Nutritional Analysis of Wheat (Triticum aestivum L.) Germplasm in Kenya

Nutritional Analysis of Wheat (Triticum aestivum L.) Germplasm in Kenya

J.N. Ndung’u*1, E.N. Kimani, and P.N. Njau

National Plant Breeding Research Centre- KARI-

Njoro,

Private Bag - 20107,

Njoro - KENYA

Introduction Wheat (Triticum aestivum L.) is the most widely grown

food crop in the world.

In Kenya, it is ranked second after maize in cereal

crops research priorities.

Mineral elements are essential components of wheat

metabolism and often accumulate in grain.

Humans require at least 22 of these mineral elements

for:

Well being which can be supplied by appropriate

diet like wheat

.....introduction

It is estimated that over 60 percent of the

world’s 7 billion people are:

Iron deficient and over 30 percent are

zinc deficient.

In addition, protein, calcium and

magnesium deficiencies are common in :

developed and developing countries

including Kenya.

Resistant starch (RS) is known to have

healthy benefits for human

Should be encouraged to form part of

daily diet

Micronutrient malnutrition (Hidden hunger)

Source: World Health Organization

Solution Challenge

1 Micronutrient supplements for children (Fe&zinc) Malnutrition

2 The Doha development agenda Trade

3 Micronutrient fortification (iron and salt iodization)

Malnutrition

4 Expanded immunization coverage for children Diseases

5 Biofortification Malnutrition

6 Deworming, other nutrition programs in school Malnutrition

7 Lowering the price of schooling Education

8 Increase and improve girl’s schooling Women

9 Community-based nutrition promotion Malnutrition

10 Provide support for women’s reproductive role Women

Reference: http://www.copenhagenconsensus.com

http://www.copenhagenconsensus.com/Default.aspx?ID=788

Main Objective

To Analyze the Contribution of Kenya Wheat

Cultivars to the Improved Nutrition.

Materials and methods

Twenty one wheat accessions (Commercial varieties, advanced

stem rust lines and one mutant line) used in this study (Table)

Accessions planted at Njoro site: (Table /Map)

Experiment design: 4x4 partially balanced lattice design,

replicated three times.

Recommended practices followed to sustain plant growth and

production of grain.

Samples in lab milled using Retsch mill

……..Materials and Methods

Mineral analysis determined using AAS following the

method of Okalebo (2002). (Figure 2)

Crude protein analysis was determined using NIR method.

Resistant starch assay was determined following Megazyme

procedure RSTAR 11/02 AOAC Method 2002.02, AACC

Method 32-40

Data subjected to ANOVA using GLM (SAS : 9.1.3)

Differences between means ranked by Fisher’s least

significant difference (LSD) test

…..Materials and Methods

Correlation coefficients determined to establish the

relationship between the accessions.

Similarity levels obtained using MINITAB statistical

analysis software (1996).

Results and Discussion

The analysis of variance showed genotypes were significantly (p≤0.01)

different in mean values for minerals, RS and protein

For the mineral contents, a linear regression equation y = 0.00238x with

R2 = 0.9991 was observed eg zinc

Calibration curve for mineral analysis (Fe, Zn,

Mg and Ca)

y = 0.0238x

R2 = 0.9991

0.0000

0.0500

0.1000

0.1500

0.2000

0.2500

0.00 2.00 4.00 6.00 8.00 10.00 12.00

Concentration (ppm)

Absorb

ance

…….Results and Discussion

Sig. difference (p≤0.01)

among accessions.

Mbega and Popo highest

level of 546.2 ppm and 533.5

ppm respectively.

KM 14, KSSR III, KSSR IV,

Kulungu, Kongoni and

Chozi scoring lowest at104.5

ppm, 95.6 ppm, 94.1 ppm,

90.2 ppm, 82.8 ppm and 81.4

ppm respectively.

