA with 125 g
starch and 25 mL distilled water The starch suspensions were heated at 60 degC from 0 ndash 2 min
the temperature was increased to 105 degC from 3 ndash 8 min with a constant rate and held at 105 degC
from 9 - 11 min The cooked samples were stored at -18 degC for 20 hours and then kept at room
temperature for 4 hours Water was decanted and the weight difference was determined The
86
freeze-thaw cycle was repeated five times The freeze-thaw stability was expressed as water loss
after each freeze-thaw cycle
Starch thermal properties
Thermal properties of starch were determined using Differential Scanning Calorimetry
(DSC) (Lindeboom et al 2005) Starch samples of 10 mg were weighed into aluminum pans
(Perkin-Elmer Kit No 219-0062) with 20 μL distilled water The pans were sealed and the
suspensions were incubated at room temperature (25 degC) for 2 hours to achieve equilibrium The
pans were then scanned at 10 degCmin from 25 degC to 120 degC The onset temperature (To) peak
temperature (Tp) and completion temperature (Tc) were the temperature to start the peak reach
the peak and complete the peak respectively Additionally enthalpy of gelatinization was
determined by the area under the peak
Swelling power and solubility
Swelling power and water solubility of starch were obtained at 93 degC (Vandeputte et al
2003) Starch samples of 05 g were added to 12 mL distilled water and mixed vigorously The
suspensions were immediately set in a water bath with a rotating rack at 93 degC for 30 min The
suspensions were then cooled in ice water for 2 min and centrifuged at 3000 g for 15 min The
supernatant was carefully removed with a pipette and the weight of wet sediment was recorded
The removed supernatants were dried in a 105 degC oven over night The weight of dry sediment
was recorded The swelling power and water solubility were expressed using the following
equations
Swelling power = wet sediment weight [dry sample weight times (1 ndash water solubility))
Water solubility = dry sediment weight dry sample weight times 100
87
Swelling power is expressed as a unitless ratio
Statistical analysis
All experiments were repeated three times Multiple comparisons were conducted using
Fisherrsquos LSD in SAS 92 (SAS Inst Cary NC USA) Correlations were calculated using
PROC CORR code in SAS 92 A P value of 005 was considered as the level of significance
unless otherwise specified
Results
Starch content and composition
Total starch content of quinoa seeds on a dry basis ranged from 532 g 100 g in the
variety lsquoBlackrsquo to 751 g 100 g in a commercial sample named lsquoYellow Commercialrsquo (Table 2)
Varieties lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo were lower in total
starch content all below 60 g100 g The Port Townsend seeds and commercial seeds contained
higher levels of starch mostly over 70 g100 g
Apparent amylose contents ranged from 27 in lsquo49ALCrsquo to 169 in lsquoCahuilrsquo all
lower than the corn starch standard which was 264 Varieties lsquoCahuilrsquo lsquoBlackrsquo and lsquoYellow
Commercialrsquo contained higher apparent amylose 147 to 169 It is worth noting that
lsquo49ALCrsquo contained the lowest apparent and total amylose contents 27 and 47 respectively
Total amylose of the other varieties ranged from 111 in lsquoQQ63rsquo to 173 in lsquoCahuilrsquo
The degree of amylose-lipid complex differed among the samples ranging from 34 in
lsquoCahuilrsquo to 43 in lsquo49ALCrsquo and lsquoCol6197rsquo Statistically however only lsquo49ALCrsquo and
lsquoCol6197rsquo were significantly higher than lsquoCahuilrsquo in degree of amylose-lipid complex
Starch properties
88
Amylose leaching property exhibited great differences among samples (Table 3)
lsquo49ALCrsquo and lsquo1ESPrsquo showed the highest amylose leaching at 862 and 716 mg 100 g starch
respectively lsquoCahuilrsquo lsquoJapanese Stainrsquo and lsquoRed Commercialrsquo were the lowest with amylose
leaching less than 100 mg 100 g starch lsquoBlackrsquo and lsquoBlancarsquo were relatively low as well with
210 and 171 mg amylose leaching 100 g starch The other varieties were intermediate and
ranged from 349 to 552 mg 100 g starch
Water solubility of quinoa starch ranged from 07 to 45 all lower than that of corn
starch which was 79 lsquoJapanese Strainrsquo lsquoQQ63rsquo lsquoCommercial Yellowrsquo and lsquoPeruvian Redrsquo
were the highest in water solubility 26 to 45 The starch water solubility in the other varieties
was between 10 and 19
Swelling power of quinoa starch ranged from 170 to 282 all higher than that of corn
starch (89) lsquo49ALCrsquo and lsquo1ESPrsquo showed the highest swelling powers 282 and 276
respectively lsquoYellow Commercialrsquo and lsquoRed Commercialrsquo showed relatively lower swelling
power 188 and 196 respectively The remaining varieties did not exhibit differences in
swelling power with values between 253 and 263
α-Amylase activity
Activity of α-amylase in quinoa flour separated the samples to three groups (Table 3)
lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquoOro de Vallersquo showed high α-amylase activity from
086 CU to 116 CU (Ceralpha Unit) lsquoBlackrsquo lsquo49ALCrsquo and lsquoCopacabanarsquo were lower in α-
amylase activity 043 031 and 020 CU respectively The other varieties and commercial
samples exhibited particularly low α-amylase activities with the values lower than 01 CU
Starch gel texture
89
Texture of starch gels included hardness springiness and cohesiveness (Table 4)
Hardness of starch gel of lsquoCahuilrsquo and lsquoJapanese Strainrsquo represented the highest and the lowest
values 900 and 201 g respectively Hardness of the other varieties ranged from 333 g in
lsquo49ALCrsquo to 725 g in lsquoBlackrsquo
lsquoJapanese Strainrsquo and lsquoYellow Commercialrsquo exhibited the highest and lowest springiness
values of the starch gels 092 and 071 respectively Springiness of other starch samples ranged
from 075 to 085 and were not significantly different from each other
Cohesiveness of starch gels ranged from 053 to 089 The starch gels of lsquoJapanese
Strainrsquo lsquoCol6197rsquo and lsquoCopacabanarsquo were more cohesive at 089 083 and 078 respectively
The starch gels of lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and lsquo1ESPrsquo were moderately cohesive
with the cohesiveness of 072 ndash 073 Other varieties exhibited less cohesive starch gels lsquoQQ63rsquo
and commercial samples showed the least cohesive starch gels 053 ndash 057 For comparison the
hardness springiness and cohesiveness of the corn starch gel was 721 084 and 073
respectively These values were among the upper-to-middle range of those counterpart values of
the texture of quinoa starch gels
Starch thermal properties
Thermal properties of quinoa starch include gelatinization temperature and enthalpy
(Table 5) Onset temperature To of quinoa starch ranged from 515 ordmC in lsquoYellow Commercialrsquo to
586 ordmC in lsquoBlancarsquo Peak temperature Tp ranged from 595 ordmC in lsquoRed Commercialrsquo to 654 ordmC
in lsquoJapanese Strainrsquo Conclusion temperature ranged from 697 ordmC in lsquoCol6197rsquo to 788 ordmC in
lsquoJapanese Strainrsquo The commercial samples exhibited lower gelatinization temperatures To Tp
90
and Tc of the corn starch were 560 626 and 743 ordmC respectively They were within the ranges
of those values of the quinoa starches
Enthalpy refers to the energy required during starch gelatinization The enthalpy of
quinoa starch ranged from 99 to 116 Jg Starch from lsquoCahuilrsquo exhibited the highest enthalpy
116 Jg higher than that of lsquo49ALCrsquo and lsquoQQ63rsquo However enthalpies of other samples were
not significantly different Corn starch enthalpy was 105 Jg comparable to those of quinoa
starches
Starch pasting properties
Starch viscosity was investigated using the RVA (Table 6) Peak viscosity of quinoa
starches ranged from 193 to 344 RVU Varieties lsquoBlancarsquo and lsquoCahuilrsquo showed the highest peak
viscosities 344 and 342 RVU respectively lsquoJapanese Strainrsquo and lsquoQQ63rsquo were lowest in starch
peak viscosity 193 and 213 RVU respectively The peak viscosity of corn starch was 255 RVU
falling within the middle range of quinoa peak viscosities
The tough is the minimum viscosity after the first peak The trrough of quinoa starch
ranged from 137 to 301 RVU The starches of lsquoBlackrsquo lsquoBlancarsquo lsquoCahuilrsquo lsquoCherry Vanillarsquo and
lsquoOro de Vallersquo showed highest trough values from 252 to 301 RVU lsquo49ALCrsquo lsquo1ESPrsquo
lsquoCopacabanarsquo lsquoJapanese Strainrsquo and lsquoQQ63rsquo were lowest in trough ranging from 137 to 186
RVU The trough of corn starch was 131 RVU lower than that of all quinoa starches
Starch breakdown of lsquo49ALCrsquo was 119 RVU higher than that of other samples except
corn starch which was 124 RVU lsquoJapanese Strainrsquo and lsquoOro de Vallersquo showed the lowest
breakdowns 12 and 17 RVU respectively Breakdown of the other samples ranged from 39 to
97 RVU
91
Final viscosity of lsquoCahuilrsquo starch was 405 RVU significantly higher than that of other
varieties At the other extreme final viscosity of lsquo49ALCrsquo starch was 225 RVU significantly
lower than that of the other varieties The final viscosity of corn starch was 283 RVU close to
that of lsquoJapanese Strainrsquo and lsquoQQ63rsquo but lower than that of the other quinoa samples
The highest setback was observed with lsquo1ESPrsquo starch (140 RVU) At the other extreme
the setback of lsquoOro de Vallersquo was 53 RVU which was lower than the other quinoa samples
Additionally setbacks of lsquoBlancarsquo lsquo49ALCrsquo and lsquoJapanese stainrsquo starches were also among the
lower range varying from 82 RVU to 88 RVU The remaining varieties exhibited higher setback
from 101 RVA to 127 RVU Setback of corn starch was 152 RVU significantly higher than all
the other quinoa starches
RVA peak times of quinoa starches varied significantly among the samples lsquoJapanese
Strainrsquo lsquoBlancarsquo lsquoCahuilrsquo and lsquoOro de Vallersquo required longer time to reach the peak viscosity
with peak times of 105 to 113 min Other varieties showed shorter peak times between 79 to
99 min The starch of lsquo49ALCrsquo however only needed 64 min to reach peak viscosity shorter
than those of other quinoa samples The peak time of corn starch was 73 min shorter than those
of quinoa starches except lsquo49ALCrsquo
Freeze-thaw stability of starch
Freeze-thaw stability of starches was expressed as the water loss () of each freeze-thaw
cycle Quinoa starch samples and corn starch showed similar trends in freeze-thaw stability
Most water loss occurred after cycles 1 and 2 Starch gels on average (excluding lsquo49ALCrsquo) lost a
cumulative total of 522 ndash 689 of water after cycle 2 and a total of 745 ndash 823 after cycle 5
Furthermore the starch gels of lsquoQQ63rsquo and lsquo1ESPrsquo lost the least water indicating higher freeze-
92
thaw stability Conversely the starch gel of lsquoJapanese Strainrsquo lost the most water in every cycle
indicating the lowest degree of freeze-thaw stability
lsquo49ALCrsquo and lsquo1ESPrsquo starches exhibited freeze-thaw behavior that was different
compared to the other samples After freezing the samples of lsquo49ALCrsquo and lsquo1ESPrsquo produced
gels that were less rigid more viscous than the other samples Further they did not lose as much
water after the first cycle The sample of lsquo1ESPrsquo however turned into a solid gel from cycle 2 to
5 And the water loss of the lsquo1ESPrsquo gel was close to that of other samples during cycles 2 and 5
Correlations between starch properties and the texture of cooked quinoa
Correlations between starch properties and texture of cooked quinoa were examined
(Table 7) using texture profile analysis (TPA) of cooked quinoa of Wu et al (2014) Total starch
content was moderately correlated with adhesiveness of cooked quinoa (r = -048 P = 009) but
was not significantly correlated with any of the other texture parameters Conversely apparent
amylose content was highly correlated with all texture parameters (067 le r le 072) Total
amylose content also exhibited significant correlations with all texture parameters (056 le r le
061) Furthermore the degree of amylose-lipid complex was negatively correlated with all
texture parameters (-070 le r le -060) and amylose leaching proportion was highly correlated
with the texture of cooked quinoa (-084 le r le -074)
Water solubility and swelling power of starch were not observed to correlate well with
any of the texture parameters Higher α-amylase activity tended to yield more adhesive (r = 055)
and more cohesive (r = 051 P = 007) texture However α-amylase activity was not correlated
with the hardness gumminess or chewiness of cooked quinoa
93
Some texture parameters of starch gels were associated with the texture parameters of
cooked quinoa The hardness of starch gels was not correlated with the hardness of cooked
quinoa but was weakly correlated with adhesiveness (r = 059) Weakly positive correlations
were found between starch gel hardness and cooked quinoa cohesiveness gumminess and
chewiness (049 le r le 051 P le 010) Springiness and cohesiveness of starch gels were not
correlated with the measured textural properties of cooked quinoa
Onset gelatinization temperature (To) of starch exhibited weak correlations with
adhesiveness (r = 049 P = 009) and cohesiveness (r = 051 P = 007) but was not correlated
with the other texture parameters Peak gelatinization temperature (Tp) of starch was correlated
with cohesiveness (r = 056) and hardness adhesiveness gumminess and chewiness (047 le r le
056 P le 010) No correlation was found with conclusion temperature (Tc) and texture Starch
enthalpy did correlate with the texture parameters (r = 064 in hardness 069 le r le 072 in other
texture parameters)
Starch viscosity measurements were variably correlated with the texture of cooked
quinoa Peak viscosity correlated adhesiveness (r = 054 P = 006) and cohesiveness (r = 047 P
= 010) but not with the other texture parameters Trough was more highly correlated with
adhesiveness cohesiveness gumminess and chewiness (r = 077 in adhesiveness 055 le r le
063 in other texture parameters)
It is interesting to note that starch breakdown only correlated with adhesiveness of
cooked quinoa (r = -060) and not with any other texture parameter Setback was not correlated
with any texture parameter These two RVA parameters breakdown and setback are usually
considered to be important indexes of end-use quality In quinoa however breakdown and
94
setback of starch apparently are not predictive of cooked quinoa texture In addition final
viscosity was also correlated with adhesiveness (r = 068) and cohesiveness (r = 058) and
correlated moderately with gumminess and chewiness (r = 053 P = 006) Peak time was
correlated with adhesiveness (r = 077) cohesiveness (r = 068) gumminess (r = 060) and
chewiness (r = 060) and to a lesser extent with hardness (r = 053 P = 006)
Correlations between starch properties and seed DSC RVA characteristics
Total starch content correlated with seed hardness (r = -073) seed coat proportion (r = -
071) and starch viscosities (peak viscosity trough and final viscosity) (-068 lt r lt -060) and
also to a lesser extent with seed density (r = 054 P = 006) and starch thermal properties (To
Tp and enthalpy) (-051 lt r lt -049 008 lt P lt009) (Table 8)
Water solubility of starch was correlated with starch viscosity such as peak viscosity (r =
-049 P = 009) and breakdown (r = -048 P = 010) Swelling power was only correlated with
peak time (r = -054 P = 006) (data not shown)
Apparent amylose content was correlated with protein content (r = 058) and optimal
cooking time (r = 056) but total amylose content did not show either of these correlations Both
apparent and total amylose contents were correlated with starch gel hardness starch enthalpy
and starch viscosity such as trough breakdown final viscosity and peak time
The degree of amylose-lipid complex exhibited negative correlations with seed protein
content (r = -07) and optimal cooking time of quinoa seed (r = -067) Moreover amylose
leaching was negatively correlated with protein content (r = -062) starch gel hardness (r = --
064) starch Tp (r = -058) and enthalpy (r = -064) optimal cooking time (r = -055) and starch
viscosities such as breakdown (r = 062) and peak time (r = -081) Additionally α-amylase
95
activity was correlated with protein content (r = 066) seed density (r = -072) seed coat
proportion (r = 055) starch To (r = 061) and starch viscosities such as peak viscosity (r =
070) trough (r = 072) and final viscosity (r = 061)
Discussion
Starch content and composition
Total starch content does influence the functional and processing properties of cereals
The total starch content of quinoa was reported to be between 32 and 69 (Abugoch 2009)
