FSFB, 3rd International Congress, 14-17 October, 2008, Querétarorespyn2.uanl.mx/especiales/2009/ee-01-2009/documentos/04... · 2009-04-02 · FSFB, 3rd International Congress, 14-17

FSFB, 3rd International Congress, 14-17 October, 2008, Querétaro

36

FP-01

Production of crystallized pear (var. D´anju) using osmotic dehydration

Manivel, R. A; Yahuaca, J. B.

Laboratorio de Análisis de Alimentos, Laboratorio de Biotecnología

Facultad de Quimicofarmacobiología, Universidad Michoacana de San Nicolás de Hidalgo

Calle Tzintzuntzan #173 Col. Matamoros, Morelia Mich. México

E-mail: ramch03hotmail.com

Osmotic dehydration represents a technological alternative to reduce post-harvest losses

of fruits. The objective of this work was to study the influence of the concentration of

the osmotic agent (sucrose) and the temperature on the osmotic dehydration of pear

fruits. For the study pears var. "D´anju" were obtained from the local market, selected,

peeled, sliced quarters and immersed in osmotic solution (sucrose syrup of 50° and 60°

Brix) at 70°, 80°and 90°C. The pieces were removed after 30, 60, 120, 180, 240, 300,

360, 420 y 480 min. The variables studied were solute gain (GS), water loss (PA) in

fruits and °Brix reduction in the syrup. For all treatments, water loss and solids gain

increased at significant level in the high concentration solution (60°Brix) and high

temperature (90° C). The highest PA, and GS were obtained in shorter time when the

pear immersed was at 60°Brix at 80° and 90°C than with 50°Brix at all temperatures.

The observations of the present work about GS and PA allow concluding that the

concentration of the syrup and the temperature influences the process of osmotic

dehydration of pear. In all cases the water loss was more important than the solids gain.

(keywords: Osmotic dehydration; water loss; solids gain; temperature; concentration)


37

FP-02

Effect of Osmotic Dehydration on the Quality of a Banana Snack Product

Tapia-Molina, A. R., Calderón-Santoyo, M. Luna-Solano, G. and Ragazzo-Sánchez, J. A.

1Instituto Tecnológico de Tepic. Laboratorio Integral de Investigación en Alimentos. Av. Tecnológico

No. 2595 C.P. 63175. Tepic, Nayarit, MÉXICO, Tel. (311) 213 15 43. 2Instituto Tecnologico de Orizaba, Division de Estudios de Posgrado e Investigacion, Av. Oriente 9 no.

852, Orizaba, Veracruz, 94320 [email protected]

Osmotic dehydration was examined as a pretreatment before frying in order to produce

a fried banana snack with a low fat content. A relationship between dehydration kinetics

as well as frying kinetics and the type of solution used for osmotic dehydration before

frying of banana snacks has been developed to demonstrate that oil uptake during frying

is a direct function of water content. The effect of osmotic dehydration on sensory

properties (flavor and texture) and microbiological quality (aerobic bacterial, fungal,

and yeast counts) of the banana snack was also investigated. Sugar solutions at two

concentrations (40° and 60 °Bx) and 3 soaking times (2, 4, and 6 h) were used. Results

showed that osmotic drying pretreatment significantly reduced oil uptake in banana

snacks during frying and sensory properties were improved. The osmotic treatment also

maintained the good microbiological status of the product.

(keywords: Osmotic dehydration, frying, banana snack)


38

FP-03

Evaluation of Ohmic Heating Processing Parameters on Nixtamalized Corn Flour

Quality

Gaytán-Martínez, M., Figueroa-Cárdenas, JD., Vázquez-Landaverde, P., Morales-Sánchez, E.

Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional. Libramiento

Norponiente No. 2000. Real de Juriquilla. C.P. 76230. Querétaro, Qro. México.

*[email protected]

Nixtamalization (alkaline cooking) is the primary step in the production of products

such as corn chips, corn tortillas and tortilla chips. The process involves cooking and

steeping of corn in excess water with lime added to produce nixtamal. Commercial

nixtamalization results in 5–14% corn solids loss in the liquid effluent generated during

cooking-steeping and washing. Loss of corn solids not only causes economic loss to

corn processors but also creates costly waste and wastewater disposal problems. Ohmic

heating works by passing an electric current through the food causing internal heat

generation. The objective of this work was to assess which ohmic heating process

parameters had a greater impact on the quality of nixtamalized corn products. The

independent variables analyzed were particle size (0.5 and 0.8 mm), moisture content

(50 - 70%), lime concentration (0-0.4%), voltage (80 - 110 V) and the final cooking

temperature (90 – 110 °C). Three main products were obtained: flour, dough and

tortillas. For flour and dough, water-absorption capacity and viscosity were measured;

while yield, texture and moisture content were measured for tortillas. Results showed

that moisture, final cooking temperature and voltage were the most significant factors

( =0.05) influencing product quality. The response variables more affected by the

process were viscosity, moisture and yield. It was concluded that ohmic heating is able

to produce nixtamalized corn products with good quality, having great potential to be

used in the corn processing industry.

(key words: nixtamalization, ohmic heating, corn products.)


39

FP-04

Determination of Reducing Sugars in Selected Variants of Agave mezcalero (Agave

duranguensis) from the Southeast of Durango

Cifuentes, D. L. A.; Gómez, O. S; Hernández, V. V.

Biotecnología y alimentos, CIIDIR-IPN, Unidad Dgo. Sigma s/n Fracc. 20 de Noviembre II C. P. 34220

Durango, Dgo. México. e-mail: [email protected].

The production of mezcal is made from Agave at southeast of Durango. Frequently,

Agave has strong variation in total reducing sugars, weight of head and time of

maturation, these differences make to vary the volume and quality of mezcal from lot to

lot. To determine the variation of weight of heads and their total of reducing sugars,

three localities were selected: Ejidos El Caliche, Los Olagues y Los Ojitos from

Nombre de Dios, Durango. The sample was obtained from 513 agaves (heads) from

Ejido El Caliche, to determine the variation of weight (kg) of agaves used to produce

mezcal. The determination of total reducing sugars was conducted on samples from 17

selected agaves in Ejidos El Caliche, Los Olagues y Los Ojitos. It was found that 66.1%

of the agaves used to produce mezcal, oscillate between 6.9 and 18.8 kg, whereas

agaves with weights of 30.7 to 54.6 kg only constitutes 28% and finally, agaves of 66.4

to 233 kg only represent the 5.9%. Statistical differences were found related to reducing

sugars, in the heads sampled from different selected sites. The total reducing sugars

concentration presented a variation 8 to 26%. The greatest reducing sugars

concentration for the head harvested was in Ejido Los Olagues with 22.5% and Ejido

Ojitos de Moreno with 22.3%. The average of total reducing sugars from three ejidos

was 17.6%. In conclusion, the relation found between weight and total reducing sugars

was, agaves with weight of 70 to 233 kg, had total reducing sugars from 13 to 16%,

whereas agaves of 25 to 60 kg had a concentration from 8 to 26%.

(keywords: cenizo, mezcal, Agave duranguensis)


40

FP-05

Evaluation of stability and production of carbon dioxide in mother doughs and

direct doughs from strong flours

Gómez, O. S.; Orea, L. G.; Hernández, V. V.

aBiotecnología y alimentos, CIIDIR-IPN, Unidad Dgo. Sigma s/n Fracc. 20 de Noviembre II C. P. 34220

Durango, Dgo. México.Correo-e: [email protected].

The study of rheology of baking doughs is important for wheat trading, flour quality and

its transformation into bread. Bakers can standardize the phases of baking process, but it

is necessary to have the knowledge about stability of doughs, CO2 retention capacity

and volume that doughs can develop, because these properties are directly related to the

quality of bread. In this work the stability and production of CO2 from baking doughs

were evaluated using different percentages of mother dough and direct dough. The

flour used in this work was Turbo remix 40 of good baking quality. The fermentation

time of mother dough was 3 h, 6 h and 9 h. The mother dough percentages used were

100, 75, 50, 25 and zero, the complement was direct dough; the developing dough and

its CO2 production were evaluated to each sample. The rheofermentograms were

obtained in the Rheofermentometer F2 showed important parameters such as maximum

height (Hm), height of second fermentation (h), time, maximum volume, height of

bread (T1), time to end of the test (T2), maximum height of gaseous detachment (H‟m),

maximum time of gaseous detachment (T‟1), time where the curves are separeted ((Tx),

total volume of CO2 (Vt), lost volume (Vp), retained volume (Vr), and retention

coefficient (Cr). A completely randomized design with a factorial arrangement was

used. The data obtained were analyzed by means of analysis of variance, with p≤0.05

and comparison of means by the Tukey test. The best rheological treatment of dough

was obtained when 25% of mother dough, fermented during 6 h, at 25°C, 70% relative

humidity and 75% direct dough were utilized. With a CO2 retention coefficient of

96.8%, volume of dough was considered as very good, showing good stability.

(keywords: flour, rheofermentograms, rheology).


41

FP-06

Effect of Hot Air Drying on Quality Parameters of Pulp of Lychee (Litchi chinensis

Sonn) Fruit

Castro-Ahumada, J. O., Carrillo-López, A., Caro-Corrales, J. J., and Zazueta-Morales, J. J.

Maestría en Ciencia y Tecnología de Alimentos, Universidad Autónoma de Sinaloa, Apdo. Postal 1354,

CP 80000, Culiacán, Sinaloa, México. Corresponding: [email protected].

Ninety eight percent of Mexican Lychee (Litchi chinensis Sonn.) fruit is

commercialized as fresh fruit, but the highly perishable nature of the fruit produces very

high postharvest losses (about 50%). It is very important to study new alternatives to

process this fruit. The objective of this work was to study the effect of drying

temperature (60, 70, and 80°C) on the dried pulp quality (bulk density (BD), shrinkage,

water adsorption (WA), water activity (aw), and total color difference (E)) and

engineering parameters (mass transfer coefficient (kY) and effective diffusivity (Deff)).

The whole fruit was blanched, peeled, cutted and dried, the experiment was carried out

at a constant air velocity (1.45 m/s) using a laboratory convective tray drier, the air was

heated using liquified petroleum gas (LPG). Effective moisture diffusivity was

estimated using the finite element method (FEM) because the shape of the fruit was

irregular, and the results were analyzed as mean values with standard deviations.

Differences between mean values were established using Fisher‟s test Values were

considered at 95% level of significance (p<0.05). Most of analyzed responses were

significantly (p<0.05) affected by temperature. BD and shrinkage increased as

temperature was higher, and as temperature increased WA and aw decreased. The E of

lychee was significantly affected by temperature and the fruit dried with the lowest

temperature showed the lowest E value. The moisture flux increased as temperature

increased, but the kY did not significantly change. Deff increased as drying advanced.

Good agreement was observed between unaccomplished moisture fraction estimated

using FEM and those obtained from experiments for different drying air temperatures.

The results suggested that the best temperature to dry lychee is 70ºC because of the

good results found in every analyzed responses and the short required time to be

processed.

(keywords: Lychee fruit, hot air drying, quality parameters, finite element method)


42

FP-08

Functionality and Stability of Polyphenols of Oat-Soy Cookies

Heras-Ramírez, M.E., Vidal-Quintanar, R.L.

Departamento de Investigación y Posgrado en Alimentos. Universidad de Sonora P.O. Box 1658, Colonia

Centro. Hermosillo Sonora Mex. Phone and fax + (662) 259-22-07 al 09 [email protected]

Cookies were formulated with three levels of soybean, oats and fat sources (33) to

evaluate the stability and functionality of the polyphenols during high temperature

storage, 45-75°C, and 55% humidity. In a previous study, the oats-soybean cookies had

95% acceptances (p<0.5) with four points or higher value (0-5 scale). The main

objective was to measure the rate of lipid oxidation and the presence of polyphenols as

an antioxidant in the cookies during the storage time. Lipid oxidation was evaluated by

conjugated dienes acids, peroxide value and p-anasidine index. The amount of

polyphenols compound present in each cookie formula was evaluated by the Folin-

Ciocalteu method and the antioxidant activity by the TAS total antioxidants method of

Randox Laboratory. Each type and concentration of fat was observed to have a

different effect (p<0.05) in lipid oxidation rate, antioxidant remaining and quality of

cookies. The amount and antioxidant activity were lost at higher rate for the fish oil

formulas than for shortening. The activity of the polyphenols antioxidants had a first

order rate reaction type. The fish oil cookies had lost 90% (p<0.05) of its shelf life in

the first week compared with 3-4week of the others cookies formulas. Oats-soybean

cookies with olive oil contained lower saturated fat, enticing sensory characteristics, and

had longer shelf life than salmon oil.

(key words: antioxidants, functional cookies, lipid oxidation, shelf life)


43

FP-09

Response Surface Methodology applied to obtain precooked dehydrated slices of

Winter Squash (Cucurbita moschata D.) cv. Cehualca

Aguilar-Gutiérrez, F., Zazueta-Morales, J.J., Caro-Corrales, J.J., Camacho-Hernández, I.L., Jacobo-

Valenzuela, N., and Aguilar-Palazuelos, E.

Maestría en Ciencia y Tecnología de Alimentos, Universidad Autónoma de Sinaloa, Apdo. Postal 1354,

CP 80000, Culiacán, Sin., México. Correspondence (e-mail: [email protected]).

Winter squash (Cucurbita moschata Duchense) is a vegetable produced and consumed

in Mexico as a decorative for typical regional candies but it is used mainly as an animal

feed. Its high carotene and dietary fiber, makes necessary the study for new

technological alternatives for a better improvement in human feed. The objective of this

project was to study the effect of the thickness (Th: 4, 6 and 8 mm) and drying

temperature (DT: 60, 72 and 84 °C) on physicochemical characteristics (Water

adsorption index, WAI; swelling index, SI; shrinkage, S and color: L*, a*, b*, C and

°Hue) of precooked dehydrated slices of winter squash cv. Cehualca. A 3x3 factorial

experimental design and response surface methodology were used for data analysis and

optimization of the process. Values of R2

adj for WAI, SI, and S were 0.63, whereas for

L*, b* and C they were 0.47. Values of p of Fmodel0.001 and variability coefficients

17% were obtained (but for SI and a*). Most of the evaluated responses showed lack

of fit (p0.05). As Th of slices decreased and DT increased, WAI and S increased;

while as Th and DT decreased, SI increased. On the other hand, Th showed a higher

effect on color parameters than DT. In general, the highest values of the L*, b* and C

parameters were achieved at low thickness of the slices (4 mm). The obtained data

suggest it is possible to manufacture precooked dehydrated slices from winter squash

cv. Cehualca which could be used as snack foods, with the eventual benefit of its high

carotene and dietary fiber. Nevertheless, more studies to optimize the process and to

estimate the loss of nutriments as on sensorial acceptance are recommended.

(key words: drying, winter squash, cehualca, snack foods)


44

FP-10

Growth Evaluation of Nile Tilapia Oreochromis niloticus Fed Using a Non

Conventional Protein Food Formulation

Mendiola-Campuzano J.V.H., Duran-Mendoza, T., Hernández-Vélez, R.M., Angulo-Guerrero, O., Urrieta

Saltijeral, J.M.

Departamento de Ingeniería Química, Bioquímica y ambiental. Instituto Tecnológico de Villahermosa.

Carretera Vhsa-Frontera Km 3.5 Ciudad Industrial Villahermosa, 86010 Tabasco, México. Unidad de

Investigación en alimentos (UNIDA). Instituto Tecnológico de Veracruz. Miguel Angel de Quevedo

2779. Col. Formando Hogar. Veracruz, Ver. División Académica multidisciplinaria de los Ríos de la

Universidad Juárez Autónoma de Tabasco. Tenosique, Tabasco.

[email protected] ; [email protected]

In recent years animal feed industry for aquaculture has registered an increase in

production worldwide. The quality of balanced food is highly dependent on appropriate

good quality raw materials. In the present work an experimental food with animal and

vegetable protein sources (33 % by weight), in substitution of fishmeal was formulated

in order to evaluate nutrimental and microbiological quality, as well as its in vitro

digestibility, and the effect in the growth of young Oreochromis niloticus. Treatments

were compared with a commercial food Nutripec

. In both foods nutrimental quality

(protein, crude fiber, fat, free nitrogen extract, ashes and humidity), microbiological

analyses (coliforms, mesophiles, fungi and yeast), digestibility in vitro (enzymatic

method) and the effect on growth (by means biometry‟s) of 180 organisms were

evaluated. A Pearson‟s square design was applied to determine the composition of

supplementing nutrients. The results for the experimental food showed an acceptable

nutrimental and microbiological quality, a high digestibility but its effect on growth was

smaller in comparison with organisms fed with a commercial food for young tilapia

(Nutripec®), the average weight gain was greater for commercial food (8,646±4,943 g)

compared to experimental food (5,555±2,329 g). However, a homogenous population

growth was obtained with the experimental food. This represents an advantage during

tilapia culture since we avoided competition by food and space, because the fish have

similar length and weight. The physicochemical parameters evaluated in a pilot unit of

aquaculture (temperature, pH, dissolved oxygen, total ammonium), stayed in optimal

ranks for tilapia culture. It is concluded that the experimental food can be a good

alternative in the feeding of young tilapia to obtain a homogeneous population of a

productive system.

(keywords: formulation, growth evaluation, experimental food, Oreochromis niloticus.)


45

FP-12

Clean Production of Smoked Trout (Oncorhynchus mykiss) Processing. A

Preliminary Study

Medina, H. E., Burciaga, S. M. E., Pérez, L. M. E., Delgado, E.

CIIDIR-IPN, Unidad Dgo., Becarias COFAA; Instituto Tecnológico de Dgo.

Sigma S/N Fracc. 20 de Noviembre II, Durango, Dgo. [email protected] A clean production is defined as processing or manufacturing system, in which waste

minimization and prevention practices are continuously applied. These practices include

preservation of raw materials and energy, disposal of toxic inputs, and reduction in toxic

outputs. The aim of this investigation was to standardize the process for smoked trout.

The results will be applied to establish a clean production of trout processing. Rainbow

trout (Oncorhynchus mykiss) were eviscerated and their fillets immersed in a brine with

5% NaCl for three different periods (15, 20 or 30 min). The amounts of solid and liquid

residues obtained during processing were determined. Data were analyzed by ANOVA

at a significance of α = 0.05. The results show that after 30 min. in the salt solution,

samples reached the required salt concentration (1.13%). The time that the fillet

remained immersed in the brine had a significant effect (p = 0.004) on salt concentration

of the fillet. Only 55.5% of the trout could be used as fillet, while the rest may be

considered as an industrial residue. A total of 2 L/kg trout of residual wastewater was

produced. These residues contain elevated concentration of organic matter, which

makes them highly polluting. Industrial residues as the ones generated from this work

may be used as raw materials in other processes, such as fishmeal, fish oil and biodiesel

production. Further investigations will include a water processing system to treat

residual water from the process.

(keywords: trout production, processing, cleaner production)


46

FP-13

Rye and whole wheat sourdough bread enriched with fermented chick pea

Aguilera-Reyes LV, Reyes-Vega ML, De la Garza-Toledo H

Universidad Autónoma de Coahuila, Departamento de Investigación en Alimentos

Blvd. V Carranza s/n, 25280 Saltillo, Coahuila, México Corresponding author: [email protected]

Bread production is based in an ancient Egyptian technology that evolved upon the

time; however, the actual technology, faster than the ancient, is responsible of the new

flavor of bread, which has lost some desirable sensory characteristics. The objective of

this work is the development of sourdough bread enriched with a fermented paste of

chick pea to improve nutritional value of bread. Chick pea was fermented with

Lactobacillus casei and incorporated into wheat flour, water and sugar to obtain a

sourdough. This was used to prepare rye and whole wheat dough, which were baked to

obtain the corresponding sourdough bread. Rye and whole wheat breads were also

prepared without sourdough. The following characteristics were determined: pH,

bacteria and yeast count of fermented chick pea paste and sourdough, bread weight,

height, thickness, and length, texture profile analysis (TPA, Instron) and sensory

analysis, as well as crust thickness. In addition, the bread cells were observed by means

of a scanning electron microscope. Sourdough breads were more porous than traditional

bread, their crust was thicker and sensory analysis showed that their flavor and texture

were improved. TPA confirmed the last characteristics. Sourdough bread cells were

approximately of the same size with well structured walls. Sourdough bread obtained by

this method, especially rye sourdough bread was very well accepted by consumers.

(keywords: rye sourdough bread, whole wheat sourdough bread, chick pea)


47

FP-14

Manufacture of Asadero Cheese with a vegetable rennet from Solanum

elaeagnifolium

Aquino-Favela, A., López-Díaz, J.A., Vargas-Requena, C.L. y Martínez-Ruiz, N.R.

Laboratorio de Ciencias de los Alimentos; Laboratorio de Biotecnología, Departamento de Ciencias

Básicas, Instituto de Ciencias Biomédicas, Universidad Autónoma de Ciudad Juárez, Anillo Envolvente

del Pronaf y Estocolmo s/n, Cd. Juárez, Chihuahua, México. C.P. 32300.

email: [email protected]

The growing production of cheese in the world has led to a shortage in animal rennet.

Chymosin is the responsible enzyme of milk coagulation, acting by a specific

proteolysis on the casein of milk. Due to rennet shortage, the cheese industry has to look

for new alternatives such as microbial rennet from Mucor pusillus, Endothia parasitica

and Mucor miehei and the vegetal rennets from Cynaras, Gallium, Pinguicula, Whitania

and Ficus. In the north of Mexico and south of the United States, there is a plant known

as “Trompillo” (Solanum elaeagnifolium) and people from the State of Chihuahua use

its fruit in the production of artisan cheese. The information about this plant and its fruit

is very scarce and its use in the cheese manufacture is still empiric; these reasons

motivated this investigation. In this work it was established the coagulant capacity of

Trompillo extract on the casein‟s milk and finally this extract was applied in the

manufacture of Asadero cheese. The Trompillo‟s fruit composition was analyzed in

different maturations levels using the AOAC methods. Next, enzyme extraction was

carried out by precipitation with ammonium sulfate and coagulant activity (rennet

strength) was determined. Finally, the extract obtained was used in the Asadero cheese

manufacture. The cheese was compared with an Asadero cheese elaborated with

commercial rennet, by means of sensory test. The results showed that the mature fruit

had a higher protein concentration and resulted in a better coagulation. Regarding the

coagulant activity, the extract obtained from this fruit had lower rennet strength than

commercial rennet. However, in the sensory test the Asadero cheese made with vegetal

rennet was preferred over the Asadero cheese made with commercial rennet. From those

results, it is possible to establish that Trompillo‟s (Solanum elaeagnifolium) fruit can be

used for as a source of vegetal rennet, and can be used by the Cheese Industry as an

animal rennet substitute.

(key words: cheese, rennet, Trompillo)


48

FP-15

Effect of the Process Conditions on Humidity and Solubility of Spray Dried Sabila

Gel (Aloe vera)

Pool-Gómez, J.E.M. Solís, S., Tamayo, J., Escamilla-Sánchez, J.B. and Rivera–Muñoz G.

1Universidad Autónoma de Campeche. Facultad de Ciencias Químico Biológicas

2Instituto Tecnológico de Mérida. Departamento de Ingeniería Química y Bioquímica

Km. 5 Carretera Mérida-Progreso S/N, Mérida, Yucatán, México C.P. 97118

Mérida, Yucatán. [email protected]

In Yucatan, sabila (Aloe vera) represents a good alternative for increasing income of the

farmers by means of its cultivation and industrialization. Hence, this activity is a very

important option for the regions of the state where the henequen was cultivated before.

The sabila is considered an exotic plant, whose leaves are constituted of an epidermis,

vascular faces and a crystalline colorless mucilaginous cellular tissue known as gel.

This gel is demanded in the international market in concentrated form of 1:20, 1:40 and

freeze dried gel powders with a concentration of 1:200. An alternative for this process is

the spray drying. For this reason, the objective of this work was to evaluate the effect of

spray drying temperature, (140 and 160°C); air flow, (21 and 28 m3h

-1); spray drying

pressure, (0.6 and 1.2 bar) and dilution of the gel in water, (1:1 and 1:0,5). This

evaluation was carried out using a factorial design 24. The best sabila powder was

achieved using a drying temperature of 160 °C, an air flow of 28 m3h

-1, a feeding flow

of 350 mLh-1

, a spray pressure of 1.2 bar and a sabila gel dilution of 1:1. With this

condition, the spray dried gel powders produced had a moisture content of 5.17±1.21%

and a solubility of 20.58±0.96 %.

(keywords: sabila gel, spray drying, Aloe vera)


49

FP-16

Tangential Filtration of Macro and Micromolecules

Orozco-Alvarez, C., García-Salas, S., Ríos-Domínguez, I.

Bioengineering Department. Inter-Professional Unit of Biotechnology. IPN.

Av. Acueducto S/N. Col. Barrio La laguna Ticomán. G. A. Madero. México, D.F.

Fax: 57 29 60 00 ext. 56305. e-mail: [email protected].

We worked the ultrafiltration and reverse osmosis in a spiral pilot equipment with a

filtration area of 6.5 m2 and a membrane step of 0.8 x10

-3 m. Working conditions were

at 25 ºC, pressures from 0 to 2000 kPa and pHs was about 6 and 7. We also applied a

polarizing gel model to determine k and Cg constants. In the ultrafiltration equipment

the results were as follows: When working with suspension yeast at 30 g/L and at the

maximum pressure we obtained a 5 x10-6

m/s flux, while at 250 g/L, filtration flux is

reduced to 60%. In applying the polarizing gel model we obtained a k value of 4.5 x10-6

m/s and a Cg of 323 g/L. When working with whey at 30 g/L and at the maximum

pressure we obtained a 2.8 x10-6

m/s flux. At 200 g/L, filtration flux is reduced to 50%.

Constants values in the polarizing gel model were: a k of 1 x10-6

m/s and a Cg of 570

g/L. The results in the reverse osmosis equipment were as follows: When working with

NaCl solution at 1 g/L and at the maximum pressure we obtained a 15 x10-6

m/s, and

this is reduced up to seven times when the concentration of salts rose up to 150 times. In

applying the polarizing gel model we obtained a k value of 2 x10-6

m/s and a Cg of 535

g/L. When working with sucrose solutions at 150 g/L and at the maximum pressure we

obtained a 12 x10-6

m/s flux, and this is reduced up to six times when the concentration

of sucrose is raised four times. Constants values in the polarizing gel model for k y Cg

were 6.4 x10-6

m/s and 850 g/L, respectively.

(keywords: ultrafiltration, reverse osmosis, yeast, whey, sucrose)


50

FP-17

Calculation Methodology to Predict Drying Time in a Solar Dryer

Orozco-Alvarez, C., Angeles-Martinez, D., Garcia-Salas, S.

Bioengineering Department. Inter-Professional Unit of Biotechnology. IPN.

Av. Acueducto S / N. Col. Barrio La Laguna Ticomán. G. A. Madero. Mexico City

Fax: 57 29 60 00 ext. 56305. e-mail: [email protected]

The current project developed a sequence of calculations to estimate the drying time of

a specific material using a solar dryer of integral type that works with natural air

convection and is heated inside the dryer by solar radiation. Calculation bases are

presented below. Material to dry: carrot slices of 5 mm thick; initial and final moisture,

91 % and 15 % respectively; air temperature inside the drier: 50 to 65 °C; speed of air

entering the drier: 0.1 to 0.5 m / s, with an absolute humidity of 0.01, and leaving the

dryer a temperature of 5 to 10 °C lower than the temperature of entry. In the calculation

sequence, different temperatures and drying air flows are tested up to get the drying of

the material, accomplishing with the following conditions: air relative humidity at the

exit of the dryer should be lower than balance humidity, and in the final calculation we

must verify that air velocity is equal to the proposed value at the beginning of the

sequence.

With the above conditions already met, sequence calculation gives the following results.

At a temperature of 65 ºC drying time is of 11 hours of sunlight; while at 50 °C time is

increased up to 33 hours, these drying times are similar to those reported in

experimental works. Knowing that it can be obtained a solar radiation of 400 W/m2 a

day, we can go through the sequence of calculation to estimate the size of a solar type-

tent dryer to perform the drying of a determined fruit or vegetable quantity.

(keywords: drying, solar radiation, fruits, vegetables)


51

FP-18

Analysis of Quality Protein Changes in Nixtamalized QPM Flours as a Function of

the Steeping Time

Rojas-Molina, E. Gutiérrez, M.E. Cortés-Acevedo, A. Falcón, R. Bressani, A. Rojas,

C. Ibarra, J.L. Pons-

Hernández, S.H. Guzmán-Maldonado, A. Cornejo-Villegas, and M.E. Rodríguez.

Facultad de Ciencias Naturales, Licenciatura en Nutrición, Universidad Autónoma de Querétaro,

Querétaro, México.Departamento de Posgrado e Investigación. Facultad de Ingeniería, Universidad

Autónoma de Querétaro, Cerro de las Campanas S/N, Querétaro, México.Facultad de Estudios Superiores

Cuautitlán, Universidad Nacional Autónoma de México, Campus Cuautitlán, Cuautitlán,

México.Laboratorio de Neurofarmacología Marina, Instituto de Neurobiología, Universidad Nacional

Autónoma de México, Campus Juriquilla.Centro de Ciencia y Tecnología de Alimentos, Universidad del

Valle de Guatemala.

Facultad de Química, Departamento de Investigación en Productos Naturales, Universidad Autónoma de

Querétaro. Cerro de las Campanas S/N, Querétaro, México.7Unidad de Biotecnología. Campo

Experimental Bajío, INIFAP. Celaya Guanajuato, México.8Centro de Física Aplicada y Tecnología

Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro, C.P. 76230, A.P.

1-1010, Mé[email protected], [email protected]

This work shows the protein changes in Quality Protein Maize (QPM H-368C) during

the traditional nixtamalization process as a function of the steeping time from 0 to 15 h.

Protein content (N x 6.25), pH, protein fractionation, reactive lysine, essential amino

acids and protein digestibility were analyzed to explain the protein quality modifications

in nixtamalized corn flours (NQF). The thermo-alkaline process increased significantly

(P ≤ 0.05) the protein content (5.57 ± 0.86%) in NQF obtained at 3, 5, 7, 9, 11, 13 and

15 h of steeping time compared with native corn or corn without treatment (NC). The

pH of NQF were not proportional to the steeping time and significantly different (P ≤

0.05) between them. At 5 h critical steeping time the total lysine and reactive lysine

content decreased severely (36 and 32% respectively) with statistical differences (P ≤

0.05) compared to NC. On the other hand, the tryptophan content decreased

significantly (P ≤ 0.05) at steeping times from 5 to 15 h (38.70 ± 6.7%) compared to

NC. The changes in the lysine and tryptophan content were not proportional to the

steeping time. The protein recovery in the albumins and globulins fraction diminished

(P ≤ 0.05) with respect to raw corn. The protein recovery for γ-zeins, glutelin-like,

glutelins and residue increased. A significant (P ≤ 0.05) decrease in the essential amino

acids in NQF obtained from 3 to 7 h of steeping time compared with NC was found.