All above RDA (20-50

ppm)

Iron Concentration(ppm)

0

100

200

300

400

500

600

Kon

goni

Kulun

gu

KSR

R IV

KSR

R I

Fahari

KSR

R II

I

Chrik

u

Kwale

Ngam

ia

Dum

a

KM

14

Varieties

Co

ncen

trati

on

(p

pm

)

Iron

……Results and Discussion


among accessions.

Nyangumi scored

highest at 218.2 ppm

Seven varieties had

conc. lower than 100

ppm and they include

KM 14, Njoro BW II,

Chiriku, KSSR I, Paka,

Fahari and KSSR IV

All above RDA 50 ppm

Zinc Concentration

0

50

100

150

200

250

Kon

goni

Kulun

gu

KSR

R IV

KSR

R I

Fahari

KSR

R II

I

Chrik

u

Kwale

Ngam

ia

Dum

a

KM

14

Accessions

Co

ncen

trati

on

(p

pm

)

Zinc


Differences in iron and zinc conc. among varieties is

attributed to:

Allelic variation at a chromosomal locus that promotes early

senescence and remobilization of protein, iron and zinc

from senescing leaves to seeds.

Despite planting at same E, Iron and zinc contents are

significantly influenced by:

Date of planting, genotype and environment

Late planting and irrigation can significantly increase the

iron and zinc contents.

Seeding rates or nitrogen fertilization do not significantly

affect levels of iron and zinc in wheat grain



among genotypes.

Popo variety scored


but not significantly (p

≥0.01) differenr to Chozi

at 1927.7 ppm

Chiriku recorded a low

of 350.9 ppm.

All above RDA 350 ppm

Magnesium Concentration

0

500

1000

1500

2000

2500

Kon

goni

Mbu

ni

Kulun

gu

Tembo

KSR

R IV

Pak

a

KSR

R I

NjB

wII

Fahari

KSR

R II

KSR

R II

I

Choz

i

Chrik

u

Pop

o

Kwale

Nya

ngum

i

Ngam

ia

K. H

eroe

Dum

a

Mbe

ga

KM

14

Accessions

Co

ncen

trati

on

(p

pm

)

Magnesium



among accessions.

Variety Kwale scored


Chiriku variety having

lowest concentration of

143.8 ppm

All low RDA 1000 ppm

Calcium Concentration (ppm)

0100200300400500600700

Kon

goni

Mbu

ni

Kulun

gu

Tembo

KSR

R IVPak

a

KSR

R I

NjB

wII

Fahari

KSR

R II

KSR

R II

I

Choz

i

Chrik

u

Pop

o

Kwale

Nya

ngum

i

Ngam

ia

K. H

eroe

Dum

a

Mbe

ga

KM

14

Accessions

Co

ncen

trati

on

(p

pm

)

Calcium


GxE effects influence wheat grain magnesium and calcium contents

Increasing conc of essential mineral elements in wheat grain can be also done by:

Application of mineral fertilizers

Breeding wheat varieties with increased ability to acquire and accumulate these minerals in grain through e.g induced mutation



among genotypes.

KSSR II had highest

conc. of 0.1 g/100g

followed closely by

Njoro BW II with a

value of 0.04 g/100g.

Paka variety had lowest

conc. of 0.001 g/100g.

Resistant Starch Concentration (g/100g)

0

0.02

0.04

0.06

0.08

0.1

0.12

Kon

goni

Mbu

ni

Kulun

gu

Tembo

KSR

R IVPak

a

KSR

R I

NjB

wII

Fahari

KSR

R II

KSR

R II

I

Choz

i

Chrik

u

Pop

o

Kwale

Nya

ngum

i

Ngam

ia

K. H

eroe

Dum

a

Mbe

ga

KM

14

Accessions

Co

ncen

trati

on

(g

/100g

)

Resistant Starch


Wheat varieties e.g KSSR II high in RS can be:

Associated with improved gut health through raising Short Chain

Fatty acids e.g Butyrate

Reduction of colon cancer

low supply of these acids is associated with increased risk of

non-infectious diseases.