Among our varieties most of the Port Townsend varieties and commercial quinoa contained
more than 69 starch It is interesting to note that the Port Townsend samples lsquo49ALCrsquo lsquo1ESPrsquo
lsquoCol6197rsquo and lsquoQQ63rsquo were also more sticky or more adhesive after cooking than other
varieties These varieties may exhibit better performance in extrusion products or in beverages
which require high viscosity
Amylose content affects texture and gelation properties The proportion of amylose and
amylopectin impacts the functionality of cereals in this study both apparent and total amylose
contents were determined Total amylose includes those amylose molecules that are complexed
with lipids
Amylose content of quinoa was reported to range from 35 to 225 dry basis
(Abugoch 2009) generally lower than that of common cereals which is around 25 Overall
both apparent and total amylose contents of the quinoa in the present study fell within the range
which has been reported lsquo49ALCrsquo was an exception showing significantly lower apparent and
total amylose contents of 27 and 47 respectively Thus this variety is close to be being a
lsquowaxyrsquo which refers to the cereal starches that are comprised of mostly amylopectin (99) and
96
little amylose (~1) As the waxy wheat showed an excellent expansion during extrusion
(Kowalski et al 2014) lsquo49ALCrsquo is a promising variety to produce breakfast cereal or extruded
snacks
The degree of amylose-lipid complex showed great variability among the samples 34 ndash
433 whereas the value in wheat flour was reported to be 32 (Bhatnagar and Hanna 1994) or
13 to 23 (Zeng et al 1997) Degree of amylose-lipid complex showed significant and
negative correlations with all texture parameters such as hardness adhesiveness cohesiveness
gumminess and chewiness
The effect of amylose-lipid complex on product texture has been reported in previous
studies The degree of amylose-lipid complex correlated with the texture (hardness and
crispness) and quality (radial expansion) of corn-based snack (Thachil et al 2014) Wokadala et
al (2012) indicated that amylose-lipid complexes played a significant role in starch biphasic
pasting
Starch properties
Amylose leaching was also highly variable among the quinoa varieties 35 ndash 862 mg
100g starch Vandeputte et al (2003) studied amylose leaching of waxy and normal rice
starches The amylose leaching values at 65 ordmC were below 1 of starch comparable with those
in quinoa starch Pronounced increase of amylose leaching was observed at the temperatures
higher than 95 ordmC Patindol et al (2010) found that both amylose and amylopectin leached out
during cooking rice The proportion of the leached amylose and amylopectin influenced the
texture of cooked rice We found similar results indicating correlations between amylose
leaching and texture of cooked quinoa
97
Water solubility of quinoa starch was significantly lower than that of corn starch whereas
swelling power of quinoa starch was higher than that of corn starch Both water solubility and
swelling power were determined at 95 ordmC Lindeboom et al (2005) determined swelling power
and solubility of quinoa starch among eight varieties at 65 75 85 and 95 ordmC The water
solubility at 95 ordmC ranged from 01 to 47 which was lower than the corn starch standard of
100 The swelling power at 95 ordmC ranged from 164 to 526 lower than the corn starch
standard of 549 The quinoa starch in this study showed a narrower range of swelling power
170 to 282
α-Amylase activity
The quinoa in this study had significantly different α-amylase activity (003 ndash 116 CU)
Previous studies reported low α-amylase activity in quinoa compared to oat (Maumlkinen et al
2013) and traditional malting cereals (Hager et al 2014) Moreover the activity of α-amylase
indicates the degree of seed germination and the availability of sugars for fermentation In the
study of Hager et al (2014) α-amylase activity increased from 0 to 35 CU during 72 h
germination
Texture of starch gel
Starch gel texture has been previously studied on corn and rice starches but not on
quinoa starch Hardness of rice starch gel was reported to be 339 g by Charoenrein et al (2011)
and 116 g by Jiang et al (2011) Hardness of corn starch was reported to be around 100 g in the
study of Sun et al (2014) much lower than the standard corn starch hardness in this study 721
g Compared to those of rice and corn starch quinoa starch gel exhibited harder texture which
may be caused by either genetic variation or different processing procedures to form the gel
98
Additionally springiness and cohesiveness of rice starch gel were reported as 085 and 055
respectively (Jiang et al 2011) Quinoa starch gel exhibited comparable springiness and higher
cohesiveness than those of rice starch gel
Thermal properties of quinoa starch
The thermal properties of quinoa starch in this study were comparable to those of rice
starch (Cai et al 2014) The study of Lindeboom et al (2005) however found lower
gelatinization temperatures and higher enthalpies compared to the present study which may be
due to varietal difference
Furthermore correlation between thermal properties of quinoa starch and flour (Wu et al
2014) was investigated Gelatinization temperatures To Tp and Tc of starch and whole seed
flour were highly correlated especially To and Tp exhibited high r of 088 The enthalpy of
starch and flour however was not significantly correlated In this case quinoa flour can be used
to estimate quinoa starch gelatinization temperatures but not the enthalpy Additionally since
flour is easier to prepare compared to starch further studies can be conducted with a larger
number of quinoa samples to model the prediction of starch thermal properties using flour
thermal properties
Starch pasting properties
Viscosity and pasting properties of starch play a significant role in the functionality of
cereals Jane et al (1999) studied the pasting properties of starch from cereals such as maize
rice wheat barley amaranth and millet The peak viscosities ranged from 58 RVU in barley to
219 RVU in sweet rice lower than those of most quinoa starches except lsquoJapanese Strainrsquo and
lsquoQQ63rsquo Final viscosities ranged from 54 RVU in barley to 208 RVU in cattail millet all lower
99
than those of the quinoa starches in the present study Setback of cereal starches mostly ranged
from 6 RVU in waxy amaranth to 74 RVU in non-waxy maize lower than those of most quinoa
starches except lsquoOre de Vallersquo Cattail millet starch exhibited the setback of 208 RVU higher
than those of quinoa starches
The relationships between RVA pasting parameters of quinoa starch and flour were
studied by Wu et al (2014) Final viscosity of starch and flour was correlated negatively (r = -
063 P = 002) The other RVA parameters did not exhibit significant correlation between starch
and flour RVA In other words RVA of quinoa flour cannot be used to predict RVA of quinoa
starch In addition to starch the fiber and protein in whole quinoa flour may influence the
viscosity As quinoa is normally utilized as whole grain or whole grain flour instead of refined
flour the flour RVA should be a better indication on the end-use functionality
Freeze-thaw stability of starch
Quinoa starches in the present study did not show high stability during freeze and thaw
cycles Praznik et al (1999) studied freeze-thaw stability of various cereal starches Similar to
the present study Praznik et al concluded quinoa starches exhibited low freeze-thaw stability
Conversely Ahamed et al (1996) found quinoa starch exhibited excellent freeze-thaw stability
Unfortunately the variety was not indicated Overall it is reasonable to assert that for some
quinoa cultivars the starch may have better freeze-thaw stability than in other cultivars
However most quinoa varieties in published studies did not show good freeze-thaw stability
Correlations between starch characteristics and texture of cooked quinoa
The quinoa starch characteristics correlated with the texture of cooked quinoa in some
aspects Total starch content however did not show any strong correlations with TPA
100
parameters as was initially expected Since quinoa is consumed as whole grain or whole flour
fiber and bran may exhibit more influence on the texture than anticipated from the impact of
starch alone
The quinoa varieties with higher apparent and total amylose contents tended to yield a
harder stickier more cohesive more gummy and chewy texture Similar correlations are found
with cooked rice noodle and corn-based extrusion snacks The hardness of cooked rice was
positively correlated with amylose content and negatively correlated with adhesiveness (Yu et al
2009) Epstein et al (2002) reported that full waxy noodles were softer thicker less adhesive
and chewy and more cohesive and springy compared to normal noodles and partial waxy
noodles Increased amylose content in a corn-based extrusion snack resulted in higher amylose-
lipid formation and softer texture (Thachil et al 2014)
Higher levels of amylose-lipid complex in starch were associated with softer less
adhesive less cohesive and less gummy and less chewy cooked quinoa The correlation between
the degree of amylose-lipid complex and texture of cooked rice or quinoa has not been
previously reported Kaur and Singh (2000) however found that amylose-lipid complex
increased with longer cooking time of rice flour Additionally cooking time is a key factor to
determine texture ndash the longer a cereal is cooked the softer less sticky less cohesive and less
gummy and chewy the texture
Correlations were found between amylose leaching and cooked quinoa TPA parameters
especially hardness gumminess and chewiness with r of -082 Increased amylose leaching
yielded a softer gel made from potato starch (Hoover et al 1994) However the correlations of
101
amylose leaching and α-amylase activity with texture of end product for quinoa have not been
reported previously
Swelling power and water solubility were reported to influence the texture of wheat and
rice noodle (Crosbie 1991 McCormick et al 1991 Konik et al 1993 Ross et al 1997
Bhattacharya et al 1999) However in the present report no correlation was found between
swelling power water solubility and the texture of cooked quinoa Additionally the study of
Ong and Blanshard (1995) indicated a positive correlation between enthalpy and the texture of
cooked rice Similar results were found in this study
RVA is a fast and reliable way to predict flour functionality and end-use properties
Pasting properties of rice flour have been used to predict texture of cooked rice (Champagne et
al 1999 Limpisut and Jindal 2002) In our previous study cooked quinoa texture correlated
negatively with the final viscosity and setback of quinoa flour (Wu et al 2014) In this study
texture correlated with trough breakdown final viscosity and peak time of quinoa starch
However RVA of quinoa flour and starch did not correlate with each other Flour RVA might be
a convenient way to predict cooked quinoa texture
Correlations between starch properties and seed DSC RVA characteristics
Quinoa with higher total starch tended to have a thinner seed coat This makes sense
because starch protein lipids and fiber are the major components of seed An increase in one
component will result in a proportional decrease in the other component contents
Additionally the starch RVA parameters (except peak viscosity) can be used to estimate
apparent or total amylose content based on their correlations Further studies should be
conducted with a larger sample size of quinoa and a more accurate prediction model can be built
102
The samples with lower protein or those requiring shorter cooking time tended to contain
higher levels of amylose-lipid complex Additionally amylose-lipid complex was reported to
influence the texture of extrusion products (Bhatnagar and Hanna 1994 Thachil et al 2014) For
this reason protein and optimal cooking time are promising indicators of the behavior of quinoa
during extrusion
Conclusions
In summary starch content composition and characteristics were significantly different
among quinoa varieties Amylose content degree of amylose-lipid complex and amylose
leaching property of quinoa starch exhibited great variances and strong correlations with texture
of cooked quinoa Additionally starch gel texture pasting properties and thermal properties
were different among varieties and different from those of rice and corn starches Enthalpy
RVA trough final viscosity and peak time exhibited significant correlations with cooked quinoa
texture Overall starch characteristics greatly influenced the texture of cooked quinoa
Acknowledgments
This project was supported by the USDA Organic Research and Extension Initiative
(NIFAGRANT11083982) The authors acknowledge Girish Ganjyal and Shyam Sablani for
using the Differential Scanning Calorimetry (DSC) thanks to Stacey Sykes for editing support
Author Contributions
G Wu and CF Morris designed the study together and established the starch isolation
protocol G Wu collected test data and drafted the manuscript CF Morris and KM Murphy
edited the manuscript KM Murphy provided quinoa samples
103
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Carbohydr Res 261(1)13-24
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of amylopectin branch chain length and amylose content on the gelatinization and pasting
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Chem 71(4)511-7
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92(2)145-53
Limpisut P Jindal VK 2002 Comparison of rice flour pasting properties using Brabender
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Staumlrke 54(8)350-7
Lindeboom N Chang PR Falk KC Tyler RT 2005 Characteristics of starch from eight quinoa
lines Cereal Chem 82(2)216-22
Mahmood T Turner MA Stoddard FL 2007 Comparison of methods for colorimetric amylose
determination in cereal grains Starch‐Staumlrke 59(8)357-65
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Maumlkinen OE Zannini E Arendt EK 2013 Germination of oat and quinoa and evaluation of the
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Matos M Timgren A Sjoo M Dejmek P Rayner M 2013 Preparation and encapsulation
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McCormick K Panozzo J Hong S 1991 A swelling power test for selecting potential noodle
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antimicrobial activity Food Chem 173755-62
Patindol J Gu X Wang YJ 2010 Chemometric analysis of cooked rice texture in relation to
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Perdon AA Siebenmorgen TJ Buescher RW Gbur EE 1999 Starch retrogradation and texture
of cooked milled rice during storage J Food Sci 64(5)828-32
107
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background of technological properties of selected starches Starch‐Staumlrke 51(6) 197-211
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starch Starch‐Staumlrke 51(4)116-20
Ramesh M Zakiuddin Ali S Bhattacharya KR 1999 Structure of rice starch and its relation to
cooked-rice texture Carbohydr Polym 38(4)337-47
Rayner M Sjoumlouml M Timgren A Dejmek P 2012 Quinoa starch granules as stabilizing particles
for production of Pickering emulsions Faraday Discuss 158(1)139-55
Ross AS Quail KJ Crosbie GB 1997 Physicochemical properties of Australian flours
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Sun Q Xing Y Qiu C Xiong L 2014 The pasting and gel textural properties of corn starch in
glucose fructose and maltose syrup PloS one 9(4)e95862
Thachil MT Chouksey MK Gudipati V 2014 Amylose-lipid complex formation during
extrusion cooking effect of added lipid type and amylose level on corn-based puffed snacks
Int J Food Sci Tech 49(2)309-16
Vandeputte GE Derycke V Geeroms J Delcour JA 2003 Rice starches II Structural aspects
provide insight into swelling and pasting properties J Cereal Sci 38(1)53-9
Wokadala OC Ray SS Emmambux MN 2012 Occurrence of amylosendashlipid complexes in teff
and maize starch biphasic pastes Carbohydr Polym 90(1)616-22
108
Wu G Morris C F Murphy K M 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79(11)2337-45
Yu S Ma Y Sun DW 2009 Impact of amylose content on starch retrogradation and texture of
cooked milled rice during storage J Cereal Sci 50(2)139-44
Zeng M Morris CF Batey IL Wrigley CW 1997 Sources of variation for starch gelatinization
pasting and gelation properties in wheat Cereal Chem 74(1)63-71
109
Table 1-Quinoa varieties tested
Variety Original Seed Source Location
Black White Mountain Farm White Mountain Farm Colo USA
Blanca White Mountain Farm White Mountain Farm Colo USA
Cahuil White Mountain Farm White Mountain Farm Colo USA
Cherry Vanilla Wild Garden Seeds Philomath Oregon
WSUa Organic Farm Pullman Wash USA
Oro de Valle Wild Garden Seeds Philomath Oregon
WSUa Organic Farm Pullman Wash USA
49ALC USDA Port Townsend Wash USA