Equally important was the reduction in protein digestibility observed in NQF steeped at

long steeping times (from 11 to 15 h) with significant (P ≤ 0.05) differences compared

with NC. The protein solubility distribution along the steeping step and the essential

amino acids location, specifically lysine in corn kernel could explain partially the

protein quality changes observed in this research. Finally, these results contribute to

conciliate the discrepancies associated with the protein quality modifications in

nixtamalized corn reported previously in literature.

(keywords: QPM, protein quality, lysine, tryptophan, nixtamalization).


52

FP-19

Effect of Temperature and Steeping Time on Calcium and Phosphorus Content in

Nixtamalized Corn Flours Obtained by the Traditional Nixtamalization Process

I. Rojas-Molina, E. Gutiérrez, J.L. Arjona-Román, L. Baños, M. Cortés-Álvarez, L. Campos-Solís, M.

Hernández, A. Cornejo and M.E. Rodríguez.


Querétaro, México.Departamento de Posgrado e Investigación. Facultad de Ingeniería, Universidad

Autónoma de Querétaro, Cerro de las Campanas S/N, Querétaro, México.Facultad de Estudios Superiores

Cuautitlán, Universidad Nacional Autónoma de México, Campus Cuautitlán, Cuautitlán, México.Instituto

de Materiales, Universidad Nacional Autónoma de México, México.Posgrado en Ciencias Biomédicas,

Universidad Nacional Autónoma de México, México.Universidad del Valle de México, Campus

Querétaro, México.

Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Campus

Juriquilla, Querétaro, C.P. 76230, A.P. 1-1010, Mé[email protected] ó

[email protected]

This research shows the effect of temperature (72, 82 and 92°C) and steeping time (0, 1,

3, 5, 7, 9, 11, 13 and 15 h) on calcium and phosphorus content in nixtamalized corn

flours (NCF) obtained by the traditional nixtamalization process. Atomic absorption

spectroscopy and UV-vis spectroscopy methods were used to study the calcium and

phosphorus content, as well as, the Ca/P ratio in NCF. Additionally, the deposition and

identification of calcium compounds in nixtamalized corn pericarp were analyzed by

low vacuum scanning electron microscopy, energy dispersive spectrometry and X-ray

diffraction techniques. Furthermore, dry matter loss in NCF is reported. It was found

that as the temperature increases the Ca enhances and the phosphorus content decreases

with statistical differences (P ≤ 0.05) between thermal treatments. Calcium compounds

were found in pericarp samples, which were identified as calcite. The thermo-alkaline

process increased significantly (P ≤ 0.05) the carbonate calcium content (8.98% ± 0.14,

9.28% ± 0.24 and 9.89% ± 0.24) in NCF obtained at 72, 82 and 92°C, respectively. It

was found statistical differences (P ≤ 0.05) in phosphorous content in NCF obtained at

different cooking temperatures. In addition, there was a significant correlation between

phosphorus levels and steeping time at 92°C (r = -0.91). The calcium/phosphorous ratio

in NCF obtained at 72, 82 and 92°C was in average 0.45 ± 0.03, 0.61 ± 0.05 and 0.82 ±

0.05, respectively. In consequence, the Ca/P ratio increased when cooking temperature

enhanced, nevertheless, there was no a correlation between Ca/P ratio and steeping

time. There was a high correlation (P≤ 0.01) between dry matter loss and steeping time

(r = 0.99) in NCF, this fact influenced the Ca/P ratio due to calcium attached to

pericarp. Maximum values in Ca/P ratio were detected at 7 h of steeping time in NCF

obtained at 82 and 92°C and at 9 h in NCF cooked at 72°C. These results can be used

with industrial purposes, in order to assess a maximum calcium/phosphorus ratio, and at

the same time, to avoid the loss of pericarp for increasing the functional properties of

NCF.

(keywords: calcium, phosphorus, nixtamalization, calcium/phosphorus ratio)


53

FP-20

Study of calcium Ion Diffusion in Nixtamalized Quality Protein Maize as a

Function of the Cooking Temperature

E. Gutierrez, Isela Rojas-Molina, J. L. Pons-Hernandez, H. Guzman, B. Aguas-Angel, J. Arenas, Pilar

Fernandez, G. Herrera, M.E. Rodríguez.

Departamento de Posgrado e Investigación. Facultad de Ingeniería, Universidad Autónoma de Querétaro,

Cerro de las Campanas S/N, Querétaro, México.Facultad de Estudios Superiores Cuautitlán, Universidad

Nacional Autónoma de México, Campus Cuautitlán, Cuautitlán, México. E-mail:Facultad de Ciencias

Naturales, Licenciatura en Nutrición, Universidad Autónoma de Querétaro, Querétaro, México.Instituto

Nacional de Investigaciones Forestales Agrícolas y Pecuarias, Campus Celaya, Celaya, Guanajuato,

México.

Instituto de Física, Universidad Nacional Autónoma de México, México, D. F. Instituto de Geografía,

Universidad Nacional Autónoma de México, México, D.F.Centro de Física Aplicada y Tecnología

Avanzada, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro, C.P. 76230, A.P.

1-1010, C.P. 76000, México. [email protected], [email protected]

In this report, the effect of temperature on the calcium content of Quality Protein Maize

(QPM H-368C) during the nixtamalization process as a function of the steeping time for

three cooking temperatures (72, 82 and 92°C) is presented. Also, for the first time, we

report in physicochemical terms the end of the cooking stage during the nixtamalization

process that was established when the moisture content in corn kernels reached a value

of 36% (w/w) with a lime concentration of 1% (w/v) independent of the cooking

temperature. Atomic absorption spectroscopy was used to determine the calcium

concentration in the whole kernel and in its different anatomical components, pericarp,

endosperm, and germ, as well as in 10% of the outermost layers, the next 10%, and the

remaining 80% of the endosperm as a function of the steeping time. It was found that if

the cooking temperature increases, the calcium content increases also. For steeping

times in the range of 5–7 hr, a relative maximum was found in the calcium contents of

0.24, 0.21, and 0.18%, w/w, in QPM H-368 flours at 92, 82, and 72°C, respectively.

Calcium was found in the most external layers in the endosperm and minimum diffusion

occurs in the internal 80%. Phosphorous was measured by using UV spectroscopy and

the results showed that it remains constant at 0.24% throughout the process. Scanning

electron microscopy analysis was used to explain the calcium ion diffusion in the

kernel. The physical changes in the pericarp govern the calcium diffusion process.

(keywords: ion diffusion, calcium, thermo-alkaline treatment)


54

FP-21

Physicochemical Characterization of Nopal Pads (Opuntia ficus indica) and Dry

Vacuum Nopal Powders as a Function of the Maturation

I. Rojas-Molina, M. E. Rodríguez-Garcia, C. de Lira, E. Hernández-Becerra, M. A. Cornejo-Villegas, E.

Gutiérrez, R. Reynoso, L. C. Quintero, A. Del-Real, T. A. Zepeda, C. Muñoz-Torres and M. A. Aguilera.


Querétaro, México. E-mail: [email protected] ó [email protected]. Departamento de

Posgrado e Investigación. Facultad de Ingeniería, Universidad Autónoma de Querétaro, Cerro de las

Campanas S/N, Querétaro, México. Centro de Física Aplicada y Tecnología Avanzada, Universidad

Nacional Autónoma de México, Campus Juriquilla, Querétaro, C.P. 76230, A.P. 1-1010,

México.Programa de Posgrado en Alimentos del Centro de la República (PROPAC). Facultad de

Química. Universidad Autónoma de Querétaro. Facultad de Estudios Superiores Cuautitlán, Universidad

Nacional Autónoma de México, Campus Cuautitlán, Cuautitlán, México. Laboratorio de Espectroscopia

de Absorción Atómica. Centro de Geociencias, Universidad Nacional Autónoma de México, México.

This paper presents the physicochemical and nutrimental characterization of fresh nopal

(Opuntia ficus indica, Redonda variety) and nopal powder produced at different stages

of development. Nopal powder was obtained by dry vacuum technique using 102 mm

Hg and low temperature (40°C). The results showed that the nutrimental and mineral

composition of nopal changes as a function of the maturation as follow: The ash content

increases from 18.41 for nopalitos (60 g of weight) to 23.24% (nopal pads 200 g);

calcium content increases from 1.52 to 3.72%, while phosphorous exhibits an opposite

trend: 0.43 to 0.27%, respectively. Calcium oxalate was determined by X-ray

diffraction, scanning electron microscopy (SEM) and quantified by using atomic

absorption spectroscopy. Calcium oxalate decreases from 7.95 to 3.47 mg/g and the

Ca/P ratio varies from 3.6 to 11. The soluble fiber decreases from 25.22 to 14.91%,

while insoluble fiber increases from 29.87 to 41.65%. These results suggest that nopal

could be an important source of minerals within the diets of people in Mexico and the

rest of Latin America.

(keywords: Opuntia spp, calcium oxalates, mineral content)


55

FP-22

Modelling the Kinetics of Fluidized Bed Drying of Peas Using Peleg‟s Approach

Juan Mercado Flores, Melva López Orozco, Gerardo Martínez Soto, Jazmín Camarena Martínez.

Instituto de Ciencias Agrícolas de la Universidad de Guanajuato.

[email protected]

In this research work, it is presented the application of a mathematical method based on

the Peleg equation for the kinetics of food drying. It took 16 experiments in which a

certain amount of peas (Pisum sativum) were dehydrated in a fluidized bed dryer. A

Greek-Latin square experimental design with 4 variables was used: Heat temperature,

radius of the particle, air´s velocity and bed height, in 4 levels each one. Sample mass

was determined at regular time intervals of 10 min until the equilibrium moisture was

reached. The Peleg´s Method was used on these data and were obtained two important

dry parameters by linear regression, “a”, mass fraction lose of water; and, 1/b, the time

when “a” is diminished by a half and it was obtained an average determination

coefficient of R2 = 0.9967. Once these parameter were obtained, it was analyzed their

dependence of the 4 variables by a variance method using the statistical program

Statgraphics Plus 5.1. With this model, it was achieved the simplification of the study of

process of dry by flowed bed in peas. Furthermore, an equation was determined to ease

the collecting data for a dry process simulator under condition close to the studied ones.

(keywords; Pisum sativum, bed dryer, peas)


56

FP-23

Textural and Sensory Evaluation of Cookies Prepared with Chickpea (Cicer

arietinum) and Wheat (Triticum spp.) Flour Mixtures

Sánchez Cruz, V.; Chaires-Martínez, L. and Jiménez-Avalos, H.A.

Food Research Center. Instituto Tecnológico Superior de Alamo Temapache (CIA-ITSAT). Potrero del

Llano-Tuxpan, Km 6.5. Xoyotitla, Alamo Temapache. Veracruz, México. Tel. 0176584-40038 and 39.

email. [email protected]

Chickpea is one of the most important leguminous produced in Mexico, its annual

production occupies the third place; however, it does not present a high consumption

per capita due to diverse factors although it has a great nutritional value. Thus, the aim

of this work was to elaborate cookies with mixtures of chickpea and wheat flour at

several proportions and to evaluate its textural and sensorial properties. Chickpea flour

was produced in the lab whereas wheat flour was of commercial brand. Cookies were

prepared and the texture of the dough and of the finished product was evaluated using a

CNS Farnell Brokfield (QTS-25) texture analyzer. Dough was placed in 50 ml vessels

and uniaxially compressed into 15 mm in a double cycle at a constant rate of 30

mm/min and a 5 s waiting period, with a 2.5 cm in diameter cylindrical acrylic probe

attached to the same texture analyzer. For the cookies, a compression proof was carried

out using uniaxially deforming samples of 7 mm at a constant speed of 30 mm/min

using the three point bend probe. Statistical analysis was carried out with a TexturePro

v2.0 and SPSS v11.0 software. Results shown that hardness in chickpea flour samples

was significantly higher (P<0.05) than that of 100% wheat flour (up to 200 %); whereas

the cohesiveness, springiness and adhesiveness parameters were significantly low (up to

70, 30 and 75 % respectively); gumminess did not present significant differences

attributed to the increasing concentration of chickpea flour. In sensorial analyses, the

acceptance proof carried out with the cookies showed that it was not notorious the

presence of chickpea flour in the samples since significant difference was not observed

in the values granted by the not trained judges; besides they accepted well the product.

With the previous thing, we conclude that chickpea flour is a good alternative to

strengthening the bakery products without affecting to great extent textural and

sensorial characteristics.

(keywords: chickpea, TPA, sensory analyses)


57

FP-24

Thixotropy and Flow Behavior of Ternary Dispersions of Biopolymers

Arámbula-Peña, A. L., Ramos-Ramírez, E. G., Salazar-Montoya, J. A.

Department of Biotechnology and Bioengineering, CINVESTAV-IPN.

Av. IPN 2508, P. O. Box 14-740, C. P. 07360 México 14, D. F. México.

Email: [email protected]

Some biopolymers have gelatinization, emulsification and thickening properties, reason

why food industries uses them like additives. The propylenglycol alginate (PGA) is

used like foam stabilizer. The gum arabic (GA) is very soluble in water and it has many

applications in the industry like foam stabilizer, flavor fixer, emulsifying of drinks,

dehydrated soaps and sauces. The tragacanth gum (TG) is resisted to acid way; the

industry uses it to stabilize soaps, ice cream, dairy and confectionary products. The

main objective of this research was the determination of the thixotropy and flow

behavior of ternary dispersions at different concentrations. Design of random blocks

was used for research of mixtures behavior at different concentrations of three

biopolymers (PGA, GA, TG). The rheological parameters were obtained by a low stress

rheometer LS 100 (Paar Physica, Germany). The mixture containing the biggest

quantity of PGA had the highest viscosity (112.9 mPa s). Whereas the mixture

containing the biggest quantity of GA had the highest thixotropy (1214.95 Pa/s), at the

same time it had the lowest viscosity (35.2 mPas). On the other hand, the mixture

containing the biggest quantity of TG had the lowest thixotropy (80.85 Pa/s). The

rheological model used to describe the mixture parameters was Ostwald-de-Waele. The

mixture containing the biggest quantity of GA presents a diminution of 63.35% in

consistency coefficient with respect to the mixture containing the biggest quantity of

TG. All mixtures presented a flow behavior index below to 1, in an interval of 0.529 to

0.667. The mixtures presented a non-Newtonian behavior of shear thinning flow; in

which when the shear rate increasing, the viscosity decreases.

(keywords: thixotropy, viscosity, biopolymers.)


58

FP-25

Creep Rheological Behavior of Dispersions Containing Gum Arabic

and Soy Protein Mixtures

Jiménez-Avalos,H. A., Ramos-Ramírez, E. G., Salazar-Montoya, J. A.

Department of Biotechnology and Bioengineering. CINVESTAV-IPN.


E-mail: [email protected] Current Address: Food Research Center. Instituto Tecnológico

Superior del Alamo Temapache, Km 6.5 Carretera Potrero del Llano-Tuxpan.

Xoyotitla, Alamo Temapache, Veracruz.

Gum arabic is used in diverse foods by its properties like thickening agent, which have

been mixed with other biopolymers as soy proteins, they give textures to the food to be

more accepted by the consumers. The aim of this study was to determinate the creep

rheological behavior of dispersions containing gum arabic (GA), soy proteins (SP) and

its mixtures (GA/SP). GA dispersions (10 and 15%, w/v), SP dispersions (1 to 8%, w/v)

and mixtures GA/SP (values of conc?) were prepared. Rheological creep test were

performed in a low stress rheometer LS 100 (Paar Physica, Germany). In creep curves

for GA dispersions, no recovery was observed when the applied stress was suspended,

since the dispersions behaved as viscoelastic liquids; while in the SP dispersions at 8%,

it was observed a recovery of 96%, behaved as viscoelastic solids. In the mixtures

GA/SP no recovery was observed when the applied stress was suspended, which

indicates that when mixing GA and SP, the typical behavior of viscoelastic liquid

predominates. Viscosities values (0) obtained according to the Kelvin model, in GA

dispersions, they were 0.15 and 0.38 Pas respectively and in SP dispersions they

presented values of 0 of 3.45x105 Pas at the maximum concentration of 8%. In the

mixtures, when incorporating GA, 0 diminished 106 % presenting values around of 1.3

Pa s, at 15/8 % (w/v). This decrease probably is due to a segregative effect when GA

were incorporated.

(keywords: creep, gum arabic, soy proteins)


59

FP-26

Rheological Properties of Mixture of Crude and Purified Mucins

Delgado-Reyes, V. A., Ramos-Ramírez, E. G., Salazar-Montoya, J. A.

Department of Biotechnology and Bioengineering, CINVESTAV-IPN.


Email: [email protected]

The mucins are polymers of proteins and carbohydrates (glycoproteins) where the chain

of oligosaccharides is united covalently to a skeleton of peptide nature by bound-ortho.

These glycoproteins are secreted by mucosal epithelial, where its protective function it

is attributed to the high viscosity that presents; are in the snot of secretions of the

gastrointestinal, respiratory and reproductive apparatuses of mammals. In this study the

rheological properties of mixture crude and purified mucins were determined.

Dispersions of crude and purified mucins at 20% concentration (w/v) and mixtures of

crude mucin (25, 50 and 75%) and purified mucin were prepared (75, 50 and 25%). The

rheological parameters ???(K, n, ) and the material functions ???(G´, G´´) were

obtained using a low stress rheometer LS 100 (Paar Physica, Germany). The model that

better represented the experimental results was the Ostwald-de-Waele, the values of the

consistency index were 48% bigger in mixtures where the purified mucin ¿this in more?

percentage (75%), the flow behavior index is an interval of 0,574 to 0.643. The studied

mucins presented a behavior of macromolecular dissolution (G´´> G´). The values of

the storage module (G´) were 72% bigger in purified mucin (20%) and 32% in the

mixtures with 25% of crude mucin, and 75% of purified mucin.

(keywords: pure mucin, crude mucin, rheology, viscoelasticity)


60

FP-27

Microencapsulation of Lactobacillus sp. by Ionic Gelation

Rosas-Flores, W., Ramos-Ramírez, E. G., Salazar-Montoya, J. A.

Department of Biotechnology and Bioengineering, CINVESTAV-IPN. Av. IPN 2508, P. O. Box 14-740,

C. P. 07360 México 14, D. F. México. *Email: [email protected]

The ionic gelation is a technique in which divalent and monovalent cations can interact

with anionic polysaccharides and it can generate three-dimensional networks. Thus it is

possible that these networks can be used to cover and protect an active ingredient, as a

flavor or cells of industrial interest. In this research, we pose a technique for

microencapsulation of Lactobacillus sp. without changing the viability of the culture

using a binary mixture of sodium alginate and gellan gum; thus it was necessary the

characterization of flow behavior of dispersions containing biopolymers. The

microencapsulation was carried out using ionic gelation through an emulsion W/O at

different agitation rates (480, 800, and 1200 rpm). In order to determine the efficiency

of microencapsulation it was necessary to count the unit forming colonies before and

after microencapsulation process. From the results we can conclude that the flow

behavior shown by dispersions studied was non-Newtonian type shear thinning, because

the flow behavior index remained below the unit in all cases. Regarding the rates of

agitation studied, we noted that the lowest speed of agitation, which affected less the

viability of the culture (10%), allowed a 90% efficiency in microencapsulation. While

for the other rates of agitation (800, 1200 rpm), the stress generated had a negative

effect on efficiency, lowering its value as much as 50%.

(keywords: emulsion, alginate, gellan gum, Lactobacillus sp., microencapsulation)


61

FP-28

“Ataulfo” Mango Nectar Stabilized with Polysaccharides

Cruz Juárez, W., Cisneros Martínez, A., Hernández Mondragón, T., Ocadiz García, M., Muñoz Aguilar,

P. y Ramírez Ortiz, M.E.

Departamento de Ingeniería y Tecnología, Facultad de Estudios Superiores Cuautitlán-UNAM, Av. 1º de

Mayo s/n, Col. Sta. Ma. Las Torres, Cuautitlán Izcalli, Edo. de México, México, C.P. 054740.

e-mail: [email protected]

Mango is a tropical fruit with much acceptance between the consumers, but is a fruit

few exploit at industrial level, except the Manila Mango, the other species have not been

used more than for direct consumption, for that reason is consider the application of the

variety ataulfo for the elaboration of a drink made out of nectar. The main technological

preoccupation in this product is the sedimentation of the mango pulp after time

preparation, for it is added stabilizers, taking care of that do not modify the

characteristics flavor, color and visual appearance. In this work four different

polysaccharides were used: Gomar guar, xantana, carboximetilcelulosa (CMC) and

pectina, two concentrations in all the cases: 0.075 and 0,1% were used. Flow behavior

was evaluated on different nectars by means flow curves in viscometer Haake

Viscotester VT550 and MV-DIN from 0,5 to 500 s-1

, in ascending and descendent form.

Analysis of the relative thixotropic areas calculated by integration. Also, a stability test

was realised putting 10 ml of nectar under centrifugation for 20 min. Results were

analyzed using analysis of variance (ANOVA) with = 0.05. The following results were

obtained, in all the cases the samples adjusted to the Power Law behavior type and

concentration of polysaccharide has significant influence on n and K parameters. When

polymer concentration was increased the K value was also increased. For n values, it

falls generally when the polysaccharide concentration was increased. Stability was

increased when polysaccharide concentration increased. Xanthan gum was the polymer

that provided more stability to the nectar.

(keywords: Polysaccharides, stability, drink, mango)


62

FP-29

Polysaccharide Effects on Rheological and Textural Properties in Water Bread

Aguirre Ponce, J. D., Herrera Trejo, D. K., Rodríguez Carmona, O. Y., Sampedro Pérez, S. I., Muñoz

Aguilar, P. y Ramírez Ortiz, M.E.

Departamento de Ingeniería y Tecnología, Facultad de Estudios Superiores Cuautitlán-UNAM, Av. 1º de

Mayo s/n, Col. Sta. Ma. Las Torres, Cuautitlán Izcalli, Edo. de México, México, C.P. 054740.e-mail:

[email protected]

Nowadays, in the food industry is important to analyze and study both training as the

stabilization of solid foam. In bakery products added with hydrocolloids, are modified

some rheological and textural properties according to polysaccharide used. However,

the results generated add them to reflect better uniformity in crumb and a delay of

ageing on the bread, very important factor in the quality of the finished product and

therefore the shelf life. This paper describes the behavior of comparative form and

functionality, of guar gums, xanthan and mezquite, added in a water bread, each one

with three concentrations (0.25, 0.50 and 1% w/w?). We used a rheometer Haake (RM

software version 3.11.01), with a plaque rough 35 mm in diameter and 1mm gap, to

determinate the linear zone () took place a scanning of 39 to 1000 Pa at 1 Hz; after

there was a sweep of frequencies from 0.1 to 100 Hz ( T= 25°C) to establish the

viscoelastic behavior. To assess the texture was used a test profile texture with a

texturometer (Lloyd TA500 with cell loading 1Kg); took place at 2 different conditions:

bread (penetration crust) was assessed with a cone of acrylic, 15 °, crumb was evaluated

in a transversal cut, with a cylinder of 1/8 in; parameters considered were hardness and

cohesiveness, particularly to chewiness for the crumb and gumminess for the crust

(T=25 ° C). To statistical analysis was used an Anova with a = 0.05. The results

obtained were as follows: All doughs evaluated showed that G ' (elastic behaviour) was

always higher than G'' (viscous behavior) because increasing the concentration. As for

the textural properties, the hardness of bread increased proportionately with the

concentration of gums. It was noted that the guar gum at low concentrations produced

better effects by reducing the hardness. Rather gum xanthan, increasing its

concentration retained more water reflected in a high value on the hardness. The

mezquite gum introduced a stable behavior to varying concentrations, because it did not

have very drastic changes in the assessments made. Based on the analysis showed that

the concentration is a significant parameter for the hardness (p <0.005).

(keywords: polysaccharides, bread, texture properties, rheological behavior)


63

FP-30

Mango (Mangifera indica L.) Jam Low in Sugars

Ortiz Melchor, R., Fuentes Romero, M.E. y Ramírez Ortiz, M.E.

Departamento Ingeniería y Tecnología, Facultad de Estudios Superiores Cuautitlán- UNAM, Av. 1º de

Mayo s/n, Col. Sta. Ma. Las Torres, Cuautitlán Izcalli, Edo. de México, MéxicoC.P. 54740 * E-mail: [email protected]

The last market tendencies denote an increasing demand of hypocaloric foods by

different causes. In first place, the limitation or exclusion of the diet of sugars is for

disease reasons, as the diabetes case, that the people have altered the glucose

metabolism and therefore limited its consumption of specific form. In addition, they are

the injurious effects that on the health have the rich diets in carbohydrates and fats, and

finally the aesthetic reasons or fashionable. Mango pulp of Tommy Atkins variety was

used it was 14 ºBrix and an acidity of 9 g/L. Also, low methoxyl pectin and two

modified starches (a potato starch cross-linked and other stabilized with acetic

anhydride), were used. Three concentrations: 3.5, 4,5 and 5.5% for starches and 0.65,

0.75 and 0,8% for pectin were used. To diminish the sugar content, sucralose in a single

concentration was used. Textural behavior was evaluated using a texture analyzer TA-

XT2 with 2.54 cm cylinder probe. They were obtained from the texture profile, the

hardness, adhesiveness, cohesiveness and gumminess like parameters that they describe

to this product. Analysis of variance with = 0.05 was employed for data analysis. It

was obtained that the hardness, adhesiveness and gumminess of the jam were increased

with the increase of polymer concentration in significant form (P < 0.05) Nevertheless,

jams made with pectin showed values very superiors respect to the elaborated with

starches, this probably is due to the different gel formation mechanisms, that involves in

the case of the pectin the formation of ionic and hydrogen bonds, forming therefore one

more reinforced three-dimensional network, whereas for starches only hydrogen bonds

were involved. A tendency similar is showed for cohesiveness of samples made with

starches, the value of this was increased when starch concentration was increased and in

the case of samples made with pectin, values were constant, probably because the

formation of ionic bonds of this is limited by the ion concentration in the formulation

that was constant for the three formulations and in this way the cohesiveness of gel not

is modifies.

(keywords: polysaccharides, gel texture properties)


64

FP-31

Evaluation of Chemical, Physical and Rheological Characteristics of Flours

Obtained From Bread Wheat With Different Percentage of the “Yellow Berry

Defect”

López-Ahumada , G.A., Ramírez-Wong, B., Milán-Carrillo, J., Zazueta-Morales, J.J., Garzón-Tiznado,

J.A., Figueroa, J.D.

Departamento de Investigación y Posgrado en Alimentos. Universidad de Sonora. Rosales y Blvd.. Luis

Encinas s/n. Col. Centro. Tel y fax: 662259-22-07 a 09. Hermosillo, Son., c.p 83000.

[email protected]

Recently, in the State of Sonora Mexico, bread wheat cultivars have been affected by a

physiological disorder named “yellow berry”. A research was performed to characterize

chemically, physically and rheologically flours obtained from a commercial bread

cultivar (Tarachi) with 0, 11, 45, 60 and 100 % of yellow berry. Flours were evaluated

for moisture content, ash content, protein content, sedimentation volume, falling

number and wet gluten. In addition, rheological determinations were made with the

farinograph, alveograph and the rapid viscoamylograph. A completely randomized

experiment design was carried out. The percentage of yellow berry in the bread wheat

cultivar affected the evaluated characteristics. Include the range values of moisture, ash,

protein content, etc obtained Significant differences (p<0.05) were observed in moisture

and protein contents, falling number, sedimentation, wet gluten; development time and

water absorption measured with the farinograph and tenacitiy, elasticity and dough

work deformation measured with the alveograph. Significant differences (p<0.05) also

were observed in bread volume. It was concluded that flour obtained from wheat with

11% of “yellow berry” gave still bread with acceptable volume.

(keywords: yellow berry, bread wheat, bread volume)


65

FP-32

Rheological Characterization and Texture Profile Analysis of a Squeeze and Low

in Sugar Mango Jam Elaborated with Different Polysaccharides

López-Hernández, G., Hurtado-López, C; Valtierra-Aguilar, M, Ramirez Ortíz María Eugenia; Romero

Arreola Verónica .

Departamento de Ingeniería y Tecnología, Facultad de Estudios Superiores Cuautitlán. Universidad

Nacional Autónoma de México. Cuautitlan Izcalli, Edo. De México. [email protected]

Mexico counts with a wide variety of tropical fruits such as mango that, in spite of

having a great acceptance in the market as raw material, it has not been properly

industrialized. In this project the elaboration of a squeeze and sugar reduced “ataulfo”

mango jam was proposed. In this project it was established the use of three

polysaccharides (low methoxyl amidated pectin =LMP amidated=, propyleneglycol

alginate and carrageenan) at three concentrations (0.5%, 0.75% y 1%). Fifty percent of

sugar was reduced and replaced by maltodextrin of 20 DE. Flow curves and rheological

parameters were obtained using the Haake Viscosimeter VT-550 (𝛾 from 1 to 500 1/s)

with SV-DIN, and the Haake Rheometer RT-20 (𝛾 from 1 to 10 1/s) with the serrated

plate PP35 and a distance of 1 mm. To get TPA curve it was occupied the Lloyd TA500

with a 254 mm cylyndrical geometry, using a load cell of 50 kg m/s2, the sample was

placed en petri dishes. The penetration distance was 7 mm at a speed of 0.0016

mm/min. Parameters considered were hardness and adhesiveness. Data were analyzed

from ANOVA with a α0.05 in a Minitab software. For the product consistency (kc, τ0,

hardness), neither the kind of polysaccharide nor the concentration have a significant

influence. However, from Tukey test a 7.2% probability to obtain the same hardness

and 14.9% to obtain a similar adhesiveness between each polysaccharide was found.

Also a probability of 3.5% was found to get a similar hardness and 0.3% for a similar

adhesiveness between each concentration. The kind of polysaccharide and concentration

did not affect the model defining the behavior, which is Casson. We conclude that low

methoxyl amidated pectin is a gelling polysaccharide suitable for this type of jam ,

because it confers low viscosity, hardness and adhesiveness, which if higher would not

allow flow of the jam from a squeeze bottle.

(keywords: mango jam, rheological analysis, low methoxyl amidated pectin)


66

FP-33

Effect of Drying Time, Bean Depth, Temperature and Air Flow on Volatile

Acidity, pH and Phenols Totals of Mexican Cocoa Beans.

Barrios Viñas, M.L., and García Alamilla, P.

Universidad Juárez Autónoma de Tabasco (UJAT). División Académica de Ciencias Agropecuarias

(DACA). Centro de Investigación en Ciencias Agropecuarias (CICA). Carret. Vhsa – Teapa Km. 25.

Villahermosa, Tabasco, México. E- mail: [email protected]

Tel: 993358-1585 fax (142 9151 y 142 91 50) ext 6604

Departamento de Investigación y Postgrado. Instituto Tecnológico de Villahermosa. Villahermosa,

Tabasco, México.

