Post on 18-Aug-2015
Development of superior quality bread wheat at KALRO
John N. Ndung’u and Rosemary
Chebwosony,Lucy Kuria, Peter Kimani, Margaret Meso and Joseph Owira
KALRO - NJORO
Why Grain Quality? Why Grain Quality?
Quality for : Breeder Farmer Primary processors (Flour millers) Secondary processors (bakers, biscuit, etc) Marketing agencies
Bread wheatFlat breadsSteamed breadleavened breadTandyrMandazi Injera Porridge CakesCookies/Biscuitsetc
Diverse end uses Diverse end uses
Durum wheat
• Pasta products (macaroni, spaghetti)
• Causcaus• Local bread• Injera
Triticale• Bread • Morning
cereals• Injera• etc
To meet Urban and local needs !!
Wheat quality Wheat quality characterizationcharacterization
Kernel (grain) characteristics
Milling and flour characteristics
Dough/baking (rheological)
End product characterization
Kernel (grain) Kernel (grain) characteristicscharacteristics
Dockage (%)
Test weight (Kg hl-1)
1000 grains weight (g)
Grain moisture content (%)
Hard/vitreous kernels (Vitreousness)
Falling number (sec)
Protein content (grain or flour)
Protein quality
Milling and flour characteristicsMilling and flour characteristics
Flour yield (%) Ash (%)ColorSemolina qualityStarch damageFlour water absorptionFlour protein concentrationFlour chemical composition (%)SDS sedimentation testWet gluten contentGluten index
Dough/baking (rheological) Dough/baking (rheological) parametersparameters
Farinograph
Alveograph
Extensigraph
Mixograph
Farinograph
Mixogram
Alveograph
End product characterizationEnd product characterization
BreadVolumeWeightTexture (internal and external texture)Internal characteristics
Biscuits:DiameterTexturetaste
• Flat bread• Pasta products
• etc
Wheat Quality Improvement in Wheat Quality Improvement in KenyaKenya
Objectives1.Identify main wheat end-uses and grain
quality requirements2.Understand the genetic and G x E factors
influencing wheat quality attributes and end-use quality.
3.Apply quality characterization/screening to:oWheat breeding linesoUsing efficient and high throughput screening
tools.
Interactions on Development of Interactions on Development of superior quality wheat at KALROsuperior quality wheat at KALRO
Breeders: Breeding materials and released varieties◦(Yields, acid soils, dry areas, stem rust)
Pathologists: Lines and varieties being screened for diseases (stem rust, BYDV)
Agronomists: Lines and varieties under agronomic management trials
Entomologist: Lines and varieties being screened for field and storage pests (RWA, Weevils)
Biotechnology (Double haploids and mutants)FarmersMilling companies
Development of superior quality Development of superior quality bread wheat at KALRO bread wheat at KALRO
Breeding activities : F1-F2 Screening for yield and disease resistance : F3-F4 (40 -60 thousand lines) oScreening: Yield, Disease resistance & Quality : F5 o (2 -6 thousand lines) F6 NIR
TestoScreening: Yield, Disease resistance & Quality :F7o (500 – 1000 lines) (All above at Njoro site)
Observation Trials Screening: Yield, Disease resistance &Quality : Milling,
Twt, Protein (100 - 200 lines) Observations (2-3 sites)
Farin/AlveographPYT/AYT: Quality (200-500 lines) (6-7 sites) A.