1ESP USDA Port Townsend Wash USA
Copacabana USDA Port Townsend Wash USA
Col6197 USDA Port Townsend Wash USA
Japanese Strain USDA Port Townsend Wash USA
QQ63 USDA Port Townsend Wash USA
Yellow Commercial Multi Organics company Bolivia
Red Commercial Multi Organics company Bolivia a WSU Washington State Univ
110
Table 2-Starch content and composition
Variety Total starch
(g 100 g)
Apparent amylose
()
Total
amylose ()
Degree of amylose
lipid complex ()
Black 532f 153a 159ab 96bc
Blanca 595de 102cd 163a 361ab
Cahuil 622d 169a 173a 34c
Cherry Vanilla
590de 105cd 116bc 164abc
Oro de Valle 573ef 114bcd 166a 300abc
49ALC 674c 27e 47d 426a
1ESP 705bc 86d 152abc 389ab
Copacabana 734ab 120bc 153abc 222abc
Col6197 725ab 102cd 140abc 433a
Japanese Strain
723ab 116bcd 165ab 305abc
QQ63 713abc 84d 111c 241abc
Yellow Commercial
751a 147ab 150abc 118abc
Red Commercial
691bc 100cd 164a 375ab
Corn starch - 264 - -
111
Table 3-Starch properties and α-amylase activity
Variety Amylose leaching (mg 100 g starch)
Water solubility ()
Swelling power
α-Amylase activity (CU)
Black 210ef 16de 260bcd 043d
Blanca 171efg 10de 260bcd 086c
Cahuil 97fg 16cde 253cd 106b
Cherry Vanilla 394d 15de 253cd 116a
Oro de Valle 420d 16de 245d 103b
49ALC 862a 07e 282a 031e
1ESP 716b 13de 276ab 003g
Copacabana 438cd 14de 263bc 020f
Col6197 552c 19cd 257cd 009g
Japanese Strain 31fg 45a 170f 005g
QQ63 315de 26bc 262bc 008g
Yellow Commercial
349d 32b 188e 005g
Red Commercial 35g 26bc 196e 003g
Corn starch - 79 89 -
112
Table 4-Texture of starch gel
Variety Hardness (g) Springiness Cohesiveness
Black 725ab 082ab 064cd
Blanca 649abc 083ab 072bc
Cahuil 900a 085ab 072bc
Cherry Vanilla 607abc 078bc 072bc
Oro de Valle 448abc 078bc 064cd
49ALC 333bc 081bc 061cd
1ESP 341bc 081bc 073bc
Copacabana 402bc 084ab 078ab
Col6197 534abc 083ab 083ab
Japanese Strain 765ab 092a 089a
QQ63 201c 078bc 053d
Yellow Commercial 436bc 071c 057d
Red Commercial 519abc 075bc 055d
Corn starch 721 084 073
113
Table 5-Thermal properties of starch
Variety Gelatinization temperature Enthalpy (Jg)
To (ordmC) Tp (ordmC) Tc (ordmC)
Black 560b 639bc 761bc 112abc
Blanca 586a 652ab 754bcd 113abc
Cahuil 582a 648ab 755bcd 116a
Cherry Vanilla 563b 627cd 747bcd 111abc
Oro de Valle 562b 623d 739cd 106abc
49ALC 524ef 598f 747bcd 101bc
1ESP 530de 608ef 738cd 103abc
Copacabana 565b 622d 731de 106abc
Col6197 540cd 598f 697f 105abc
Japanese Strain 579a 654a 788a 104abc
QQ63 545c 616de 766ab 99c
Yellow Commercial 515f 599f 708ef 107abc
Red Commercial 520ef 595f 700 f 116ab
Corn starch 560 626 743 105
114
Table 6-Pasting properties of starch
Variety Peak viscosity
(RVU)a
Trough
(RVU)
Breakdown
(RVU)
Final viscosity
(RVU)
Setback
(RVU)
Peak time
(min)
Black 293abc 252abc 41efg 363ab 111abcd 92e
Blanca 344a 301a 42defg 384ab 82de 111ab
Cahuil 342ab 297a 45def 405a 108abcd 106bc
Cherry Vanilla 313abc 263abc 50de 369ab 106abcd 99d
Oro de Valle 294abc 277ab 17fg 330abc 53e 105c
49ALC 256cde 137f 119a 225d 88cde 64i
1ESP 269bcd 172ef 97ab 313bc 140a 79h
Copacabana 258cde 186def 72bcd 308bc 122abc 81gh
Col6197 270bcd 231bcd 39efg 347ab 116abcd 86fg
Japanese Strain 193e 181def 12g 264cd 83de 113a
QQ63 213de 152f 60cde 254cd 101bcd 88ef
Yellow Commercial
290abc 223cde 67bcde 350ab 127ab 93de
Red Commercial 327abc 242bc 85bc 366ab 125ab 92ef
Corn 255 131 124 283 152 73 aRVU = cP12
115
Table 7-Correlation coefficients between starch properties and texture of cooked quinoaa
Hardness Adhesiveness Cohesiveness Gumminess Chewiness
Total starch content
-032ns -048 -043ns -039ns -039ns
Apparent amylose content
069 072 069 072 072
Actual amylose content
061 062 056 061 061
Degree of amylose-lipid complex
-065 -060 -070 -070 -070
Amylose leaching
-082 -075 -074 -082 -082
α-Amylase activity
018ns 055 051 032ns 032ns
Starch gel hardness
042ns 059 051 049 049
DSC
To 034ns 049 051 041ns 041ns
Tp 047 052 056 052 052
ΔH 064 072 069 070 070
RVA
Peak viscosity 031ns 054 047 041ns 041ns
Trough 044ns 077 063 055 055
Breakdown -034ns -060 -044ns -038ns -038ns
Final viscosity 045ns 068 058 053 053
Peak time 053 077 068 060 060
ns non-significant difference P lt 010 P lt 005 P lt 001 aTPA is the Texture Profile Analysis of cooked quinoa data were presented in Wu et al (2014)
116
Table 8-Correlations between starch properties and seed DSC RVA characteristicsa
Total
starch content
Water solubility
Apparent amylose content
Total amylose content
Degree of amylose-lipid complex
Amylose leaching
α-Amylase activity
Protein -047ns 023ns 058 031ns -069 -062 066
Seed hardness
-073 -041ns -003ns -021ns -020ns 019ns 053
Bulk density
054 049 -020ns -015ns 031ns 019ns -072
Seed coat proportion
-071 -041ns 027ns 021ns -028ns -038ns 055
Starch gel hardness
-045ns 017 ns 065 053 -044ns -064 046ns
Starch DSC
To -049 -004ns 041ns 043ns -033ns -049 061
Tp -050 010ns 047ns 045ns -042ns -058 052
Enthalpy -051 -011ns 059 055 -041ns -064 049
Starch viscosity
Peak viscosity
-066 -049 028ns 027ns -020ns -023ns 070
Trough -068 -017ns 056 057 -031ns -052 072
Breakdown
022ns -048 -061 -067 027ns 062 -025ns
Final viscosity
-060 -022ns 063 060 -037ns -046ns 061
Peak time -032ns 045ns 058 072 -029ns -081 043ns
117
Cooking quality
Optimal cooking time
-043ns 019ns 056 040ns -067 -055 029ns
ns non-significant difference P lt 010 P lt 005 P lt 001 aSeed characteristics data were presented in Wu et al (2014)
118
Chapter 5 Quinoa Seed Quality Response to Sodium Chloride and
Sodium Sulfate Salinity
Submitted to the Frontiers in Plant Science
Research Topic Protein crops Food and feed for the future
Abstract
Quinoa (Chenopodium quinoa Willd) is an Andean grain with an edible seed that both contains
high protein content and provides high quality protein with a balanced amino acid profile
Quinoa is a halophyte adapted to harsh environments with highly saline soil In this study four
quinoa varieties were grown under six salinity treatments and two levels of fertilization and then
evaluated for quinoa seed quality characteristics including protein content seed hardness and
seed density Concentrations of 8 16 and 32 dS m-1 of NaCl and Na2SO4 as well as a no-salt
control were applied to the soil medium across low (1 g N 029 g P 029 g K per pot) and high
(3 g N 085 g P 086 g K per pot) fertilizer treatments Seed protein content differed across soil
salinity treatments varieties and fertilization levels Protein content of quinoa grown under
salinized soil ranged from 130 to 167 comparable to that from normal conditions NaCl
and Na2SO4 exhibited different impacts on protein content Whereas the different concentrations
of NaCl did not show differential effects on protein content the seed from 32 dS m-1 Na2SO4
contained the highest protein content Seed hardness differed among varieties and was
moderately influenced by salinity level (P = 009) Seed density was affected significantly by
119
variety and Na2SO4 concentration but was unaffected by NaCl concentration The plants from 8
dS m-1 Na2SO4 soil had lower density (066 gcm3) than those from 16 dS m-1 and 32 dS m-1
Na2SO4 074 and 072gcm3 respectively This paper identifies changes in critical seed quality
traits of quinoa as influenced by soil salinity and fertility and offers insights into variety
response and choice across different abiotic stresses in the field environment
Key words quinoa soil salinity protein content hardness density
120
Introduction
Quinoa (Chenopodium quinoa Willd) has garnered much attention in recent years
because it is an excellent source of plant-based protein and is highly tolerance of soil salinity
Because soil salinity affects between 20 to 50 of irrigated arable land worldwide (Pitman and
Lauchli 2002) the question of how salinity affects seed quality in a halophytic crop like quinoa
needs to be addressed Protein content in most quinoa accessions has been reported to range from
12 to 17 depending on variety environment and inputs (Rojas et al 2015) This range
tends to be higher than the protein content of wheat barley and rice which were reported to be
105- 14 8-14 and 6-7 respectively (Shih 2006 Orth and Shellenberger1988 Cai et
al 2013) Additionally quinoa has a well-balanced complement of essential amino acids
Specifically quinoa is rich in lysine which is considered the first limiting essential amino acid in
cereals (Taylor and Parker 2002) Protein quality such as Protein Efficiency Ratio is similar to
that of casein (Ranhotra et al 1993) Furthermore with a lack of gluten protein quinoa can be
safely consumed by gluten sensitiveintolerant population (Zevallos et al 2014)
Quinoa shows exceptional adaption to harsh environments such as drought and salinity
(Gonzaacutelez et al 2015) Soil salinity reduces crop yields and is a worldwide problem In the
United States approximately 54 million acres of cropland in forty-eight States were occupied by
saline soils while another 762 million acres are at risk of becoming saline (USDA 2011) The
salinity issue leads producers to grow more salt-tolerant crops such as quinoa
Many studies have focused on quinoarsquos tolerance to soil salinity with a particular
emphasis on plant physiology (Ruiz-Carrasco et al 2011 Adolf et al 2012 Cocozza et al
121
2013 Shabala et al 2013) and agronomic characteristics such as germination rate plant height
and yield (Prado et al 2000 Chilo et al 2009 Peterson and Murphy 2015 Razzaghi et al
2012) For instance Razzaghi et al (2012) showed that the seed number per m2 and seed yield
did not decrease as salinity increased from 20 to 40 dS m-1 in the variety Titicaca Ruiz-Carrasco
et al (2011) reported that under 300 mM NaCl germination and shoot length were significantly
reduced whereas root length was inhibited in variety BO78 variety PRJ biomass was less
affected and exhibited the greatest increase in proline concentration Jacobsen et al (2000)
suggested that stomatal conductance leaf area and plant height were the characters in quinoa
most sensitive to salinity Wilson et al (2002) examined salinity stress of salt mixtures of
MgSO4 Na2SO4 NaCl and CaCl2 (3 ndash 19 dS m-1) No significant reduction in plant height and
fresh weight were observed In a comparison of the effects of NaCl and Na2SO4 on seed yield
quinoa exhibited greater tolerance to Na2SO4 than to NaCl (Peterson and Murphy 2015)
Few studies have focused on the influence of salinity on seed quality in quinoa Karyotis
et al (2003) conducted a field experiment in Greece (80 m above sea level latitude 397degN)
With the exception of Chilean variety lsquoNo 407rsquo seven other varieties exhibited significant
increases in protein (13 to 33) under saline-sodic soil with electrical conductivity (EC) of
65 dS m-1 Mineral contents of phosphorous iron copper and boron did not decrease under
saline conditions Koyro and Eisa (2008) found a significant increase in protein and a decrease in
total carbohydrates under high salinity (500 mM) Pulvento et al (2012) indicated that fiber and
saponin contents increased under saline conditions with well watersea water ratio of 11
compared to those under normal soil
122
Protein is one of the most important nutritional components of quinoa seed The content
and quality of protein contribute to the nutritional value of quinoa Additionally seed hardness is
an important trait in crops such as wheat and soybeans For instance kernel hardness highly
influences wheat end-use quality (Morris 2002) and correlates with other seed quality
parameters such as ash content semolina yield and flour protein content (Hruškovaacute and Švec
2009) Hardness of soybean influenced water absorption seed coat permeability cookability
and overall texture (Zhang et al 2008) Quinoa seed hardness was correlated with the texture of
cooked quinoa influencing hardness chewiness and gumminess and potentially consumer
experience (Wu et al 2014) Furthermore seed density is also a quality index and is negatively
correlated with the texture of cooked quinoa such as hardness cohesiveness chewiness and
gumminess (Wu et al 2014)
Chilean lowland varieties have been shown to be the most well-adapted to temperate
latitudes (Bertero 2003) and therefore they have been extensively utilized in quinoa breeding
programs in both Colorado State University and Washington State University (Peterson and
Murphy 2015) For these reasons Chilean lowland varieties were evaluated in the present study
The objectives of this study were to 1) examine the effect of soil salinity on the protein content
seed hardness and density of quinoa varieties 2) determine the effect of different levels of two
agronomically important soil salts NaCl and Na2SO4 on seed quality and 3) test the influence
of fertilization levels on salinity tolerance of quinoa The present study illustrates the different
influence of NaCl and Na2SO4 on quinoa seed quality and provides better guidance for variety
selection and agronomic planning in highly saline environments
Materials and Methods
123
Genetic material
Quinoa germplasms were obtained from Dr David Brenner at the USDA-ARS North
Central Regional Plant Introduction Station in Ames Iowa The four quinoa varieties CO407D
(PI 596293) UDEC-1 (PI 634923) Baer (PI 634918) and QQ065 (PI 614880) were originally
sourced from lowland Chile CO407D was released by Colorado State University in 1987
UDEC-1 Baer and QQ065 were varieties from northern central and southern locations in Chile
with latitudes of 3463deg S 3870deg S and 4250deg S respectively
Experimental design
A controlled environment greenhouse study was conducted using a split-split-plot
randomized complete block design with three replicates per treatment Factors included four
quinoa varieties two fertility levels and seven salinity treatments (three concentration levels
each of NaCl and Na2SO4) Three subsamples each representing a single plant were evaluated
for each treatment combination Quinoa variety was treated as the main plot salinity level as the
sub-plot and fertilization as the sub-sub-plot Salinity levels included 8 16 and 32 dS m-1 of
NaCl and Na2SO4 The details of controlling salinity levels were described by Peterson and
Murphy (2015) In brief fertilization was provided by a mixture of alfalfa meal
monoammonium phosphate and feather meal Low fertilization level referred to 1 g of N 029 g
of P and 029 g of K in each pot and high fertilization level referred to 3 g of N 086 g of P and
086 g of K in each pot Each pot contained about 1 L of Sunshine Mix 1 (Sun Gro Horticulture
Bellevue WA) (dry density of 100 gL water holding capacity of ca 480 gL potting mix) The
124
entire experiment was conducted twice with the planting dates of September 10th 2011 and
October 7th 2011
Seed quality tests
Protein content of quinoa was determined using the Dumas combustion nitrogen method
(LECO Corp Joseph Mich USA) (AACCI Method 46-3001) A factor of 625 was used to
convert nitrogen to protein Seed hardness was determined using the Texture Analyzer (TA-
XT2i) (Texture Technologies Corp Scarsdale NY) and a modified rice kernel hardness method
(Krishnamurthy and Giroux 2001) A single quinoa kernel was compressed until the point of
fracture using a 1 cm2 cylinder probe traveling at 5 mms Repeat measurements were taken on 9
random kernels The seed hardness was recorded as the average peak force (Kg) of the repeated
measures
Seed density was determined using a pycnometer (Pentapyc 5200e Quantachrome
Instruments Boynton Beach FL) Quinoa seed was placed in a closed micro container and
compressed nitrogen was suffused in the container Pressure in the container was recorded both
with and without nitrogen The volume of the quinoa sample was calculated by comparing the
standard pressure obtained with a stainless steel ball Density was the seed weight divided by the
displaced volume Seed density was collected on only the second greenhouse experiment
Statistical analysis
Data were analyzed using the PROC GLM procedure in SAS (SAS Institute Cary NC)
Greenhouse experiment repetition was treated as a random factor in protein content and seed
hardness analysis Variety salinity and fertilization were treated as fixed factors Fisherrsquos LSD
125
Test was used to access multiple comparisons Pearson correlation coefficients between protein
hardness and density were obtained via PROC CORR procedure in SAS using the treatment
means
Results
Protein
Variety salinity and fertilization all exhibited highly significant effects on protein
content (P lt 0001) (Table 1) The greatest contribution to variation in seed protein was due to
fertilization (F = 40247) In contrast salinity alone had a relatively minor effect and the
varieties responded similarly to salinity as evidenced by a non-significant interaction The
interactions however were found in variety x fertilization as well as in salinity x fertilization
both of which were addressed in later paragraphs It is worth noting that the two experiments
produced different seed protein contents (F = 4809 P lt0001) experiment x variety interaction