Please Include a brief introduction. The drying time (??), bean depth (2.5–7.5 cm.),

extraction rate of air flow (0.3–1.2 m/s), and temperature (40–70°C) on volatile acidity,

total acidity, pH, phenols totals was studied. The drying process of cocoa beans was

realized?? in a tray drier until the moisture content of the beans was reduced to 7.5 %.

The samples were dried according to a central composite rotatable design configuration

for three factors. The data were analyzed using MATLAB program for statistical

analysis. The regression coefficients were then used to plot three dimensional on the

response surface methodology. The drying system in trays manifested near levels of

volatile acidity to the limits settled down by Augier 1999, however the pH values didn't

reach the value of 5.0 recommended in the international level. For the total acidity they

were superior values to 3 ml/g under the study conditions. The best drying treatment

was obtained at the combination of bean depth 3 cm, extraction rate of air flow of 0.4

m/s and temperatures drops of 50°C.

(key words: cocoa beans drying, response surface methodology, volatile acidity, pH,

phenols totals)


67

FP-34

Evaluation of Fat Pepper (pepper dioica l. merril) Dehydration in Fluid Bed with

Tempering Cycles, using the Residual Enzymatic Activity as a Quality Parameter

Flores-Martínez, N.L., Cruz y Victoria, M.T., Anaya-Sosa, I.

Laboratorio de Graduados en Alimentos. Escuela Nacional de Ciencias Biológicas (IPN). Prol. de Carpio

y Plan de Ayala s/n. 11340. México D.F.

Fat pepper (Pimenta dioica L. Merril) is a fruit with high moisture content that is

dehydrated with commercial purposes. In order to export a high quality product, it is

necessary to find a suitable drying technology to maintain the quality of the fruit.

Therefore, the aim of this work was to implement the tempering drying technique,

which has been proved to be a simple and highly efficient methodology to reduce the

moisture content (12% w.b.), to dehydrate fat pepper. The parameters considered to

measure the quality of the fruit were peroxidase enzyme (Worthinton manual) and

ascorbic acid retention (Xylene extraction method). The experimental design consisted

of a 22

factorial where the operation temperatures were 60°, 70° and 80°C, and the

tdrying/tcycle ratio was 0.5, 1 and 1.5. The operating conditions were determined according

to the minimum fluidizing velocity (Umf), which was 4.75 m·s-1

. Thus, the operation

velocity (Uop) was 1.2 times the Umf value, and the ratio diameter : length of the drying

chamber (L/D) was 0.5. The diameter of the fresh pepper was reduced by 43% (from 7.5

to 4.3 mm) after the drying process. The apparent and packed densities increased after

the process; sphericity was taken as the unit because of the geometrical shape of the

pepper fruit. For each of the evaluated temperatures, we observed a constant drying rate

period ranging from 20 to 55 min, which represents 1/4 to 1/5 of the total drying time

without tempering cycles. The use of tempering cycles enabled the removal of 2/3 of the

moisture content of the fruit at the same velocity, which means that the amount of

removed water can be increased up to three times compared to conventional drying

techniques. The values of the diffusion coefficient using the second Fick`s law were

found in the range (4.39-6.63) x10-8

m2 s

-1. Peroxidase retention increased with the

tempering cycles at 70° C compared to the control, while the ascorbic acid retention

decreased 50% with batch drying and tempering drying.

(keywords: fluidized bed, tempering cycles, peroxidase)


68

FP-35

Characterization of product quality attributes and morphological changes of

laminated snack during frying

Santacruz-Vázquez Claudia; Santacruz-Vázquez Verónica;

Cerón-Luna Higinio; Campos-Rodríguez Gustavo.

Benemérita Universidad Autónoma de Puebla. Facultad de Ingeniería Química.

CP. 72560. Puebla, México. e-mail: [email protected]

Frying is one of the most popular unit operations to process food. Frying makes food

more palatable. Economical potential for development of innovative and improved

frying processes was reported in literature. Typical examples of frying technology still

includes improving oil quality, oil absorption mechanism, and engineering

considerations of residence time and design of fryers. Deep-fat frying, or immersions

frying, is defined as the process of cooking and dehydration of foods by immersing

them in hot oil ocurring several chemical and physical changes. Starch gelatinization,

protein denaturation, and flavor development are the most frequently structural changes

that occur during frying of food. Physical changes are manifested as a decrease in

moisture content, increase in product temperature, oil content, and crust formation. The

aim of this work was the characterization of product quality attributes and

morphological changes of laminated snack prepared with wheat flour, in order to

provide critical information that can be used to describe the structural changes in the

product during frying. Snack food were prepared with wheat flour and samples were

deep-fried in cartamo oil at lab-scale temperatures of 180, 190 and 200 ºC with frying

times of 30, 60, 90, 120, 150, 180, 210, 240, 270 y 300 s. Microstructural changes were

determined by Stereomicroscope (magnification 10X) and the fractal dimension (FD) of

the microscopic images was determined using a box counting technique. The

differences in means among samples were analyzed with Tukey‟s test. The results

indicated that expansion of snack food happened during the first 90 s of frying. The

snack food expansion increased as a result of some bubbles developed at the surface due

to gas expansion. The snacks become more porous in number and size. The pore size

distribution (values?) became more uniform as frying time increased and the

temperature increased. The frying time and temperature of oil correlated well with

microstructural changes represented by the normalized changes of fractal dimension

(ΔFD/FD0). The combination of all quality attributes is responsible for produccing the

best final product.

(keywords: pores; texture; expansion; snack; morphological changes)


69

FP-36

Development of Low Cost-High Nutrional Value Sauce Fortified with -Carotene

Santacruz-Vázquez, V., Santacruz-Vázquez C., Mateos-Bonilla C., García-Juárez S., Monter-Vázquez N.

Facultad de Ingeniería Química, Benemérita Universidad Autónoma de Puebla, Av. San Claudio s/n.

ciudad universitaria, Puebla, Puebla, C.P. 72570, [email protected]

The antioxidants are chemical substances that are characterized for delay the oxidation

of diverse originating substances from the oxidation of fatty acids, that bring about

negative effects for the health of the human being. carotene is an additive whose

antioxidant activity has been widely recognized, reason for which the objective of this

work was the design of a fortified sauce from papaya with -carotene in a 1%

concentration w/w which presented similar characteristics to commercial ketchup

sauces. During the development of the final product, several formulations were tested

which added -carotene to them in a 1% concentration w/w and which were

characterized with the following methods: sensorial acceptance, color, sweet flavor and

consistency. The microbiological tests consisted in determination of fungi, coliforms

and mesophilic aerobic bacteria The physico-chemical characterization was obtained by

means of the determination of the proximal analysis, color and concentration of -

carotene by HPLC method. The selection of the final formulation was the one that

presented major similarity with commercial ketchup sauces. The developed product

presented a water activity of 0.858; pH 4.36 and moisture content of 88%, shelf life of

60 days, and a sensorial acceptance of 8 in hedonic scale of 9 points. Referring to the

microbiological determinations of coliforms, fungi and mesophilic aerobic bacteria it

was obtained over the course of approximately 36 hours. The levels of viable cells were

counted and increased approximately 2 and 2.5 log cycles, respectively microbial counts

of log10 to log10 CFU/g for coliforms and fungi, lower values to the accepted ones in

the CODEX. he -carotene concentration in the final products was 0.75% of initial

-carotene concentration, which showed that 25% of carotene were thermally

destroyed during processing of sauce.

(keywords: Papaya sauce, -carotene, fortified products design)


70

FP-37

Dehydration and Rehydration of Freeze Dried Corn Grains

Santacruz-Vázquez Claudia; Santacruz-Vázquez Verónica; Monter-Vázquez Nataly; Juárez Vázquez

Adriana.

Benemérita Universidad Autónoma de Puebla. Facultad de Ingeniería Química y Alimentos Ciudad

Universitaria. C. P. 72570. Puebla, México.

[email protected]

Corn grains (Zea mays L.), were freeze dried for 28 h. Freeze-dried products were then

rehydrated at 20°, 40° and 80°C in distilled water. A simple diffusive-type equation was

used to represent water uptake during rehydration. The progression of the rehydration

coefficient (RC) was followed as a function of time (30 min). Effective diffusion

coefficients were modeled as a function of temperature using an Arrhenius-type

relationship. Color and texture of rehydrated samples will be compared to initial

parameters. Samples were also tested for firmness before freeze-drying and after

rehydration (5 min) at different bath temperatures (20–80°C), by a puncture test on a

Texture Analyzer. The firmness was taken as the maximum force recorded in Newtons.

Microstructure observation of fresh and dried samples was carried out in a

Stereomicroscope Stemi 2000 (magnification 10X). Obtained images were stored as bit

maps in gray scale (0-255). The scanning differential box counting method (SDBC) was

used to evaluate the fractal dimension of images by means of ImageJ 1.34 software. The

results showed that corn grains had higher RC when rehydrated at a temperature 80°C.

Rehydration data as a function of time of processing showed a hyperbolic shape with an

initial steep increase in water uptake followed by a decrease in rehydration rate and a

final stage. Temperature showed a marked effect on rehydration of freeze-dried

products. Effective diffusion coefficients increased with temperature, the values are near

of 8.00x10-8

(m2/s). Diffusion coefficients were correlated as a function of temperature.

Firmness and color after rehydration decreased from initial values, indicating that

rehydrated freeze-dried corn grains do not have the same textural and color properties of

the fresh products. At 20°C rehydration temperature, firmness seemed to be higher than

for products rehydrated at other temperatures. The fractal dimension SDBC of freeze-

dried corn grains (FDSDBC), was 2.745. Rehydration ratio of freeze-dried foods is in

general 4–6 times higher than air-dried foods, making freeze-dried products an excellent

option for ready-to-eat instant meals or soups.

(keywords: freeze dried; corn grains; rehydration coefficient)


71

FP-38

Structural and Textural Evaluation of Gluten-Free Bread Crumb

Santacruz-Vázquez Claudia; Santacruz-Vázquez Verónica; Manzano-Hernández Jazmín; García-Juárez

Sandra.

Benemérita Universidad Autónoma de Puebla. Facultad de Ingeniería Química.

CP. 72560. Puebla, México. e-mail: [email protected].

Coeliac disease is caused by a reaction to gliadin, a gluten protein found in wheat. Upon

exposure to gliadin, the enzyme tissue transglutaminase modifies the protein, and the

immune system cross-reacts with the bowel tissue, causing an inflammatory reaction.

The replacement of the gluten network in the development of gluten-free cereal

products is a challenging task for the cereal technologist. The functionality of proteins

from gluten-free flours could modify the structure and texture of gluten free bread. The

aim of this work was to evaluate the cellular structure of gluten-free bread crumb using

digital image and texture analysis and was compared with bread crumb baked with

added gluten.The bread was formulated with different mixtures of ingredients and was

baked in swing oven at 180° C for 40 min. Physicochemical characterization was

carried out to analyze the contents of ash, protein, fat, fiber and carbohydrates. Once the

samples were baked and packed on the day of production, the texture was determined.

Softness was measured using a texturometer TAXT2. Microstructure observation at

different sections of bread samples was carried out in a Stereomicroscope Stemi 2000

(magnification 10X). Crumb brightness, mean cell area, and crumb density (number of

cells/cm2), were determined by image analysis. The differences in means among

samples were analyzed with Tukey‟s test. The moisture content of free bread of gluten

was of 42.39%; protein 6.46%, fat 9.64%; fiber 1.10%; ash 1.28%; and carbohydrates

39.12%. The ingredients used in the tested formulation influenced in the microstructure

of gluten free bread crumb having a larger pore distribution, whereas in bread crumb

baked with added gluten the size of pores is smaller and with a more homogeneous pore

distribution. The structural parameters of bread crumb were strongly related to fracture

stress, with crumb density and brightness showing highly significant correlations.These

results demostrate that the remplacement of the gluten in the formulation of bread had

an important role in the microstructure and textural analysis of crumb.

(key words: gluten free; bread crumb; microstructure; textural evaluation; coeliac)


72

FP-39

Evaluation of polyelectrolyte complex between chitosan-oligosaccharides with

pectic polysaccharides using colorimetric and spectroscopic methods

Zamora-Iruegas C. A., A.M. Rangel-Rodríguez and Contreras-Esquivel J. C.

1 Departamento de Investigación en alimentos, Facultad de Ciencias Químicas, Universidad Autónoma

de Coahuila, blvd. Venustiano Carranza y José Cárdenas s/n. Col. República

Saltillo, Coahuila 25280.

CoyoteFoods Biopolymer and Biotechnology S. de R.L. Saltillo, Coahuila, Mexico.

E-mail: [email protected]

In the present study polyelectrolyte complexes (PECs) were prepared with chitosan-

oligosaccharides (COS) and pectic polysaccharides. The aim of this work was evaluate

the complex formation between pectic polysaccharides and COS. Pectins with degree

of esterification degree (DE) of 0, 30, 60, 90 %, rhamnogalacturonan and pectin

galactan were used for evaluate formation of PECs. Pectic polysaccharides were mixed

with COS of molecular weight of chitosan oligosaccharides of 3, 10 and 50 kDa. The

formation of PECs complex was evaluated by colorimetric method using brilliant

remazol blue (BBR). Chemical structural characterization of PECs was performed by

FTIR. The results showed that the dye interacts with the COS by bonding the amino and

sulfate groups, which produces a blue precipitate after centrifugation of the solution of

PECs. The BBR concentration in the solution after centrifugation is directly

proportional to the quantity of formed PECs. We found that there is the formation of

low, medium and high complex groups, where in the first group we found the PECs of

COS with pectin of 90 % DE. The second group comprised the pectin galactan, while

the last group showed the pectin of 0, 30 60 % DE and rhamnogalacturonan. Results

showed that pectins of low DE showed higher complex formation, indicating that the

DE affected the PECs formation. In the PECs of COS 3 kDa with pectic

polysaccharides is observed the higher yields (88 %) of PECs. We found that COS of

lower molecular weight have better capacity to form PECs. The characterized PECs

showed changes in the absorption bands at 1640-1620 cm-1

the carboxyl group

decreased due to complex formation. The band of amino proton at 1520 cm-1

increased

due to the acid pH of the medium. The colorimetric and spectroscopic methods are

efficient techniques to evaluate complex formation between pectic polysaccharides with

COS for PECs formation.

(keywords: pectin, chitosan, polyelectrolyte)


73

FP-40

An Alternative Method for Extraction of Candelilla Wax (Euphorbia

antysyphilitica).

De león-Zapata, M.,Saucedo-Pompa, S., Contreras-Esquivel, J.C., Jasso-Cantu, D.,

Sáenz-Galindo, A., Aguilar, C.N.

Departamento de investigación en alimentos. Facultad de ciencias químicas. Universidad Autónoma de

Coahuila. Blvd. Venustiano Carranza PO BOX 252. ZIP 25000, Saltillo, Coahuila, México. Tel: +52 844

4161238, Fax: +52 844 4159534, *E-mail: [email protected]

Universidad Autónoma Agraria Antonio Narro. Calzada Antonio Narro s/n. Buenavista, Saltillo,

Coahuila, México.

The candelilla plant (Euphorbia antysyphilitica Zacc) is an endemic species of the

Mexican semi-desert. The producers from the State of Coahuila exploit this natural

resource. Wax extraction from candelilla is one of the most important economic

activities in this region because from it depends economically significant numbers of

farmers. Current wax extraction process is carried out by artisanal methods

implemented over a century ago which involves the immersion of the plant in a solution

of sulfuric acid, which is used in large quantities and very high concentrations,

representing serious health problems and pollution. Due to this problem, we propose

new agents to extract this edible candelilla wax, we also tested some modifications in

the extraction process in order to avoid emissions of toxic chemicals which damage the

health of the person responsible for this activity and also to the environment. Three new

extraction agents proposed in this study were used at different concentrations. these

substances are biodegradable and do not represent any significant damage to health or

the environment, are cheaper, as well as control the wax was extracted through

traditional methods (20% H2SO4) as control. The obtained waxes were characterized by

infrared spectroscopy, nuclear magnetic resonance of hydrogen and carbon. These

agents showed similar wax extraction yields compared with traditional process (p ≤

0.05), besides introducing lower amount of impurities in wax and showing a better

quality. By using these substances, it was obtained a better performance than with

sulfuric acid, in addition to being less expensive.

(key words: Candelilla, wax, extraction)


74

FP-41

Phosphate Effect over Potato Yield and Physicochemical Properties of Potato

Starch

Juárez-Robles, D.R., Martínez-Barajas, E., Bernal, L.

Coordinación de Investigación. Escuela de Ciencias Químicas. Universidad La Salle. Benjamín Franklin

47. Col. Hipodromo Condesa. C.P. 06140 México, D.F. *[email protected]

Phosphorus (P) is an essential nutrient for plants because it is a key component in

metabolic processes. The effect of two levels of P (100 and 500 µM) over potato

production was evaluated. The yield, tuber composition and the properties of starch

purified from tubers were analyzed. The results indicated that the yield was reduced by

39% when plants were cultivated with a low level of P. Moisture, ashes, crude fiber and

fat contents were similar between tubers coming from both treatments; while protein

level was increased in tubers produced by plants cultivated with low P. Starch

phosphorylation was reduced by 16% in plants cultivated with low P, but the amylose

level was increased. Starch amylolysis and the viscosity provided were also diminished

by P deficiency. The differences in phosphorylation and amylose content were assumed

to contribute to the differences in rheological properties and amylolysis susceptibility.

(keywords: potato, starch, phosphate)


75

FP-42

Development of a Nutritive Snack by Extrusion Using Corn and Chickpeas.

Velasco-González, O.H., Nava-Pérez, E., Mares, Q. S de J., Ramírez, W. B., Pajarito, R. A.

CIIDIR-IPN-DURANGO, Sigma S/N, Frac. 20 de Nov. II, Durango, Dgo. México. C.P. 34220

[email protected]; [email protected]; [email protected]; [email protected]

Nowadays in Mexico the consumption of poorly nutritious food is high, using the great

acceptance inside the children community. Presently in Durango‟s schools the

consumption of this type of food has been restricted, and recently the rules for the right

commercialization of this products has been published. In 2006 the Official Newspaper

of Baja California Sur published that the consumption of “junk food” was prohibited.

However there are no alternative food products available yet. One solution was the

manufacture of a new product that was able to replace poorly nutritious food, with a

product having high of amino acids content, which can be comparable to that

recommended by FAO. In this project we used chick-peas that were not able to be used

in the commercial trades, also we used yellow corn, using a Brabender K-19 extruder.

The proportion of flours was adjusted based on the amino acid content reported by the

National Nutrition Institute (INN), using a central composite design 22, with three

repetitions in the central point. The variables used were: humidity of the flour and

temperature, while the response variables were the expansion index, cutting force and

density. The results were analyzed using the response surface methodology. The best

conditions that permits a better product with the higher expansion index, lower density

and cutting force was 158 ºC in temperature, and 15 % humidity. This represents a

viable alternative for the utilization of Mexican chick-peas, in the production of integral

expanded snacks.

(keywords: extrusion, integral snack, nutritive snack, chick-pea)


76

FP-43

Comparative Hardness of Expanded Snacks Elaborated with Corn-Beans Flour,

using two Varieties of Durango‟s Beans.

Velasco-González, O.H., Nava-Pérez, García, A. M., Ramírez, W. B., Pajarito, R. A.

CIIDIR-IPN-DURANGO, Sigma S/N, Frac. 20 de Nov. II, Durango, Dgo. México. C.P. 34220

[email protected]; [email protected]; [email protected]; [email protected]

At the CIIDIR-IPN-Durango research center, new extruded snacks elaborated with corn

and beans flours were developed, with a protein efficiency ratio (PER) value of 2.28

and 90% of digestibility. The snacks with cheese flavor were best accepted, followed by

the chili-lemon flavored, and finally by the jalapeño chili flavored. However, these

products had relatively higher density and during their extrusion developed relatively

high shear forces, than is desirable in this type of products and processing, probably

because of their higher protein (13%) content. The reduction of these two parameters is

necessary to obtain a good product and adequate processing conditions. Thus, in this

work, different varieties of beans (Garbancillo and Bayo Victoria) and extruding

conditions were used, and their effect on the hardness and density of the expanded

products was determined. The corn and the beans were ground in a hammer mill, mixed

in a proportion of 70-30 % beans-corn, and moisture content was adjusted to 18%. The

mix was extruded at 190oC in a Brabender K-19 extruder at 150 rpm, using a length to

diameter (L/D) ratio of 20:1, and compression ratio of 1:3. The expanded products

presented densities of 0.444 g/cm3 for the Garbancillo flour and of 0.521 g/cm

3 for the

Bayo Victoria flour. The shearing force resulted higher in the Bayo Victoria flour with

2.373 Kgf than in Garbancillo with 2.184 Kgf. The expanded index of Garbancillo snack

was the highest with a value of 1.399, while for the Bayo Victoria snack it was of 1.261.

It is concluded that Garbancillo variety was more suitable for producing integral snacks

with lower density, lower shearing force, and higher expansion index.

(keywords: extrusion, integral snacks, nutritive snacks, beans)


77

FP-44

Improving the Carotenoids Stability by Applying Entropic Barriers at the

Nanoscale

Pascual-Pineda, L.A., Flores-Andrade, E., Azuara-Nieto, E., Alamilla-Beltrán, L., Chanona-Pérez, J.,

Gutiérrez-López, G.F.

Instituto de Ciencias Básicas, Universidad Veracruzana, Av. Dr. Rafael Sánchez Altamirano s/n, Col.

Industrial-Animas, Apdo. Postal 575, Xalapa 91000, Veracruz; [email protected].

Nanotechnology is focused on the characterization, fabrication and manipulation of

biological and nonbiological structures smaller than 100 nm. In particular, it has been

demonstrated that many desirable traits of food such as texture, color, flavour, or

stability, depend on the way that foods are structured. The purpose of this work was to

study the effect of the nanopores present at the wall material, on the stability of

carotenoids obtained from paprika. The carotenoids were encapsulated by coacervation

using a nanostructured material (ZAA) with 75% zeolite: 25% calcium alginate, and

another non-nanostructured (AA) with 100% calcium alginate. Moisture sorption

isotherms of both types of capsules were determined at 25°, 35° and 45° C, over a water

activity range of 0.1-0.9, using the gravimetric method. The red and yellow isochromic

carotenoid pigments fractions were measured after 15 days of storage at 25° and 35°C,

using a spectrophotometric technique at 472 and 508 nm. The minimum integral

entropy can be interpreted as the point of maximum stability, since water molecules are

best organized and less available for taking part in spoilage reactions. The minimum

integral entropy for the capsules ZAA was found at aw= 0.3 and for the capsules AA

occurs at aw= 0.1. The lowest degradation of carotenoids took place in the capsules

stored at the water activity corresponding to the minimum integral entropy. Therefore

the nanostructured material (ZAA) protected the carotenoids at higher water activities

than the non nanostructured (AA). According to the enthalpy-entropy compensation, the

water adsorption on the capsules AA was enthalpy driven at all water activities studied

(isokinetic temperature TB= 358.4±1.6 K). On the other hand, the enthalpy-entropy

compensation for the water adsorption process on the capsules ZAA showed two

zones:1) the first at low water activities (0.1-0.3), controlled by entropy (TB1= 56.4±4.8

K), and 2) the second over a water activity range of 0.3-0.9, controlled by enthalpy

(TB2= 376.9±3.6 K). AFM images and thermodynamic properties suggested that the

adsorption process and the carotenoids stability were controlled by entropic barriers

when the water molecules were adsorbed in the micropores (pore diameter < 2 nm).

(keywords: carotenoids stability, nanotechnology, thermodynamic properties)


78

FP-45

Modern Extrusion System for Rainbow Trout (Oncorhynchus mykiss)

Feed Production

Araiza-Rosales, E., Delgado, E., Atienzo-Lazos, M.; González-Herrera, S.M., Medrano-Roldan, H.; Siles-

Terrazas, M., Ramírez Wong, B., Cisneros-Arreola, D., Mata-Escobedo, M.I.

Graduate School of Biochemistry Engineering, Technological institute of Durango. Blv. Felipe Pescador

1830 Ote., Colonia Nueva Vizcaya, Durango, Dgo, Mexico, C.P. 34080. Granja Piscícola del Norte,

Durango. Universidad de Sonora, Departamento de Investigación y Posgrado en Alimentos, Hermosillo

Sonora, Mexico. Instituto Tecnológico Villamontemorelos. Carretera Durango-Mezquital, Durango,

México. edelgad@itdposgrado-bioquímica.com.mx

Rainbow trout (Oncorhynchus mykiss) is a carnivorous species that requires high quality

animal protein, and highly digestible. Fish flour is used in traditional fish farming, and

is an expensive raw material. Bean flour and bean protein may partially replace fish

flour, and may be a good source of protein for fish farming in Mexico. The aim of this

work was to produce a rainbow trout feed with high vegetable protein content. Four fish

diets were designed with different contents of fish flour, bean flour, bean protein

(Phaseolus vulgaris) and commercial soybean protein. The samples were extruded at

different speed, temperature and moisture. The functional and rheological properties of

the extrudates were analyzed. Extrusion temperature and moisture affected significantly

(p<0.05) the apparent density of fish flour feed, but not the feed containing soybean

protein and bean flour (p> 0.05). Fish flour, bean flour and soybean protein

concentration had no effect (p< 0.05) on bulk density of the extrudates. The water

absorption and the water solubility index were not affected (p< 0.05) by bean flour and

soy protein concentration, moisture content or extrusion temperature, compared to fish

flour extruded feed. Soybean protein affected (p< 0.05) extrudates hardness, compared

to the fish meal extrudates. Bean flour had no effect (p > 0.05) on extrudates hardness,

compared to the fish meal extrudates. A new extrusion technology was developed; to

produce rainbow trout feed with a high concentration of vegetable protein. This feed

will be tested on rainbow trout.

(keywords: rainbow trout, feed, extrusion, diets)


79

FP-47

Optimization of the Physicochemical and Sensory Properties of an Amaranth

Beverage

Contreras, L. E., Gutiérrez, R. J. F., Lozano, G. S., Villanueva, R. S., Añorve, M: J. and Jaimez, O. J.

Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Hidalgo, Carretera Pachuca-

Tulancingo km 4.5, Mineral de la Reforma, C.P. 42184, Hidalgo. [email protected]

Atole is a Mexican prehispanic beverage prepared traditionally with corn; although

cereals as wheat, rice and amaranth have also been used. Amaranth presents an

attractive nutritional value due to its high protein content and an adequate amino acids

balance. Recently, this cereal has been included in a lot of foods as cookies, bread,

traditional candies and drinks. In Hidalgo, Mexico, there is a food micro-industry that

produces a powdered amaranth beverage with different flavors: chocolate, strawberry

and walnut. However, this product presents some problems in their texture, color and

flavor intensity. The aim of this work was to improve the formulation of an amaranth

beverage , focusing in its physicochemical and sensory properties. The optimization of

the original formulation was realized considering a statistical experimental design where

the variables considered were: viscosity, flavor, color, popped and unpopped amaranth

flour. The atole prepared with unpopped amaranth flour presented the best solubility

and viscosity properties. The flour presented some toxic compounds such as trypsin

inhibitors and phytic acid in low concentrations; lectins and tannins were not detected.

The results of a preference test showed that the optimized formulation of the amaranth

atole, was significantly preferred by consumers compared with the original one. The

major component of the final formulation was carbohydrates (78.00-78.85%) and an

interesting protein content was observed (8.28-8.70%). The optimized formulations of

chocolate, strawberry and walnut presented the same viscosity behavior at the different

temperatures assayed; however, the strawberry atole raised the highest final viscosity.

Shelf life of the final formulations was carried out at ambient temperature, 40 and 50°C,

there were not significant differences in acidity and iodine index during 30 days of

study. These results allow to estimate the shelf life of the products of about 180 days.

(key words: amaranth, atole, cereal)


80

FP-48

Organogelation of Candelilla Wax in Vegetable Oil with and without Tripalmitin

Alonzo-Macías, M., Toro-Vazquez, J. F.

Departamento de Investigación y Posgrado en Alimentos, Facultad de Química, Universidad Autónoma

de Querétaro. Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí

San Luis Potosí, 78210 SLP. [email protected] y [email protected]

We investigated the development of a solid phase in dispersions of candelilla wax (CW;

0.5% to 3.0%) in safflower oil (SFO) in the presence of 0.5% or 1.0% tripalmitin (TP).

CW has as its main component hentriacontane (78.9%), a n-alkane (C31H64) with self

assembly properties in organic solvents (i.e., vegetable oils). The development of the

solid phase (i.e., organogel) at different temperatures (Tset) was followed by DSC,

polarized light microscopy, rheometry, and texture measurements using in all cases a

cooling rate of 10°C/min. The results showed that under dynamic conditions

organogelation of CW occurred at temperatures above the crystallization temperature of

TP (TCr). Nevertheless, under isothermal conditions at Tset above (i.e., Tset = 5°C or

15°C) the TCr of tripalmitin in the SFO, the TP crystallized probably on the organogel

structure. This process modified the three-dimensional structure of the organogel with

the subsequent effect on the rheological properties of the system, as evaluated by the

elastic modulus (G‟), the phase shift angle (), the yield stress (*), and the hardness. In

general, CW organogels in the presence of 1% TP showed higher G‟ values than in the

absence of TP at Tset of 5°C and 15°C. However, at the same Tset‟s * was always higher

in CW organogels developed in SFO without TP than in organogels developed in SFO

with 1% TP. Similar results were also observed by the organogels‟ hardness. This

research showed that the presence of high melting TAGS in vegetable oils modifies the

functional properties of organogels.

(keywords: candelilla wax, organogelation, crystallization.)


81

FP-49

Tortilla Production as an Alternative Use for Wheat with Yellow Berry

Matus-Barba, E.A., López-Ahumada, G.A., Torres-Chávez, P.I., Salazar-García, M.G., Ramírez-Wong,

B., Fernández-Ramírez, M.V.

Departamento de Investigación y Posgrado en Alimentos. Universidad de Sonora, Rosales y Blvd.. Luis

Encinas s/n., Col Centro, Tel y Fax: 259-22-07 a 09, Hermosillo, Sonora. c.p. 83000.

[email protected]

During the last years, in the Sonora State, in the Northwestern México, wheat cultivars

have been affected by the physiological disorder called yellow berry. This disorder

affects mainly the endosperm texture and protein content. A research was conducted in

order to evaluate the physicochemical and rheological properties of flours of these

cultivars. Tortilla preparation was also evaluated. The cultivar Tarachi with different

levels (0, 11, 45, 60 and 100 %) of yellow berry was used. Wheat was milled in a

Quadrumat Senior mill. Flour was analyzed for protein and moisture contents,

sedimentation volume, dry gluten, alveograms and farinograms. Tortillas were

produced at industrial level, and were stored and evaluated for moisture content,

rollability and firmness for up to 144 h. A completely randomized experimental design

was carried out. Significant differences (p<0.05) were observed in all the parameters

evaluated. It was possible to obtain tortillas of good quality with up to 60% of yellow

berry.