Good RS contributes to bowel good health by:

Encouraging the growth of healthy bacteria in the bowel

Discourages the growth of potentially harmful bacteria


Sig. difference (p≤0.01) among

genotypes.

KSSR II and Popo at 18.1 percent

and 17.8 percent

Chiriku recorded the lowest

percent at 12.2 although:

It was still above 11 percent

that is described as desirable by

millers and bakers.

Higher the protein level, higher

the nutrition and premium paid by

millers

Used in improvement of weak soft

wheat with low protein

Protein Concentration (%)

0

5

10

15

20

Kon

goni

Mbu

ni

Kulun

gu

Tembo

KSR

R IVPak

a

KSR

R I

NjB

wII

Fahari

KSR

R II

KSR

R II

I

Choz

i

Chrik

u

Pop

o

Kwale

Nya

ngum

i

Ngam

ia

K. H

eroe

Dum

a

Mbe

ga

KM

14

Accessions

Co

ncen

trati

on

(%

)

Protein


Calcium Iron Magnesium Zinc RS Protein

Calcium 1.000 0.065 0.581 0.575 -0.160 0.366

0.780 0.006 0.006 0.488 0.103

Iron 1.000 0.234 0.244 -0.135 0.129

0.308 0.287 0.560 0.577

Magnesium 1.000 0.857 -0.270 0.466

0.0001 0.236 0.033

Zinc 1.000 -0.363 0.232

0.106 0.311

RS -1.000 0.316

0.162

Protein 1.000

Table: Phenotypic correlation coefficient of minerals, RS and protein


The positive correlation indicates:

Nutritional quality traits are linked and is possible to enhance one

trait while increasing on the other

The positive correlations observed in this study have also been

reported in other related studies in the world

Positive protein and minerals relationships are possibly due to:

enzyme cofactor requirements during protein formation

since micronutrients acts as metallic activators.

……Results and Discussion Dendogram showing similarity coefficients of

combined quality traits at Njoro site At a 80 % similarity

coefficient:

4 cluster groups

delineated

composed of 4

wheat groupings of

wheat in Kenya.

Groups I, II, III and

IV

Have different end

use

131220141619181115178214795103621

73.64

82.43

91.21

100.00

Similarity

Observations

Conclusion and Recommendations

Great variation in different wheat nutritional parameters

attributed to the different cultivars

Observed values for protein and mineral contents suggest the

potential for improving the nutritive health of the population.

This can contribute greatly to sustaining national development

efforts.

Healthy population always leads to a prosperous Nation

Some cultivars can be used as parents for nutritional breeding

ACKNOWLEGEMENTS •KARI

•IAEA

•Cereal Chemistry staff, KARI-Njoro

•Wheat Breeding staff, KARI-Njoro

Thank you…

Njoro – Site Kenya

Njoro

e - 2 - 3

– 5 -

- 1 - , 0 -

- 1 - 3

4 -

Environmental descriptors of Njoro site

Trial site Alt.

masl

Soil type Annual

Rainfal (mm)

Mean maximum

Temperature (0C)

Mean minimum

Temperature (0C)

Njoro (NPBRC) 2300 Fluvisols 1200 28 16.8

(Return

)

Figure: Analysis of wheat accessions for minerals using Atomic Absorption Spectrophotometer

(Shimadzu Model AA- 6300, Tokyo-Japan). (Return)

Table : Twenty one accessions of wheat (Return)

Variety Variety Variety

Kongoni Chozi Kwale

Mbuni Chiriku Nyangumi

Kulungu Ngamia KSRR I

Tembo K. Heroe KSRR II

Njoro BwII Duma KSRR III

Paka Mbega KSRR IV

Fahari Popo KM 14

Documents

Nutritional Analysis of Wheat (Triticum aestivum L.) Germplasm in Kenya