was observed (F = 1494 P lt0001) (data not shown) Upon closer examination this interaction
was caused by variety QQ065 which produced an overall mean protein content of 129 in
experiment 1 and 149 in experiment 2 Protein contents of the other three varieties were
essentially consistent across the two experiments
Across all salinity and fertilization treatments the variety protein means ranged from
130 to 167 (data not shown) As expected high fertilization resulted in an increase in
protein content across all varieties The mean protein contents under high and low fertilization
were 158 and 136 respectively (Table 2) The means of Baer and CO407D were the
126
highest 151 and 149 respectively QQ065 contained 141 protein significantly lower
than the other varieties
Even though salinity effects were relatively smaller than fertilization and variety effects
salinity still had a significant effect on protein content (Table 1) The two types of salt exhibited
different impacts on protein (Table 2) Protein content did not differ according to different
concentrations of NaCl with means (across varieties and fertilization levels) from 147 to
149 Seed from 32 dS m-1 Na2SO4 however contained higher protein (152) than that from
8 dS m-1 and 16 dS m-1 Na2SO4 (144 and 142 respectively)
A significant interaction of salinity x fertilization was detected indicating that salinity
differentially impacted seed protein content under high and low fertilization level (Figure 1)
Within the high fertilizer treatment protein content in the seed from 32dS m-1 Na2SO4 was
significantly higher (167) than all other samples which did not differ from each other (~13)
Within the low fertilizer treatment protein content of seeds from 8 dS m-1 and 16 dS m-1
Na2SO4 were significantly lower than those from the NaCl treatments and 32dS m-1 Na2SO4
The significant interaction between variety and fertilization (Table 1) was due to the
different response of QQ065 Protein mean of QQ065 from high fertilization was 144 lower
than the other varieties CO407D UDEC-1 and Baer exhibited a decline of 16 - 18 in
protein under low fertilization while QQ065 dropped only 5
Hardness
Variety exhibited the greatest influence on seed hardness (F = 21059 P lt0001)
whereas fertilization did not show any significant effect (Table 1) Salinity exhibited a moderate
127
effect (F = 200 P = 009) Varieties responded consistently to salinity under various fertilization
levels since neither variety x salinity nor salinity x fertilization interaction was significant
However a variety x fertilization interaction was observed which will be discussed in a later
paragraph Similar to the situation in protein content experiment repetition exhibited a
significant influence on seed hardness Whereas the hardness of CO407D was consistent across
the two greenhouse experiments the hardness of other three varieties all decreased by 8 to 9
Mean hardness was significantly different among varieties CO407D had the hardest
seeds with hardness mean of 100 kg (Table 3) UDEC-1 was softer at 94 kg whereas Baer and
QQ065 were the softest and with similar hardness means of 77 kg and 74 kg respectively
Salinity exhibited a moderate impact on seed hardness (P = 009) The highest hardness
mean was observed under 16 dS m-1 Na2SO4 whereas the lowest was under 8 dS m-1 NaCl with
means of 89 and 83 kg respectively
A significant fertilization x variety interaction was found for seed hardness The hardness
of UDEC-1 and Baer did not differ across fertilization level whereas CO407D was harder under
low fertilization and QQ065 was harder under high fertilization
Seed density
Variety and salinity both significantly affected seed density whereas fertilization did not
show a significant influence (Table 1) The greatest contribution to variation in seed density was
due to variety (F = 2282) Salinity exhibited a relatively smaller effect yet still significant (F =
282 P lt005) Neither variety x salinity interaction nor salinity x fertilization interaction was
observed which indicated that varieties similarly responded to salinity under high and low
128
fertilization levels An interaction of variety x fertilization was found and the details were
presented later
Across all salinity and fertilization treatments CO407D had the highest mean density
080 gcm3 followed by Baer with 069 gcm3 (Table 4) UDEC-1 and QQ065 had the lowest and
similar densities (~065 gcm3)
With regard to salinity effect the Na2SO4 treatments exhibited differential influence on
seed density Density means did not significantly change due to the increased concentration of
NaCl ranging from 068 to 071 gcm3 (Table 4) The samples from 8 dS m-1 Na2SO4 soil had
lower density (066 gcm3) than those from 16 dS m-1 and 32 dS m-1 Na2SO4 074 and
072gcm3 respectively
A significant variety x fertilization interaction was found With closer examination
UDEC-1 and Baer yielded higher density seeds under high fertilization whereas CO407D and
QQ065 did not differ in density between fertilization treatments
Correlations of protein hardness and density
Correlation coefficients among seed protein content hardness and density are shown in
Table 5 No significant correlation was detected between protein content and seed hardness
However both protein content and hardness were correlated with seed density The overall
correlation coefficient was low (r = 019 P = 003) between density and protein A marginally
significant correlation was found between density and protein content of the seeds from NaCl
salinized soil under low fertilization No correlation was found between density and protein
content of the seeds from NaCl salinized soil under high fertilization or Na2SO4 salinized soil
129
The overall correlation coefficient was 038 (P lt 00001) between density and hardness
The low fertilization samples from both NaCl and Na2SO4 soil showed significant correlations
between density and hardness with coefficients of 051 and 047 (both P lt 0005) The high
fertility quinoa did not exhibit any correlation between density and hardness
Correlation with yield leaf greenness index plant height and seed minerals contents
Correlation between seed quality and yield leaf greenness index plant height and seed
mineral concentration were obtained using data from Peterson and Murphy (2015) (Table 6)
Seed hardness significantly correlated with yield and plant height (r = 035 and 031
respectively) Protein content and density however did not correlate with yield leaf greenness
or plant height Correlations were found between quality indices and the concentration of
different minerals Protein was negatively correlated with Cu and Mg (r = -052 and -050
respectively) Hardness was negatively correlated with Cu P and Zn (r = -037 -056 -029
respectively) but was positively correlated with Mn (r = 057) Density was negatively
correlated with Cu (r = -035)
Discussion
Protein
Although salinity exhibited a significant effect on seed protein content the impact was
relatively minor compared to fertilization and variety effects In another words over a wide
range of saline soil quinoa can grow and yield seeds with stable protein content
130
Protein content of quinoa growing under salinized soil ranged from 127 to 167 (data
not shown) within the general range of protein content under non-saline conditions which was
12 to 17 (Rojas et al 2015) Saline soil did not cause a significant decrease in seed protein
It is interesting to notice that the samples from 32 dS m-1 Na2SO4 tended to contain the highest
protein especially in variety QQ065 The studies of Koyro and Eisa (2008) and Karyotis et al
(2003) also indicated that protein content significantly increased under high salinity (NaCl)
whereas total carbohydrates decreased In contrast Ruffino et al (2009) found that quinoa
protein decreased under 250 mM NaCl salinity in a growth chamber experiment It is reasonable
to conclude that salinity exhibits contrasting effects on different quinoa genotypes QQ065 and
CO407D both significantly increased in protein under 32 dS m-1 Na2SO4 however the yield
decline was 519 and 245 respectively (Peterson and Murphy 2015) This result indicted
that CO407D was the variety most optimally adapted to severe sodic saline soil tested in this
study
Na2SO4 level exhibited a significant influence on protein content whereas NaCl level did
not In the study of Koyro and Eisa (2008) however seed protein of the quinoa variety Hualhuas
(origin from Peru) increased under the highest salinity level of 500 mM NaCl compared to lower
NaCl levels (0 ndash 400 mM) This disagreement of NaCl influence may be due to diversity of
genotypes It is worth noting that quinoa protein contents in this paper were primarily above 13
based on wet weight (as-is-moisture of approximately ~8 -10) even under saline soil and low
fertilization level This protein content is generally equal to or higher than that of other crops
such as barley and rice (Wu 2015) In conclusion quinoa maintained high and stable protein
content under salinity stress
131
Hardness
Quinoa seed hardness was only moderately affected by salinity (P = 009) indicating that
quinoa primarily maintained seed texture when growing under a wide range of saline soil
CO407D exhibited the hardest seed (100 kg) whereas Baer and QQ065 were relatively soft (74
ndash 77 kg) A previous study indicated a hardness range of 58 ndash 109 kg among 11 quinoa
varieties and 2 commercial samples (Wu et al 2014) The commercial samples had hardness
values of 62 kg and 71 kg Since commercial samples generally maintain stable quality and
indicate an acceptable level for consumers seed hardness around 7 kg as in Baer and QQ065
should be considered as acceptable quality The hardness of CO407D was close to that of the
colored variety lsquoBlackrsquo (100 kg) which had a thicker seed coat than that of the yellow seeded
varieties It was reported that a thicker seed coat is related to harder texture (Fraczek et al 2005)
Even though the greenhouse is a highly controlled environment and the two experiments
were conducted in similar seasons (planted in September and October respectively) seed protein
and hardness were still different across the two experiments However ANOVA indicated
modest-to-no significant interactions with salinity and fertilization such that responses to salinity
and fertilization were consistent with little or no change in rank order Even though experiment x
variety was significant the F-values were relatively low compared to the major effects such as
variety and fertilization and neither of them was crossing interaction This is a particularly
noteworthy result for breeders farmers and processors
Density
132
The range of seed density under salinity 055 ndash 089 gcm3 was comparable to the
density range of 13 quinoa samples (058 ndash 076 gcm3 ) (Wu et al 2014) Generally CO407D
had higher seed density (071 ndash 089 gcm3) which indicated that seed density in this variety was
affected by salinity stress In contrast the density of QQ065 did not change according to salinity
type or concentration which indicated a stable quality under saline soil
Correlations
The correlation between seed hardness and density was only significant under low fertilization
but not under high fertilization The high fertilization level in the greenhouse experiment
exceeded the amount of fertilizer that would normally be applied in field environments whereas
the low fertilization level is closer to the field situation Therefore correlation between hardness
and density may still exist in field trials
Conclusions
Under saline soil conditions quinoa did not show any marked decrease in seed quality
such as protein content hardness and density Protein content even increased under high Na2SO4
concentration (32 dS m-1) Varieties exhibited great differential reactions to fertilization and
salinity levels QQ065 maintained a similar level of hardness and density whereas seed of
CO407D was both harder and higher density under salinity stress If only seed quality is
considered then QQ065 is the most well-adapted variety in this study
The influences of NaCl and Na2SO4 were different The higher concentration of Na2SO4
tended to increase protein content and seed density whereas NaCl concentration did not exhibit
any significant difference on those quality indexes
133
Acknowledgement
The research was funded by USDA Organic Research and Extension Initiative project
number NIFAGRANT11083982 The authors acknowledge Alecia Kiszonas for assisting in the
data analysis
Author contributions
Peterson AJ set up the experiment design in the greenhouse and grew harvested and
processed quinoa samples Wu G collected seed quality data such as protein content seed
hardness and density Peterson AJ and Wu G together processed the data Wu G also drafted the
manuscript Murphy KM and Morris CF edited the manuscript
Conflict of interest statement
The authors declared to have no conflict of interest
134
References
AACC International Approved Methods of Analysis Method 46-3001 Crude protein ndash
Combustion method Approved November 8 1995 Reapproved November 3 1999
Availablenline only AACCI St Paul MN
Adolf VI Shabala S Andersen MN Razzaghi F Jacobsen SE 2012 Varietal differences of
quinoas tolerance to saline conditions Plant Soil 357 117ndash29
Bertero HD 2003 Response of developmental processes to temperature and photoperiod in
quinoa (Chenopodium quinoa Willd) Food Rev Int 19 87ndash97
Cai S Yu G Chen X Huang Y Jiang X Zhang G Jin X 2013 Grain protein content variation
and its association analysis in barley BMC Plant Boil 13 35
Chilo G Molina MV Carabajal R Ochoa M 2009 Temperature and salinity effects on
germination and seedling growth on two varieties of Chenopodium quinoa Agri-Scientia 26
15ndash22
Cocozza C Pulvento C Lavini A Riccardi M dAndria R Tognetti R 2013 Effects of
increasing salinity stress and decreasing water availability on ecophysiological traits of
quinoa (Chenopodium quinoa Willd) grown in a mediterranean-type agroecosystem J Agron
Crop Sci 199 229ndash40
Fraczek J Hebda T Slipek Z Kurpaska S 2005 Effect of seed coat thickness on seed hardness
Can Biosyst Eng 47 41ndash5
135
Gonzaacutelez JA Eisa SSS Hussin SAES Prado FE 2015 Quinoa an Incan crop to face global
changes in agriculture In Murphy KM Matanguihan J editors Quinoa Improvement and
Sustainable Production Hoboken NJ John Wiley Sons p 7ndash11
Hruškovaacute M Švec I 2009 Wheat hardness in relation to other quality factors Czech J Food Sci
27 240ndash8
Jacobsen S Quispe H Mujica A 2000 Quinoa an alternative crop for saline soils in the Andes
in Scientist and Farmer Partners in Research for the 21st Century (Program Report 1999-
2000) ed International Potato Center (Peru) 403ndash8
Jancurovaacute M Minarovicovaacute L Dandar A 2009 Quinoandasha review Czech J Food Sci 27 71ndash9
Karyotis T Iliadis C Noulas C Mitsibonas T 2003 Preliminary research on seed production
and nutrient content for certain quinoa varieties in a salinendashsodic soil J Agron Crop Sci 189
402ndash8
Koyro HW Eisa S 2008 Effect of salinity on composition viability and germination of seeds of
Chenopodium quinoa Willd Plant Soil 302 79-90
Krishnamurthy K Giroux MJ 2001 Expression of wheat puroindoline genes in transgenic rice
enhances grain softness Nat Biotechnol 19 162ndash6
Morris CF 2002 Puroindolines the molecular genetic basis of wheat grain hardness Plant mol
Biol 48 633ndash47
136
Orth RA Shellenberger JA 1988 Chapter 1 Origin production and utilization of wheat In
Pomeranz Y editor Wheat Chemistry and Technology 3th edition St Paul MN American
Association of Cereal Chemists Inc p 11ndash2
Peterson A Murphy K 2015 Tolerance of lowland quinoa cultivars to sodium chloride and
sodium sulfate salinity Crop Sci 55 331ndash8
Pitman MG Laumluchli A 2002 Global impact of salinity and agricultural ecosystems In Laumluchli
A Luumlttge U editors Netherlands Springer p 3ndash20
Prado FE Boero C Gallardo M Gonzaacutelez JA 2000 Effect of NaCl on germination growth and
soluble sugar content in Chenopodium quinoa Willd seeds Bot Bull Acad Sinica 41 27ndash34
Pulvento C Riccardi M Lavini A Iafelice G Marconi E dAndria R 2012 Yield and quality
characteristics of quinoa grown in open field under different saline and non-saline irrigation
regimes J Agron Crop Sci 198 254ndash63
Ranhotra G Gelroth J Glaser B Lorenz K Johnson D 1993 Composition and protein
nutritional quality of quinoa Cereal Chem 70 303ndash5
Razzaghi F Ahmadi SH Jacobsen SE Jensen CR Andersen MN 2012 Effects of salinity and
soilndashdrying on radiation use efficiency water productivity and yield of quinoa (Chenopodium
quinoa Willd) J Agron Crop Sci 198 173ndash84
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile D
137
Bertero D Nieto C editors State of the Art Report of Quinoa in the World in 2013 Rome
FAO amp CIRAD p 67-8
Ruffino A Rosa M Hilal M Gonzaacutelez J Prado F 2010 The role of cotyledon metabolism in the