(key words: yellow berry, bread wheat, quality tortilla)


82

FP-50

Assesment of Rheological Behavior of Avocado Pulp and Suspensions

N. Mejia Resendiz, G. Luna Solano, J.M. Tejero Andrade, J.S. Rocha Aragón, R. Cerecero Enríquez.

Unidad de desarrollo e Investigación en alimentos- Instituto Tecnológico de Veracruz, Division de

estudios de porgrado e investigacion, Instituto Tecnologico de Orizaba, Oriente 9 No.582 Col. Emilizano

Zapata C.P. 94320 Orizaba, Ver. Tel. / Fax. 52 (272) 7257056 ext.115 e-mail:

[email protected]

Avocado (Persea americana mill) is one of the most important fruit in manufacturing

and economic although this is native from Mexico. The principal cause because the pulp

cannot process is the enzymatic activity caused by pholyphenol oxidase activity

(Corrales, 1991). The present work consisted in: determination of the best state of

maturity with one texture analysis, weight loss, °Brix and color analysis, stabilization of

the pulp by means of treatment by microwave-freezing, rheological characterization of

the pulp and suspensions (15, 30, 60% w/v) of avocado in concentric cylinder geometry,

the suspensions were stabilized with Tween 80 (0.01%) later, the samples were

evaluated by optical microscopy, besides the activity of polyphenol oxidase was

obtained versus time and pH, and analysis for samples with different concentration of

the enzymatic extract (50,100,200,300 µL). The results show that the best state of

maturity was day 5 after harvest, and the fruit showed in this period a weight loss of

8.5% with stress compression about 10 N/mm2

and 4.5 °Brix. The samples can be in

storage until 6 months to 5°C. Statistical analysis showed that the best treatment was of

650 Watts and 30 seconds, to conserve the parameters L, a and b close to the standard.

The rheological caracterization showed that the pulp and 60% w/v have a pseudoplastic

behavior and Newtonian for 15 and 30% w/v solids. The suspensions with Tween 80

have an unimodal normal distribution so the suspensions are stable and homogeneous

until 48 h, and the enzimatic activity was evaluated during 120 s, and the major activity

was found at pH 7. During the kinetics of the enzymatic samples treated with

microwaves they showed 50% lower activity compared with the natural samples from

which the most stable was the sample with 120 µL of enzyme extract (during 120 s)

according to the absorbance.

(keywords : polyphenol oxidase, rheology, maturity, microwave-freezing).


83

FP-51

Growth, Development and Pigmentation of Strawberry (Fragaria vesca L) under

the Effect of Salicylic Acid

Anchondo Aguilar, Addy, Núñez Barrios Abelardo y Ruiz Anchondo Teresita y Martínez Téllez, Jaime.

Facultad de Ciencias Agro tecnológicas, Universidad Autónoma de Chihuahua

Campus 1, Ciudad deportiva. [email protected]

Strawberry may become an economic alternative crop to apple and pecan production in

the State of Chihuahua. However cultivation of strawberry is still limited in the

Northern part of Mexico mainly due to low yields and restricted water availability.

Increasing strawberry production is the first step to help farmers and producers to have

an economically costly and competitive crop. The application of growth regulators such

as salicylic acid (SA), may improve yield and quality of strawberries fruit as well water

efficiency. The objective of this research was to understand the effect of SA on the

growth, development and yield of strawberries as well as its impact on xanthophylls and

anthocyanin production. Plants were grown under greenhouse conditions and the

treatments of salicylic acid were spray-applied on the leaves under three concentration

doses, 10-6

, 10-7

and 10-8

mg/L, including a control with no SA. Data were collected on

plant height, number of flowers and fruit number. Spectrometry UV-VIS and

chromatography were used to quantify fruit pigmentation. The experiment was set as a

completely randomized design with five replicates. Results showed that the effect of the

different concentration of salicylic acid treatments did not produce changes on plant

height and number of flowers, however the mean of SA treatment was greater than the

control. The treatment SA10-8

produced a larger number of flowers however this effect

did not show up in the total number of fruit per plant. However treatment SA 10-6

reached greater number of fruits than the control and significantly increasing yield by

21%. Pigmentations was also improved by the salicylic acid as indicated by

pigmentation readings from the control to SA 10-6

and from SA 10-7

to SA 10-8

. The

conclusion is that the application of growth regulators such as salicylic acid may

improve yield and fruit quality in strawberry.

(keywords: salicylic acid, strawberries, growth regulators, yield)


84

FP-52

Strawberry Pulp Drying in a Spouted-Fluid Bed Dryer with Inert Solids

Velázquez, C.C., García, L. I. N., Gallardo, V. T.,

y Osorio, R. G.

Departamento de Ingeniería Bioquímica, Escuela Nacional de Ciencias Biológicas. Prol. de Carpio y Plan

de Ayala, México., 11340 México. [email protected]

The effect of drying conditions and glass transition temperature (Tg) on the sticking

behavior and recovery efficiency of the product during strawberry pulp drying with no

additives, was studied in a spout-fluid bed dryer with draft tube immersed in inert

solids. The Tg obtained for the strawberry powder was 43ºC, locating the sticking

interval between 53-63ºC (10-20ºC above Tg). Based on this, the drying runs were

carried out at 60 and 70ºC with 30g pulp pulse feeding at 5 and 10 mL/min feed rate,

using a spout and annular air flow rate equivalent to 1.5 Ums and 0.7 Umf respectively.

The drying times used were 15 and 25 min between feeding pulses. The thermal

degradation of the product was assessed by color change, ascorbic acid and total

phenols retention. The result showed that the amount of product adhered to the inert

solids was not affected by any of the drying temperatures showing that the sticking

temperature was below 60°C. The recovery efficiency increased slightly (from 13 to

19%) as the drying time increased, but it was not affected by the feeding rate. Ascorbic

acid and total phenols retention were not affected by drying temperatures, but decreased

10-15% with the increase in drying time. The color of the rehydrated pulp was darker

than the original pulp showed by the ∆E and ∆L parameters. Drying runs at 50°C with

15g feeding pulses were also carried out at both drying times to be below the sticking

temperature. The use of 50°C showed a considerably reduction on the amount of

product adhered to the inert solids and markedly improved the recovery efficiency (from

19 to 33%). The quality of the strawberry powder increased, since there was no

degradation of ascorbic acid or total phenols and the change in color was smaller than

when the pulp was dried at 60°C. The addition of maltodextrin DE10 to the pulp in 20

maltodextrin:80 dried pulp solids ratio, did not modified the Tg, but produced a

reduction in the amount of product adhered to the inert solids and increased the recovery

efficiency to 39%.

(keywords: spouted fluid-bed, strawberry, powder, glass transition temperature)


85

FP-53

Chayote Marmalade Supplemented with Chia Seed

Trinidad-Pérez, Y., Beltrán-Mendoza I., Antonio-Castelan M., Alonso-Calderón, A., Montalvo-Paquini C.

Universidad Politécnica de Puebla, Tercer carril del ejido “Serrano” San Mateo Cuanalá, Mpio. Juan C.

Bonilla, Estado de Puebla. [email protected]; *[email protected]

Chayote (Sechium edule), the vine, is a tuberous rooted perennial that climbs by

clinging with tenacious tendrils. Most varieties have fruits with ridges; some are

smooth; knobby, fuzzy; dark green, almost white, or brown. Chayotes are sometimes

eaten raw in salads and salsas, but are more often cooked by boiling, sauteing or baking.

Although very young fruits can be eaten in their entirety, it is usually best to peel the

older, more mature fruits. An attempt has been made to increase the life of the fruit by

drying it. Other way to be prepared is in sweet, looking for higher acceptance between

children. The objective of this work was to obtain different chayote marmalade

formulations; some of them were prepared using chia seeds (Salvia hispanica L.). These

seeds typically contain 25 % dietary fiber (mostly soluble), significant levels of

antioxidants and the oil contains a high concentration of omega 3 fatty acid. The

chayote pulp had a pH of 6.4 and its total solids measured 6 ºBrix. Three different

marmalade formulations were prepared, containing 1 and 2.5% chia seeds and the

control. The final amount of soluble solids was calculated at 62 - 66 ºBrix for a pH

range of 3.6 – 3.9, which are the values recommended by NMX (Mexican Norms). The

amount of fiber increased 3% with chia seeds. The different marmalades formulations

were evaluated by a panel of 60 untrained tasting judges. Odour, smell, taste, and

texture were evaluated using a hedonic scale of 6. All formulations were accepted by

the most of the panel, the best characteristic evaluated was taste. From the point of view

of new products with excellent nutritional value, the marmalade containing chia seeds

looks very attractive. It also represents an alternative of commercialization for

communities such as Santa Catarina Villanueva, Quecholac, Puebla where Chayote is

growth.

(key words: chia seeds (Salvia hispanica L.), chayote (Sechium edule), Marmalades)


86

FP-54

Chemical Characterization and Response to Cold Storage

of Prickly Pears Fruit of Opuntia joconostle

García-Trejo, M., Martínez-Márquez, B., Fosado-Quiroz, R. E.

Departamento de Investigación y Posgrado, Instituto Tecnológico Superior del Occidente del Estado de

Hidalgo.

Paseo del Agrarismo 2000. Carretera Mixquiahuala-Tula km 2.5. Mixquiahula de Juárez, Hidalgo.


In this work, Actopan crops of prickly pear fruit (Opuntia joconostle) were partially

characterized from a chemical point of view, and the possibility of long-term storage of

their fruit to different periods of cold storage was investigated over 6 weeks in terms of

physiological and quality parameters. Vegetal raw material was tender prickly pears at

commercial maturity appearance that were sorted and divided in two lots, without any

treatment and applying a heat treatment with water at 55°C to reduce chilling injury and

fungal development and packed in polyethylene bags in a cold storage room at 4°C. The

results were: 1) the pulp contained a higher amount of calcium, potassium and

magnesium (1274, 503 and 216 mg/kg respectively) compared with other species,

ingestion of two fruits provides more calcium than recommended adult diet; 2) although

the sugar content is very low ( 2 % w/w), citric acid is present in considerable amount;

3) combining hot water and cold storage yielded the lowest levels of chilling injury and

were greatly beneficial improving visual quality over a 5 week period, the application of

this approach as an alternative to conventional fungicide treatments; 4) the enzymes

evaluated show particular behavior during the ripening of each morphospecies

suggesting a fine biochemical control and not a clear relationship between fruit

softening and enzyme activity. In particular, peroxidase seems to be present in small

amount and is not highly active. Furthermore proteolytic activity increases considerably

until 14 day and then decreases. The results obtained can be considered satisfactory;

prickly pear is a neglected nutritional source and has been widely appreciated when

compared with other products commonly available on the market.

(keywords: Opuntia joconostle, prickly pear, minimally processed products, browning,

minerals, peroxidase, proteolytic activity)


87

FP-55

Technofunctional Properties in Mixture of Semolina and Jatropha curcas Flour for

Enriched Spaghetti

Flores-Miranda, G.A., Gómez-Montes E.O., Soto-Simental S., Martínez-Herrera J. and Guemes-Vera N.

Instituto de Ciencias Agropecuarias, Universidad Autonoma del Estado de Hidalgo. Av. Universidad km

1, C.P. 43600 Col. Rancho Universitario Tulancingo-Hidalgo-México. 2 Centro de Productos Bióticos del Instituto Politécnico Nacional.


The benefits of this oil seed in baked goods can be brought to poorer populations in

Mexico by adding Jatropha curcas flour, becasue this oil seed has 60% protein content.

The objective of the present study was to evaluate the technofunctional properties in

mixture of semolina and Jatropha curcas flour. The mixtures were prepared by

replacing semolina with different amounts of Jatropha curcas flour, in order to

increase the protein content. A detailed investigation of the rheological properties of the

dough and the cooking quality of pasta was performed in comparison to standard

semolina spaghetti. The extensibility the dough decreased with the addition of Jatropha

curcas flour. The hardness and cohesivity decreased with the addition of Jatropha

curcas flour. Dried spaghetti fortified with 10% of Jatropha curcas flour had

rheological features comparable with the semolina sample and also the behaviour during

cooking results to be satisfactory. The semolina with 10% of Jatropha curcas flour

showed 32.5% protein content. Sensory evaluation showed that changes in flavor were

not detected in the formulation with 10%.

(keywords: Jatropha curcas flour, spaghettis, rheological properties)


88

FP-56

Incorporation of Orange Peel Oil Microcapsules in Papaya Tissue

Salazar-López, E.I., Azuara-Nieto, E., Jiménez-Fernández, M., Beristain-Guevara, C.I.

Instituto de Ciencias Básicas, Universidad Veracruzana, Av. Dr. Rafael Sánchez Altamirano s/n, Col.

Industrial-Animas, Apdo. Postal 575, Xalapa 91000, Veracruz.; [email protected].

Essential oils are considered to act as preservatives, besides improving texture and

flavor to foods. Therefore, the development of complementary methods, especially

using natural conservators such as essential oils, is an interesting area of research.

Microencapsulation is a physical process able to preserve a substance in a finely divided

state and release the substance on demand. The objective of this work was to combine

osmotic dehydration (OD) and microencapsulation (ME) to produce papaya tissue

impregnated with microcapsules of orange peel oil. Solutions of gum arabic in

deionised water containing 230 g solids/kg were prepared. An emulsion was made by

dispersing orange peel oil in the gum arabic solutions in order to obtain a ratio of 250 g

oil/kg gum solids. There were obtained two new emulsions by blending sucrose (E1) or

fructose (E2) to adjust the solids concentration to 600 g solids/kg. Papaya slices were

osmo-dehydrated in the emulsions E1 and E2 during 180 min at 40°C. After the OD

process a vacuum drying step was carried out at 60°C, until the water activity of papaya

slices was 0.4. Total oil in the samples was determined using a hydrodistillation

apparatus and moisture content with a vacuum oven for 24 h at 70°C. Color changes

were measured in a Hunter Lab Colorflex. Content of vitamin C in papaya slices was

determined with a second order derivative spectrophotometric method. All experiments

were repeated three times. Water lost (WL), solids gain (SG) and vitamin C loss (VCL)

of papaya slices processed with the emulsions E1 and E2 were 80%, 5%, 30% and

82%, 12%, 15%, respectively. The emulsion E1 produced papaya slices with 14 g oil/kg

fruit and the samples treated with emulsion E2 gained 15 g oil/kg fruit. These oil

concentrations can provide antifungal and antioxidant activity to the food. SEM images

showed microcapsules of 1-5 μm into the intercellular spaces of papaya tissue. This

technique can be used to incorporate functional substances in the tissue of fruits and

vegetables.

(key words: essential oil, osmotic dehydration, microencapsulation)


89

FP-57

Pectin Extraction from Citric Fruit Pomaces Through the Use of Vacuum Infusion

of

Acid Poligalaturonase produced by Aspergillus kawachii

Cardona-Oyervides, L.M., Contreras-Esquivel, J.C., Aguilar, C.N., Rodríguez-Herrera, R.

Departamento de Investigación en Alimentos, Facultad de Ciencias Química. Universidad Autónoma de

Coahuila, Blvd. Venustiano Carranza y José Cárdenas s/n Col. República. Saltillo, Coahuila 25280.


The pectin extraction methods have been largely studied, but some of these methods are

dangerous for analysts, the environment and for the product itself. The chemical

extraction may cause equipment damages, especially if corrosive acids are used. Some

researchers have developed other techniques to improve yields and reduce

contamination, such as microbial and enzymatic methods, resulting the last the most

promising alternative. The objective of this work was to extract citric pectin by vacuum

infusion on an Aspergillus kawachii 4308 (National Research Biological Center, Japon)

acid polygalacturonase raw enzymatic extract. For the pectin extraction, an extracting

agent (oxalic or citric acid) in a 0.25% w/v proportion, 500 µl of concentrated

enzymatic raw extract and 15 g of citric pomace (lemon, orange, grapefruit and

mandarin) were used, then the recipient was vacuum sealed (-0.4 bar) and shaken in a

CoyoteZyme reactor ABL rotator mixer (Coahuila, Mexico). From the four evaluated

citric pomaces, lemon pomace gave the best yields with both extracting agents,

nevertheless, oxalic acid gave better yields, up to 16.5% higher than citric acid at 6 h of

reaction time. As the extraction time increased, the yield improved. When applying

vacuum, the gases contained in the vegetable tissue were released leaving porosity,

which enhanced the enzyme activity on pectin, extracting it due to better tissue contact.

(key words: pectin extraction, citrus, Aspergillus kawachii, polygalacturonase)


90

FP-58

Thermo-Mechanical Properties of Safflower Oil Organogels with Candelilla Wax

or Dotriacontane as Gelator

Toro-Vazquez, J.F., Morales-Rueda, J.A., Dibildox-Alvarado E., Charó-Alonso, M.A., and Weiss, R.G.

Universidad Autónoma de San Luis Potosí, Facultad de Ciencias Químicas, México;

Universidad Autónoma de Querétaro, DIPA-PROPAC, México

Georgetown University, Washington, DC.

Facultad de Ciencias Quimicas-CIEP, Av. Dr. Manuel Nava 6, Zona Universitaria, San Luis Potosí, SLP

78210, México. phone: 52-444-8262440 ext 502 and 525. E-mail: [email protected]

The main component of candelilla wax (CW) is hentriacontane, an n-alkane (C31H64)

with self-assembly properties in organic solvents. It has been shown that independent of

the cooling rate and the gel setting temperature (Tset), CW develops thermoreversible

organogels with vegetable oils. However, the structural organization of CW organogels

depend on the cooling rate, the thermodynamic drive for gelation, and the annealing at

high Tset. To investigate these events, it was evaluated the rheological (G‟), thermal and

microstructural properties of CW organogels (1% and 3%) in safflower oil at Tset‟s of

5ºC and 25ºC using two cooling rates (1ºC/min and 10ºC/min). The results were

compared with the ones obtained with organogels of pure dotriacontane (C32H66) in

safflower oil. The DSC results of both pure geltors showed the formation of rotator

phase. The thermal properties of organogels showed that at both cooling rates, the

gelation (Tg) was higher with dotriacontane (C32) than CW. It showed that more CW

than C32 is required to achieve the same Tg. This observation, as well as the higher

melting enthalpy (HM) and larger crystal size of the C32 structures, indicated that C32

was able to form gels more efficiently than CW. The HM behavior and the

microphotographs suggested that the presence of other impurities might result in the

development of a lower crystallinity and crystals‟ size in CW than the ones achieved by

C32. Regarding to the G‟ profile, for the same gelator concentration and time-

temperatures conditions, lower G‟ were observed in the C32 organogels than in the CW

organogels. This result was probably associated with the higher solid phase content

(SPC) and smaller crystal size present in the CW organogels. In addition, independently

of gelator, samples cooled at slow cooling rate (1ºC/min) developed higher G‟ and HM

than the ones at 10ºC/min. Finally, the increase of HM as a function of time might be

associated to the development of a higher structural order from the one originally

achieved (e.g., rotator phase).

(keywords: candelila wax, n-alkanes, organogels, rotator phase)


91

FP-59

Effect of Processing Variables on Drying Parameters of Osmotically Dehydrated-

Convective Dried Apple and Convective Dried Apple

Arenas-Herrera A. K., Delgadillo-Sánchez K. L., González-Velázquez A., González-Sánchez, J. and

Vargas-Ugalde, M.E.

Facultad de Estudios Superiores Cuautitlán, U.N.A.M. Av. 1º. Mayo s/n dom. conocido C. Izcalli, Edo.

de Méx. C.P. 54740, México. *[email protected]

The effect of osmotic solution concentration (osc) and temperature (T) on processing

time (t), diffusion coefficient (De), activation energy (Ea) and structural damage in

osmotic dehydration-convective drying (OD-CD) process and the effect of T on the

same parameters in convective drying (CD) process were studied. Apple of Golden

delicious variety was washed, peeled and cut in rings 0.038 m of external diameter

before the drying processes. Osmotic saccharose solutions of 40, 50 and 60°Brix at

three temperatures (50, 60 and 70 ºC) were employed for OD of apple rings for 3 h.

Convective drying was performed at same temperatures. A factorial design was applied

(number of experiments?). It was observed that increasing of T and osc increased De.

Calculated values were from 7x10-8

to 5x10-7

m/s2. Ea values were from 138 to 146

kJ/mol. For CD, the increase of T, increased drying rate. OD-CD apple had a greater

hardness than CD apple, because of the solids gain during the OD process. With OD-

CD, a lower moisture content was reached, employing less time than that required when

only CD was applied. The use of microscopy showed that the OD-CD apple had a better

structural appearance compared with CD samples.

(keywords: osmotic dehydration, convective drying, diffusion, texture)


92

FP-60

Replacing Egg White Ovalbumin in Aerated Product (mousse)

Ayala González. G.B, Barbosa Rodríguez, E.C., Jiménez Galicia, M., Martínez Valles, L.A., Santana

Pérez, D.E., Ramírez Ortiz, M.E.* y Romero Arreola, V.

Universidad Nacional Autónoma de México. Facultad de Estudios Superiores

Cuautitlán. Laboratorio de Propiedades Reológicas y Funcionales en Alimentos.

Av. Primero de mayo s/n, Cuautitlán Izcalli, Edo. de México 54740, México.


The product consumption derived from egg, in spite of its excellent nutritious

properties, presents disadvantages related to the health of the consumer, the cholesterol

contained in the yolk, the allergenic reactions that appear with their consumption in

addition to the fort taste that is distributed to foods where it is included, are reasons that

motivate to study the possibility of replacing this protein by some of equivalent

functional capacities. The objective of this work was to evaluate the functional

properties of three proteins like egg white ovalbumin (EWA) substitutes in aerated

product (mousse). Three foaming agents namely isolated soy protein (ISP), sodium

caseinate (SC) and wheat protein (WP) were used. The addition rate of foaming agent

was 0.5%, 0.75% and 1% w/w. The functionality was evaluated by means of yield;

foam liquid stability (FLS) and texture profileaAnalysis (TPA). Results obtained

matched the characteristics of wheat protein product with the original product (with

EWA), improving the yield in 180% and FLS with smaller concentrations to the

employee with ovalbumin and presenting textural properties (hardness, elasticity and

cohesiveness) similar to those of mousse with EWA.

(keywords: protein, foam, texture properties)


93

FP-61

Thermodynamic Analysis of Canola Oil Microcapsules Using Different Wall

Materials

Bonilla, E., Vernon-Carter, E. J., Azuara, E. and Beristain, C. I.

Instituto de Ciencias Básicas, Universidad Veracruzana, Apdo. Postal 575, Xalapa, Ver., México

Departamento de Procesos e Hidráulica, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael

Atlixco 186, Col. Vicentina, C.P. 09340 México D.F., México

Xalapa 91000, Veracruz, [email protected]

Beneficial effects on health of poly-unsatured fatty acids (PUFA) have increased interest to

incorporate these bioactive lipids in foods. However, numerous challenges in production,

transport and storage exist, due to high oxidation susceptibility. Microencapsulation of

lipids as core material with a suitable wall material can provide new functions because they

can suppress or retard oxidation of encapsulated PUFA. Stability is greatly influenced by

the moisture sorption characteristics of the product. The thermodynamics of water sorption

in dried foodstuffs has drawn interest because it provides a more thorough interpretation of

the sorption isotherm phenomenon and helps to better understand the sorption mechanism.

The objective of this work was to use a thermodynamic method to investigate moisture

content where minimum integral entropy is found. Soy protein isolate (SPI), whey protein

concentrate (WPC) and mesquite gum (MG) solutions (30% w/v) were used to emulsify

canola oil. The ratio oil-wall material used was 0.25. Emulsions were spray dried in

laboratory scale equipment. Samples were placed in desiccators containing saturated salt

slurries in the range of aw from 0.11 to 0.85 at 25°, 35° and 45° C. All the isotherms were

fitted using GAB equation and both differential and integral thermodynamic parameters

were estimated according to Othmer method. The point of minimum integral entropy was

found at 6.69 kg H2O/100 kg d.s. (aw = 0.389) for MG, 4.13 kg H2O/100 kg d.s. (aw =

0.235) for SPI, and 3.77 kg H2O/100 kg d.s. (aw = 0.300) for WPC. Enthalpy-entropy

compensation for water vapor adsorption showed two adsorption zones: first at low

moisture content (0-0.38) was controlled by entropic mechanism (TB = 295.51 ± 3.55 K,

Thm = 307.9 K; TB = 140.27 ± 4.91 K Thm = 307.9 K and TB = 62.76 ± 3.19 , Thm = 307.9 K)

for SPI, WPC and MG, respectively; and the second zone was found at higher moisture

content (0.38-1.0) was controlled by enthalpic mechanism (TB = 394.62 ± 3.34 K, Thm =

307.9 K; TB = 351.54 ± 1.37K, Thm = 307.9 K y TB = 463.89 ± 6.77 K, Thm = 307.9 K) for

SPI, WPC and MG, respectively.

(keywords: sorption isotherms, thermodynamic properties, minimum integral entropy, water

activity, microencapsulation)


94

FP-62

Preparation of Protein Isolate from Mamey Sapote Seed Meal

Bravo-Delgado C. H., Herman y Lara E., Martínez-Sánchez C. E., Bernardino-Nicanor A., Vivar-Vera M.

A.

Coordinación de Posgrado-Maestría en Ciencias en Alimentos. Instituto Tecnológico de Tuxtepec. Av.

Dr. Víctor Bravo Ahuja S/N. Col. 5 de Mayo. C.P.68350. Tuxtepec, Oaxaca, México. Tel.

012878751044. *[email protected]

The mamey sapote (Pouteria sapota) is a tropical fruit tree that is native and cultivated

in the southern of Mexico. Today the tree is also cultivated in Central America, the

Caribbean and South Florida. The seed of the fruit has traditionally been considered a

source of oil. The oil extraction process produces a waste which generally is discard

causing contamination. However this residue may represent an important alternative

source of protein. The aim of this work was to prepare a protein isolate from mamey

sapote seed meal and to characterize some properties. Mamey sapote seed meal

(MSSM) was prepared by defatting dried seed almonds with hexane in a batch reactor

and grinding until particle size of 0.5 mm. The pH of solubility and isoelectric point (pI)

were established in order to obtain the protein isolate by the method of isoelectric

precipitation. Proximal chemical analysis of MSSM and protein isolate were

determined. Results were obtained by triplicate and deviation standard was calculated.

The proximate composition of MSSM was crude fiber 11.47±0.63%, fat 3.77±0.23%,

ash 7.35±0.88% and showed high content of carbohydrates (53.78±2.1%) and protein

(24.06±0.01% d.b.) similar to cereals seeds and some legumes. The solubility pH, and

pI established for production of protein isolate from MSSM were 9.8 and 3.5,

respectively. The protein isolate was produced with a high yield of 88.45±2.61% and

high protein content of 95.06±4.08%. It has low content of fat (1.33±0.37%), ash

(1.56±0.16) and crude fibre (2.20±0.59%). This study showed that MSSM is a material

suitable for production of protein isolates with high yield and purity using the isoelectric

precipitation method.

(keywords: mamey sapote seed meal, protein isolates, isoelectric precipitation)


95

FP-63

Effect of Blanching Pretreatment on the Oil Uptake Behavior during the Deep-Fat

Frying of Taro (Colocasia esculenta) Chips

Bravo-Delgado, H.R., Ruiz-López, I.I., Ramírez-Figueroa, E., Delgado-Licon, E., Paz-Gamboa, E.

Coordinación de Posgrado e Investigación. Instituto Tecnológico de Tuxtepec. Av. Dr. Víctor Bravo

Ahuja S/N. Colonia 5 de Mayo. C.P. 68350. Tuxtepec, Oaxaca, México. *[email protected]

Taro (Colocasia esculenta) is one of the most widely cultivated edible aroids in the

tropical and subtropical countries. In Mexico, taro is mainly produced in Oaxaca

municipalities as Tuxtepec and Valle Nacional with a production as high as 6000

tons/yr. The taro roots are rich in starch (15-25% wet basis) and their consumption has

been suggested in applications similar to that of potatoes, as fried products. The frying

process imparts desired quality attributes such as flavor, texture, appearance, and

mouth-feel. However, this process is incompatible with the recent trends toward

healthier food and low-fat products, which has motivated the development of strategies

to reduce the oil uptake (OU). The aim of this study was to evaluate the effect of the

blanching pretreatment and process variables on the OU behavior during the deep-fat

frying of taro chips. Process conditions were obtained from a 24 factorial design with

product thickness (1 and 2 mm), oil temperature (180 and 200°C), frying time (1 and 3

min), and blanching pretreatment (BP) application (with and without blanching) as

independent variables. The BP consisted in the immersion of the taro slices in hot water

at 83±2°C during 3 min. All samples were dried in an oven at 70°C for 20 min prior the

frying process. From each experiment the final OU was obtained as the response

variable. The statistical analysis of the results demonstrated that increasing the oil

temperature causes a decrease on the OU in both the blanched and non-blanched

samples (p > 0.95). In addition, higher product thicknesses and longer frying times were

found to increase the OU in the non-blanched taro chips, while the opposite trend was

found for the blanched slices (p > 0.95). Furthermore, the effect of application of the BP

was significant on the OU with resulting lower fat contents (up to an 80% of OU

reduction) (p > 0.95) thus allowing the development of a low-fat fried product from taro

with less than 10% of fat content (wet basis).

(keywords: frying, oil uptake, taro)


96

FP-64

Duck Meat Ham

Carranza-Pérez G.Y., Castañeda-Nares A.L., Lulo-Piñón F., Mendoza-Preciado P.G., Zavala-Aranda C.

Departamento de Ingeniería Química y Bioquímica, Instituto Tecnológico de Morelia, Av.

Tecnológico1500, Col. Lomas de Santiaguito. *Dr. Juan Bautista Figueroa 9, Col. Fidel Velázquez,

[email protected]

Ham is a widely consumed cold meat; nevertheless the excessive starch addition in its

manufacturing results in poor nutritional quality to meet consumer requirements. In

Mexico, ducks are one of the most unused poultry species; actually, these are animals

with a non-demanding feeding. Ducks are resistant to several illnesses and can

withstand diverse weather conditions. The objective of this project was to elaborate a

ham-type product from duck meat with high nutritional quality. The duck meat was

mixed with brine (phosphates, salt, glucose, magnesium erithorbate, California

condiment, glutamate, binding agents and water), and treated with a refrigeration step-

resting process, then it was stuffed and cooked in a water bath until the coldest point

reached a temperature between 63 and 68ºC. Sensory characteristics were compared

with other hams from the market. The color of duck meat ham was more intense than

that of the traditional jams. With regarding to microbial counts, the product met the

Mexican standards (NOM-113-SSA1-1994 and NOM-114-SSA1-1994). Proximate

analysis showed that the duck meat ham has higher protein content and unsaturated fatty

acids than the commercial products, microbial analyses showed suitable sanitary quality

in the elaboration of the duck meat jam.