establishment of quinoa (Chenopodium quinoa)seedlings growing under salinity Plant Soil
326 213ndash24
Ruiz-Carrasco K Antognoni F Coulibaly A K Lizardi S Covarrubias A Martiacutenez E A
Shabala S Hariadi Y Jacobsen SE 2013 Genotypic difference in salinity tolerance in quinoa is
determined by differential control of xylem Na+ loading and stomatal density J Plant Physiol
170 906ndash14
Shih FF 2006 Chapter 6 Rice protein In Champagne ET editor Rice Chemistry and
Technology 3rd edition St Paul MN American Association of Cereal Chemists Inc p
143-4
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Taylor JRN Parker ML editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science amp Business Media p 96-101
USDA (United States Department of Agriculture) 2011 Soil and water resources conservation
act (RCA) P 31 Access from
httpwwwnrcsusdagovInternetFSE_DOCUMENTSstelprdb1044939pdf
Wilson C Read J Abo-Kassem E 2002 Effect of mixed-salt salinity on growth and ion
relations of a quinoa and a wheat variety J Plant Nutri 25 2689ndash704
138
Wu G Morris CF Murphy KM 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79 2337ndash45
Wu G 2015 Chapter 11 Nutritional properties of quinoa In Murphy KM Matanguihan J
editors Quinoa Improvement and Sustainable Production Hoboken NJ John Wiley amp
Sons Inc p 193-205
Zhang B Chen P Chen CY Wang D Shi A Hou A Ishibashi T 2008 Quantitative trait loci
mapping of seed hardness in soybean Crop Sci 48 1341ndash9
Zevallos VF Herencia LI Chang F Donnelly S Ellis HJ Ciclitira PJ 2014 Gastrointestinal
effects of eating quinoa (Chenopodium quinoa Willd) in celiac patients Am J Gastroenterol
109 270ndash8
Zurita-Silva A 2011 Variation in salinity tolerance of four lowland genotypes of quinoa
(Chenopodium quinoa Willd) as assessed by growth physiological traits and sodium
transporter gene expression Plant Physiol Bioch 49 1333ndash41
139
Table 1-Analysis of variance with F-values for protein content hardness and density of quinoa seed
Effect F-values
Protein Hardness Density
Model 524 360 245
Variety 2463 21059 2282
Salinity 975 200dagger 282
Fertilization 40247 107 260
Variety x Salinity 096 098 036
Variety x Fertilization 2062 1094 460
Salinity x Fertilization 339 139 071
Variety x Salinity x Fertilization 083 161dagger 155
dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the 001 probability level Significant at the lt0001 probability level
140
Table 2-Salinity variety and fertilization effects on quinoa seed protein content ()
Salinity Protein content ()
Variety Protein content ()
Fertilization Protein content ()
8 dS m-1 NaCl 147bc1 CO407D 149ab High 158a
16 dS m-1 NaCl 148ab UDEC-1 147b Low 136b
32 dS m-1 NaCl 149ab Baer 151a
8 dS m-1 Na2SO4 144cd QQ065 141c
16 dS m-1 Na2SO4 142d
32 dS m-1 Na2SO4 152a 1Different letters in a given column indicate significant differences (P lt 005)
141
Table 3-Salinity variety and fertilization effects on quinoa seed hardness (kg)
Salinity Hardness (kg)1 Variety Hardness (kg)
8 dS m-1 NaCl 83 CO407D 100a2
16 dS m-1 NaCl 87 UDEC-1 94b
32 dS m-1 NaCl 85 Baer 77c
8 dS m-1 Na2SO4 87 QQ065 74c
16 dS m-1 Na2SO4 89
32 dS m-1 Na2SO4 88 1Hardness was significant at the 009 probability level 2Different letters in a given column indicate significant differences (P lt 005)
142
Table 4-Salinity variety and fertilization effects on quinoa seed density (g cm3)
Salinity density (g cm3) Variety density (g cm3)
8 dS m-1 NaCl 069bc1 CO407D 080a
16 dS m-1 NaCl 068bc UDEC-1 066bc
32 dS m-1 NaCl 071abc Baer 069b
8 dS m-1 Na2SO4 066c QQ065 065c
16 dS m-1 Na2SO4 074a
32 dS m-1 Na2SO4 072ab 1Different letters in a given column indicate significant differences (P lt 005)
143
Table 5-Correlation coefficients of protein hardness and density of quinoa seed
Correlation All NaCl Na2SO4
High fertilization
Low fertilization
High fertilization
Low fertilization
Protein -Density 019 013ns 029dagger 026ns 019ns
Hardness - Density 038 027ns 051 022ns 047
ns Not significant dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the lt0001 probability level
144
Table 6-Correlation coefficients of quinoa seed quality and agronomic performance and seed mineral content
Protein Hardness Density
Yield 004 035 006
Plant Height -004 031 011
Cu -052 -037 -035
Mg -050 004 0
Mn -006 057 025dagger
P -001 -056 -015
Zn -004 -029 -028dagger
dagger Significant at the 010 probability level Significant at the lt005 probability level Significant at the 001 probability level Significant at the lt0001 probability level
145
Figure 1-Protein content () of quinoa in response to combined fertility and salinity treatments
146
Chapter 6 Lexicon development and consumer acceptance
of cooked quinoa
ABSTRACT
Quinoa is becoming increasingly popular with an expanding number of varieties being
commercially available In order to compare the sensory properties of these quinoa varieties a
common sensory lexicon needs to be developed Thus the objective of this study was to develop
a lexicon of cooked quinoa and examine consumer acceptance of various varieties A trained
panel (n = 9) developed appropriate aroma tasteflavor texture and color descriptors to describe
cooked quinoa and evaluated 21 quinoa varieties Additionally texture of the cooked quinoa was
determined using a texture analyzer Results indicated panelists using this developed lexicon
could distinguish among these quinoa varieties showing significant differences in aromas
tasteflavors and textures Specifically quinoa variety effects were observed for the aromas of
caramel nutty buttery grassy earthy and woody tasteflavor of sweet bitter grain-like nutty
earthy and toasty and texture of firm cohesive pasty adhesive crunchy chewy astringent and
moist The varieties lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Drsquo exhibited adhesive texture that has not
been seen in any commercialized quinoa Subsequent consumer evaluation (n = 102) on 6
selected samples found that the lsquoPeruvian Redrsquo was the most accepted overall while the least
accepted was lsquoQQ74rsquo Partial least squares analysis on the consumer and trained panel data
indicated that overall consumer liking was driven by higher intensities of grassy aroma and firm
and crunchy texture The attributes of pasty moist and adhesive were less accepted by
consumers This overall liking was highly correlated with consumer liking of texture (r = 096)
147
tasteflavor (r = 095) and appearance (r = 091) of cooked quinoa From the present study the
quinoa lexicon and key drivers of consumer acceptance can be utilized in the industry to evaluate
quinoa product quality and processing procedures
Keywords quinoa lexicon sensory evaluation
Practical application The lexicon of cooked quinoa can be used by breeders to screen quinoa
varieties Furthermore the lexicon will useful in the food industry to evaluate quinoa ingredients
from multiple farms harvest years processing procedures and product development
148
Introduction
Quinoa is classified as a pseudocereal like amaranth and buckwheat With its high
protein content and balanced essential amino acid profile quinoa is becoming popular
worldwide From 1992 to 2012 quinoa exports increased dramatically from 600 tons to 37000
tons (Furche et al 2015) Quinoa price in retail stores increased from $9kg in 2013 to $13kg -
$20kg in 2015 (Arco 2015) Quinoa has been incorporated into numerous products including
bread cookies pasta cakes and chocolates (Pop et al 2014 Alencar et al 2015 Casas Moreno
et al 2015 Wang et al 2015) Some of these products are gluten-free foods thus targeting the
gluten-sensitive market segment (Wang et al 2015)
Popularity of quinoa inspired US researchers to breed varieties that are compatible with
local weather and soil conditions which greatly differ from quinoarsquos original land the Andean
mountain region Since 2010 Washington State University has been breeding quinoa in the
Pacific Northwest region of United States Of the quinoa varieties evaluated in the breeding
program agronomic attributes of interest include high yield consistent performance over years
and tolerance to drought salinity heat and diseases (Peterson and Murphy 2013 Peterson
2013) However beyond agronomic attributes the grain sensory profiles of these quinoa
varieties are also important to assist in breeding decisions as well as screening
genotypescultivars for various food applications
In order to provide a complete descriptive profile of the cooked quinoa a trained sensory
evaluation should be used along with a complete lexicon of the sensory attributes of importance
Currently no quinoa lexicon is available and descriptions of quinoa sensory properties are
149
limited From currently published research papers attributes describing quinoa taste have been
limited to bitter sweet earthy and nutty (Koziol 1991 Lorenz and Coulter 1991 Repo-Carrasco
et al 2003 Stikic et al 2012 Foumlste M et al 2014) and texture of cooked quinoa has been
described as creamy smooth and crunchy (Abugoch 2009) Thus to address the lack of quinoa
lexicon one objective of this study is to develop a lexicon describing the sensory properties of
quinoa
Beyond developing a lexicon to describe quinoa consumer preference of the different
quinoa varieties is also of great interest Most previous sensory studies in quinoa focused on
acceptance of quinoa-containing products while consumer acceptance on plain grain of quinoa
varieties has not been studied Because of the lack of cooked quinoa studies with consumers rice
may be considered as a model to study quinoa because of their similar cooking process Tomlins
et al (2005) found consumer preference of rice was driven by the attributes of uniform clean
bright translucent and cream with consumers not liking the brown color of cooked rice and
unshelled paddy in raw rice In another study Suwannaporn et al (2008) found consumer
acceptance of rice products was significantly influenced by convenience grain variety and
traditionnaturalness
This study presenting a quinoa lexicon along with consumer acceptance of quinoa
varieties provides critical information for both the breeding programs and food industry
researchers Given the predicted importance of texture in consumer acceptance of quinoa texture
analysis was conducted to evaluate the parameters of hardness adhesiveness cohesiveness
chewiness and gumminess in quinoa samples
150
This lexicon describing the sensory attributes of cooked quinoa will be a useful tool to
evaluate quinoa varieties compare samples from different farms harvest years seed quality and
cleaning processing procedures Finally the sensory attributes driving consumersrsquo liking can be
utilized to evaluate optimal quinoa quality and target different consumers based on preference
Materials and methods
Quinoa samples
The present study included twenty-one quinoa samples harvested in 2014 which included
sixteen varieties from Finnriver Organic Farm (Finnriver WA) and five commercial samples
from Bolivia and Peru (Table 1)
Quinoa preparation
Following harvest the samples from Finnriver Farm were cleaned in a Clipper Office
Tester (Seedburo Des Plainies IL USA) to separate mixed weed seeds and threshed materials
Furthermore the samples were soaked for 30 min rubbed manually under running water and
dried at 43 ordmC until the moisture reached lt 11 Generally a moisture of 12 - 14 is
considered safe for grain storage (Hoseney 1989)
To prepare quinoa samples for sensory evaluation samples were soaked for 30 min and
mixed with water at a 12 ratio These mixtures were brought to a boil and simmered for 20 min
Following cooking the quinoa was cooled to room temperature Samples of cooked quinoa (10
g) were served in 30 mL plastic containers with lids (SOLO Lakeforest IL USA) Quinoa
151
samples were cooked and placed in covered cups within 2 h before evaluation Unsalted
crackers plastic cups used as cuspidors and napkins were provided to each panelist
Trained sensory evaluation panel
This project was approved by the Institutional Review Board of Washington State
University Sensory panelists (n = 9) were recruited via email announcements Panelists were
selected based on their interest in quinoa and availability All participants signed the Informed
Consent Form They received non-monetary incentives for each training session and a large non-
monetary reward at the completion of the formal evaluation
Demographic information was collected using a questionnaire Panelists included 4
females and 5 males ranging in age from 21 to 60 (mean age of 35) Regarding quinoa
consumption frequency four panelists frequently consumed quinoa (few times per month to
everyday) whereas five panelists rarely consumed quinoa As quinoa is a novel crop to most of
the world this was expected Since rice is a comparable model of quinoa frequency of rice
consumption was also considered with all panelists being frequent rice consumers
Sensory training and lexicon development
The training consisted of 12 sessions of 15 hours totaling 18 hours In the early stages
of the panel training attribute terms and references were discussed Panelists were first presented
with samples in covered plastic containers The samples widely varied in their sensory attributes
and included the varieties of lsquoBlackrsquo lsquoBolivian Redrsquo and lsquoBolivian Whitersquo The panelists
developed terms to describe the appearance aroma flavor taste and texture of the samples
Additionally the same samples were evaluated by an experienced sensory evaluation panel with
152
terms collected from this set of evaluators Terms were collected from panelists professionals
and literature describing rice (Meilgaard et al 2007 Limpawattana and Shewfelt 2010) The
term list was presented and discussed with panelist consensus being used to determine which
sensory terms appeared in the final lexicon
The final lexicon and associated definitions are presented in Table 2 This lexicon
included the sensory attributes of color (black red yellow) aroma (caramel grain-like bean-
like nutty buttery starchy grassygreen earthymusty woody) tasteflavor (sweet bitter grain-
like bean-like nutty earthy and toasted) and texture (soft-firm separate-cohesive pasty
adhesivenesssticky crunchycrumblycrisp chewygummy astringent and waterymoist)
References standards for each attribute were introduced The references were discussed and
modified until the panelists were in agreement Panelists reviewed the reference standards at the
beginning of each training session Since aroma varies over time all aroma references were
prepared 1-2 h before training During training three to four quinoa samples were evaluated and
discussed in each session The ability to detect attribute differences and the reproducibility of
panelists were both monitored and visualized using spider graphs and line graphs Using this
feedback panelists were calibrated paying extra attention to those attributes that were outside of
the panel standard deviation Practice sessions were continued until the panelists accurately and
consistently assessed varietal differences of quinoa
The protocols applied to evaluate samples and references were consistent among
panelists At the start of the evaluation the sample cup was shaken to allow the aroma to
accumulate in the headspace Panelists then lifted the cover and immediately took three short
sharp sniffs to evaluate the aroma Panelists then determined the color and its intensity Finally
153
panelists used the spoon to place the sample in-mouth and evaluate the tasteflavor and texture
Between each sample panelists rinsed their palate using water and unsalted crackers A 15-cm
line scale with 15-cm indentations on each end was used to determine the intensity of attributes
The values of 15 and 135 represented the extremely low and high intensity respectively Using
the lexicon panelists were trained to sense and quantify the attributes of cooked quinoa on
aroma color tasteflavor and texture
Following the development of the lexicon formal evaluations were conducted in the
sensory booths under white lights Compusensereg Five (Guelph Ontario Canada) provided scales
and programs for evaluation and collected results Panelists followed the protocol and used the
lexicon and 15-cm scales to evaluate the sensory attributes of the cooked quinoa samples
Twenty-one quinoa samples were tested in duplicate Panelists attended one session per day and
four sessions in total During each session panelists evaluated 10 or 11 samples with a 30 s
break after each sample and a 10 min break after the fifth sample Each variety was assigned
with a random three-digit code and the serving order was randomized
Consumer acceptance panel
From the 21 samples evaluated by the trained panelists six were selected for consumer
evaluation These six samples selected were diverse in color tasteflavor and texture as defined
by the trained panel results Consumers (n = 102) were recruited from Pullman WA Of the
consumers 49 were male and 52 were female with age ranging from 19 to 64 (mean age of 33)
The consumers showed different familiarity with quinoa with 29 indicating that they were
154
familiar with quinoa 40 having tried quinoa a few times and 32 having never tried quinoa
before All consumers had consumed rice before
The project was approved by the Institutional Review Board of Washington State
University Each consumer signed an Informed Consent Form and received a non-monetary
incentive at the end of evaluation The evaluation was conducted in the sensory booths under
white light Six quinoa samples were assigned with three-digit code and randomly presented to
each consumer using monadic presentation Quinoa samples were cooked and distributed in
evaluation cups and lidded (~10 gcup) the day before stored at 4 degC overnight and placed at
room temperature (25 degC) for 1 h prior to evaluation
During evaluation consumers followed the protocol instructions and indicated the degree
of acceptance of aroma color appearance tasteflavor texture and overall liking using a 7-point
hedonic scale (1 = dislike extremely 7 = like extremely) provided by Compusensereg Five
(Guelph Ontario Canada) A comments section was provided at the end of each sample
evaluation to gather additional opinions and information Between samples panelists took a 30 s
break and cleansed their palates using unsalted crackers and water
Texture Profile Analysis by instrument (TPA)
The texture of 21 cooked quinoa samples were conducted using a TA-XT2i Texture
Analyzer (Texture Technologies Corp Hamilton MA USA) (Wu et al 2014) Samples were
cooked using the same procedure as in the trained panel evaluation and cooled to room
temperature prior to evaluation
Statistical analysis
155
Sample characteristics and trained panel results were analyzed using three-way ANOVA
and mean separation (Fisherrsquos LSD) PCA was performed on the trained panel data Using
trained panel data and consumer evaluation data partial least square regression analysis was
performed Additionally correlations between instrument tests and panel evaluation on texture
and tasteflavor were determined XLSTAT 2013 (Addinsoft Paris France) was used for all data
analysis
Results and Discussion
Lexicon Development
A lexicon was created to describe the sensory attributes of cooked quinoa (Table 2) A
total of 27 attributes were included in the lexicon based on color (black red yellow) aroma
(caramel grain-like bean-like nutty buttery starchy grassygreen earthymusty and woody)
tasteflavor (sweet bitter grain-like bean-like nutty earthy and toasted) and texture (firm
cohesive pasty adhesivenesssticky crunchy chewygummy astringent and waterymoist)
Rice is considered as a good model of quinoa lexicon developments since both products
have common preparation methods The lexicon for cooked rice has been developed for the
aroma tasteflavor and texture properties of rice (Lyon et al 1999 Meullenet et al 2000
Limpawattana and Shewfelt 2010) Many attributes from these previously developed rice
lexicons can be applied to cooked quinoa For instance rice aroma and flavor notes such as
starchy woody grain nutty buttery earthy sweet bitter and astringent are also present in
quinoa Hence those notes were also included in the lexicon of cooked quinoa in present study
with quinoa varieties showing differences in these attributes
156
This present lexicon presents some sensory attributes not found to be significantly
different among the quinoa varieties These attributes include grain-like bean-like and starchy
aroma bean-like flavor and chewy texture Even though the trained panel did not detect
differences in this study future studies may find differences among other quinoa varieties for
these attributes so they were kept in the lexicon For instance the flavoraroma notes of
lsquorancidoxidizedrsquo lsquosourrsquo lsquometallicrsquo may also be present in other quinoa varieties or have these
attributes develop during storage as has been shown in rice (Meullenet et al 2000)
The lexicon also expanded the vocabularies to describe quinoa This lexicon is a
valuable tool with multiple practical applications such as describing and screening quinoa
varieties in breeding and evaluating post-harvest process and cooking methods
Lexicon Application Evaluation of the 21 quinoa samples
The effects of panelist replicate and quinoa variety on aroma tasteflavor and texture of
cooked quinoa were evaluated (n = 9) (Table 3) The quinoa variety exhibited significant
influences on most attributes listed in the lexicon (P lt 005) except for grain-like bean-like and
starchy aroma and bean-like flavor Generally quinoa variety effects were greater in the
perceived texture of cooked quinoa than in the aroma and flavor attributes however bitterness
was also highly significant among varieties Although panelists were trained over 18 h and
references were used for calibration significant panelist effects were still observed Based on the
inherent variation of human subjects such panelist effects commonly occur in sensory evaluation
of a complex product (Muntildeoz 2003) In future studies increased training and practice to further
clarify attribute definitions may reduce panelist effects (Muntildeoz 2003)
157
Examining the details of aroma attributes quinoa variety effect significantly influenced
the aroma attributes of caramel nutty buttery grassy earthy and woody (Figure 1) Principal
Components Analysis (PCA) was performed in order to visualize differences among the
varieties For aroma the first two components described 669 of the variation among quinoa
samples PC1 was primarily defined by the grassy and woody aromas while PC2 was primarily
described by more starchy and grain-like aromas The proximity of the attributes to a specific
quinoa sample reflected its degree of association For instance lsquoCalifornia Tricolorrsquo was most
commonly described by earthy woody grassy bean-like and nutty aroma lsquoTemukorsquo exhibited
sweet and grain-like aroma Yellowwhite quinoa such as lsquoTiticacarsquo lsquoRed Headrsquo lsquoQuF9P39-51rsquo
and lsquoPeruvian Whitersquo showed significantly more nutty (6) aroma compared to brown and red
quinoa varieties (48 ndash 51) (Table 1S) lsquoBlackrsquo lsquoCahuilrsquo and lsquoPeruvian Redrsquo exhibited more
grassy aroma (47 ndash 49) compared to lsquoTiticacarsquo lsquoLinaresrsquo and lsquoNL-6rsquo (38 ndash 39) lsquoBlackrsquo
showed the most earthy aroma (54) among all varieties
PCA was also performed to show how the varieties differed in their flavortaste
properties (Figure 2) The first two components described 646 of the varietal differences The
lsquoBlackrsquo variety was found to have more bitter and earthy flavors lsquoPeruvian Whitersquo was most
commonly described by sweet and nutty flavor and lack of earthy flavors lsquoTemukorsquo was mostly
defined by its bitter taste and lack of sweetness nutty grain-like and toasty flavors Overall
sweet and bitter taste and grain-like nutty earthy and toasty flavor exhibited significant
difference among quinoa varieties (plt005) The lsquoQuF9P39-51rsquo lsquoKaslaearsquo lsquoBolivian Whitersquo
and lsquoPeruvian Whitersquo were assigned the highest values in sweet taste (46 ndash 47) significantly
sweeter than lsquoBlackrsquo lsquoCherry Vanillarsquo lsquoTemukorsquo lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCalifornia Tricolorrsquo
158
(36 ndash 40)(Table 4) lsquoTemukorsquo and lsquoCherry Vanillarsquo were the most bitter samples (56 and 52
respectively) It is worth noting that the commercial samples were assigned the lowest bitterness
scores ranging from 22 ndash 27 significantly lower than the field trial varieties (34 ndash 56) Similar
to earthy aroma lsquoBlackrsquo also exhibited the earthiest flavor (52) Additionally lsquoCahuilrsquo and
lsquoCalifornia Tricolorrsquo showed high scores in earthy flavor (both 48) Toasty flavor varied from
38 in lsquoLinaresrsquo and lsquoQuF9P1-20rsquo to 51 in lsquoCahuilrsquo
Quinoa bitterness is caused by saponin compounds present on the seed coat It has been
reported that saponin can be removed by abrasion pearling and rinsing (Taylor and Parker
2002) However in the present study despite two cleaning process steps (airscreen and rinsing)
there was still bitter flavor remained Besides processing genetic background can also affect
saponin content Some sweet quinoa varieties (lsquoSajamarsquo lsquoKurmirsquo lsquoAynoqrsquoarsquo lsquoKrsquoosuntildearsquo and
lsquoBlanquitarsquo in Bolivia and lsquoBlancade Juninrsquo in Peru) have been developed with total seed
saponin content lower than 110 mg100 g (Quiroga et al 2015) However these varieties are not
adapted to the growing conditions in the Pacific Northwest (Peterson and Murphy 2015) The
quinoa varieties in WSU breeding program are primarily from Chilean lowland and those
varieties are more highly adapted to temperate areas In this case sweet quinoa varieties from
Bolivia and Peru were not included in this study However in 2015 a saponin-free quinoa
variety lsquoJessiersquo was grown in different locations of Washington State with a comparable yield
to bitter varieties The sensory evaluation of this new variety lsquoJessiersquo would be meaningful
Earthy which may be referred to as moldy and musty is caused by geosmin (a bicyclic
alcohol with formula C12H22O) which produced by actinobacteria (Gerber 1968) Samples with a
dark color (lsquoBlackrsquo lsquoCalifornia Tricolorrsquo and lsquoCahuilrsquo) tended to exhibit more earthy aroma and
159
flavor Possibly the pericarpseed coat composition of dark quinoa favors the actinobacteria-
producing geosmin
Overall texture attributes of cooked quinoa exhibited greater differences in values
(Figure 3) Among commercial quinoa varieties the red quinoa was firmer more gummy and
more chewy in texture compared to the yellowwhite commercial quinoa Several WSU field trial
varieties (lsquoQQ74rsquo lsquoLinaresrsquo and CO407D) exhibited greater variation in adhesiveness The first
two PCA factors explained 817 of the variation among samples lsquoPeruvian Redrsquo was most
accurately described by firm and crunchy texture and a lack of pasty sticky and cohesive
texture In contrast lsquoLinaresrsquo lsquoCO407Daversquo and lsquoQQ74rsquo were mostly described as pasty sticky
and cohesive yet lacking in firmness and crunchiness Mixed color or red color samples
(lsquoPeruvian Redrsquo lsquoBlackrsquo lsquoCahuilrsquo and lsquoCalifornia Tricolorrsquo) tended to be both firmer and
crunchier compared to the samples with light color However some yellow samples such as
lsquoTiticacarsquo and lsquoKU-2rsquo also had hard texture The varieties lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Daversquo
had the softest texture and also exhibited the least crunchy but the most pasty sticky and moist
texture Additionally compared to field trial varieties commercial samples tended to be lower in
intensity for the attributes of cohesiveness pastiness adhesiveness and astringency Moreover
astringent is the dry and puckering mouth feeling which is caused by the combination of tannins
and salivary proteins The differences found in this study among quinoa varieties may be caused
by processing protocols (removal of tannins to various degrees) or diverse genetic backgrounds
Consumer acceptance
160
Consumers evaluated six selected quinoa samples including the field trial varieties of
lsquoBlackrsquo lsquoTiticacarsquo lsquoQQ74rsquo and the commercial samples of lsquoPeruvian Redrsquo lsquoBolivian Redrsquo and
lsquoBolivian Whitersquo The selected samples were diverse in color texture and included both WSU
field trial varieties and commercial quinoa Among the field trial varieties the lsquoBlackrsquo variety
exhibited more grassy aroma earthy flavor and chewy texture lsquoTiticacarsquo had more caramel
aroma and lsquoQQ74rsquo was more adhesive than the other samples
The quinoa varieties varied significantly in consumer acceptance of color appearance
taste flavor texture and overall acceptance (P lt 0001) (Table 5) Overall lsquoPeruvian Redrsquo was
more accepted by consumers compared to lsquoTiticacarsquo and lsquoQQ74rsquo lsquoBlackrsquo received a similar
level of acceptance with all the commercial samples and the acceptance of lsquoTiticacarsquo did not
differ from lsquoBolivian Redrsquo and lsquoBolivian Whitersquo In aroma acceptance no significant difference
was found among the varieties In color lsquoPeruvian Redrsquo and lsquoBolivian Redrsquo received
significantly higher scores In appearance lsquoPeruvian Redrsquo was rated higher than all other
varieties except lsquoBolivian Redrsquo while lsquoQQ74rsquo gained the lowest rate Additionally lsquoQQ74rsquo was
less accepted in tasteflavor than all commercial samples but did not differ from other field trial
varieties lsquoBlackrsquo and lsquoTiticacarsquo Furthermore the texture of lsquoQQ74rsquo was the least accepted and
other varieties did not show any significant differences
However low acceptance in adhesive texture of cooked quinoa does not indicate the
adhesive quinoa varieties will not have market potential Adhesiveness in cooked rice is
correlated with high amylopectin and low amylose (Mossman et al 1983 Sowbhagya et al
1987) Hence adhesive quinoa may also contain low amylose Additionally previous studies
found waxy cereal or starch (0 amylose and 100 amylopectin) exhibited excellent
161
performance in extrusion Kowalski et al (2014) found that waxy wheat extrudates exhibited
nearly twice the expansion ratio as that of normal wheat Koumlksel et al (2004) found hulless waxy
barley to be promising for extrusion using low shear screw configuration Van Soest et al (1996)
reported high elongation (500) in extruded maize starch Consequently the adhesive quinoa
varieties have great potential to apply in extruded or other puffed foods
Consumer preference of the sensory attributes was analyzed using Partial Least Square
Regression (PLS) (Figure 4) The attributes presented by lsquoPeruvian Redrsquo including lsquograssyrsquo
aroma lsquograinyrsquo flavors and lsquofirmrsquo and lsquocrunchyrsquo textures were preferred among consumers The
less preferred attributes included lsquopastyrsquo lsquowaterymoistrsquo lsquoadhesiversquo and lsquocohesiversquo all attributes
used to describe the lsquoQQ74rsquo variety Overall acceptance was driven by crunchy texture (r =
090) but negatively correlated with lsquocohesiversquo lsquopastyrsquo and lsquoadhesiversquo texture (r = -096 -087
and -089 respectively) Specifically aroma acceptance of cooked quinoa was negatively
correlated with lsquowoodyrsquo (r = -083) Texture acceptance was positively correlated with lsquofirmrsquo(r =
084) and lsquocrunchyrsquo (r = 094) but was negatively correlated with lsquocohesiversquo (r = -096) lsquopastyrsquo
(r = -095) lsquoadhesiversquo (r = -096) and lsquomoistrsquo (r = -085) Even though lsquoearthyrsquo is a common
attribute in foods such as mushroom and beets this study on quinoa indicated that earthy aroma
and flavor were not the attributes driving consumersrsquo liking of cooked quinoa Color and
appearance did not exhibit significant correlation with color intensity of cooked quinoa
however the varieties with red or dark colors (lsquoPeruvian Redrsquo lsquoBolivian Redrsquo and lsquoBlackrsquo)
were more highly accepted by consumers compared to samples with light color (lsquoTiticacarsquo
lsquoBolivian Whitersquo lsquoQQ74rsquo) In sum consumers preferred cooked quinoa with grassy aroma firm
and crunchy texture and lack of woody aroma and low cohesive pasty or adhesive texture
162
The variety lsquoBlackrsquo was accepted at a similar level as commercial samples in aroma
tasteflavor texture and overall evaluation With a closer examination of the consumer
demographic consumers who were more familiar with quinoa rated the lsquoBlackrsquo quinoa variety
with higher scores (average of 7) compared to those panelists less familiar with quinoa who
assigned lower average scores (59) (Figure 1S) This tricolor quinoa (browndark mixture) is not
as common as red and yellowwhite quinoa in the US market However the potential of tricolor
quinoa may be great due to the relative high consumer acceptance as well as high gain yield in
the field
Instrumental Texture Profile Analysis (TPA)
The physical properties of cooked quinoa were determined using the texture analyzer
(Table 6) Samples differed in all six texture parameters lsquoNL-6rsquo lsquoPeruvian Redrsquo lsquoBolivian Redrsquo
and lsquoCalifornia Tricolorrsquo exhibited the hardest texture while lsquoTemukorsquo lsquoQQ74rsquo lsquoIslugarsquo
lsquoLinaresrsquo and lsquoCO407Daversquo displayed the lowest hardness values Consistent with trained panel
evaluation lsquoQQ74rsquo lsquoLinaresrsquo and lsquoCO407Daversquo were more adhesive than all other varieties
lsquoTiticacarsquo was the springiest variety while lsquoKaslaearsquo and lsquoQuF9P1-20rsquo were the least springy