(key words: duck, meat, ham)


97

FP-65

Drying Red Bell Pepper (Capsicum annuum) Fluidized Bed with Tempering

Cycles.

Carrillo-Montes, J. P.; Anaya-Sosa, I.; Santiago-Pineda, T.

Laboratorio de graduados en Alimentos. Escuela Nacional de Ciencias Biológicas (IPN). Prol. de Carpio

y Plan de Ayala s/n. 11340. D.F. México. Apoyo económico de CGPI20080125, PIFI, COFAA, EDD y

al CONACYT

E-mail: [email protected] , [email protected] , [email protected]

Red bell pepper (Capsicum annuum) is a valuable food because of its flavor and color.

Paprika is a dried and ground form of this pepper that is used as a spice as well as an

ingredient for other food products (Kalsec, 2007). Batch drying with tempering cycles

has shown to be an important method for food dehydration, since it reduces drying

times compared to conventional drying methodologies, and improves the quality and

color of the product (Tolaba, 1991; Anaya et al., 2003; Chua et al., 2003; Fano, 2006).

The aim of this work was to evaluate the technical viability of drying red bell pepper in

cubes using tempering cycles in a fluidized bed dryer. The experimental factorial design

was 23, in which the evaluated parameters were; drying temperature (T) of 60ºC and

80°C; intermittence (α) of 0.3 (15 minutes of drying and 35 minutes of tempering) and

0.5 (15 minutes of drying and 15 minutes of tempering), and the scalding calcium

chloride solution at 0.1% and 0.5%. The response variables were effective diffusivity,

drying time (duration of heating) and process time (heating time plus tempering time).

The ANOVA statistical analysis with a significance of α=0.05, gave the following

results: temperature affects the drying time and diffusivity (the former was affected by

intermittence as well), while processing time was significantly affected by all primary

and combined effects. It was observed that the tempering cycles reduced up to 50% the

effective drying time, compared to a conventional drying process for an intermittence

value of 0.3 and up to 60% for an intermittence value of 0.5. Therefore, tempering

cycles for red bell pepper drying can be useful techniques because of the reduction in

drying times.

(keywords: Capsicum annuum, drying, tempering, drying time).


98

FP-66

Study on Drying of Sprouted Onion (Allium cepa L.)

Castañeda-Pérez, E; Cruz-y-Victoria, M.T.; Anaya-Sosa, I; Vizcarra-Mendoza, M.

Departamento de Graduados en Alimentos, ENCB - IPN

1Área de Ing. Química, DIPH, UAM-I

Prol. Manuel M. Carpio, No. s/n. Esq: Plan de Ayala. de Gobierno. Piso: 3. Col: Santo Tomás . Del:

Miguel Hidalgo. C.P.: 11340. México, D.F. [email protected], [email protected]

Onion (Allium cepa L.) is one of the main food crops of the genus Allium, and the

second vegetable most widely produced in the world, just after tomato (Lycopersicum

esculentum L.). Onions possess distinctive aroma and flavor that make them a

condiment used worldwide. Moisture content makes food products highly perishable

and reported losses range from 15 to 20% due to sprouting. In this work we utilized

dehydrated "white globe" variety onions, using vibro-fluidized bed drying with

tempered cycles, that has proven advantageous on the final quality of the products. For

the experiments we used 3 air temperatures (60, 70 and 80 ° C). The onion was sliced to

1.5 cm per side and the thickness of the slabs was ca. 5 mm. At 60 °C there was a period

of constant drying of 15 min, from which 3 different periods of tempered were applied:

the time resting well, two and three times the normal drying time. At 70 °C two

vibration intensities (high and low) were evaluated and found no significant differences

in the drying curves. In high vibration at 70 ° C and tempered at 15x15 (drying-rest) the

highest mean value of Fick‟s diffusion coefficient (4.61x10-10

m2/s) was attained.

(key words: drying, onion sprouted, vibro-fluidized )


99

FP-67

Development of Bakery Products with Low Fat and Soluble Fiber Added

Castillón-Jardón, J.; Valenzuela Escobar E.; Cerecero S Rosalía

Facultad de Química, Universidad Autónoma del Estado de México, Toluca Estado de México. Instituto

Tecnológico de Orizaba Veracruz

[email protected]; [email protected]; [email protected]

The aim of this work was the development of bakery products using different bread

formulae elaborated with three types of fat, such as; butter, margarine and hydrogenated

fat, and adding soluble fiber (maize dextrin FMC 106). The bread formula was set using

a base of sponge cake dough which contained 300 g wheat flour, 75 g fat, and soluble

fiber. Three bread formulae were elaborated using different fats, as previously

mentioned. The maize dextrin was mixed with each of the fat types previously, and

then, added to the remaining ingredients. The dough was baked at 180 °C during 25

min, and then the bread went through the texture analyzer to evaluate its texture

behavior using the TPA (Shimadzu Texturometer). The starting tests of those three

formulae showed fat separation during the dough preparation. Therefore, it was decided

to reformulate reducing fat content from 75 g to 25 g, down to 10 g, keeping the same

maize dextrin equivalence about starting formula. This modification represented more

that 60 % of fat reduction. We evaluated and analyzed the pH, water absorption and

TPA on dough and the mixture of fat and maize dextrin. The results showed

improvement of bread functionality and softness for at least 3 weeks. In conclusion, we

obtained bread with reduced fat, and a source of soluble fiber.

(keywords: bread, soluble fiber, texture)


100

FP-68

Effect of Different Processing Parameters on the Physicochemical, Functional and

Structural Properties of Nixtamalized corn/bean Snacks

Castillo-Vázquez, K. C., Ochoa-Martínez, L. A., Delgado, E., Gallegos-Infante, J. A., Figueroa-Cárdenas,

J.D

Instituto Tecnológico de Durango. Blvd. Felipe Pescador 1830 0te. CINVESTAV Unidad Querétaro.

Libramiento Norponiente 2000. kacecavaz @hotmail.com

Snack production is an important sector of the food industry, with high annual sales

world-wide. Cereals are traditionally the main source of calories and proteins in human

nutrition. When supplemented with certain legumes, the resulting mixed flour can cover

the nutritional demand on essential amino acids and a proper balance may be obtained at

a ratio of 70% corn and 30% legumes. The aim of this work was to evaluate the effect

of different processing parameters on the physicochemical, functional and structural

properties of nixtamalized corn/bean snacks. Corn (Zea mays L) was nixtamalized and

milled; beans (Phaseolus vulgaris L) were cooked, ground and dried. Nixtamalized corn

dough and bean flour were mixed at different ratios and processed into snacks, by air

convective dryer or by hot plate cooking. Moisture content, percentage of cristallinity,

pasting properties, scanning electron microscope studies, and dough adhesiveness were

measured. Statistical comparisons between samples were made by one-way ANOVA,

including a control dough, which contained nixtamalized corn dough and no bean flour.

The dough had an initial moisture content of 56.5 %, and after processing the moisture

content decreased (p< 0.05) in both processing methods. As bean flour concentration in

the snack increased, dough viscosity decreased (p<0.05). Results show that both air

convection and hot plate processing gelatinized the starch present in the snack,

consequently, the viscosity decreased (p< 0.05), compared to the non processed snacks.

Bean flour did not affect (p>0.05) the gelatinization temperature of the dough,

compared to the nixtamalized corn dough devoid of bean flour. Bean flour inclusion

increased (p < 0.05) the adhesiveness of the dough, compared to the control.

(key words: nixtamalized corn, bean, pasting properties, cristallinity).


101

FP-69

Fat Loss During the Kneading of Oaxaca-type Cheese and its Effect on Texture

Colín Cruz M. A.; Rodriguez Guadarrama R.; Castillón Jardón J.

Departamento de Alimentos, Facultad de Química, Universidad Autónoma del Estado de México. Paseo

Colón y Paseo Tollocan S/N, Toluca 50 000.

[email protected]; [email protected]; [email protected]

During the kneading of Oaxaca cheese, milk fat is released and lost in the water used for

kneading. Losses are greater when using milk containing more than 3.0 % fat. In this

study Oaxaca-type cheese was prepared using milk standardized with different fat

contents: 1.5%, 2.0%, 2.5%, 3.0% and whole milk (3.8%). Fat content in the whey at

draining and in the water used for kneaded was measured. Additionally, fat content in

cheeses was determined along with texture profile during their shelf life. It was found

that fat loss in the draining whey and in the water collected after kneading increased

with the content of fat in the cheese milk. Fat losses diminished in the kneading water

when the number of washes increased, but in the cheeses made with whole milk there

were fewer differences in fat losses between kneading. Fat content in cheese and yield

were greater when fat in milk was increased. Low-fat cheese was harder and more

elastic, as well as dry. Shear resistance and tensile strength in the cheeses increased as

fat content decreased, and concomitantly diminished during their shelf life. It was

concluded that fat losses during Oaxaca-type cheese manufacturing is significant and

that standardization of milk fat to 2.0% allowed to retain more than 15% of fat in the

final cheese, which corresponds to a type II Oaxaca cheese (partially skim milk). In

order to prepare a type I cheese, containing more than 22% fat, cheese milk should be

standardized to 3.0% fat. Fat has a significant influence on Oaxaca-type cheese texture.

(key words: kneading, fat losses, Oaxaca cheese)


102

FP-70

Protein Quality Evaluation in Varieties and Lines of Chickpea (Cicer arietinum L.)

Grown at Different Fertilization Levels.

Cota-Gastélum, A.G., Yánez-Farías, G.A., Falcón-Villa, M.R., Anduaga-Cota, R., Romero-Baransini,

A.L., Barrón-Hoyos, J.M.

Departamento de Investigación y Posgrado en Alimentos. Universidad de Sonora. Blvd. Encinas y

Rosales. Colonia Centro. Hermosillo, Sonora, México, C.P. 83142. , Apdo. Postal 1658.

[email protected]

The aim of this work was to evaluate the in vitro protein quality of two varieties and one

advanced line of chickpea related to fertilization level. Two commercial varieties of

chickpea (Costa and Blanco Sinaloa), and one advanced line (Hoga L10) obtained from

the Coast of Hermosillo Experimental Station of the INIFAP were cultivated under

similar environmental conditions and three levels of nitrogen fertilization (60, 120 or

200 kg/Ha) were applied. Protein, non-protein and total nitrogen using trichloroacetic

acid extracts were determined. Additionally, in vitro digestibility by the multi-

enzymatic method and available lysine were determined. Significant differences were

observed among the two varieties and the advanced line in all the analysis, with the

exception of in vitro digestibility. The effect of fertilization level was observed in all of

protein quality determinations. Results indicate that when the level of fertilization was

120 kg/Ha, a significant increase in the percentage of protein, non-protein and total

nitrogen, as well as in the percentage of digestibility were measured. Available lysine

was statistically higher in all the samples grown with a fertilization level of 200 kg of

N/Ha. These indicators of protein quality may supplement the agronomical and

commercial parameters that are commonly evaluated in improvement programs of

chickpea for selection of new varieties for commercial production.

(key words: advanced line, fertilization, available lysine, in vitro digestibility)


103

FP-71

Physical and Chemical Properties of Four Maize Populations with Different

Polyembryony Levels

Cruz-Requena, M., C., Rodríguez – Herrera,

R., Aguilar – González, CN., and Espinosa-Velásquez J.

Departamento de Investigación en Alimentos, Facultad de Ciencias Químicas, Universidad Autónoma de

Coahuila. Blvd. V. Carranza e Ing. José Cárdenas V. s/n. Col. República Ote. C.P. 25280. Saltillo,

Coahuila. [email protected]

Departamento de Fitomejoramiento, Universidad Autonoma Agraria Antonio Narro, Buenavista Saltillo

Coahuila

Polyembryony is a phenomenon defined by the presence of multiple seedlings per

single seed. There are many plant species that show this phenomenon, including corn

(maize) and mango. Polyembryony provides agronomical advantages; however, there is

still a lack of technical information regarding it possible uses in the food industry. The

purpose of this study was to compare some relevant physical and chemical properties of

two monoembryonic maize varieties (a mixture of experimental hybrids [HIB] and a

high oil corn [HOC]), and two polyembryonic maize populations (a dwarf low

polyembryonic population [BBP], and a dwarf high polyembryonic [BAP] population).

For the physical characterization, weight of one thousand kernels (PMG), kernel

hardness, floating rate, grain size, grain bulk density and grain anatomical structure

were evaluated. The chemical analysis tests performed were: proximal crude protein,

crude fiber, ether extract, ash, starch and moisture, all according to the AOAC. A

randomized complete block design was used in each case. Data were analyzed using

ANOVA and when required, means were compared using Tukey‟s Multiple Range test

(p ≤ 0.05). Results showed that the population with the highest ether extract was HOC

with 6.01%, while the polyembryonic populations had the lowest oil content. The

highest protein concentration was observed for the BBP population, while the highest

content of moisture and crude fiber were measured in the HOC population. No

differences among populations were observed for ash. In the physical characterization

intermediate and soft grain hardness were observed for all maize population, and HIB

were tougher. Grain size was different between monoembryonic and polyembryonic

populations, where the latter showed greater width. The BBP population had the highest

endosperm proportion, while the BAP population had the highest pericarp proportion

and HOC showed the greatest percentage of germ.

(keywords:proteins, fiber, ash, endosperm, germ)


104

FP-72

An Alternative Method for Extraction of Candelilla Wax (Euphorbia

antysyphilitica).

De león-Zapata, M., Saucedo-Pompa, S., Contreras-Esquivel, J.C., Jasso-Cantu, D.,

Sáenz-Galindo, A., Aguilar, C.N.

Departamento de investigación en alimentos. Facultad de ciencias químicas. Universidad Autónoma de

Coahuila. Blvd. Venustiano Carranza PO BOX 252. ZIP 25000, Saltillo, Coahuila, México. Tel: +52 844

4161238, Fax: +52 844 4159534, E-mail: [email protected]

Universidad Autónoma Agraria Antonio Narro. Calzada Antonio Narro s/n. Buenavista, Saltillo,

Coahuila, México.

The candelilla plant (Euphorbia antysyphilitica Zacc) is an endemic species of the

Mexican semi-desert. The state of Coahuila contains the most important areas devoted

to the exploitation of this natural resource. Wax extraction from candelilla is one of the

most important economic activities of a large number of farmers. The current wax

extraction process is carried out by artisanal methods that were developed over a

century ago. The process involves the immersion of the plant in diluted sulfuric acid,

which is used in large quantities. This poses serious potential health problems and

pollution. In this work, we propose new agents to extract this edible candelilla wax; we

also tested some modifications in the extraction process in order to avoid emissions of

toxic chemicals, which may damage the health of the people involved in this activity,

and also to the environment. Three new extraction agents were used at different

concentrations. These substances are biodegradable and do not represent any significant

damage to human health or the environment and are less expensive. A control batch of

wax was extracted by traditional methods (20% H2SO4). The waxes were characterized

by infrared spectroscopy and nuclear magnetic resonance of hydrogen and carbon.

These agents showed similar wax extraction yields compared with the traditional

process (p ≤ 0.05). Additionally, the process reduced the content of impurities and

produced better quality in the waxes. By the use of these agents, waxes had a better

performance than those prepared with sulfuric acid, and may be less expensive to

produce.

(keywords: candelilla, wax, extraction)


105

FP-73

Process and Quality Evaluation of Mamey (Pouteria sapota) Pulp

Díaz, M. J., Sauri, D. E., Tamayo, C. E., Centurión, Y. A.,

División de Estudios de Posgrado e Investigación. Instituto Tecnológico de Mérida. Km 5 carretera

Mérida Progreso s/n CP. 97118. Mérida, Yucatán. [email protected]

Most tropical fruits are highly perishable and have a short shelf life; this group includes

Mamey (Pouteria sapota). Processing of these produce becomes necessary to develop

new products to add value and allow further commercialization. In order to expand

marketing options, Mamey producers commonly prepare raw pulp form fully-ripened

fruits. This pulp does not receive any treatment other than freezing. In this study we

evaluated the process, along with the physical, chemical, sensory and microbial quality,

in order to provide a safe product with an added value. Four batches of mamey pulp

were prepared, and then divided into 14 samples of 1 kg each and kept frozen (-18 °C).

Analyses were made with both the fresh pulp and with the frozen samples for 3 and 6

months. The response values tested were: general acceptance, color, carotenoids,

vitamin C, pH, acidity, °Brix, as well as molds and yeasts, mesophiles, total coliforms,

faecal coliforms and Salmonella counts. The results showed that the same values of

carotenoids, vitamin C, acidity, pH and °Brix values were maintained during frozen

storage. The microbial analysis indicated a significant reduction in yeast, fungi,

mesophiles and total coliforms counts, while the tests for the presence of total coliforms

and Salmonella were negative. Data from Mamey pulp analyses demonstrated that the

product may be considered as suitable for human consumption, because we found no

pathogenic microorganisms that would threaten the health of the final consumer.

Furthermore, the pulp can be preserved for at least 6 months without major losses in its

nutritional quality.

(keywords: mamey pulp, freezing, mesophiles, total coliforms, faecal coliforms,

Salmonella)


106

FP-74

Preparation of Muffin Bread Added with Modified Starch and Microwave Baked

García-Zaragoza, J., Sánchez-Pardo, M., Ortiz-Moreno, A., Hernández-Ortega, M.*

*Departamento de Ingeniería Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico

Nacional. Prolongación Carpio y Plan de Ayala Col. Santo Tomas, México, D .F.

[email protected]; * [email protected]

The bakery industry uses modified starches in order to improve the functional properties

of bread, such as softness, and to increase its shelf life. The proper use of his type of

additives together with microwave baking could help to prepare products with good

quality at a low cost. There is an apparent lack of scientific information that could

explain the changes on bread‟s characteristics when baked using microwaves. Hence, it

becomes necessary to generate information in this topic. In the present study the effect

of two baking processes (microwave vs. conventional oven) of muffin breads with the

addition of modified starch were compared. Using surface response analysis, the baking

conditions for microwave baking were determined; for conventional baking, conditions

previously reported were used. Two formulations were employed for the two different

baking procedures: one with and one without modified starch. Proximate analysis,

sensory evaluation, image analysis and energy content calculations were made for the

four formulations. The microwave baked muffin breads had lower moisture and water

activity, with harder texture than the conventionally baked muffin breads. Starch

retrogradation on the four products produced similar amounts of resistant starch. The

energy content did not show significant differences among the four products. The

modified starch added to the microwave baked muffin breads lead to increased starch

gelatinization, which induced crumbs that were similar to the crumbs of the

conventionally baked muffins. The volume of microwave baked breads increased

compared to the conventionally baked breads made without modified starch. Addition

of modified starch and microwave baking could help to improve some functional

properties of muffin bread.

(key words: modified starch, microwave oven, muffin bread)


107

FP-75

Kinetics of pyruvic acid formation during the drying process variable of garlic

Gómez, G.N., Rodríguez R.J.

, Méndez L.L.

Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional, Unidad Oaxaca, Instituto

Politécnico Nacional (CIIDIR-IPN Oaxaca). Hornos 1003, Sta. Cruz Xoxocotlán. C.P. 71230. Oaxaca,

Oax. México. * [email protected]

The quality of garlic was evaluated on the basis of its sensorial attributes, mainly color,

and its flavor or pungency. Favor characteristic comes from sulfur compounds present

in garlic which is formed by reaction of the enzyme allinase, producing allicin, and

pyurvic acid. Measurement of pyruvic acid has been used to evaluate the quality of

fresh and dehydrated garlic. In this work the pyruvic acid content in samples of garlic

dehydrated by convective drying was evaluated, with profiles of cyclical temperature in

pseudosquare wave-form, with cycles of 40ºC to 60º C (ascending) and 60ºC to 40ºC

(descendent). The samples were prepared in slices of 1.98±0.2 mm of thickness. The

modified method of Schwimmer and Weston for the pyruvic acid determination was

used, as an indirect measurement of allicin content in garlic. During the dehydration

experiments, the air velocity was stabilized at 1.5 m/s. The temperature and the masking

time had important effects in the kinetic of allicin production. Cycles of 60-40 °C (20-

60 °C) are recommended to keep the capacity of pyruvic acid formation.

(keywords: pyruvic acid, allicin, garlic, cyclical temperature, pungency, convective

drying)


108

FP-77

Physicochemical and Textural Properties of Cookies is Ruled by Soy-Oats Ratio in

a Nutritional Formula.

Gutiérrez-Félix, E.C., Morales-Sesma, Z., Vidal-Quintanar, R.L.

Departamento de Investigación y Posgrado en Alimentos, Universidad de Sonora. A.P. 1658, Col. Centro.

Hermosillo, Sonora, C.P 83000. Tel-fax: + 52-662-259-2207/08/09. [email protected]

Cookies were formulated with three levels of soy, oats, and fat sources to measured

texture, polyphenols antioxidants, and sensory properties. We studied the effect of

various levels of combination of soy flour, soy concentrate, and soy milk with flaked

oats. Additionally, the shortening of the formula was substituted by olive or salmon oils.

The main objective was to measure the proportion, and the effect of oats and soy type in

the polyphenols concentration, antioxidant activity, texture, and sensory properties of

formulated cookies. The stability of the product was analysed as a function of fat type,

and concentration added. Each type and concentration of fat was observed to have a

different effect in the quality of cookies. High rate of soy type and oats in the formula

produced a dry, flat, and hard product. The best sensory characteristics were produced

with shortening, soy milk, 30% and 40% of flaked oats. Conditions giving place to

lowest effective moisture diffusion coefficient produced the lowest dehydration, and the

best sensory characteristics in all products. The texture and chewyness were the leading

sensory characteristics in the cookies. Soy milk and flaked oats gave excellent

properties to the cookies. As expected, soy and oats combination improved polyphenols

content, and antioxidant activity of the cookies.

(key words: cookies, oats, sensory properties)


109

FP-78

Microencapsulation by Spray Drying of Polyphenols Extracted from Olive Mill

Waste Water

Gutiérrez-Jiménez, L. Kranz Peter, Soto-Cruz, O., Rutiaga-Quiñonez, O.

Departamento de Ingenierías Química y Bioquímica, Instituto Tecnológico de Durango, Blvd. Felipe

Pescador 1830 Ote. Durango, Dgo. C.P. 34080. [email protected]

The food industry generates a large percentage of sub-products from the raw material.

Today is very important research into new uses of this waste such is the case of olive oil

industry since it generates large amounts of waste in the production process. These are

very important both in the economy and in the environment of the towns where this

crop is produced. The aim of this project is the evaluation of the effect of spray drying

parameters and the core material in the polyphenol compounds extracted from olive

press waste water (alpachi) by determination the total content of polyphenols, by the

technique of Folin-Ciocalteus before and after encapsulation technique and identify the

chemical characteristics of the extract phenolic from olive mill waste water, and the

products obtained (HPLC).

(key words: microencaptulation, polyphenols, alpachi)


110

FP-79

Study of the Chemical Degradation of Vanillin through an Autoxidation.

Hernández-Ramos, D., Pérez-Silva, A ., Ariza-Castolo, A.

Departamento de Ingeniería Química y Bioquímica, Instituto Tecnológico de Tuxtepec, Calzada Dr.

Víctor Bravo Ahuja s/n C.P. 68300 Tuxtepec, Oaxaca, México.

* Corresponding author [email protected]

Departamento de Química. Centro de Investigación y de Estudios Avanzados del I.P.N. Av.Instituto

Politécnico Nacional 2508 Col. San Pedro Zacatenco C.P. 07360 México D.F. [email protected]

Vanillin (4-hydroxy-3-methoxybenzaldehyde) is one of the most important flavours in

the food and pharmaceutical industry. It is obtained from the fruit of the orchid Vanilla

planifolia, which requires a curing process to develop its characteristic aroma, which is

the result of changes experienced by the pods. However, during the curing process there

is an important loss of vanillin (50 %), which could be due in part to an autoxidation of

vanillin or Maillard type of reactions of vanillin, which may cause the formation of

color and other flavor compounds. The objective of this work was to study the

mechanisms of degradation that vanillin may suffer through autoxidation. Vanillin (300

mM, Sigma-Aldrich) was dissolved in an aqueous medium and remained in incubation

at a temperature of 80 °C for 24, 48 and 192 h at pH 5 (characteristic of pods). Aliquots

were taken at specified times and each one was analyzed by thin layer chromatography

and 1H and

13C nuclear magnetic resonance (NMR). The

1H and

13C NMR spectra

showed that the autooxidation of vanillin was evident after 192 h (8 d). Afterwards, a

separation by column chromatography was performed, thus obtaining three fractions.

Each fraction was analyzed by NMR. The compound identified in fraction 1 was

vanillin (C8H8O3), while fraction 2 comprised a mixture of three compounds C8H8O4

(vanillic acid), C16H14O6 (divanillin) and C14H14O4 (biguaiacol). Fraction 3 contained a

mixture of the two dimers. The correlation between the compounds identified after

autoxidation of vanillin, and their presence in pods benefit is still ongoing. The

percentage of degraded vanillin after 192 h was 3.5%. The degradation of vanillin in

buffer systems takes place in a natural way since it does not require any chemical

catalyst or enzyme to achieve its degradation.

(keywords: vanillin, autoxidation, NMR)


111

FP-80

Difussion Coefficient and Shrinkage During Apple and Potato Drying

Herrera-Pérez, L.A., Martínez-González, A, Martínez-González, M., Morlán-Contreras, C., Venegas-

Olvera, A. and Vargas- Ugalde, M. E.


de Méx. C.P. 54740, México. [email protected]

Drying is an unit operation of simultaneous heat and mass transfer widely used in the

food industry to increase the shelf life of many products. Drying conditions affect

product properties - physical, chemical, mechanical, sensory and nutritional, among

others - and also transfer rates. The aim of this work was to study temperature influence

on difussion coefficients during convective drying of apple and potato plates in a tray

dryer, to relate it with product shrinkage. Temperatures of 348, 358 and 368 K were

applied. A factorial design was used. Shrinkage was measured as the percentage of

product volume reduction. For both cases, drying rate increased with temperature.

Apple drying rate was higher than potato drying rate. Final moisture content for apple is

lower than that for potato. For both cases, shrinkage was greater during the first hour

than during the rest of the process. Because of starch gelatinization, potato shrinkage is

lower than apple shrinkage. For both cases diffusion coefficient was inversely

proportional to shrinkage. For apple, at higher temperature, shrinkage was greater, for

potato an opposite behaviour was observed. At 348 K, after 1.2 h potato volume

remained constant. Diffusion coefficients values for apple were from 3x10-8

to 5x10–7

m2/s. For potato, these values were from 3.6x10

-8 to 4.5x10

-7 m

2/s.

(keywords: shrinkage, drying, diffusion coefficient)


112

FP-81

Effect of Soaking Temperature on Cooking Time for Chickpea Grains

Jiménez-Guadalupe, A. L., Piña-Sanabria, M., Flores-Servín F. González-Sánchez J., and Vargas-

Ugalde, M. E.


de Méx. C.P. 54740, México. [email protected]

The aim of this work was to study the effect of soaking temperature on cooking time for

leguminous. Chickpea (Cicer arietinum) grains of 4.85 mm of radius, were soaked in

water at three temperatures (293, 303 and 313 K) during different processing times (2,

3, and 4 h) A factorial design was employed. For each experiment 0.1 kg of chickpeas

and 0.3 dm3 of water were used. Water absorption was measured as grain‟s weight gain.

Weight was registered every 0.33 h, until the experimental time was achieved. A

Universal Texture Machine Instron was employed to measure hardness of grain. Second

Fick‟s law was applied to calculate diffusion coefficients of water. Their values were

from 2.28x10-10

to 4.55x10-10

m2/s. Activation energy value obtained between 303 and

313 K was 54.71 kJ/mol. Hardness of grains soaked at different temperatures and

cooked at 102.9 kPa for 0.4 h, was compared with that of industrially processed

chickpeas. Hardness value for commercial grains was 1.12 kN. For the grains under

study, the values range was from 0.68 to 1.55 kN. Best soaking conditions found in this

work were 2 h at 303 K, obtaining a hardness of 1.12 kN.

(keywords: soaking, hardness, diffusion, chickpea)


113

FP-82

Properties of Carboxymethyl Cellulose (CMC) obtained from Pineapple (Ananas

comosus) and Mamey Sapote peel (Pouteria sapota) Mixes.

Juárez-Barrientos, J. M., Ramírez-Figueroa, E., Herman-Lara, E., Nogueira-Terrones, H., Ramírez-

Rivera, E.

Departamento de Posgrado de la Maestría en Ciencias en Alimentos. Instituto Tecnológico de Tuxtepec,

Calzada Dr. Víctor Bravo Ahuja s/n Tuxtepec 68300 Oax.

[email protected]; [email protected].

The mamey sapote (Pouteria sapota) is native of southern Mexico. Today is cultivated

not only in Mexico, but also in Central America, the Caribbean, and South Florida for

its melon, which is commonly eaten in many Latin American countries. In Tuxtepec,

Oaxaca (Mexico) are produced 96,800 tons of pineapple and 6,000 tons of zapote

mamey annually. Industrial process or transformation of these fruits produces 16,210

ton of waste, meanly peels, which are lignocellulosic materials that are not used and

cause a negative impact on environment. Cellulosic derivatives of high commercial

value as CMC can be obtained from these waste. The aim of this study was to determine

the influence of some pretreatments on the properties of the CMC obtained. Efficient

pretreatments can increase the cellulose content and reduces others compounds presents

in the wastes. Wastes were characterized before and after pretreatments (proximal

analysis, cellulose, lignin and hemi cellulose contents). The following pretreatments

were applied: A) wastes was autoclaved at 121 ° C and 15 psi during 60 minutes and

then boiled in H2O2 (2% v/v) during 5 hours , B) wastes were suspended in NaOH

2.0M and autoclaved at 121 ° C and 15 psi during 60 minutes, C) wastes were

suspended in water (1:2) and autoclaved at 121 °C and 15 psi during 10 min, after that

wasted were suspended in NaOH 2.0 M and autoclaved at 121 °C and 15 psi during 60

min, and finally boiled in H2O during 5 h. Water content of pretreated wastes was

reduced by vacuum filtration and then dried in a cabinet dryer. CMC was obtained using

the direct etherification technique and compared with a commercial CMC. A

multifactorial experimental design was used in order to observe the pretreatments

effects. Results show that pretreatment C increases cellulose contents from 44.5% up to

96.9% and from 31.41% to 97.7% for mamey sapote and pineapple wastes, respectively.

Lignin content was drastically reduced. The CMC obtained from pretreatment C had a

degree of substitution of 0.80, a purity of 99.6% and pseudo plastic rheological

behavior, similar to a commercial food grade CMC.

(keywords: lignocellulosic material, pretreatment, cellulosic derivative,

carboxymethylcellulose).


114

FP-83

Effect from Combining Polysaccharides on Texture Properties of Strawberry Ate

Martínez Jacome, J.G., Torralba Gordillo, H., Zepeda Becerril, A., López Pérez, L. A.,

Romero Arreola, V., Ramírez Ortiz, M. E.