varieties The commercial samples with the exception of lsquoPeruvian Whitersquo exhibited a more
gummy texture lsquoTiticacarsquo and lsquoBolivian Whitersquo were the chewiest samples In contrast varieties
of lsquoTemukorsquo lsquoQQ74rsquo lsquoIslugarsquo lsquoLinaresrsquo lsquoQuF9P1-20rsquo and lsquoCO407Daversquo showed the least
gummy and chewy texture The result was comparable to an earlier study (Wu et al 2014)
Similarly quinoa varieties with darker color (orangeredbrowndark) tended to yield harder
texture compared to the varieties with light color (whiteyellow) which is caused by the thicker
seed coat in dark colored quinoa In this study adhesive quinoa varieties lsquoQQ74rsquo lsquoLinaresrsquo and
163
lsquoCO407Daversquo were found to have higher adhesiveness values (-17 kgs to -13 kgs) compared
to other varieties previously reported (-029 kgs to 0) (Wu et al 2014)
Correlations of instrumental tests and trained panel evaluations of texture were
significant for hardness and adhesiveness (r = 070 and -063 respectively) (Table 7) Since
adhesiveness was calculated from the first negative peak area of the TPA graph a negative
correlation coefficient was observed but still indicating a high level of agreement between
instrumental and panel tests Springiness tested by TPA was not correlated with texture
attributes
Cohesiveness from the instrumental test was negatively correlated with cohesiveness
from the trained panel texture evaluation (r = -066) Instrumental cohesiveness also exhibited
positive correlations with the trained panel evaluation of firmness and crunchiness (r = 080 and
076 respectively) and negative correlations with pastiness adhesiveness moistness (r = -072
-075 and -082 respectively) Upon a closer examination of the definitions in the instrumental
test cohesiveness was defined as lsquohow well the product withstands a second deformation relative
to its resistance under the first deformationrsquo and is calculated as the ratio of second peak area to
first peak area (Wiles et al 2004) In the sensory lexicon cohesiveness was defined as lsquodegree
to which a substance is compressed between the teeth before it breaksrsquo (Szczesniak 2002) These
differential definitions or explanations of these attributes may have caused the different results
Additionally the gumminess and chewiness from the instrumental evaluation were not
significantly correlated with their counterpart notes from the trained panel evaluations but
correlated with other sensory attributes evaluated by the trained panel Instrumental gumminess
164
was positively correlated with firm and crunchy textures(r = 079 and 078 respectively) but
negatively correlated with cohesive pasty adhesive and moist (r = -067 -068 -075 and -
078 respectively) Additionally a positive correlation was found between instrumental
chewiness and firmness from the panel evaluation (r = 057) whereas negative correlations were
found between instrumental chewiness and panel evaluated cohesiveness pastiness
adhesiveness and moistness (r = -043 -045 -055 and -052 respectively) In the instrumental
texture profile gumminess is calculated by hardness multiplied by cohesiveness and chewiness
is calculated by gumminess multiplied by springiness (Epstein et al 2002) Hence gumminess
was significantly correlated with hardness and cohesiveness and chewiness was significantly
correlated with gumminess In another study of Lyon et al (2000) pasty and adhesive were
expressed as lsquoinitial starchy coatingrsquo and lsquoself-adhesivenessrsquo respectively in cooked rice and
were both negatively correlated with instrumental hardness Generally the instrument test is
more accurate and stable but the parameter or sensory attributes were relatively limited Sensory
panels are able to use various vocabularies to describe the food however accuracy and precision
of panel evaluations were lower than for the instrument Consequently both tools can be
important in sensory evaluation depending on the objectives and resources availability
Future Studies
A lexicon of cooked quinoa was firstly developed in this paper Further discussion and
improvement of the lexicon are necessary and require cooperation with industry and chefs The
lexicon is not only useful in categorizing varieties but also can be used to evaluate post-harvest
practice cooking protocols and other quinoa foodsdishes Additionally quinoa seed quality
varies among years and locations and sensory properties also change over different
165
environments To validate the sensory profile of varieties especially adhesiveness evaluation
should be repeated on the samples from other years and locations Finally multiple dishes food
types should be included in future consumer evaluation studies to identify the best application of
different varieties
Conclusion
A lexicon of cooked quinoa was developed based on aroma tastefavor texture and
color Using the lexicon the trained panel conducted descriptive analysis evaluation on 16
quinoa varieties from field trials and 5 commercial samples Many sensory attributes exhibited
significant differences among quinoa samples especially texture attributes
Consumer evaluations (n = 102) were conducted on six selected samples with diverse
color texture and origin Commercial samples and the variety lsquoBlackrsquo were better accepted by
consumers The adhesive variety lsquoQQ74rsquo was the least accepted quinoa variety in the plain
cooked quinoa dish However because of its cohesive texture lsquoQQ74rsquo shows possible
application in other dishes and foods such as quinoa sushi and extruded snacks Furtherly Partial
Least Square Regression indicated the consumerrsquos preferred attributes were grassy aroma and
firm and crunchy texture while the attributes of pasty adhesive and cohesive were not liked by
consumers
Correlations of panel evaluation and instrumental test were observed in hardness and
adhesiveness However chewiness and gumminess were not significant correlated between panel
test and instrumental test Further training should be addressed to clarify the definitions of
sensory attributes With the assistance and calibration from instruments such as the texture
166
analyzer and electronic tongue panel training can be more efficient and panelists can be more
accurate at evaluation
Acknowledgements
The study was funded by the USDA Organic Research and Extension Initiative
(NIFAGRANT11083982) The authors acknowledge Washington State University Sensory
Facility and their technicians Beata Vixie and Karen Weller The authors also acknowledge
Sergio Nunez de Arco and Sarah Connolly to provide commercial samples Thanks to Raymond
Kinney Max Wood and Hanna Walters who managed the plants harvested the seeds and
collected the data of yield and 1000-seed weight on field trial quinoa varieties Thanks also go to
the USDA-ARS Western Wheat Quality Lab which provided equipment for protein and ash tests
and the texture analyzer
Author contributions
CF Ross and G Wu together designed the study G Wu conducted panel training
collected and processed data and drafted the manuscript KM Murphyrsquos research group provided
the quinoa samples and assisted cleaning process CF Ross CF Morris and KM Murphy edited
the manuscript
167
References
Abugoch LEJ 2009 Chapter 1 quinoa (Chenopodium quinoa Willd) Adv Food Nutr Res
581ndash31
Arco SND Quinoas Calling In Murphy KM Matanguihan J editors Quinoa improvement
and sustainable production Hoboken NJ John Wiley amp Sons Inc p 211
Casas Moreno MM Barreto-Palacios V Gonzalez-Carrascosa R Iborra-Bernad C Andres-Bello
A Martiacutenez-Monzoacute J Garciacutea-Segovia P 2015 Evaluation of textural and sensory properties
on typical spanish small cakes designed using alternative flours J Culinary Sci Technol 13
19-28
Epstein J Morris CF Huber KC 2002 Instrumental texture of white salted noodles prepared
from recombinant inbred lines of wheat differing in the three granule bound starch synthase
(Waxy) genes J Cereal Sci 35 51-63
Foumlste M Nordlohne SD Elgeti D Linden MH Heinz V Jekle M Becker T Impact of quinoa
bran on gluten-free dough and bread characteristics Eur Food Res Technol 2014 239 767-
75
Furche C Salcedo S Krivonos E Rabczuk P Jara B Fernaacutendez D Correa F 2015 Chapter 41
International quinoa trade In Bazile D Bertero D Nieto C editors State of the art report
on quinoa in 2013 Rome FAO amp CIRAD p 317 ndash 20
Gerber NN1968 Geosmin from microorganisms is trans-1 10-dimethyl-trans-9-decalol
Tetrahedron Lett 9 2971-4
168
Koumlksel H Ryu GH Basman A Demiralp H Ng PK 2004 Effects of extrusion variables on the
properties of waxy hulless barley extrudates FoodNahrung 48 19-24
Kowalski RJ Morris CF Ganjyal GM 2015 Waxy soft white wheat extrusion characteristics
and thermal and rheological propertiesCereal Chem 92 145-53
Koziol MJ 1991 Afrosimetric estimation of threshold saponin concentration for bitterness in
quinoa (Chenopodium quinoa Willd) J Sci Food Agr 54 211-9
Limpawattana M Shewfelt R 2010 Flavor lexicon for sensory descriptive profiling of different
rice types J Food Sci 75 199-205
Lorenz K Coulter L Quinoa flour in baked products Plant Food Hum Nutr 1991 41 213-23
Lyon BG Champagne ET Vinyard BT Windham WR Barton FE Webb BD McKenzie KS
1999 Effects of degree of milling drying condition and final moisture content on sensory
texture of cooked rice Cereal Chem 76 56-62
Lyon BG Champagne ET Vinyard BT Windham WR 2000 Sensory and instrumental
relationships of texture of cooked rice from selected cultivars and postharvest handling
practices Cereal Chem 77 64-9
Meilgaad MC Civille GV Carr BT 2007 Chapter 11 The spectrum descriptive analysis
method In Meilgaad MC Civille GV Carr BT Sensory evaluation techniques Boca Raton
FL CRC Press p 225 ndash 32
169
Meullenet JF Marks BP Hankins JA Griffin VK Daniels MJ 2000 Sensory quality of cooked
long-grain rice as affected by rough rice moisture content storage temperature and storage
duration Cereal Chem 77 259 ndash 63
Mossman AP Fellers DA Suzuki H 1983 Rice stickiness I Determination of rice stickiness
with an Instron tester Cereal Chem 60 286ndash92
Muntildeoz AM 2003 Training time in descriptive analysis In Moskowitz HR Muntildeoz AM and
Gacula MC editors Viewpoints and controversies in sensory science and consumer product
testing Trumbull Food amp Nutrition Press Inc p 351 ndash 6
Peterson AJ Murphy KM 2015 Quinoa cultivation for temperate North America
considerations and areas for investigation In Murphy KM Matanguihan J editors Quinoa
Improvement and Sustainable Production Hoboken NJ John Wiley amp Sons Inc p 173-92
Palmer GH 1994 Chapter 5 Storage In Hoseney RC editor Cereal science and technology
2nd edition St Paul MN American Association of Cereal Chemisty Inc p 107
Pop A Muste S Man S Mureșan C 2014 Improvement of tagliatelle quality by addition of red
quinoa flour Bulletin UASVM Food Sci Tech 71 225-6
Pulvento C Riccardia M Biondib S Orsinic F Jacobsend SE Ragabe R DrsquoAndriaa R Lavinia
A 2015 Chapter 613 Quinoa in Italy research and perspectives In Bazile D Bertero D
Nieto C editors State of the art report on quinoa in 2013 Rome FAO amp CIRAD p 460
Quiroga C Escalera R Aroni G Bonifacio A Gonzaacutelez JA Villca M Saravia R Ruiz A 2015
Chapter 31 Traditional processes and technological innovations in quinoa harvesting
170
processing and industrialization In Bazile D Bertero D Nieto C editors State of the art
report of quinoa in the world in 2013 Rome FAO amp CIRAD p 231
Repo-Carrasco R Espinoza C Jacobsen SE 2003 Nutritional value and use of the Andean
crops quinoa (Chenopodium quinoa) and kantildeiwa (Chenopodium pallidicaule) Food Rev Int
19 179-89
Rojas W Pinto M Alanoca C Pando LG Leoacutenlobos P Alercia A Diulgheroff S Padulosi S
Bazile D 2015 Chapter 15 Quinoa genetic resources and ex situ conservation In Bazile
D Bertero D Nieto C editors State of the art report on quinoa in 2013 Rome FAO amp
CIRAD p 67
Sowbhagya CM Ramesh BS Bhattacharya KR 1987 The relationship between cooked-rice
texture and physicochemical characteristics of rice J Cereal Sci 5 287ndash97
Suwannaporn P Linnemann A and Chaveesuk R 2008 Consumer preference mapping for rice
product concepts Brit Food J 110 595-606
Stikic R Glamoclija D Demin M Vucelic-Radovic B Jovanovic Z Milojkovic-Opsenica D
Milovanovic M 2012 Agronomical and nutritional evaluation of quinoa seeds
(Chenopodium quinoa Willd) as an ingredient in bread formulations J Cereal Sci 55 132-8
Szczesniak AS 2002 Texture is a sensory property Food Qual Prefer 13 215-25
Taylor JRN Parker ML 2002 Chapter 3 Quinoa In Belton PS JRN Taylor editors
Pseudocereals and less common cereals grain properties and utilization potential Springer
Science Business Media p 108 ndash 10
171
Tomlins KI Manful JT Larwer P and Hammond L 2005 Urban consumer preferences and
sensory evaluation of locally produced and imported rice in West Africa Food Qual Prefer
16 79-89
Van Soest JJG De Wit D Vliegenthart JFG 1996 Mechanical properties of thermoplastic waxy
maize starch J Appl Polym Sci 61 1927-37
Wang S Opassathavorn A Zhu F 2015 Influence of quinoa flour on quality characteristics of
cookie bread and Chinese steamed bread J Texture Stud 46 281-92
Wiles JL Green BW Bryant R 2004 Texture profile analysis and composition of a minced
catfish product J Texture Stud 35 325-37
Wu G Morris C F Murphy K M 2014 Evaluation of texture differences among varieties of
cooked quinoa J Food Sci 79 2337-45
172
Table 1-Quinoa samples
Varietya Color Source
Titicaca Yellowwhite Denmark
Black Blackbrown mixture White Mountain Farm Colorado USA
KU-2 Yellowwhite Washington USA
Cahuil Brownorange mixture White Mountain Farm Colorado USA
Red Head Yellowwhite Wild Garden Seed Oregon USA
Cherry Vanilla Yellowwhite Wild Garden Seed Oregon USA
Temuko Yellowwhite Washington USA
QuF9P39-51 Yellowwhite Washington USA
Kaslaea Yellowwhite MN USA
QQ74 Yellowwhite Chile
Isluga Yellowwhite Chile
Linares Yellowwhite Washington USA
Puno Yellowwhite Denmark
QuF9P1-20 Yellowwhite Washington USA
NL-6 Yellowwhite Washington USA
CO407Dave Yellowwhite White Mountain Farm Colorado USA
Bolivian White White Bolivia
Bolivian Red Red Bolivia
California Tricolor
Blackbrown mixture California USA
Peruvian Red Red Peru
Peruvian White White Peru aThe first 16 varieties (Tititcaca ndash CO407Dave) were grown in Chimacum WA
173
Table 2-Lexicon of cooked quinoa as developed by the trained panelists (n = 9)
Attribute Intensitya Reference Definition
Aroma
Caramel 10 1 piece of caramel candy (Kraft) (81 g) in 100 mL water
Aromatics associated with caramel tastes
Grain-like 10 Cooked brown rice (15 g) (Great Value)
Rice like wheaty sorghum like
Bean-like 8 Cooked red bean (10 g) (Great Value)
Aromatics associated with cooked beans or bean protein
Nutty 10 Dry roasted peanuts (10 g) (Planters)c
Aromatics associated with roasted nuts
Buttery 10 Unsalted butter (1cm1cm01cm) (Tillamook)c
Aromatics associated with natural fresh butter
Starchy 10 Wheat flour water (11 ww) (Great Value)c
Aromatics associated with the starch
Grassygreen 9 Fresh cut grass collected 1 h before usingc
Aromatics associated with grass
Earthymusty 8 Sliced raw button mushrooms (fresh cut)c
Aromatic reminiscent of decaying vegetative matters and damp black soil root like
Woody 7 Toothpicks (20)c Aromatics reminiscent of dry cut wood cardboard
TasteFlavor
Sweet 3 9 2 and 5 (ww) sucrose solution (CampH pure cane sugar)b
Basic taste sensation elicited by sugar
Bitter 5 8 mgL quinine sulfate acid (Sigma)
Basic taste sensation elicited by caffeine
174
Grain-like 10 Cooked brown rice (Great Value)
Tasted associated with cooked grain such as rice
Bean-like 10 Cooked red beans (Great Value)
Beans bean protein
Nutty 10 Dry roasted peanut (Planters)c Taste associated with roasted nuts
Earthy 7 Sliced raw button mushrooms (fresh)
Taste associated with decaying vegetative matters and damp black soil
Toasted 10 Toasted English muffin (at 6 of a toaster) (Franze Original English Muffin)
Taste associated with toast
Texturee
Soft - Firm 3
7
Firm tofu (Azumaya)b
Brown rice (Great Value)
Force required to compress a substance between molar teeth (in the case of solids) or between tongue and palate (in the case of semi-solids)d
Separate - Cohesive
15
7
Cracker (Premium unsalted cracker)
Cake (Sponge cake Walmart Bakery)
Degree to which a substance is compressed between the teeth before it breaks
Pasty
10 Mashed potato (Great Value Mashed Potatoes powder)
Smooth creamy pulpy slippery
Adhesiveness sticky
10
3
Sticky rice (Koda Farms Premium Sweet Rice)
Brown rice (Great Value)
Force required to remove the material that adheres to the mouth (the palate and teeth) during the normal eating process
Crunchy 13 Thick cut potato chip (Tostitos Restaurant Style
Force with which a sample crumbles cracks or shatters
175
Tortilla Chips)b
Chewygummy
15
7
Gummy Bear (Haribo Gold-Bears mixed flavor)
Brown rice (Great Value)