Facultad de Estudios Superiores Cuautitlan-UNAM, Av. 1º de Mayo s/n, Col. Sta. Ma. Las Torres, C.

Izcalli, Edo. de México, 54740. email: [email protected]

In the nourishing industry, the study of the foods properties has become excellent by the

increasing necessity that these satisfy specific needs of performance (physical,

chemical, rheological, texture properties) since on these the degree of quality of a

product for the consumer depends. The project consisted in the elaboration of

strawberry ate, using mixtures of polysaccharides pertaining to the group of the rubbers

whose mixtures present synergism with which it looks for to have better consistency

and minor syneresis. The used mixtures were Locust Bean-Carrageenan Kappa-II, and

Xanthan-Locust Bean, in different ratios and concentrations (high 1.125%-0.9%, and

low 0.375%-0.6%,), respectively, giving in the total formulation 1.5% polysaccharides.

The samples were were cut into cylinders 1.5 cm in diameter, and evaluated using

texture profile analysis (TPA) in a Lloyd TA500 texturometer, using a 1/8 in cylinder, a

preload 1x10-4

Kgf, speed of 1.7mm/s, and distance of 10 mm. From the TPA curve

hardness, cohesiveness, elasticity, chewiness, and adhesiveness were obtained. A

factorial experimental design 23 was used, and analyzed with the MINITAB software

version 15, and α=0.05. The hardness varied significantly (P = 0.009) in relation to the

kind of mix and concentration of polysaccharides. Xanthan 0.75%-Locust Bean 0.75%

showed the smallest hardness value, while the highest corresponded to Xanthan

1.125%-Locust Bean 0.375%. The cohesiveness increased in inverse relation to

hardness, the mixture with greater cohesiveness was Locust Bean 0.9%- Carrageenan

Kappa-II 0.6%. The elasticity showed significant variation (P=0.016) in relation to the

mixture having high values, but the variation of mixture Locust Bean-Carrageenan

Kappa-II with respect to concentration was not significant (P=0.915). The chewiness

had variation (P=0.650) as far as the mixture Xanthan-Locust Bean, which showed low

values when mixed with Carrageen K-II. The values of adhesiveness are similar for the

mixture Locust Bean-Xanthan, but those of the mixture Locust Bean-Carrageenan

Kappa-II differ significantly, independent of its concentration. Among the proportions

and concentrations used, the best one is Carrageneenan Kappa-II 0.75%-Locust Bean

0.75%, the sensory properties were accepted by the consumers, had intense color, smell

to strawberries, and appealing aspect. These characteristics make this mixture the ideal

for developing strawberry gell-form sweets, using polysaccharides.

(key words: polysaccharides, gel texture properties, xanthan gum, locust bean gum,

carrageenan gum)


115

FP-84

Technological Modification of Traditional Nixtamalization Process and its

Impact on Nutritional Quality of Corn Tortilla

Maya-Cortés D.C., Martínez-Flores, H. E., Figueroa, J. D.C., Cuevas-Villanueva, R.A. , Cortés-Martínez,

R.

Student of the Programa Institucional de Maestría en Ciencias Biológicas. Universidad Michoacana

de San Nicolás de Hidalgo. Morelia, Mich. Facultad de Químico Farmacobiología. Universidad

Michoacana de San Nicolás de Hidalgo. Morelia, Mich. CINVESTAV-IPN. Unidad Querétaro.

Querétaro, México. Instituto de Investigaciones Químico Biológicas. Universidad Michoacana de

San Nicolás de Hidalgo. Morelia, Mich.

[email protected], [email protected]

An essential step for the production of tortilla is boiling of the corn in lime by using a

process called nixtamalization, which provides better nutritional quality to tortilla as

compared with raw corn. Nevertheless, this process presents technological and ecological

disadvantages due to the great volume of nejayote (waste water containing high amount

of soluble solids and lime), and nutrients loss. The objective of this work was to

characterize some chemical components in tortilla done by a new ecological process of

nixtamalization. In this process Ca(OH)2 was replaced by other calcium source, namely

calcium sulphate. Ecological process consisted of the following steps: whole corn grains

were heated at 90º C for 40 min and steeped during 12 h. Grains were washed twice, to

remove pericarp fragments from the grains, and milled to obtain “masa”. Then, the masa

was processed to tortillas in a Celorio Machine. Tortillas prepared by the ecological

process had 14.05%, 6.03%, 55.52%, 45.81%, and 54.02% more fat, protein, insoluble

dietary fiber, soluble dietary fiber, and total dietary fiber than the tortilla produced by the

traditional nixtamalization process. In addition, nejayote from traditional and ecological

process had 3.91% and 2.54% of total solids, respectively.

(keywords: corn tortillas, nixtamalization, nejayote, ecological process)


116

FP-85

Study on the Feasibility of Industrialization of a Fermented Milk

Beverage from Kefir

Mendoza-Madrigal, A. G., Reyes-Ocampo, J.G., Cruz-Pacheco, K. G., Arteaga-Martinez, M. R., Peña-

Avila, J.C., Moran-Silva, A., Ramirez-Romero, G., Jiménez-Guzman, J., Chanona-Perez, J.J., Perea-

Flores M. J.

Universidad Autónoma Metropolitana Iztapalapa. Av. San Rafael Atlixco N° 186, Col. Vicentina C.P.

09340, México D.F. [email protected]

Functional food and active components provides health´s benefits that go beyond the

basic nutrition; such as fermented milks which are used as a transportation system of

probiotics, due to provide viably micro-organisms that supply health benefits when the

ingested of viably micro-organisms is appropriate. Kefir beverage is considered a

probiotic food. However it is industrially produced in Asia and Europe only, despite the

health benefits that its consumption reports. The aim of this study was to make a study

to industrialize a fermented milk beverage in Mexico from a lyophilized kefir strain. For

its manufacture the strain Probat KC3(Danisco) was used on pasteurized milk. On the

other hand, a marketing study, financial and plant design simulation were made to

evaluate project feasibility. The project simulation was made considering 10 years of

plant operation. Results indicate the project is feasible and the product designed could

penetrate in the market competing with similar beverages with a share of 1% of the

national demand. The product also presented 81% acceptability by the potential

consumers; total investment was of 11.2 million pesos, recovering capital the third year

of the plant operation, which will be located in Guanajuato with a total area of 1955 m2.

A waste water treatment plant will be operating with the purpose of covering the

Mexican waste water effluent standardsto attain the certificate of clean industry. The

financial indicators were: 24% and 56% for the acceptable minimum rate of return, and

the internal rate of return respectively, which demonstrates a profitable project.

(keywords: industrialization, kefir, functional food)


117

FP-86

Chocolate truffle characterization

Olguín-Martínez, L. E.*, Ramírez-Schoettlin, A., Favela-Torres, T.

1Becarias COFAA EDD. ENCB-IPN. Ing. Bioquímica, Escuela Nacional de Ciencias Biológicas.

Instituto Politécnico Nacional, Carpio y Plan de Ayala s/n Col. Sto. Tomás. México 11340 D. F.

[email protected]*, [email protected]

Tempering and seeding are crystallization methods to develop a uniform solid with

particular combination of polymorphic forms. This work objective was to characterize

isothermal crystallization parameters for the metastability or polymorphism of a

chocolate truffle. It was measured the extent of growth of crystals and magnitude of the

resulting variations in crystalline structures when changes to the crystallisation process

were made. Several factors affecting crystallization and growth were altered during

experimentation, including seeding, mixing and shearing, tempering, cooling method, or

a combination of these. Crystallization of the cocoa butter was examined using an

Olympus BX40 microscope, at 40X magnification. Polarized lenses were also used to

capture any reflected or refracted light. QDA sensory profiling and “compression” test

water activity (Aw) were conducted. Shearing and mixing were the major influence

over crystallization. It was concluded that although cooling rate has fair control over

crystallization on its own, shearing and seeding are greater manipulation factors.

Combinations of these factors are the most significant parameters when attempting to

control crystal forms.

(key words: chocolate, crystals, polymorphic)


118

FP-87

Determination of a, b, and L, Water activity, Weight Reduction and Vitamin C

Content in Dehydrated Product of Litchi Fruit

Osorio, E.O*., Ortiz, M.A., Dorantes, A.L.

*Departamento de Ingeniería Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico

Nacional. Prolongación Carpio y Plan de Ayala Col. Santo Tomas, México, D .F.


The litchi fruit is native of subtropical China and is grown as a commercial crop in

some countries like Hawaii, and Mexico. Most tropical fruits are highly perishable,

showing a short post harvest life at room temperature, which implies losses over 30 %.

The objective of this work was to evaluate the vitamin C content, color, flavor, weight

reduction and water activity in samples dehydrated by osmotic treatment, followed by

air drying. Fresh fruits were treated by three methods 1) blanching by conventional

method (Cm) with water at 85 ºC 2) blanching by microwave method (Mm) with 0.848

KW h/kg microwave energy and 3) non-blanched fruits. After that, samples were

dehydrated by osmotic method in two steps a) with sucrose syrup at 60 ºBrix /1 h, and

b) with sucrose syrup at 70 ºBrix / 3 h, followed by air drying at 60 ºC /5 h. Color was

evaluated by measuring L, a, b and hue, parameters using a Color Mate colorimeter.

Vitamin C content was determined by a spectrophotometric method at 520 nm. Flavor

was evaluated using a hedonic scale with untrained panelist. Water activity was

measured with a Rotronic hygrometer, and weight reduction by difference. The results

of the L value analysis of the litchi product were for Cm= 56.79 and for Mm= 61.58 and

untreated fruits was 58.0. Vitamin C content was similar in blanched fruit with Mm, and

in fruits treated with Cm. The vitamin C content was 35 mg/100 g in non-blanched

fruits. The decrease of water activity for each sample was Cm= 0.670, Mm 0.650 and

non-blanched fruits = 0.630. Weight reduction was similar in three samples Cm= 67.68

%, Mm= 71.28 %, untreated fruit = 67.68 %. Results for flavor evaluation in dehydrated

products showed that untreated fruits were 67 % accepted, while Cm was 63 % and Mm

60 %. In conclusion osmotic dehydration can be successfully applied to obtain a litchi

product, with good characteristics of flavor, color and vitamin C content, with better

stability against microorganisms because of intermediate water activity.

(key words: osmotic dehydration, water activity, vitamin C content, litchi)


119

FP-88

Characterization and Cooling Capacity of a Horizontal Pilot Scale Scraped

Surface Heat Exchanger

Quintanar H., Ma. J.; Flores M. J.L; Osório R.G. I.; Santiago P., T.

aBecario COFAA, EDD;

b Becario PIFI, CONACYT;

cDepto. Ingeniería y Tecnología FES-UNAM

Departamento de Ingeniería Bioquímica. E. N. C. B. – I.P.N. Prol. Carpio y Plan de Ayala s/n, México

D.F. CP 11340; [email protected]

Scraped surface heat exchangers (SSHE) are widely used in the food industry to process

heavy liquid like puree, concentrated juice, marmalades where continuous operations

are desired. In this work a 0.020 m3/h capacity, 0.0615 m

2 internal surfaces, stainless

steel pilot scraped surface heat exchanger was characterized. Papaya puree (Maradol

Var.) was employed as a working fluid and ethylene glycol (1:1 aqueous solution) as a

cooling medium. SSHE temperature, feed velocity and impeller rotation were taken as

variables factors at two levels according to a 23 experimental design, with three central

point repetitions. The parameters considered were: papaya puree temperature at the

discharge, cooling capacity of the equipment, ascorbic acid and papain percentage

retention. At the same time, the puree thermodynamic properties were also determined,

so were the experimental and theoretical internal convective heat transfer coefficients

for each run. Theoretical coefficient values were calculated using the Skelland‟s

equation (1979). The results showed that the equipment had an average cooling capacity

of 600 W. Ascorbic acid and papain had an average retention of 90% and 80%

respectively. Papaya puree heat capacity (3.8432 kJ/ kg) was determined by Charm‟s

equation (1971). Thermal conductivity (0.61W/m°C) was measured with a

thermoconductimeter KD2 apparatus and verified by Choi and Okos equation (1983).

Effective average viscosity of 9.56 Pa.s was determined by the Haake RT20 rheometer

at 10°C. The average experimental and theoretical internal coefficient values were:

1185.80 W/m2°C, and 850 W/m

2°C, respectively. ANOVA statistical analysis was

carried out to verify the significance of the results using the Minitab software, version 5,

with a = 0.05.

(keywords: scraped surface heat exchanger, cooling, papaya, papain)


120

FP-89

Sugar Free Confectionery: Gummies

Ramírez-Schoettlin, A., Olguín-Martínez, L. E., Favela-Torres, T.

ENCB-IPN. Ing. Bioquímica, Escuela Nacional de Ciencias Biológicas. Instituto Politécnico Nacional,

Carpio y Plan de Ayala s/n Col. Sto. Tomás. México 11340 D. F. 1Becarias COFAA EDD.

[email protected]; [email protected]

Sugar free confectionery comprises many different products, instead of sugar they may

contain bulk sweeteners such as sorbitol and fructose which compared to sugar do not

affect the insulin and blood sugar levels of the body and this makes it particularly suited

to diabetics. The aim was to develop low sugar gummies. The gelatin and arabic gum

used required pre-hydration and dispersion in water to ensure functionality, we boiled to

final moisture content according to required texture, cooled and formed. Sucrose was

substituted by fructose and sorbitol resulting products with transparent texture, stability

and typically 10% residual water. To formulate it a factorial design was used, where

variables used were solids from sorbitol and fructose, and their concentration in

products functional properties, evaluating sweetness and texture by sensory analysis. In

this experimental method we took as factors, fructose and sorbitol concentration to

know in advance all posible combinations, resulting 16 formulas to be discarded, and

we concluded that a higher concentration of sorbitol has a negative effect in flavor

aceptance (4:1). A higher fructose concentration affected products and contributes to an

opact product. This way we predicted four formulas that enhaced flavor and texture and

statistical analysis gave the best formula. Glucose content was evaluated by glucose

oxidase enzimatic tests. Final formula had 95% less glucose compared with the normal

product, 40 g of product had 0.22 g of glucose which may be readily metabolized. It

was necessary to increase temperature to 115º C in order to control sorbitol

higroscopicity. We controled their rheology and texture, improved storage properties,

prevented deterioration in texture and properties (stickiness), and provided a method of

modifying texture and viscoelasticity of gummies by the addition of a combination of

hydrocolloids. 5 The presence of hydrocolloids conferred stability to the dispersion of

other components such as colours, flavours, acids, functional ingredients.

(keywords: low sugar, gummies, confectionery, diabetic)


121

FP-90

Thermodynamic Analysis of the Effect of Water Activity on the Stability of Spray-

Dried Encapsulated Paprika Oleoresin.

Rascón, M. P., Beristain, C. I. , García, H. S. and Salgado, M. A

.

Instituto de Ciencias Básicas, Universidad Veracruzana, Apdo. Postal 575, Xalapa, Ver., México. Unidad de investigación y desarrollo de alimentos, Instituto Tecnológico de Veracruz, C.P.: 91860,

Veracruz, Ver., México. Xalapa 91000, Veracruz. e-mail: [email protected]

Color of the paprika oleoresin is mainly due to nine major carotenoid pigments,

naturally present in multiple forms of etherification. Commercial quality of paprika

oleoresin depends on a high concentration and stability of pigments to guarantee that the

initial chromatic characteristics last throughout its shelf life. Carotenoid degradation is

influenced by some conditions as temperature and oxygen, in order to avoid

autoxidation reactions, microencapsulation by spray drying can be used. Additionally,

microcapsules stability is greatly influenced by its moisture sorption characteristics;

thermodynamic parameters have been used to study the stability of foods. The purpose

of the present study was to evaluate the performance of soy protein isolated (SPI),

modified starch (Capsul) as compared to gum arabic (GA) on carotenoids retention

during microencapsulation of paprika oleoresin by spray drying at different inlet

temperatures (160°, 180° and 200°C) and found the best storage conditions of

microcapsules through thermodynamic parameters calculation. All treatments showed

that carotenoids retention increases at high inlet temperatures, which was associated to a

rapid film formation around core material. In all treatments the relationship between

both carotenoid fractions (R/Y) oscillated around 1. The highest carotenoid retention

was achieved with SPI and capsul as wall materials at Tinlet= 200 °C y Toutlet = 110 °C,

so microcapsules obtained at these conditions were selected to carry out sorption

isotherms at 25°, 35° and 45 °C. Through minimum integral entropy calculation the

point of maximum stability was found at water activities (aw) of 0.35, 0.50 and 0.77 for

microcapsules elaborated with SPI, GA and Capsul respectively. Gibbs free energy

calculation showed that microcapsules elaborated with gum arabic were the most

hygroscopic. It was observed through scanning electronic microscopy that all

microcapsules showed structural integrity on its walls at a wide interval of aw (0.1-

0.743) except those elaborated with gum arabic, which were dissolved at aw = 0.743.

(keywords: microencapsulation, spray drying, water activity, integral entropy, Gibbs

free energy).


122

FP-91

Structural Properties of Garlic (Allium sativum, L.) During Air Drying Under a

Trapezoidal Temperature-Time Wave Like Curve

López, O. A.

, Rodríguez, R. J.

, Méndez, L L.

Instituto Politécnico Nacional, CIIDIR Unidad Oaxaca Calle Hornos # 1003, Santa Cruz Xoxocotlán,

Oaxaca, C.P. 71230.Tel. y Fax: (951) 517 06 10 y 517 04 00 Ext. 82753. E-Mail.

[email protected]

In this work, particle density (measured in a Quantachrome steropycnometer), apparent

density (buoyancy principle) and apparent porosity (calculated) of garlic were evaluated

during air drying under a trapezoidal temperature-time wave like curve. At the end of

drying, the glass transition temperature (MDSC Q100, TA Instruments) was

determined. Four wave periods (60, 80, 120 and 160 min) for every cycle were used

(mean temperature 50° C and ΔT 10°); starting temperatures of the cycles were 40 and

60 ºC. Based on analysis of variance (ANOVA), we inferred that apparent density,

porosity and transition temperature depend on wave period and moisture content. As

moisture content increased from 9.49% to 178.46 % d.b., the apparent density decreased

from 1360 to 1065 Kg/m3, and porosity increased from 2.17 to 22.04. The particle

density increased during the first part of drying and decreased in the second half. As the

period increased from 60 to 160 min, the glass transition increased from 54.74 to 60.57

°C.

(keywords: particle density, porosity, glass transition temperature, cyclic drying)


123

FP-92

Evaluation of Extruded Snacks From Taro-Nixtamalized Maize Flour Blends

Rodríguez-Miranda J., Martínez-Sánchez C. E., Herman-Lara

E., Ruíz López I. I., Martínez-Bustos F.,

Delgado-Licon E. Vivar-Vera M. A.

Coordinación de Posgrado-Maestría en Ciencias en Alimentos. Instituto Tecnológico de Tuxtepec. Av.

Dr. Víctor Bravo Ahuja S/N. Col. 5 de Mayo. C.P.68350. Tuxtepec, Oaxaca, México. Tel.

012878751044. [email protected]

Taro is a tropical tuber with high starch content, whose cultivation in Mexico has

increased. However, its use has been limited due to its short post-harvest life. The

mixture of taro flour with nixtamalized (no creo que halla esta palabra en ingles9 maize

flour and its processing by extrusion technology is an alternative to obtain a new

valuable-added food product with long shelf life. The aim of this work was to evaluate

extruded snacks prepared with taro-nixtamalized maize flour blends. Slices of taro

tubers were dried at 60°C h in an air convection oven and then ground at 0.5 mm

particle size. Nixtamalized maize flour was obtained by the traditional procedure and

milled at the same particle size. Flour mixtures at different proportions (0:100) of

taro:maize were extruded in a single-screw extruder at 18% feed moisture and 60 rpm

screw speed. A central composite design (Design Expert 6.0) for two independent

variables: proportion of taro:nixtamalized maize flour (0-100%) in the blend and

processing temperature (140°-180ºC) was performed. Expansion index (EI), as

dependent variable, was determined in the product in order to select the best extruded

snack. An ANOVA test was carried out with the same software. The selected snack was

analyzed through determination of proximal chemical analysis (PQA) including

resistant starch, apparent density (AD) and maximum rupture force (MRF). The results

showed that extrusion temperature did not have a significant effect (p>0.05) on EI. On

the other hand, a higher proportion of taro flour showed significantly increasing on the

EI. The most expanded snack was the blend of 85.4:14.6 taro:nixtamalized maize flour

extruded at 174.14 °C. The selected snack has low content of fat (0.44±0.1% w.b.),

protein (1.0±0.06%) and resistant starch (5.89±1.7%); relatively high content of crude

fiber (1.49±0.26%) and ash (3.46±0.28%) and high carbohydrates content

(84.41±0.58%). The AD and MRF were 331.38±17 Kg m-3

and 10.57±4.3 N,

respectively. This study showed that it was possible to obtain a product from taro:maize

flour blend with snack characteristics using extrusion technology under established

conditions.

(keywords: taro flour, nixtamalized maize flour, blend, extrusion, evaluation,

characteristics)


124

FP-93

Drying and Rehydration Study of Carrots (Daucus carota).

Rosas-Mendoza, M. E., Melquíades-Avila, Y.I., López-Cerqueda,C.

Facultad de Estudios Superiores Cuautitlan, U.N.A.M. Av. 1° mayo s/n Col. Atlanta C.P 4740 Cuautitlan

Izcalli, Estado de México, México. [email protected]

Most of the dried products are usually rehydrated for their use. This process is

influenced by the conditions of the drying process, the preparation and composition of

the sample, and the structural and chemical grade of rupture. The aim of this work was

to evaluate the effect of the drying temperature and sample geometry in the rehydration

kinetics of carrots, pretreated and dried previous to the reconstitution, as well as to

determine the effective diffusion coefficients (Deff). Two different sample geometries

(infinite slab and cylinder) were subjected to a treatment of 5 min in distilled water at

80°C before being dried in a convection oven, at 0.5 m/s air rate and different

temperatures (40°, 60° and 80º C). The rehydration was carried out immersing the

samples in a distilled water bath, in a 50:1 ratio at 80º C, recording every min the

change in weight until 80 min. To adjust the rehydration curves, 95% confidence

intervals were applied for the complete experimental data. Kinetics were obtained and

Deff computed by a Fick´s second law model. The pretreatment modify the membrane

permeability, which contributes to the mass transfer during drying, with Deff values

between 2.4 x 10-10

and 4.8 x 10-10

m2/s. However, it was observed that the rehydration

was affected by the pretreatment and drying temperatures, provoking a decrease in Deff

values (3.46x10-10

to 4.79x10-10

m2/s), due to the structure collapse (in open porosity)

caused by the shrinkage during time needed to dry carrots, specially at lower

temperature (40º C), and by the starch gelatinization. Likewise, the lower equilibrium

moisture reached in rehydration for samples dried at 40° and 80º C, is indicative of

product changes induced by the drying times and temperatures.In addition, at 60º C the

mayor Deff values were obtained, due to the minor cellular and structural damage at this

process conditions, mainly in the cylinders that had the greatest values. These results

highlight the need for additional studies on how the product porosity is affected by

pretreatment and drying history, due to the molecular bonds disrupted and the new ones

formed during rehydration.

(keywords: rehydration, kinetics, diffusion, porosity, drying)


125

FP-94

Effect of Soybean Addition on the Texture Profile of Corn Tortilla

Rosillo de la Torre, A. and Pérez- Pérez C.

Instituto Tecnológico de Celaya. Dpto. Ingeniería Bioquímica. Av. Tecnológico y Antonio García Cubas

S/N, 38010. Celaya, Gto. Tel 0052(461) 6117575 ext 329 , fax (0052(461) 6117979. email:

[email protected]

Consumption of corn tortillas has important nutritional implications due to their calcium

and fiber content, not as well as protein. In order to increase the protein value we

formulated a tortilla containing corn (C): soybean (S) at different ratio (90:10, 80:20

and 70:30 % w C/ w S). The effect caused by soybean incorporation on the texture

profile analysis (TPA) was considered. TPA was performed with a double compression

cycle test using a Texture Analyzer TA-XT2i (Stable Microsystems Ltd., UK) with a 25

load cell and the software (Texture Expert V1.0 Stable Micosystems Ltd). The P/75

probe was used, the pre-test speed was 5.0 mm/ s, test speed was 1.0 mm/ s; penetration

distance was 5 mm and the rest period between each cycle compression was 5s. In order

to have a good estimation overall tortilla texture, measurements were effectuated cutting

10 tortillas, shaped in cylinders (2 cm diameter) and three replicates were carried out.

Statistical analysis were developed with p<0.05 and showed that hardness,

adhesiveness, chewiness, resilience, and cohesiveness were affected by the soybean

concentration. Tortillas containing 90:10 corn/soybean showed the highest hardness

(15% higher than control). Gumminess, cohesiveness and chewiness of 70:30 C/S were

40% lower than the control, and showed a slight decrease in tortilla firmness (15%

lower than control). All the corn-soybean tortillas mixtures presented good rheological

properties.

(keywords: texture profile analysis, corn tortilla, soybean)


126

FP-95

Changes in Mass Transfer, Thermal and Physical Properties During

Nixtamalization of Corn with and without Agitation at Different Temperatures

Ruiz, G. M., Quintero, R. A., Meléndez, P. C., Talamás A. R., Marquez, M. R., Lardizabal, G. D. and

Barnard J.

Departamento de Investigación y Posgrado, Facultad de Ciencias Químicas. Universidad Autónoma de

Chihuahua. Ciudad Universitaria s/n, Pascual Orozco y División del Norte. Chihuahua, Chihuahua. No.

1542-C. [email protected], [email protected]

The nixtamalization of maize grain is a process accompanied with chemical reactions

and mass transfer phenomena in which water and calcium diffusion occurs in the grain.

The mass transfer is related to the physical and chemical changes that occurred in the

grain and modify the mass and tortilla quality. The aim of this study is to evaluate the

effect of nixtamalization at different temperatures, in static and agitated systems on the

physical, chemical and thermal properties that occur during the process. Lots of 2 kg of

white dented maize (Zea mays L.) of thin pericarp, were nixtamalized in lime solution

[1.2% (w/v)] in a 1:3 relation (w/v) and the temperature effects (70°, 80°, 90°, and 100°

C) were evaluated in both static and agitated systems. Kinetics of Ca+2

and water

absorption and removed pericarp as well as temperature and enthalpies of gelatinization,

were determined in the grain. In the slurry remaining after maize cooking (nejayote)

soluble and suspended solids, and totals sugars were also evaluated. Both samples were

taken every 10 min during 60 min of cooking, afterwards every 8 h during 48 h of

steeping calcium and water contents were measures in the grain. Calcium and water

absorption, soluble solids, suspended and total sugars in the first hour of cooking

showed a linear tendency, nevertheless longer steeping times showed an exponential

tendency for calcium and water, governed by diffusional mechanisms obtained diffusion

coefficients of 7.63-8.61×10-7

m2 s

-1 for calcium absorption using Fick‟s second law. At

70° and 80° C, the effect of agitation was significant (p<0.05) on the removal of grain

pericarp, calcium and water absorption into the grain and in nejayote the amount of

suspended and soluble solids, and total sugars too. At cooking temperatures of 90° and

100° C, we did not find a significant effect (p<0.05), in the pericarp removal, calcium

and water contents. On the other hand, an increase in Ca+2

in the grain during the

cooking caused an increase in the temperature and enthalpy of starch gelatinization of

3.02-3.87, 2.44-2.88, 3.01-3.55, and 2.66-3.17 J· g-1

at 70°, 80°, 90°, and 100° C,

respectively.

(keywords: nixtamalization, corn, agitation, diffusion coefficients)


127

FP-96

Powder characteristics of pomegranate-apple juice

produced by spray drying

Ochoa-Martínez, L.A.; Trancoso-Reyes, N., Urbina-Martínez, J.M., Gutiérrez-Velázquez, M. Morales-

Castro, J.; Delgado-Licon, E.

Technical Institute of Durango, Chemical and Biochemical Department. Blvd. Felipe Pescador 1830 Ote.

Durango, México. [email protected]

One of the major problems in spray drying of fruit juices is stickiness and

thermoplasticity of their compositions. Functional properties of powders involve the

ability of the powder to dissolve in water. The objective of this study was to investigate

the physical characteristics of powders produced by spray drying of pomegranate-apple

juice under different operational conditions and to establish the antioxidant capacity.

Pomegranate-apple juice was microencapsulated by using a mini spray dryer. The

problem of stickiness in the drying chamber was overcome through the use of drying

aid agents such as mixtures of arabic gum and maltodextrin 10 DE (i.e.100/0, 80/20,

60/40, 40/60, 20/80, 0/100). Temperature of 140ºC and a feed flow rate of 10 mL/min

were selected as operating conditions of the dryer. The use of 100% of maltodextrin the

powder production was unsuccessful. The moisture content varied from 2.5 to 3.5%,

whilethe density was 0.553 g/cm3.Wettability and dispersibility were found to be related

with the concentration of arabic gum, the higher the amount of arabic gum the higher

the time to be wetted and the less the percentage of dispersibility. Insolubility index was

related with moisture content and dispersibility. A high hygroscopicity was found. The

antioxidant capacity was affected by the added concentration of drying agent aid.

(keywords: rehydration properties, antioxidant capacity, pomegranate, powder)


128

FP-97

Application of Differential Scanning Calorimetry (DSC) at the Characterization of

Mamey Sapote Seed (Pouteria sapota) Oil

Sánchez-Ortega, E., Herman-Lara, E., Vivar-Vera, M. A., Rocha-Uribe A., Gallegos-Infante, J. A.,

Marangoni, A. G., Martínez-Sánchez, C. E.

Coordinación de Posgrado-Maestría en Ciencias en Alimentos. Instituto Tecnológico de Tuxtepec. Calz.

Dr. Víctor Bravo Ahuja s/n. Col 5 de Mayo. Tuxtepec, Oax. México. CP 68350. [email protected]

The mamey sapote (Pouteria sapota) is a species of tree that is native to southern

Mexico. Today, the tree is cultivated not only in Mexico, but also in Central America,

the Caribbean, and South Florida, and its fruit is commonly eaten in many Latin

American countries. Currently, non-conventional sources of fats and oils, such as fruit

seeds, are very important. The study of the thermal properties of fats and oils is

important because many of the applications of these materials depend on the ratio of

solid (crystalline fat) to liquid oil. The purpose of this study was to characterize the

thermal behavior of mamey sapote seed oil from Mexican cultivars. Seeds without testa

were dried in an airflow reversal dryer. Subsequently they were milled and the oil was

extracted with hexane and then bleached, refined and characterized by some physical-

chemical indices. Fatty acid profile was done by GC and a TAG analysis by HPLC. The

thermal profile of sapote mamey seed oil was analyzed by DSC. Crystallization and

melting curves were obtained between –50°C and 80°C, at 5°C/min, in the oil at three

processing stages (crude, bleached and refined). We obtained a yield of 83.58% of crude

oil, requiring 3 neutralization steps with 20% NaOH to reach 0.09% of free fatty acids.

The physicochemical characterization showed that the oil acquired greater stability due

to refinement. The fatty acid profile showed the presence of C16:0, C18:0, C18:1,

C18:2, C18:3 and C20:1. HPLC chromatograms showed 5 triacylglicerides families:

PLP, POP, STO, POSt and StOSt, which are involved with polymorphic transitions

displayed by the DSC in the process of crystallization and melting. Using x-ray

diffraction and polarized light microscopy, the existence of polymorphs α, β and β‟ was

proven. According to obtained data, this seed could be considered an important source

of vegetable oil. Besides, the possible use of cold temperatures in order to reach the

total crystallization and thus the formation of a β polymorph, which is

thermodynamically most stable, indicated that the oil can be used to prepare ice cream

and confectionery.

(keywords: crystallization-curve, thermal-analysis, sapote mamey seed oil)


129

FP-98

Properties of Taro Starch Maltodextrins

Antonio-Estrada C., Martínez-Sánchez C. E., Jiménez-Hernández J., Montañez-Soto J. L., Vivar-Vera M.

A.

Coordinación de Posgrado, Maestría en Ciencias en Alimentos. Instituto Tecnológico de Tuxtepec. Av.

Dr. Víctor Bravo Ahuja S/N. Col. 5 de Mayo. C.P.68350. Tuxtepec, Oaxaca, México. Tel. 012878751044

Ext.143. [email protected]

Taro (Colocasia esculenta) is an edible tropical tuber which crop has recently increased

in Mexico. Because of its high starch content (58-80% d.b.), taro is an alternative source

of valuable derivates such as maltodextrins which could be used in the food industry.

The aim of this work was to evaluate the properties of maltodextrins obtained from taro

starch. Maltodextrins were produced from extracted taro starch by enzymatic hydrolysis

in a glass reactor. The reaction was carried out using a heat stable α-amylase at 0.02%,

starch concentration of 35% d.b., pH 6.4, 1.4 g/L CaCl2 and 95˚C to produce

maltodextrins with dextrose equivalent (DE) of 15 and 17.5%. Some chemical,

physicochemical and functional properties of dried taro maltodextrins were evaluated

and compared with commercial corn maltodextrins by ANOVA (Minitab v. 13.1).

Average degree of polymerization values of taro maltodextrins with DE of 15

(0.20±0.01) and 17.5% (0.35±0.02) were similar (p>0.05) to the values of corn

maltodextrinas with DE of 15% (0.26±0.03) and 17.5% (0.42±0.02). Average molecular

weight was found to be significantly lower (p<0.05) in taro maltodextrinas with DE of

15% (33.23±1.8 g/mol) and 17.5% (57.17±3.87 g/mol) than values of corn

maltodextrins with DE of 15% (42.25±4.55 g/mol) and 17.5% (68.83±2.68 g/mol).

There was no significant difference (p>0.05) in proximal chemical composition, aw and

pH between taro and corn maltodextrins with similar DE, except in fat content between

maltodextrins with DE of 17.5%. Taro and corn maltodextrins with the same DE had

similar values of water absorption, oil absorption and emulsifying capacities. However,

solubility index (SI) and foam capacity (FC) of taro maltodextrins with DE of 15%

(94.08±3.43%) and 17.5% (1.00±0.33%), respectively, were significantly higher

(p<0.05) than SI (87.21±2.19%) and FC (0.55±0.19%) of corn maltodextrins with DE of

15 and 17.5%, respectively. These results showed that taro starch maltodextrins could

be used like corn starch maltodextrins as fat replacers, bodying and freeze-control

agents in products such as mixtures of soup, sausage and salad dessert, freeze desserts

and ice creams. Additionally, 15% DE taro maltodextrins could be used in systems

which require good solubility as beverage powders.

(keywords: taro starch, maltodextrins, enzymatic hydrolysis, properties.


130

FP-99

Biaxial Extensional Viscosity to Predict Cookie Diameter Made with Mexican

Wheat Flours Salazar-García, M. G., Huerta-Hernández,

J.R., Cinco-Moroyoqui, F. J., Rouzaud-Sandez, O., Islas-

Rubio, A.R

Departamento de Investigación y Posgrado en Alimentos, Universidad de Sonora, Calle Rosales y Blvd.

Luis Encinas s/n Col. Centro. CP 83000 Hermosillo Son. [email protected] ;

[email protected]

Cookie diameter is controlled by the rate at which the dough expands and the time at

which the cookies structure sets. According to the American Association of Cereal

Chemistry definition of flour quality, poor cookie doughs stop lateral expansion and

increase viscosity earlier than do excellent quality doughs. Dough viscosity appears to

control cookie spread rate affecting the final cookie diameter. The lubricated uniaxial

compression technique was used to measure the biaxial extensional viscosity of cookie

dough. The objective of this study was to determine whether the lubricated uniaxial

compression technique might be used to measure differences in biaxial extensional

viscosity of cookie doughs and to determine whether dough viscosity might be a tool to

predict the cookie baking quality of wheat flour blends. Moisture, protein, ash content,

biaxial extensional viscosity and cookie diameter were determinated. Data were

evaluated by regresion analysis using the statistical analysis system. Cookie doughs

made from hard wheat flour showed higher biaxial extensional viscosity (5.19 x 106

Pa*s) than those made from a blend of wheat flour (3.25 x 106

Pa*s) or from a soft

wheat flour (2.68 x 10 6

Pa*s). Values of biaxial extensional viscosity correlated

significantly (p< 0.05) with the diameter (r= -0.947) of cookies made from Mexican

wheat flours. In conclusion, lubricated uniaxial compression appears to be an

appropriate technique to measure cookie dough viscosity and may be useful for

predicting the cookie baking quality of wheat flour blends.

(key words: biaxial extensional viscosity, cookie diameter, wheat flours)


131

FP-100

Physicochemical and Nutritional Characteristics of Blends of Corn Starch-Carrot

Using Thermo-Plastic Extrusion

Soto-Zamora, G.E. and Martínez-Bustos, F.

CINVESTAV, IPN, Unidad Querétaro, Libramiento Norponiente, No. 2000, Fracc. Real de Juriquilla.

C.P. 76230. Querétaro, Qro., México. *[email protected].

Sabatica year: CICATA-IPN. Cerro Blanco #141, Col. Colinas del Cimatario. Santiago de Querétaro,

Querétaro, CP. 76090. [email protected].

Blends of corn starch and carrot flour at different ratios were extruded in order to

obtain expanded products and pre-gelatinized flours. A central composite routable

model with three variables with =1.6818 was used. The effects of the barrel

temperature, feed moisture and the carrot content, on the color, and the functional and

physicochemical characteristics [i.e.expansion index, apparent density, penetration

strength, water absorption index (WAI), water solubility index (WSI), rheological

(viscosity), and content of and -carotenes ] were evaluated. The response variables

were analyzed using response surface methodology. The carrot content was the factor

wich presented the highest effect on color parameters (L*, a*, b*, C* and Hue), (p ≤

0.01), and -carotenes (p≤ 0.0001) and WSI (p≤ 0.1); while the barrel temperature

had a significative effect on the WAI, final viscosity, apparent density (p ≤ 0.01) and

retrogradation viscosity (p ≤ 0.1). Expanded products and pre-gelatinized flours are

excelent vehicles to the incorporation of carotenoids in diverse food systems, due to the

evaluated processing conditions did not affect considerably the pro-vitamin A content,

conferring to the extruded products nutritional advantages.

(key words: carrot, extrusion, carotenes).


132

FP-101

Chayote Marmalade Supplemented with Chia Seed

Trinidad-Pérez, Y., Beltrán-Mendoza I., Antonio-Castelan M., Alonso-Calderón, A., Montalvo-Paquini C.

Universidad Politécnica de Puebla, Tercer carril del ejido “Serrano” San Mateo Cuanalá, Mpio. Juan C.

Bonilla, Estado de Puebla. [email protected]; [email protected].

Chayote (Sechium edule), the vine, is a tuberous rooted perennial that climbs by

clinging with tenacious tendrils. Most varieties have fruits with ridges; they can be

smooth, knobby, or fuzzy; some are dark green, almost white, or brown. Chayotes are

sometimes eaten raw in salads and salsas, but are more often cooked by boiling,

sauteing or baking. Although very young fruits can be eaten entirelyy, it is usually

preferred to peel the older, more mature fruits. An attempt has been made to increase

the life of the fruit by drying it. Other way to be prepared is as candy, looking for higher

acceptance between children. The objective of this work was to obtain different Chayote

marmalade formulations; some of them were prepared using chia seeds (Salvia

hispanica L.). Chia seeds (Salvia hispanica L.) typically contain 25 % dietary fiber

(mostly soluble), significant levels of antioxidants and the oil contains a high

concentration of omega 3 fatty acids. The chayote pulp had a pH of 6.4 and its total

solids measured 6 ºBrix. Three different marmalade formulations were prepared

containing 1 and 2.5% chia seeds and the control. The final amount of soluble solids

was set at 62 - 66 ºBrix for a pH range of 3.6 – 3.9, which are the values recommended

by NMX (Mexican standards). The amount of fiber increased 3% with chia seeds. The

different marmalades formulations were evaluated by a panel of 60 untrained tasting

panelists. Odor, smell, taste, and texture were evaluated using a hedonic scale of 6. All

formulations were accepted by the majority of the panelists, the best characteristic

evaluated was the taste. From the point of view of new products with excellent

nutritional value, the marmalade containing chia seeds looks very attractive. Also

represent an alternative of commercialization for communities as Santa Catarina

Villanueva, Quecholac, Puebla where Chayote is grown.

(keywords: chia seeds, chayote, marmalade)


133

FP-102

Effect of Pre-Cooling of Seed Clove on Garlic Bulbs cv “Retinto” Production and

endogenous levels GAs

Utrilla, V. M. y Mercado, S. E.

Departamento de Investigación y Posgrado en Alimentos, Facultad de Química.

Universidad Autónoma de Querétaro, CU, Cerro de las Campanas S/N. Col. las Campanas.

76010, Santiago de Querétaro, Qro.

[email protected],[email protected]

There are evidences that garlic crop needs cool temperatures during their development;

when the cool requirements are not reached, the production has low quality with small

size bulbs and high proportions defects. It is possible that pre-cooling the “seeds cloves”

at low storage temperature (5 to 10 °C), could satisfy those requirement and to improve

bulbs quality. The objective of this study was to identify pre-cooling conditions to

improve the bulb quality and to establish a relationship with the gibberellins (GAs)

content during the bulb development. Four sets of 75 garlic bulbs cv „Retinto‟ were

stored at room temperature (RT), 5 and 10 °C during 2, 8, and 16 days. After storage,

the bulbs were shelled and the cloves were selected and distributed in three subsets

(replicates) of 200 cloves each per temperature. Before sowing, the cloves were cleaned,

disinfested and finally sowed, and cultivated in a commercial orchard. Periodically,

samples of 10 plants were taken randomizing during the crop development. Bulb and

neck diameter were measured and Gibberellin (GAs) concentration was determined in

freeze dried samples extracts by HPLC. On harvest, the bulbs were classified by size

and defects and the performance by hectare was determined. The cloves stored for 2, 8

and 16 days at 10 °C produced plants with larger bulbs (6.5 to 7 cm diameter) than

plants obtained from cloves stored at RT. The highest production rates were obtained

from plants obtained by cloves stored 2, 8 and 16 days at 10 °C (20 ton/ha) and they

also produced the higher proportions of the bigger sizes bulbs (17 ton/ha) and low

production of defects. Two fractions (F1 and F2) with gibberellin activity were found;

which decreased from 0.33 to 0.03 and 0.99 to 0.06 (meq of GA3/g freeze dried sample)

respectively. An increase was observed when the bulbing started and it decreased at the

end of development plant. These results indicated that pre-cooling of garlic bulbs for 2,

8 and 16 days at 10°C before sowing improves the garlic production and that the

bulbing process is inversely associated to GAs production in the bulbs.

(key words: Allium sativum L., purple garlic, pre-cooling, gibberellins, quality)


134

FP-103

Effect of Temperature and Chelating agent Concentration on the Yield and

Composition of Pectic Extract of Opuntia ficus indica Cladode Flour

Pérez-Martínez, J. D., Myers-Ibánez, S. , Ornelas-Paz J. J., Toro-Vazquez. J. F.

Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí. Manuel Nava 6, Zona

Universitaria, San Luis Potosí. 78210. S.L.P. México.

Centro de Investigación en Alimentación y Desarrollo A. C., Ave. Cuarta sur 3820, Fracc. Vencedores

del desierto, Delicias. 33089. Chihuahua. México. [email protected]

Pectins are food hydrocolloids used as gelling or thickening agents, and its functionality

depends basically on the content of galacturonic acid, the degree of methoxylation

(DM) and the molecular weigth. Pectin can be obtained from higher plants and its

composition varies with the species, the environmental factors and the extraction

conditions. The increasing demand of pectin has lead to explore new sources of pectin

such as cladodes of Opuntia spp. Low methoxyl pectin (LMP) has geen extracted from

Opuntia ficus indica cladodes using a chelating agent under alkaline conditions.

However, the conditions to obtain high methoxyl pectin (HMP) were not reported,

despite HMP is widely used in the food industry. Thus, the objective of this research

was to extract HMP from cladodes flour (Opuntia ficus indica) and to determine the

effect of extraction temperature and chelant concentration (EDTA) on pectin yield and

composition. The extraction of HMP was accomplished under acidic (pH=2) or neutral

conditions (pH=7) to avoid the carboxyl de-sterification promoted by the alkaline

conditions. For the pectin extraction, 0.02 kg of cladode flour was dissolved in 1.0 l of

water and heated to 85°C during 20 min, thereafter the solid residue was recovered by

centrifugation. The residue and the corresponding amount of EDTA (0.0 g/l – 16.0 g/l)

were suspended in 1.0 l of water and the pH of the suspension was adjusted to the acidic

or neutral conditions adding HCl or NaOH solutions. Finally, the system was heated to

the testing temperature (45°-85°C). After extraction, the pectin was precipitated,

washed, dried, and stored until the composition analyses. The optimum conditions of

temperature extraction and EDTA concentration were evaluated through a central

composite design with two replicates at center for either acidic or neutral conditions.

The maximum yield observed (~36% on dry basis) was superior to the reported values;

moreover, pectin yield showed a linear increase (p<0.05) with the EDTA concentration.

In contrast, temperature effect was no significant (p>0.05). Composition analyses are in

progress to determine the effect of the extraction conditions on the molecular weight,

constituent monosaccharides and DM of the extracted pectin.

(keywords: opuntia, pectin, degree of methoxylation, chelating agent)


135

FP-104

Optimization of Hot Air Dehydration of Figs (Ficus Carica L.) usingTaguchi Methodology

Montoya-Ballesteros, L.; Camargo-Wilson, C.; Robles-Ozuna, L.; Lugo-Ibarra, E.

Centro de Investigación en Alimentación y Desarrollo, A.C. Carretera a la Victoria Km. 0.6 Hermosillo,

Sonora, México, C.P. 83000. (2)Facultad de Ingeniería Ensenada. Universidad Autónoma de Baja

California. K.M. 103 Carretera Tijuana-Ensenada Ensenada, Baja California, México, C.P.22860.

[email protected], [email protected], [email protected],

[email protected]

Mexico is the third main producer of figs in America, with more than 6,000 tn per year.

The national fig industry is largely based on two cultivars: Mission and Kadota; the

Caborca Region in Sonora is the major producer of kadota variety; nevertheless more

than 80% of total production becomes loss due to the perishable nature of fruits and the

poor quality of sun-dried figs. Recent studies about dried figs show good results with

hot air dehydration in terms of processing time, moisture, color and microbian stability .

However, few studies have been done on the optimization of the parameters of drying

using design of experiments. The Taguchi Methodology (TM) is a special variant of

Design of Experiments that uses othogonal arrays to study the entire parameter space

with only a minimum number of experiments. Besides, it uses the analysis of signal-to-

noise ratio to study the interaction and effect of controlled and uncontrolled factors in

the final response. This study presents the application of TM in the optimization of the

drying process of kadota figs in a cabinet dryer, in order to obtain the minimun values

of both, total Change of Color (∆E) and Final Moisture Content. A standard L16

orthogonal array was used to study seven factors: additive solution (sodium bisulphite

and ascorbic acid), time of blanching, temperature of blanching, immersion, size of

particle, time of drying and temperature of drying. The optimum operating conditions

for the drying process were obtained at 0.45% sodium bisuphite, 15min/80°C of

blanching, immersion 15rpm; size of particle 0.83 ± .21 in, 24h/55°C drying. The final

moisture content was 5.79 ± 0.18% w.b. and the ∆E between fresh figs and dried figs

was 29.52±1.52, whereas in the sun-drying process was 62.58±0.92. The nutrimental

content of dried figs was (amount per 100g serving): 9.93% dietary fiber (6.57% of

insoluble type and 3.36%of soluble type), 45.2% calcium and 11.2% potassium. After 4

months of storage(22 ±2°C), no significant change on quality characteristics of fruits

were revealed (p=0.1). The results showed that drying of kadota figs using hot air

method has potentially good industrial application.

(keywords: kadota figs, hot air dehydration, Taguchi methodology)


136

FP-105

The Use of Microwaves on the Barley Kernel Hardness and

Their Impact on the Malting Quality

López, P. P., Figueroa, J. D. C., Sevilla, P. E., Román, G. A. D., Reynoso, C. R., Ramón A. Martínez, P.

R. A.

Departamento de Investigación y Posgrado en Alimentos, Facultad de Química. Universidad Autónoma

de Querétaro, CU, Cerro de las Campanas s/n Col. las Campanas. Querétaro 76010 Qro. E-mail:

[email protected]

It takes 5 years to genetically improve the quality of barley (Hordeum vulgare L.) for

the brewing industry. A new alternative discussed here is to physically modify the

kernel used for animal feed or malting barley by microwave irradiation to increase its

industrial quality. With this objective the effect of microwave radiation on the

mechanical properties of barley kernels, and the malting quality of different varieties of

barley was evaluated. The malting quality of feed and malting barley treated for 0, 4

and 8 s of irradiation with microwave energy were evaluated. Three varieties of barley

were used: two feed barleys (Adabella and Pastor Ortiz), and Esmeralda malting barley.

A conventional Sharp model R-501CW microwave oven was used, with a power of 1.45

kW and a frequency of 2450 MHz. The kernel hardness was evaluated by uniaxial

compression tests using a TA-XT2 Texture Analyzer. The kernel response to

compressive loading was evaluated using parallel plates. The malting quality was

evaluated by EBC methods. The results were analyzed using Tukey's test and simple

correlations using the statistical package SAS, with P < 0.05. Microwave irradiation of

4 s decreased the barley kernel hardness and made it able to be transformed into good

quality malt. The feed barley Adabella without treatment showed twice the hardness

(49.3 N), whereas Pastor Ortiz (59.8 N) almost three times that of malting barley

Esmeralda without treatment showed a kernel hardness of 23.7 N. Feed and malting

barleys irradiated for 4 s increased the malt extract content. The extract viscosity

decreased in all treatments with microwave irradiation. The diastatic power and -

amylase were not affected by the treatments selected for this study. The microwave

energy is a new alternative that allows modifying the kernel endosperm in a few

seconds and increasing the industrial quality in feed and malting barley.

(key words: Hordeum vulgare L., microwave, malting quality, kernel hardness.)


137

FP-106

Ripening Process of Chihuahua Cheese, Followed by Sensorial Evaluation and

Instrumental Texture Analysis.

Orozco-Morales, E., Nevarez-Moorillón, G.V., Rivera-Chavira, B.E., Arévalo-Gallegos, S., Gastélum-

Franco, M.G.

Facultad de Ciencias Químicas, Universidad Autónoma de Chihuahua. Campus Universitario s/n 31170

Chihuahua, Chih. [email protected]

Chihuahua cheese is a traditional product of Chihuahua, Mexico, with an estimated

production of 30,000 kg/month. Chihuahua is a leader in dairy products, but there are

problems with quality and technology applied to cheese production, because most of the

cheese producers are small or family business that uses unpasteurized milk. On the

other hand, vacuum-packing technology has promoted commercialization of non-ripped

cheese. Therefore, the microbiological and sensorial quality is not homogeneous and

cheese might not be innocuous. There are no references on the ripening process of

vacuum-packed Chihuahua cheese, or on its sensorial and rheological characteristics.

Therefore, the aim of this study was to evaluate the sensorial changes during ripening of

Chihuahua cheese, using one product elaborated with pasteurized milk, and one

elaborated with raw milk. Samples were stored at 8°C until analysis; sensorial analysis

was a ranking discriminative test of cheese flavor intensity, with 17 semi-trained

panelists, performed by triplicate. Using the pasteurized cheese, a Texture Profile

Analysis (TPA) was also determined, in terms of hardness, fracturability, cohesiveness

and springiness. The samples were analyzed after 1, 60 and 120 days for the raw milk

cheese, and 1, 30, 60, 90 and 120 days-old samples for the pasteurized cheese. Results

were analyzed by total rank method. In the raw-milk cheese, sample of 1 day was

significantly different than the cheese ripped for 120 days (p<0.05), and there was no

difference among the 60 and 120 days of ripening. In cheese produced with pasteurized

milk, samples ripped for 90 and 120 days, were significantly different than the cheese

without maturation. There was no significant difference among cheese matured for 30

and 60 days (p>0.05). Regarding TPA, there was no significant difference among the

different ripening periods, for any of the parameters tested. Although not considered as

a matured cheese, is important to characterize the ripening process of Chihuahua cheese,

since it continues to mature during the selling and consuming period. Under the actual

storing characteristics of vacuum packing and refrigeration, Chihuahua cheese ripening

process continues, and the differences in flavor can be sensorial distinguished.

(keywords: chihuahua cheese, sensorial analysis, ripening process)


138

FP-107

Osmotic-Convective Drying Kinetics of Chayote (Sechium edule)

Huerta-Mora, I.R., Martínez-Sánchez, C.E., Vivar-Vera, M.A., Ruíz-López, I.I., Ochoa-Martínez, A.,

Ramírez-Figueroa, E. and Herman-Lara, E.

Instituto Tecnológico de Tuxtepec. Calz. Dr. Víctor Bravo Ahuja s/n. C.P. 68350. Tuxtepec, Oax.

México. Tel (287)8751044. Email: [email protected]

The chayote (Sechium edule) is a vegetable which may be used as an important

nutritional supplement, which is highly appreciated in major U.S. and Europe markets.

Mexico is regarded the second country in the worldwide production of chayote. This

food is consumed fresh and its research related to the preservation process is minimal.

Drying could be an alternative way to increase their lifespan. The use of combined

drying methods can reduce the intensity of heat treatment and maintain the sensory

properties in the final product. Therefore, the objective of this work was to study the

osmotic-convective combined drying kinetics of chayote. Samples with geometry of

1x1x2 and 4x4x2 cm to perform combined drying were employed. First, osmotic

dehydration was made using sodium chloride solutions at 10, 20 and 25 °Bx with

immersion time of 3 h. Chayote osmotically dehydrated was convectively drying at

temperatures of 50 and 60 oC with two drying speeds 1.5 and 2.5 m/s using a tray dryer.

Evolution of solids gain and weight loss, and drying kinetics were obtained as results.

Chayote osmotically dehydrated with a higher salt concentration had the greatest water

loss and solid gain at any particle thickness. However, at thin thickness of particle water

loss was greater than in thick thickness, while the solids gain was higher in the thick

particles than in thin particles at higher concentrations of salt at the immersion time

established. The convective drying showed a reduction of drying time when temperature

and air speed were increased except for thick particles, where the temperature had no

effect. The osmotic-convective combined drying had a higher reduction of drying time

than convective drying when the temperature and air velocity were increased. The use

of combined methods reduced drying time concerning to convective drying from 10 to 6

hours of drying. Whereas the best operating conditions were: 20 oBx, 60 oC and 2.5 m/s

and a particle thin geometry of 1x1x2 cm. The osmotic-convective combined drying

could be a powerful tool for the chayote producers to preserve it.

(keywords: Chayote, osmotic dehydration, convective drying).


139

FP-108

Mathematical Evaluation of Water Activity in Foods

Sánchez-Álvarez, E., Martínez-Sánchez, C.E., Vivar-Vera, M.A., Ruíz-López, I.I., Ramírez-Figueroa, E.

and Herman-Lara, E.

Instituto Tecnológico de Tuxtepec. Calz. Dr. Víctor Bravo Ahuja s/n. C.P. 68350. Tuxtepec, Oax.

México. Tel (287(8751044. Email: [email protected]

The physical-chemical properties such as water activity (aw) and the sorption isotherms

in foods is one of the most important aspects of the food technologist. Nowadays, there

is little information related with the sorption phenomena of foods products in the

Papaloapan region. The objective of the present work was to evaluate experimental and

mathematically the water activity of two local fruits and one vegetable; mangoes,

passion fruit and chayote respectively. The experimental values of aw were determinate

by the hygrometric and gravimetric methods at temperatures of 20, 30 and 40 ºC. The

gravimetric method employed microclimate device where the samples were placed with

H2SO4 solutions in concentrations of 10 up to 80 %. The obtained values of aw by the

electronic method (hygrometric) was made by means of aqualab 3TE with temperature

control. The moisture contents were determined according to AOAC method. The

sorption isotherms were also simulated using theoretical equations through of software

taking into account the chemical composition of the proposed foods. The experimental

values of aw by the gravimetric method adjusted more to the reality than the obtained by

hygrometric method (aqualab), perhaps due to that the treated samples did not reach the

equilibrium. Also the simulated isotherms theoretically adjusted to the experimental

behavior obtained by the gravimetric method, where literature values of mangoes

sorption isotherm at different temperatures confirmed this trend. Software was

developed using five empirical equations: Smith, Henderson, Halsey, Oswin and

Bradley. The equation that better predicted the experimental isotherms was Smith with

2.5% of deviation in the whole interval of the isotherm at 20 oC. On the other hand and

taking into account only the ranks of experimentation from aw for each equation, the

mathematical model that better predicted the percentage of deviation was the equation

of Halsey with a 4.32% for passion fruit at 30 ºC. Nevertheless, in general the equation

of Halsey showed a deviation minor % in average of almost all the simulations. The

obtained sorption isotherms could be useful during the storage, handling and in the

simulation operations of foods drying in the future.

(keywords: foods, water activity, sorption isotherms)


140

FP-109

Rheological Evaluation of Chocolate Coatings

Gallegos-Infante, J.A., Rocha-Guzman, N.E., Gonzalez-Laredo, R.F., Medina-Torres, L., Delgado-Licon,

E., Fileto-Perez, H.A.

Departamento de Ingenierias Química y Bioquímica, Instituto Tecnológico de Durango. Blvd. Felipe

Pescador 1830 Ote, Durango, Dgo., México CP 38080. [email protected] 2 Facultad de Quimica, Universidad Nacional Autónoma de México.

Mechanical response of foods is influenced by several factors including particle size of

their components. This factor is influenced by ingredients, agitation rate, temperature,

time, viscosity, density, electrostatic forces. But not only particle size is important, the

particle size distribution is related to the molecular and microscopy structure of the

product too. Microscopic and molecular changes are related to macroscopic

modifications of food systems. The chocolate coating is complicated because is an

emulsion with reduced content of fat and sugars, thus there are changes in the structure

associated to change of fat and sugar amount, that reflected changes in their mechanical

structure, According to several authors more stable systems are obtained with the use of

rotor-stator impellers because this reduce the particle size and then increase the stability

of emulsions. The objective of this work was to make a rheological characterization of a

reduced-calories chocolate-based coating as a model food. In this work a helical ribbon

impeller and rotor-stator impeller were used. Rheological characterization of model

system using a TA-XT2i™ texture analyzer was performed. Stress relaxation and creep

tests were performed in the texture analyzer. Rheological test (G`, G``, and dynamic

stress relaxation were obtained) using an ARES 2000 rheometer. Particle size analysis

was made in a Zetasizer Nano SC. Chantilly™ coating as control was used. Raw data

from texture analyzer and rheometer were used to determine Young‟s module.

Instantaneous Yong‟s modules of 36 treatments of chocolate coating and 36 control

treatments were determined in static and dynamic forms. Highest instantaneous

Young‟s modulus for chocolate coating and control coating were 83 kPa and 92.33 kPa,

respectively in static form. Both values were obtained at 236 rpm to promote

components homogenization, leading to improved texture. We conclude that higher

speeds led to improved texture, which was supported with dynamic results. Data

obtained indicates that there are combined effect of temperature and time that increase

the value of Young module at 35°C for 36 H. Results obtained suggest that there are re-

organization of molecular forms of low caloric chocolate coatings at relative high

temperature.

(keywords: agitation rate; chocolate coatings; emulsion; low caloric foods; rheology)


141

FP-110

Effect of Temperature, Agitation Rate and Mixing Process in the Stability

of Model Emulsions

Gallegos-Infante, J.A., Rocha-Guzman, N.E., Gonzalez-Laredo, R.F., Medina-Torres, L. Quiñones-

Muñoz, T.

Departamento de Ingenierias Química y Bioquímica, Instituto Tecnológico de Durango. Blvd. Felipe

Pescador 1830 Ote, Durango, Dgo., México CP 38080. [email protected]

Departamento de Ingeniería Química, Conjunto “E”. Facultad de Química, UNAM, Cd. Universitaria,

04510 México, D. F., México.

Emulsions are an easy and efficient method to protect and deliver active compounds.

The emulsifying process is complex and hard to predict. Density, viscosity, emulsifying

agent, particle size, temperature, time and process variables are important to obtain a

stable emulsion. The objective of this work was to evaluate the effect of process

conditions on the stability of water in oil (w/o) emulsion. A W/O emulsion was made

with mineral oil, lecithin at three levels (2%, 5% and 10%), sorbitan monooleate (HLB

=4.3) at two levels 3 and 10%, water at two levels (30 and 40%), two processes of

agitation (vortex and rotor-stator) each one with two levels (vortex 1755 and 3200 rpm;

rotor-stator 900 and 1800 rpm), two levels of temperature (24° and 40° C) were used.

Emulsion stability, refraction index, apparent viscosity, rupture force, density and

fluorescence microscopy were used to characterize the behavior of the samples. No

significant differences were observed in rupture force. Significant differences were

observed for emulsion stability. The main factor temperature, and the interaction

temperature*Span 80 showed effect on emulsion separation. The behavior of emulsions

as a function of agitation showed that increased agitation rate resulted in lower

separation. Similar behavior was observed with Span 80. No statistical differences were

observed for the levels of lecithin used (P>0.2). Microphotographs showed changes in

the morphology of particles and changes in the size of the wall that surrounded particles

depending on agitation, temperature and span 80. No statistical differences were found

in viscosity, behavior associated to the use of a rheometer not sensitive enough. Vortex

mixing produced that any other factor have significant influence on separation, viscosity

and rupture force, indicating that the use of vortex changes the emulsion system

increasing dispersion. We conclude that it is important to control temperature, agitation

rate, system of agitation and stabilizing agent independently of the amount of lecithin

used.