Length of time (in sec) required to masticate the sample at a constant rate of force application to reduce it to a consistency suitable for swallowing
Astringent 12
6
Tannic acid (2gL)
Tannic acid (1gL) (Sigma)
Puckering or tingling sensation elicited by grape juice
Waterymoist 10
3
Salad tomato (Natural Sweet Cherubs)
Brown rice (Great Value)
Degree of wet or dry
Color
Red 4 9
N-W8M Board Walke
N-W16N Ballet Barree
Yellow 3 10
15B-2U Sandy Toese 15B-7
N Summer Harveste
Black 3 10
N-C32N Strong Influencee N-C4M Trench Coate
aReference intensities were based on a 15-cm scale with 0 = extremely low and 15 = extremely high bMeilgaad et al (2007) cLimpawattana and Shewfelt (2010) dTexture definitions in Szczesniak (2002) were used eAce Hardware color chip
176
Table 3-Significance and F-value of the effects of panelist replicate and quinoa variety on aroma flavor and texture of cooked quinoa as determined using a trained panel (n = 9)
Attribute Panelist Replicate Quinoa Variety PanelistVariety
Aroma
Caramel 26548 093 317 174
Grain-like 7338 000 125 151
Bean-like 7525 029 129 135
Nutty 6274 011 322 118
Buttery 21346 003 301 104
Starchy 12094 1102 094 135
Grassy 17058 379dagger 282 162
Earthy 12946 239 330 198
Woody 13178 039 269 131
TasteFlavor
Sweet 6745 430 220 137
Bitter 9368 1290 2059 236
Grain-like 7681 392 222 206
Bean-like 7039 122 142 141
Nutty 7209 007 169 153
Earthy 9313 131 330 177
Toasted 10975 015 373 184
Texture
Firm 1803 022 1587 141
Cohesive 14750 011 656 208
Pasty 3919 2620 1832 205
Adhesive 2439 287dagger 5740 183
177
Crunchy 13649 001 1871 167
Chewy 3170 870 150dagger 167
Astringent 10183 544 791 252
Waterymoist 10281 369dagger 1809 164
daggerP lt 010 P lt 005 P lt 001 P lt 0001
178
Table 4-Mean separation of significant tasteflavor attributes of cooked quinoa determined by the trained panel Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Sweet Bitter Grain-like Nutty Earthy Toasty
Titicaca 40cdef1 39bcde 73abc 51abcdef 44bcdef 47abcd
Black 36f 42bcd 69bcde 49def 52a 46abcd
KU2 41bcdef 38cde 73abc 52abcdef 40fg 44bcdefg
Cahuil 41abcdef 44b 70bcde 50abcdef 48abc 51a
Red Head 42abcd 43bc 72abcd 51abcdef 42defg 44bcdefg
Cherry Vanilla 40def 52a 66e 48ef 44bcdef 40fghi
Temuko 36ef 56a 68cde 47f 43cdef 40ghi
QuF9P39-51 47a 34e 73abc 48def 40efg 46abcde
Kaslaea 47ab 39bcde 70bcde 55ab 44bcdef 45bcdefg
QQ74 40def 38cde 66e 50abcdef 45bcde 42defghi
Isluga 41bcdef 41bcd 69cde 55a 46bcd 47abcd
Linares 39def 40bcd 65e 49cdef 43def 38i
Puno 44abcd 39bcde 72abcd 51abcdef 45bcde 43cdefghi
QuF9P1-20 42abcdef 43bc 69bcde 53abcd 45bcde 38i
NL-6 38def 37de 72abcd 55a 45bcd 44bcdefgh
CO 407 Dave 41bcdef 40bcd 67de 51abcdef 41defg 39hi
Bolivian White 47ab 22f 69bcde 50bcdef 42def 41efghi
Bolivian Red 42abcde 24f 72abcd 53abcdef 43cdef 46bcde
California Tricolor 40def 27f 74ab 53abcde 48ab 48ab
Peruvian Red 43abcd 25f 75a 48ef 45bcde 47abc
Peruvian White 46abc 26f 70bcde 55abc 37g 45bcdef
179
Table 5-Mean separation of consumer preference Different letters within a column indicate consumer evaluation scores were different among quinoa samples at P lt 005
Samples Aroma Color Appearance TasteFlavor Texture Overall
Black 56a 63b 61bc 61abc 65a 63ab
QQ74 61a 56c 53d 56c 53b 53c
Titicaca 60a 57bc 56cd 58bc 63a 59bc
Peruvian Red 60a 72a 70a 65a 68a 67a
Bolivian Red 60a 69a 66ab 64ab 67a 64ab
Bolivian White 57a 59bc 58c 62ab 63a 62ab
180
Table 6-Hardness adhesiveness cohesiveness springiness gumminess and chewiness of the cooked quinoa samples as determined using Texture Profile Analysis (TPA)
Variety Hardness
(kg)
Adhesiveness
(kgs)
Cohesiveness Springiness Gumminess
(kg)
Chewiness
(kg)
Titicaca 505abc1 -02ab 08abc 15a 384bc 599a
Black 545ab -01a 07bcd 10abc 404abc 404ab
KU-2 490abcd -01a 07bcd 09abc 363bcd 332abc
Cahuil 464bcde -01a 07bcd 08abc 344cd 281bc
Red Head 412defg -03ab 06ef 09abc 246ef 225bc
Cherry Vanilla 391efgh -02ab 05fgh 08abc 208fg 178bc
Temuko 328gh -09c 04hi 08abc 147g 120c
QuF9P39-51 451cde -02ab 07de 10abc 297de 272bc
Kaslaea 493abcd -02ab 07bcd 06c 359cd 227bc
QQ74 312h -17e 04i 09abc 132g 119c
Isluga 362fgh -05b 05ghi 08abc 171fg 137bc
Linares 337gh -16de 05ghi 09abc 159g 146bc
Puno 504abc -01a 06ef 10abc 301de 301bc
QuF9P1-20 438cdef -02ab 06fg 05c 242ef 137bc
NL-6 555a -01a 07cde 09abc 376bcd 350abc
CO407Dave 357fgh -13d 04hi 09abc 160g 141bc
Bolivian White 441cdef -01ab 05fg 14ab 242ef 340abc
Bolivian Red 572a -01ab 08ab 14ab 440ab 593a
California Tricolor
572a -01a 08a 08bc 477a 361abc
Peruvian Red 568a 00a 08ab 08abc 439ab 342abc
Peruvian White 459bcde -01a 08abc 11abc 347cd 394abc
181
Table 7-Correlation of trained panel texture evaluation data and instrumental TPA over the 21 quinoa varieties
Variables Hardness Adhesiveness Cohesiveness Gumminess Chewiness Firm 070 059 080 079 057 Cohesive -060 -051 -066 -067 -043 Pasty -060 -070 -072 -068 -045 Adhesive -067 -063 -075 -075 -055 Crunchy 072 054 076 078 055 Moist -066 -066 -082 -078 -052
daggerP lt 01 P lt 005 P lt 001 P lt 0001
182
Figure 1-Principal component Analysis (PCA) biplot of aroma evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil Red Head
Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white Kaslaea
QQ74
Isluga
Linares
Puno
QuF9P1-20 NL-6
CO 407 Dave
Bolivia white
Bolivia red California Tricolor
Caramel Grain-like
Bean-like Nutty
Buttery Starchy
Grassy
Earthy
Woody
-25
-2
-15
-1
-05
0
05
1
15
2
-3 -25 -2 -15 -1 -05 0 05 1 15 2 25 3 35 4
F2 (2
455
)
F1 (4234 )
183
Figure 2-Principal component Analysis (PCA) biplot of tasteflavor evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil
Red Head Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white
Kaslaea
QQ74 Isluga
Linares
Puno
QuF9P1-20
NL-6
CO 407 Dave
Bolivia white
Bolivia red
California Tricolor
Sweet
Bitter Grain-like
Bean-like
Nutty
Earthy
Toasted
-3
-2
-1
0
1
2
3
-4 -3 -2 -1 0 1 2 3 4 5
F2 (3
073
)
F1 (3391 )
184
Figure 3-Principal component Analysis (PCA) biplot of texturemouthfeel evaluations by the trained sensory panel (n = 9) of the 21 varieties of cooked quinoa Attributes with significantly differed among samples
Titicaca
Black
KU2
Cahuil
Red Head Cherry Vanilla
Temuko
QuF9P39-51
Commercial Red
Peruvian white
Kaslaea
QQ74 Isluga
Linares
Puno
QuF9P1-20
NL-6
CO 407 Dave
Bolivia white
Bolivia red California Tricolor
Firm Cohesive
Pasty
Adhesive
Crunchy
Chewy Astringent
Moist
-2
-15
-1
-05
0
05
1
15
2
25
-3 -25 -2 -15 -1 -05 0 05 1 15 2 25 3 35
F2 (2
212
)
F1 (5959 )
185
Figure 4-Partial Least Squares (PLS) biplot correlating aroma color appearance tasteflavor texture and overall attributes evaluated by the trained panel (n = 9) to the consumer panel (n = 102) for 6 cooked quinoa samples (Consumer acceptances are in bold italics)
Grainy aroma
Beany aroma
Nutty aroma
Buttery
Starchy
Grassy
Earthy
Woody
Sweet
Bitter grainy flavor
Beany flavor
Earthy flavor Nutty flavor
Toasty
Firm Cohesive
Pasty
Adhesive
Crunchy
Chewy
Astringent
Waterymoist
Aroma
Color Appearance TasteFlavor
Texture Overall
Black
Bolivia red
QQ74
Bolivia white
Commercial Red
Titicaca
-1
-075
-05
-025
0
025
05
075
1
-1 -075 -05 -025 0 025 05 075 1
t2
t1
186
Supplementary tables
Table 1S-Mean separation of significant aroma attributes of cooked quinoa determined by the trained panel (n = 9) Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Caramel Nutty Buttery Green Earthy Woody
Titicaca 59a1 60a 45abc 39fg 42defgh 37cdef
Black 46g 50efg 38ef 47abc 54a 46a
KU2 50efg 51defg 41cdef 40efg 38h 35ef
Cahuil 56abc 53bcdefg 43abcd 49a 48b 39bcde
Red Head 55abcd 60a 45abc 44bcde 46bcd 41bc
Cherry Vanilla 52cdef 54bcdef 43abcde 43bcdef 46bcdef 37bcdef
Temuko 55abcd 56abcde 44abc 40defg 41efgh 37bcdef
QuF9P39-51 58ab 60a 46ab 42bcdefg 44bcdefg 36def
Kaslaea 53bcde 55abcde 42abcde 41defg 40gh 37bcdef
QQ74 50efg 48fg 39def 42defg 45bcdef 38bcdef
Isluga 52cdef 57abc 43abcd 43bcdefg 46bcde 39bcde
Linares 52cdef 54bcdef 42bcde 38g 44bcdefg 37cdef
Puno 56abc 56abcde 46ab 42cdefg 46bcdef 38bcdef
QuF9P1-20 53bcdef 58ab 44abcd 42cdefg 44bcdefg 40bcd
NL-6 57abc 53bcdefg 44abcd 39fg 44bcdefg 35def
CO 407 Dave 51def 54abcde 46ab 40efg 42defgh 34f
Bolivian White 53bcde 57abcd 46ab 43bcdef 43cdefgh 39bcd
Bolivian Red 52cdef 51defg 42bcde 43bcdefg 44bcdefg 37bcdef
California Tricolor 54abcde 51cdefg 38ef 44abcd 48bc 41ab
Peruvian Red 48fg 48g 36f 47ab 46bcdef 38bcdef
Peruvian White 54abcde 60a 48a 45abcd 41fgh 40bc
187
Table 2S-Mean separation of significant texture attributes of cooked quinoa determined by the trained panel Different letters within a column indicate attribute intensities were different among quinoa samples at P lt 005 as determined using Fisherrsquos LSD
Variety Firm Cohesive Pasty Adhesive Crunchy Astringent Moist
Titicaca 70ab 63efgh 37ghi 37ghi 56bc 47d 38hij
Black 71ab 63efgh 32i 38ghi 58b 55abc 35jk
KU2 66bcd 64efg 38fghi 37ghi 49de 46de 38hij
Cahuil 68abc 61fghi 37ghi 36hi 56bc 55ab 37ij
Red Head 57fgh 68bcde 46cde 49d 45ef 55ab 48de
Cherry Vanilla 56gh 65cdef 49c 44def 43fg 55ab 49de
Temuko 49ij 70abcd 56b 57c 39gh 59a 51cd
QuF9P39-51 61defg 65def 47cd 40efgh 48def 48cd 42fgh
Kaslaea 60defg 62fghi 40defgh 40fgh 51cd 51bcd 42gh
QQ74 44j 70abc 60ab 81ab 37hi 46def 57ab
Isluga 52hi 66cdef 43cdef 55c 44efg 50bcd 48de
Linares 45j 75a 65a 86a 33i 47d 61a
Puno 58efgh 60fghij 41defg 43efg 52cd 47d 47def
QuF9P1-20 52hi 65def 43cdefg 46de 44fg 55ab 47defg
NL-6 64cde 61fghi 40efgh 41efgh 51cd 46de 46efg
CO 407 Dave 45j 72ab 59ab 80b 35hi 47d 55bc
Bolivian White 56gh 61fghi 38fghi 41efgh 50de 34g 48de
Bolivian Red 62cdef 59hij 34hi 36hi 56bc 38g 42fgh
California Tricolor 68abc 56j 32i 33i 60ab 39efg 39hij
Peruvian Red 74a 57ij 35hi 33i 64a 39fg 31k
Peruvian White 60defg 59ghij 38fghi 37hi 48def 34g 40hi
188
Figure-1S Demographic influence on preference of variety lsquoBlackrsquo
75a
66ab 61bc
54c
61bc
0
1
2
3
4
5
6
7
8
75 50 25 None Other
Liking score of lsquoBlackrsquo
Proportion of organic food consumption
52b
64a 65a 69a 70a
57ab 59ab
0
1
2
3
4
5
6
7
8
Everyday 4-5 timesper week
2-3 timesper week
Once aweek
A fewtimes per
month
Aboutevery 6months
Other
Liking score of lsquoBlackrsquo
Frequency of rice consumption
189
Chapter 7 Conclusions
Quinoa quality is a complex topic with seed composition influencing sensory and
physical properties This dissertation evaluated the seed characteristics composition flour
properties and cooking quality of 13 quinoa samples Differences in seed morphology and
composition contributed to the texture of cooked quinoa The seeds with higher raw seed
hardness lower bulk density or higher seed coat proportion yielded a firmer gummier and
chewier texture after cooking Higher protein content correlated with harder more adhesive
more cohesive gummier and chewier texture of cooked quinoa Additionally flour peak
viscosity breakdown final viscosity and setback exhibited influence on different texture
parameters Cooking time and water uptake ratio also significantly influence the texture whereas
cooking loss did not show any correlation with texture Starch characteristics also significantly
differed among quinoa varieties (Chapter 3) Amylose content ranged from 27 to 169
among 13 quinoa samples The quinoa samples with higher amylose proportion or higher starch
enthalpy tended to yield harder stickier more cohesive and chewier quinoa These studies on
seed quality seed characteristics compositions and cooking quality provided useful information
to food industry professionals to use in the development of quinoa products using appropriate
quinoa varieties Indices such protein content and flour viscosity (RVA) can be quickly
determined and exhibited strong correlations with cooked quinoa texture Furthur study should
develop a prediction model using protein content or RVA parameters to predict the texture of
cooked quinoa In this way food manufactures can quickly predict the texture or functionality of
quinoa varieties and then determine their specific application Moreover many of the test
methods were using the methods used in rice such as kernel hardness texture of cooked quinoa
190
thermal properties (DSC) and cooking qualities Such methods should be standardized in near
future as those defined by AACC (American Association of Cereal Chemists) The development
of standard methods allows for easier comparisons among different studies In Chapter 4 the
seed quality response to soil salinity and fertilization was studied Quinoa protein content
increased under high Na2SO4 concentration (32 dS m-1) The variety lsquoQQ065rsquo maintained similar
levels of hardness and density under salinity stress and is considered to be the best adapted
variety among four varieties The variety can be applied in salinity affected areas Future studies
can be applied on salinity drought influence on quinoa amino acids profile starch composition
fiber content and saponins content
Sensory evaluation of cooked quinoa was further examined in Chapter 5 Using a trained
panel the lexicon for cooked quinoa was developed Using this lexicon the sensory profiles of
16 field trial varieties and 5 commercial quinoa samples were generated Varietal differences
were observed in the aromas of caramel nutty buttery grassy earthy and woody tasteflavor of
sweet bitter grain-like nutty earthy and toasty and texture of firm cohesive pasty adhesive
crunchy chewy astringent and moist Subsequent consumer evaluation on 6 selected quinoa
samples indicated lsquoPeruvian Redrsquo was the most accepted overall whereas a sticky variety lsquoQQ74rsquo
was the least accepted Partial least square analysis using trained panel data and consumer
acceptance data indicated that overall consumer liking was driven by grassy aroma and firm and
crunchy texture The lexicon and the attributes driving consumer-liking can be utilized by
breeders and farmers to evaluate their quinoa varieties and products The information is also
useful to the food industry to evaluate ingredients from different locations and years improve
processing procedures and develop products
191
Overall the dissertation provided significant information of quinoa seed quality and
sensory characteristics among different varieties including both commercialized samples and
field trial samples not yet available in market Several quinoa varieties increasingly grown in
US were included in the studies The variety lsquoCherry Vanillarsquo and lsquoTiticacarsquo are among the
varieties gaining the best yields in US Their seed characteristics and sensory attributes
described in this dissertation should be helpful for industry professionals in their research and
product development Varieties include lsquoTiticacarsquo lsquoCherry Vanillarsquo and lsquoBlackrsquo Additionally
important tools were developed in quinoa evaluation including texture analysis using TPA and
the lexicon of cooked quinoa
As with any set of studies other research questions arise to be addressed in future
research First saponins the compounds introducing bitter taste in quinoa require further study
Sweet quinoa varieties (saponins content lt 011) should be bred and adapted to the US
Although many consumers may like the bitter taste and especially the potential health benefits of
saponins it is important to provide consumers choices of both bitter and non-bitter quinoa types
To assist the breeding of sweet quinoa genetic markers can be developed and associated with the
phenotype of saponin content As for the methods testing saponin content the foam method is
quick but not accurate whereas the GC method is accurate but requires long sample preparation
time and high capital investment An accurate more affordable and more efficient method such
as one using a spectrophotometer should be developed
Second one important nutritional value of quinoa is the balanced essential amino acids
The essential amino acids profiles change according to environment (drought and saline soil)
quinoa variety and processing (cleaning milling and cooking) and these changes should be
192
further studied It is important to prove quinoa seed maintains the rich essential amino acids even
growing under marginal conditions or being subjected to cleaning processes such as abrasion
and washing
Third betalains are the compounds contributing to the color of quinoa seed and providing
potential health benefits Betalain content type (relate to diverse colors) and their genetic loci in
quinoa can be further investigated Color diversity is one of the attractive properties in quinoa
seeds However the commercialized quinoa samples are in white or red color while more quinoa
varieties present orange purple brown and gray colors More choices of quinoa colorstypes
may attract more consumers
Finally sensory evaluation of quinoa varieties should be applied to the samples from
multiple years and locations since environment can significantly influence the sensory attributes
Also in addition to plain cooked quinoa more quinoa dishes can be involved in consumer
acceptance studies as different quinoa varieties may be suitable for various dishes