(key words: Agitation rate; emulsion; separation; stability; temperature)


142

FP-111

Chemical analysis of the oil avocado of the variety criollo (Persea americana Mill)

extracted by centrifuges and solvent (hexane)

Ariza-Ortega, J. A., Cassellis-Ramos, M.E., .Delgado-Macuil, R. J., Díaz-Reyes, J.

y Robles de la Torre, R.R.

Centro de Investigación en Biotecnología Avanzada-IPN, Tlaxcala, México. Sn. J. Molino s/n km 1.5

carretera estatal Sta. I. Tecuexcomac-Tepetitla de Lardizábal. 90600 Tel. 01 (248) 487-0765, Fax. 487-

0766. e-mail: [email protected]

Benemérita Universidad Autónoma de Puebla, Puebla, Méxio. Avenida San Claudio s/n. 90600 Tel. 01

(248) 487-0765, Fax. 487-0766.

Usually edible oils are obtained by pressing in the seeds, then the dough is subjected to

a solvent extraction to increase the yield. However it has been observed that solvents

affect the fatty acids through the formation of trans-isomers, increase the cost and

pollute the environment. For that reason alternatives are sought to obtain clean oils, that

is the case of the centrifuge. The oils are analyzed using chemical and instrumental

methods. In the first, the mains indexes are acidity (AI), iodine (YI) and peroxide (PI).

In the second, stands gas chromatography and infrared spectroscopy, IR. In a previous

work, the Hass avocado oil was examined. This paper reports chemical analyses of

Criollo avocado oil, extracted with solvents and centrifuge. The centrifuge avocado

paste was performed at 40 ºC and 11,000 rpm for 10 minutes (AAC), extraction was

conducted with hexane than 70 ºC for 4h in a Soxhlet device, (AAH). In both

treatments, was measured the volume of oil as response variable; indexes of AI, PI and

YI were determined to every oil. Results were analyzed by Anova (p<0.05). The best

result was obtained with the solvent-extraction, (p <0.05), with a yield of 93%,

however, this method harms the sensory properties of oil, the AI increased from 0.68%

to 2.40% expressed percentage of oleic acid in the centrifuge for extraction. A high

content of free fatty acids is aimed to induce a further deterioration of oil during the

frying food. In Peroxides (PI) and Iodine (YI) values of AAC and AAH there was no

significant difference (p>0.05), indicating that during solvent extraction the hydrolysis

was the mechanism that predominates in the oil deterioration.

(keywords: Persea americana Mill, avocado oil, oil extraction, fatty acids)


143

FP-113

Protective Effect of Pre-Gelatinized Starch by Extrusion on the Retention of -

carotene from Yellow Passion Fruit

Falfán-Cortés, R., Verdalet-Guzmán, I., Gaytán-Martínez, M.*, Martínez-Bustos, F.

Instituto de Ciencias Básicas, Universidad Veracruzana. Apartado postal 177, CP 91000. Xalapa, Ver.,

México.

CINVESTAV, unidad Querétaro, Libramiento Norponiente # 2000 Fraccionamiento Real de Juriquilla,

CP 76230, Querétaro Qro., México. ** CICATA-IPN. Cerro Blanco #141, Col. Colinas del Cimatario.

Santiago de Querétaro, Querétaro, CP. 76090. Email: [email protected] ;

[email protected]

The technology of extrusion is an important process in the food industry, because non-

conventional products may be obtained in a variety of forms, and sensory

characteristics. Nowadays, in addition to elaborate products with excellent sensory

qualities, there is an increasing need to produce healthful foods. The objective of this

work was to evaluate how the conditions of the extrusion process affect some functional

properties of blends of corn starch and passion fruit pulp. For this purpose, an

experimental design comprising three independent variables was used: The barrel

temperature (80 to 140ºC) in the high pressure zone, feed moisture content (16 – 30%)

and content of passion fruit (0 – 7%). The processed materials showed micro-structural

changes, expressed as a decrease in the viscoamilographic profile. As the barrel

temperature and the percentage of feed moisture increased, a decrease in the viscosity

peak was found at 92ºC. This was due to the low values of enthalpy with an absence

and/or a decrease of the representative peaks in the thermograms. The diffractograms

showed changes in structures with low values of crystallinity (25 – 30%), and the

micrographs illustrated fragmented starch granules enclosing the passion fruit pulp. The

content of beta-carotene in the processed flours was 11%, as measured by High-

Performance Liquid Chromatography (HPLC). The variable that had the greatest effect

in the functional properties of extruded blends was the concentration of the added

passion fruit, since the content of -carotene was proportional to the amount of passion

fruit in the blend. The color parameters L*, a*, b*, in the extrudates were directly

affected by the interaction of feed moisture with the amount of passion fruit pulp used

in the blends. In conclusion, the starch acts as a protective agent of beta-carotene in

passion fruit pulp during the extrusion process, and these products can be used as

vehicle for ingestion of important nutrients.

(key words: extrusion, beta-carotene, cornstarch, passion fruit)


144

FP-114

Effect of Sheep Transport and Resting Period on Blood Parameters (Ca2+

, Glucose

and Lactate) on Meat Hardness and Water Holding Capacity

Aguilar, G., J., Mota, R. D., Becerril, H. M., Guerrero, L. I.

Universidad Autónoma Metropolitana Unidad Xochimilco. Calzada del Hueso 1100, Col .Villa quietud,

Del. Coyoacan, C. P. 04960 México D. F. 58044717 Universidad Autónoma Metropolitana Unidad

Xochimilco. Calzada del Hueso 1100, Col .Villa quietud, Del. Coyoacan, C. P. 04960 México D.

F.Profesor investigador titular de la Benemérita Universidad Autónoma de Puebla. Profesor investigador

titular de la Universidad Autónoma Metropolitana Unidad Iztapalapa, Av. San Rafael Atlixco 186, Col.

Vicentina, Del. Iztapalapa, C. P. 09340 México D. F. 54837535

[email protected]

Transporting meat animals is an important part of meat production. During this

operation several factors combine, affecting meat quality. Some blood metabolites, such

as Ca2+

, glucose and lactate are involved in the transformation of muscle into edible

meat; alteration of these parameters can result in quality deterioration. The objective of

this work was to study the effect of these parameters in animals stressed by transport, as

compared to rested animals, on meat quality parameters. Twenty entire male of

Pelibuey-based breed, 6-month old weighing around 35 kg, were subjected to

transportation in as asphalt road on a truck during 6 h at 90 km/h, 0.1 m2 load density.

After arrival to the abattoir, the animals were divided into two groups; 10 animals were

allowed to rest for 8 h, whereas the other 10-animal group was stunned by captive-bold

pistol and exanguinated by severing the neck major blood vessel. Carcass cleaning and

cutting was carried out according to traditional methods. Blood samples were taken

from animals prior to transportation, after arrival to the abattoir and after slaughtering.

Calcium, glucose and lactate were measured in gasometer (GEM premier 300); samples

were placed in test tubes previously added with heparin. Variation on blood metabolites

was correlated to meat quality parameters: pH, hardness and water holding capacity

(WHC). pH was analyzed using a potentiometer; hardness was reported as maximum

value obtained by cutting samples with a Warner-Bratzler shear press, fitted to a

TAXT2 texturometer (Stable Microsystems) coupled to a Texture Expert v1.2. software.

WHC was analyzed by incorporating the meat slurries into a NaCl solution. Non

significant differences (P>0.01) were observed with respect to Ca2+

concentrations

between rested and stressed animals. Conversely, glucose and lactate were significantly

different (P<0.001) between the two groups. Although, this difference did not affect

meat pH, rested animals produced higher WHC and more tender meat.

(keywords: meat quality, lamb, animal stress, transport)


145

FP-115

Astaxanthin Extraction from Shrimp Wastes by Bacterial Ensilation

Franco-Zavaleta, M., Jiménez-Pichardo, R., Ponce-Alquicira, E, Gutiérrez-López, G.F.,

Guerrero-Legarreta, I.

Departamento de Biotecnología. Bioquímica de Macromoléculas. Universidad Autónoma Metropolitana-

Iztapalapa. San Rafael Atlixco No. 186, Col. Vicentina, México D.F., C P 09340. Tel. (55) 58 04 47 26.

Departamento de Graduados en Alimentos. Escuela Nacional de Ciencias Biológicas. Instituto

Politécnico Nacional. México. D.F.

Facultad de Química. Universidad Nacional Autónoma de México. Ciudad Universitaria. México D.F.,

México.


Astaxanthin is the most abundant carotenoid found in crustaceans. Microbial silage is a

preservation method, which consists of mixing the substrate with inoculated highly

acidifying lactic acid bacteria. Acid production prevents the growth of undesirable

microorganisms. The objective of this work was to compare bacterial silage efficiency

of two processing sequences: pigment extraction followed by substrate centrifugation,

and silage centrifugation followed by pigment extraction. Shrimp wastes (Litopaneus

vannamei) were mixed with 10% (w/w) anhydrous dextrose and 5% Pediococcus

pentosaceus inoculums. This substrate was placed in amber flasks and incubated for 48

h at 30oC. The substrate was then subjected to two sequential processes: pigment

extraction with organic solvents (petroleum ether:acetone:water) followed by

centrifugation (EC), and substrate centrifugation followed by pigment solvent extraction

(CE), in both cases a solid residue and a supernatant liquor were obtained. Both

fractions were analyzed for moisture content, ashes, total protein (Kjeldhal) and total

lipids (Soxhlet). Carotenoids were analyzed as total xanthophylls (by

spectrophotometry); total astaxanthin and astacene content was analyzed by HPLC. A

decrease in ashes and protein was observed during the fermentation period as compared

to unprocessed shrimp wastes. A reduction of 26% and 18% in ashes and protein,

respectively was observed in EC process, whereas 26% and 27% in CE. This was due to

simultaneous substrate demineralization and deproteinization. Protein was concentrated

in the solid residue, whereas lipids were solubilized in the liquor. Lipid fraction

reduction during CE process was 49% and 22% in EC process. Significantly higher

(P>0.001) total xanthophylls concentration was obtained by CE process (650.7 ppm), as

compared to total xanthophylls obtained by EC (380.3 ppm). The highest astaxanthin

was obtained by CE (5.38x10-3

mg/100mL) whereas by EC astaxanthin concentration

was 3.23x10-3

mg/100mL. Astaxanthin obtained by a bacterial silage processing was

more stable and the extraction had better yield. CE sequence was the more efficient for

pigment extraction.

(keywords: shrimp wastes, lactic acid ensilation, astaxanthin)


146

FP-116

Modeling a Pervaporation System for the Production of Anhydrous Ethanol

López-Zamora L., Villaseca-Jauregui E., Luna-Solano G.

División de Estudios de Posgrado e Investigación, Instituto Tecnológico de Orizaba

Oriente 9 No.852, Col. E. Zapata, 94320, Orizaba, Ver. Email: [email protected]

The search for low cost dehydrated ethanol has led to the development of more effective

new processes of separation, such as membranes, which has turned out to be very

feasible due to its simple design, low energy consumption, and low operation costs.

Pervaporation is a membrane technology in which a liquid mixture is in contact with a

selective membrane, and one of the components is transported across the membrane by

preferential permeation, turning into a gas phase on the other side of the membrane

using a vacuum system. The principal objective of this investigation is to simulate a

pervaporation system at laboratory and pilot level, using ASPEN PLUS 11.1, to obtain

the best conditions for this type of processing. This work shows the preliminary results

about the equipment designed at laboratory level. A tubular membrane module was

used, that allows the handling of turbulent flow, being insensitive to obstruction, and

can be easily cleaned. The use of ceramic microporous membranes is considered,

because they have more thermal and chemical stability, and they can operate at high

temperatures, helping to increase the flow rate. The mathematical model developed for

the simulation represents appropriately the mass and energy balances of the elementary

unit between 50 and 90ºC, and vacuum pressure between 9 mbar and 24 mbar, the flow

of ethanol was 1.5 L/h. The principal equation of the model is over the water flow

across the membrane, because a hydrophilic membrane is used. It is based on the Fick´s

law of mass transfer, and on the solution–diffusion model, expressing an exponential

function of water activity in the feed mixture, and of the temperature of operation. We

obtain 99.9% efficiency of this membrane. With these results we are working on a

scaling-up model to simulate processing at a pilot plant level.

(keywords: pervaporation, ethanol anhydrous, modeling)


147

FP-117

Fructan accumulation and bulb development in garlic (Allium sativum L.) cv

“Retinto”

Utrilla, V. M., Vázquez M. D.G., Vázquez, B. M.E. and Mercado, S. E.

Departamento de Investigación y Posgrado en Alimentos, Facultad de Química.

Universidad Autónoma de Querétaro, CU, Cerro de las Campanas S/N. Col. las Campanas.

76010, Santiago de Querétaro, Qro.

[email protected]

There are evidences that garlic crop needs cool temperatures during their development;

when the cool requirements are not reached, the production has low quality with small

size bulbs and high proportions defects. The principal component of bulb dry matter is

fructan (70%) so the bulb development must be associated with the fructan

accumulation process. These compounds are described as nutraceutical components to

human health. The garlic plant development is influenced by storage conditions of „seed

cloves‟, the environmental conditions (temperature, light and photoperiod) and cultural

practices. The aim of this study was to evaluate the effect of the storage temperature of

„seed cloves‟ in the fructan accumulation and endogenous gibberellins content during

the garlic bulb development cv „Retinto‟. Garlic bulbs were stored 2, 8 and 16 days at

room temperature (RT), 5 and 10ºC, and then sown in El Pardillo, a region of Zacatecas,

Mexico. Each month, ten plants were sampled from each treatment and the bulbing

index (bulb /neck diameters), gibberellins content (by HPLC) and fructan contents

(Fructans Assay Kit Megazyme®) were measured. The seeds cloves stored during 2 and

16 days at 10°C, developed plants with higher IB (7.5) than those stored at RT (6.5).

Two fractions (F1 y F2) with gibberellin activity were quantified (0.33 and 0.99 meq of

GA3/g dry matter respectively). After 136 days these contents decreased gradually until

the harvest (262 days). Whereas the initial fructan content were 24 and 26 g/100g in

bulbs from 2 and 16 days at 10°C respectively; decreasing (26 and 19 %) after 179 days,

followed by a sudden increase (55 and 43 g/100g in both conditions) at the end of

development, and keeping a close relationship with the IB. At RT the fructan content

was lower than other treatments.

(keywords: Allium sativum L; pre-storage, gibberellins, fructans)


148

FP-118

Obtaining a Powder with a high Fructan Content from Agave salmiana

Moreno-Vilet, L., Mota-Santillán, A., Michel-Cuello, C., Grajales-Lagunes A., Ruiz-Cabrera, M.A.

Facultad de Ciencias Químicas. Universidad Autónoma de San Luis Potosí. Av. Dr. Manuel Nava No. 6.

Zona Universitaria. C.P. 78210, San Luis Potosí, S.L.P. Tel. 52-444 8 26 24 40 ext 539, fax: +52 444 8 26

23 71 [email protected]

The Potosino mezcal maguey plant (Agave salmiana) is a very important and widely

distributed resource in the Potosino-Zacatecano high plateau. Since Pre-Hispanic times,

this plant has had multiple uses as a source of food, water, fiber, construction material,

fodder, and raw material for the production of mezcal; the former two being their main

forms of use. The plants from the Agave genera are characterized for storing a

considerable amount of fructooligosacarides (FOS) or fructans in their stem. The FOS

are polysaccharides formed by approximately 35 units of fructose and one of glucose

and are considered as pre-biotic. Due to their structure and type of linkage, they are not

digested by the intestinal tract enzymes and they are integrally passed on to the colon,

where they are quickly and totally fermented by the beneficial intestinal micro-flora

(Bifidobacteria and Lactobacilli). Because of their functional properties, they may also

have great applications in the food industry as a substitute of fats, sugars, or as moisture

retainers, and texture modifiers. The objective of this work was to establish the spray

drying conditions to obtain a food grade base powder with a high fructans content, from

the raw juice of Agave salmiana. Drying was performed in a laboratory spray-dryer

(Pulvis GB 22) at three inlet air temperatures (140°, 150°, and 160°C). Commercial

maltodextrin (10 DE) and arabic gum were used as carrier agents at three levels (5%,

7.55, and 10% w/v). In all the experiments, the compressor air pressure and the feed rate

were kept at 0.15 MPa and 20 ml/min, respectively. The powder yield and residual

moisture content were evaluated. The moisture content varied from 5.7 to 10.5% and

was mainly affected by the temperature and carrier agent concentration, while the

powder yield increased with higher process temperatures and higher carrier agent

concentrations.

(keywords: Agave salmiana, fructans, spray-drying, powder)


149

FP-119

Application of Ultrasound in the Process of Bovine Meat Aging

Castillo-Andrade A., Ruiz-Cabrera, M.A, Abud-Archila M., Grajales-Lagunes .


Zona Universitaria. C.P. 78210, San Luis Potosí, S.L.P.

Tel. 52-444 8 26 24 40 ext 539, fax: +52 444 8 26 23 71 [email protected]

Instituto Tecnológico de Tuxtla Gutiérrez.

The traditional aging of muscle is quite expensive because of the storage time that this

implies (15 d at 4ºC). Thus, the objective of this study was to apply ultrasound to reduce

the aging time of Semimembranosus (SM) and Semitendinosus (ST) bovine muscles. A

completely random factorial design using 3 factors (time of treatment: 0, 30 and 60 min)

and two levels (type of muscle: SM, and ST) with three replicates was employed to

evaluate the effect of ultrasound (20 kHz, at an amplitude of 100%). The response

variables were weight loss of raw meat, weight loss of cooked meat, pH, change of

color (E), aging index in raw meat and meat toughness in cooked meat after 7 and 14 d

of storage at a 4ºC. The -glucuronidase activity and the myofibril protein degradation

were also evaluated 7 and 14 d post mortem. The analysis of variance (ANOVA)

performed at a 95% confidence level indicated that the type of muscle seriously affected

weight loss in cooked meat after 7 d and 14 d, and the aging index after 14 d of storage.

As for the degradation of myofibril proteins the emergence of an approximately 30 kDa

peptide was observed indicating the troponine T proteolysis, which occurred during the

aging. For the -glucuronidase activity, the interaction between treatment time and

muscle type significantly affected its activity. Nevertheless, from the results obtained it

is concluded that the ultrasound conditions used in this work do not diminish the meat

aging time.

(keywords: ultrasound, meat, aging)


150

FP-120

Production of High Fructose Syrup by Enzymatic Hydrolysis of Agave salmiana

Fructans

Ortiz-Cerda, E, Saavedra-Leos, M.Z., Grajales-Lagunes A., Ruiz-Cabrera, M.A.


Zona Universitaria. C.P. 78210, San Luis Potosí, S.L.P.

Tel. 52-444 8 26 24 40 ext 539, fax: +52 444 8 26 23 71 *[email protected]

The Potosino mezcal maguey plant (Agave salmiana) is a very important and widely

distributed resource in the Potosino-Zacatecano high plateau. The plants from the Agave

genera are characterized for storing a considerable amount of fructans. Fructans are

olygomers or polymers with -fructofuranosyl residues, which are commonly water-

soluble and synthesized from a sucrose accumulation in the vacuole. The hydrolyzed

fructans have been mainly used as source of fermentable sugars for the production of

mezcal and tequila. Recent research has shown that fructans from maguey juice may be

used for producing high fructose syrups. These can be used in many foods and

beverages as low calorie sweeteners. This work was developed to provide the

preliminary basis for the production of high fructose syrups from the fructans present in

the Agave salmiana juice using a commercial inulinase preparation (Fructozyme L)

acting freely. A first set of experiments was established with pure inulin from chicory

roots as a substrate, to find the optimum operating conditions, in terms of pH (3-5.6),

temperature (30-80 °C), reaction time (5-480 min) and substrate concentration (100-400

ppm). Based on the quantification of reducing sugars, it was found that the optimum

reaction conditions were as follows: pH, 5; temperature, 48°C; reaction time, 40 min,

and substrate concentration, 300 ppm. These last conditions were tested in the agave

juice where 30% more reducing sugars were obtained after the hydrolysis process.

(keywords: fructose syrup, agave salmiana, inulin hydrolysis, fructans)


151

FP-121

Storage Potential of Apples from Different Genotypes Introduced

in Cadereyta, Queretaro, Mexico

Mendoza-González, S.; Martínez-Peniche, R. A.; Fernández-Montes, R.

División de Estudios de Posgrado, Facultad de Química, Universidad Autónoma de Querétaro. Centro

Universitario s/n, Col. Las Campanas. 76010, Querétaro, Querétaro, México. Tel. and Fax (442) 1-92-13-

04. INIFAP, CEBAJ, Km. 6.5 Carr. Celaya-San Miguel de Allende, Celaya, Gto., México [email protected]

Apple (Malus domestica Borkh) produced in the Mountains of Queretaro under raining

conditions shows an inferior quality than that obtained in other regions. Most common

varieties, „Golden Delicious‟ and „Red Delicious‟, ripen when the national market is

saturated, which causes low prices. A viable solution is the introduction of varieties

adapted to local conditions with high quality and early maturing or with a high storage

potential to get better prices. The aim of this study was to evaluate the storage potential

of 12 midseason and late ripening apple accessions introduced in Cadereyta, Qro. based on

weight, diameter, color, firmness, total soluble solids (SST), and total titratable acidity (TTA).

Fruits of different genotypes were stored at 4 ºC, and 85% relative humidity during five

months and analyzed every 30 days. „Lourdes‟ and „Golden Delicious‟ showed the

lowest diameter loss (5.5 %) being significantly superior to other eight accessions,

including „Red Delicious‟ and 436 which had shown a good ripening quality. „Lourdes‟

obtained the lowest weight loss (4.2 %), and firmness loss (5.4 %), but it was only

significantly superior to two accessions. „Red Delicious‟ obtained the lowest total color

difference during storage (E= 4.1), opposite to SM2 (E= 41.3). During storage of

„Lourdes‟ variety it exhibited intermediate color difference values (E= 11.3), but an

important gain in red color (a = -11.1). The highest differences in color during storage

were those observed in b (+ blue, - yellow). Genotypes 436 and 419 showed the

highest increase in SST after five months of storage (>17 %), with the highest TSS/TTA

ratio for the first one (51.5), while „Lourdes‟ and „Red Delicious‟ maintained

intermediate values in TSS and TTA, and did not show any remarkable change during

storage. „Lourdes‟ showed the best storage potential, in contrast with commercial

varieties, and with other genotypes with good ripening quality.

(key words: Malus domestica Borkh, genotype, maturity, postharvest


152

FP-122

Evaluation of the Quality Properties During Staling of Maize Tortillas

Escalante-Aburto, A., Arambula-Villa, G., Verdalet-Guzmán, I.

Instituto de Ciencias Básicas, Universidad Veracruzana. Av. Rafael Sanchez Altamirano s/n (antes Dos

Vistas) Km 3.5 Carretera Xalapa-Las Trancas, Col. Industrial Las Animas. C.P. 91192, Xalapa, Ver.

[email protected]

One of the major problems in tortilla quality is the loss of texture after elaborated and

during storage. Many studies have been reported that rapid staling (loss of freshness in

tortilla) could be caused by starch retrogradation. Other changes can also affect the

texture of tortillas, such as moisture loss due to dehydration. The aim of this study was

to evaluate the effect of retrogradation and dehydration on tortilla properties

(physicochemical, structural, rheological, morphological and textural). Two types of

maize grain (conico norteño and QPM) were used to make tortillas with the traditional

“nixtamalization” process. The extent of retrogradation (RD) of tortillas at different

relative humidity (RH), 40%, 50%, and 60%, were evaluated. The effective moisture

diffusion coefficient (EMDC) was obtained from dehydration curves at different

temperatures (5°, 25°, and 35° C). The physicochemical properties of the two types of

maize used in this work were similar to other types used for nixtamalization. The

moisture content was 46.76% and 42.94% for tortillas elaborated with conico norteño

and QPM, respectively. The RD was measured as the enthalpy of recristallized starch

(H). Results showed lower enthalpies for tortilla samples stored at 5° C with 40% and

60% RH. The higher enthalpies were for those tortillas stored at 25°C at the same RH.

The moisture loss in tortillas was different between the varieties of maize used, and was

directly affected by the dehydration temperature. The values obtained of EMDC were

6.145x10-7

cm2

s-1

for QPM tortillas, and 1.165x10-6

cm2

s-1

for conico norteño tortillas,

dehdydrated at 25° C during 4h. This indicated a higher dehydration rate for conico

norteño maize tortillas. Texture of the tortillas (cutting force and tensile strength)

showed higher values as the storage time increased; this tendency was similar for both

types of tortillas.

(keywords: tortilla, starch maize retrogradation, dehydration, EMDC)


153

FP-123

Physicochemical Characterization of Piñoncillo Oil (Jatropha curcas L) Varieties

Tabasco and Chiapas

Aparicio-Trápala, MA, Díaz-González, JA, Morales-Rebolledo, JC, Ovando-Chacón, SL y Rodríguez-

Blanco, L.

División Académica de Ciencias Agropecuarias. Universidad Juárez Autónoma de Tabasco. km 25 de la

Carretera Villahermosa - Teapa. R/a La Huasteca. Tel (993) 3581585 ext 6602 y Fax (993)1429150

Villahermosa, Tabasco. México. [email protected]

Mexico is a country rich in natural resources but many of these have not been found

useful due to a lack of systematic studies to provide scientific basis for their handling

and use. Piñoncillo (Jatropha curcas L.) was studied as a possible alternative to the

deficit of oilseeds and particularly of oil. Jatropha curcas is a biotic resource that grows

in wild form. The aim of this work was to study the composition and physicochemical

analysis of Tabasco and Chiapas varieties of piñoncillo. The results showed that the two

varieties of seeds were similar to each other. The fat was the highest component

(55.91%) and the proteins with 22.97%. In relation to the essential amino acids content,

it contained good amounts of methionine that is limiting in the oilseeds and leguminous

at the moment exploited. The physicochemical analysis of the oil gave as result an index

of Iodine of 103.2 and 106.2, saponification ratio of 202 and 187, acidity value 3.4 and

2.5, color 26A2R and 25A2R, humidity 0.1 and 0.03% and refractive index of 1.47 and

1.46 for the varieties of Tabasco and Chiapas respectively. The characteristics of the oil

were similar to each other and to the one of established conventional oils in the market

evidences that makes it an alternative of use in the food industry as oil source.

(keywords: piñoncillo, physicochemical characterization, Jatropha curcas)


154

FP-124

Comparison of the Physicochemical Behavior of Native Starches of Cassava and

Sweet Potato versus Starch used in Commercial Sausage Vienna Type

Aparicio-Trápala, MA, Gómez-Jiménez, CO, Velazquez-Martínez, R, Corzo-Sosa, CA y Pérez-Marcos,

A.

División Académica de Ciencias Agropecuarias. Universidad Juárez Autónoma de Tabasco. km 25 de la

Carretera Villahermosa - Teapa. R/a La Huasteca.Tel (993) 3581585 ext 6602 y Fax (993)1429150

Villahermosa, Tabasco. México. [email protected]

Due to the few nutritious requirements the tubercles cassava and sweet potato are

cultivated in Tabasco with good yields 3.1 ton/ha and 1.7 ton/ha respectively. These raw

materials do not become industrialized and are perishable highly despite they contain in

its cells free starch and of easy extraction with 17 and 33% of amylose. Starches with

functional properties of binders and stabilizers agents of emulsions whose use reduce

losses in thermal treatments by humidity retention can improve color, flavor, texture

and they do not confer flavor some. When comparing the effect of the application of

these two types of starches in the sausage Vienna type with three levels (5, 7.5, 10%)

like means of inhibition and agglutination with respect to effect of the commercial

starch “Ligador E-200” marks Tres Villas that consist of a starch mixture of maize,

wheat, and sweet potato the results of the completely at randomized design at α= 0.5

were not significant for the variables yield, retained water, evaporated water and

syneresis in the factors type, concentration or in their interaction. In the analysis of

texture profile (TPA), for the attribute hardness the product elaborated with 10% of

cassava starch present major shearing resistance whereas the starches of cassava to 5

and 7.5 % obtained the averages higher for the elasticity, and starches of sweet potato to

5 and 7.5 % they presented values similar to the commercial starch. The native starch

addition of cassava and sweet potato in the sausage formulation Vienna type had similar

effect that the used ones industrially when they are including a 5.0 and 7.5%. It is

recommended to complement the study with the application of the sensory analysis.

(keywords: native starches, sausage, cassava and sweet potato)


155

FP-125

Isothermal Crystallization Behavior Evaluated by Anisotropy: Structural

Order of Triacylglycerides.

Dibildox-Alvarado, E., Marangoni, A.G., Toro-Vazquez, J.F.

Centro de Investigación y Estudios de Posgrado, Facultad de Ciencias Químicas. Universidad Autónoma

de San Luis Potosí, Av. Manuel Nava No. 6 Querétaro 76010 Qro.

[email protected], [email protected]*

The isothermal crystallization of saturated triacylglycerides (TAGs; tripalmitin and

tristearin; 25%) in blends with unsaturated TAGs with three different levels of

complexity (i.e., pure triolein, safflower oil high in triolein, and native soybean oil;

75%) was studied measuring the anisotropy (r) by fluorescence polarization

spectroscopy. Previous research has shown that anisotropy measurements obtained by

FPS is a parameter associated with the structural order achieved by molecules at the

micro-environment level. Thus, the anisotropy value as a function of different time-

temperature conditions is an indirect measurement of the changes occurring in the

micro-viscosity of the liquid phase of the system. In order to achieve the anisotropy, the

blends were previously labeled with 1,6-diphenyl-1,3,5-hexatriene (DPH), a

fluorophore compound. A decrease in rotation diffusion of DPH results in an increment

in r, a process associated with higher structural order of TAGS molecules in the liquid

phase. For a given system the induction time for crystallization (Ti, determined by DSC)

increased as a direct function of TCr. However, at a given TCr the Ti increased, probably

because POO, PLO, and LLP present in SFO (10.2%) and SO (27.6%) delayed TP

nucleation. In the OOO system at all TCr investigated, r remained constant over time

decreasing during TP crystallization. The SFO system showed an increase in r right

after Ti followed by a decrease until achieving a constant value. Similar results were

observed by SO, but the increase in r was before Ti. TP crystallized in the β state in all

systems investigated. These results showed that before crystallization, TP had to be

segregated first achieving a higher structural order in the liquid phase. The kinetics of

this process depends on the molecular interactions between TAGS in the liquid phase

and the crystallizing TAGS (i.e., TP).

(keywords: crystallization, viscosity, structural order)

Documents

FSFB, 3rd International Congress, 14-17 October, 2008, Querétarorespyn2.uanl.mx/especiales/2009/ee-01-2009/documentos/04... · 2009-04-02 · FSFB, 3rd International Congress, 14-17