Amylase NPT trials: Quality (5-10 lines) NIR Baking
Parameters Considered in Breeding Parameters Considered in Breeding for Qualityfor Quality• 1. Milling (Grain)
• Milling extraction rate, duration, milling energy, level of starch damage
• 2. NIR (whole grain and flour)–(Grain Hardness, protein, zeleny, WA and
moisture)• 3.Gluten Strength
– (SDS-Sedimentation, Gluten index, W, P/L)• 4. Enzymatic Activity (Flour)
–(Falling Number)• 5.Dough Rheology (Flour)
–Farinograph, Alveograph,Extensograph and Mixograph)
• 6. Baking Test (Flour)
Quality parameters used by bread wheat breeders Quality parameters used by bread wheat breeders for quality screening in the for quality screening in the United StatesUnited States, , Europe Europe and at and at CIMMYTCIMMYTLocation Early generation
(F2-F5) Advanced generation
(F6 and higher)
United States
Protein, SDS sedimentation, hardness, mixograph
Milling (extraction, ash), Flour protein, Water absorption, Farinograph (time, stability, etc.) Dough characteristics, Loaf volume, Bread characteristics
Europe Protein, SDS sedimentation, Zeleny sedimentation, HMW glutenin subunits
Hagberg falling number, Alveograph (W, P/L), Gluten elastic recovery, Extensometer, Loaf volume, Baking score, Machinability test
CIMMYT Protein, SDS sedimentation, Hardness
Hagberg falling number, Grain and flour protein, High molecular weight glutenin subunits, Flour SDS sedimentation, Mixograph (time, tolerance), Alveograph (W, P/L), Loaf volume; Crumb structure
**Edwards, 1997
Milling TestMilling Test Types:
Buhler, Quadramat, Retsch and Perten mills
During flour milling: o The grain is broken and
endosperm particles gradually reduced in size.
o Large , plump grains show high flour yields
Afterwards:o Separation of the grain into
main parts bran, embryo and endosperm flour/ semolina
o Gradual reduction of endosperm particles to obtain refined flour or semolina (coarse particles)
o ASH Content
Near Infrared Near Infrared Spectroscopy(NIR)Spectroscopy(NIR) NIR Spectroscopy measures
absorption in the Near Infrared.o O-H, N-H, C-H, S-H bonds are
strong NIR absorbers (moisture, protein, fat, fiber, sugars, acids, etc.).
o Hydrogen, Nitrogen Oxygen have no change in dipole moment, hence no NIR absorption.
o NIRS provides both chemical and physical information in flour and grain (non destructive)
Testing samples should cover all the potential variationo Geographical origin, growing
season, etc. when developing a NIR calibration.
Farinograph TestFarinograph TestMeasures: DDT, WA,
Stability and Tolerance
D = Dough development time E = Stability G = Mixing tolerance index (5 min after peak) H = Degree of softening (12 min after peak)
Brabender FarinographBrabender Farinograph
Arrival Time (AT) Peak Time (DT) Stability Time (ST) Departure Time (Dep’t) Absorption Mixing Tolerance Index (MTI)
Mixing characteristics of a flour
Weak (DT and ST values of about one minute, or less) Strong (DTs of 3-5 minutes, and STs of 8-14 minutes) Medium-strong (DTs of 2-4 minutes and STs of 4-7 minutes) Extra strong (DTs of 4-12 minutes and STs of 20-32 minutes) .
LINK BETWEEN ENDOSPERM TEXTURE, STARCH GRANULE SHAPE& SIZE, PACKED CELL VOLUME AND PROTEIN BODY ULTRASTRUCTURE
SEM
Mixograph TestMixograph Test
Quickly analyzes small quantities of flour for dough strength.
Screen early generation lines for dough strength and WA
WA measured often serves as a measure of absorption in bread baking tests.
Bon Lee, Laboratory Supervisor
Alveograph (Chopin) Alveograph (Chopin) TestTest
Measures the extensibility, strength and deformation
Measures: Extensibility, strength, P/L ratio and deformation energy for gluten
AlveographAlveograph
P = tenacity (max. pressure reached blowing the dough piece to rupture)L = extensibility (length of the curve, cm),W = strength of the flour (area of the curve, ergsx103),P/L = configuration ratio of the curve,Ie = P200/P Elasticity (P200 = pressure after 200ml blowing or 4 cm from origin of the curve).
Alpha-amylase activity and Falling Number TestAlpha-amylase activity and Falling Number Test• Grain always susceptible to
pre-harvest germination o Carries variable levels of alpha-
amylase activity
• In the Falling Number test:– Alpha amylase activity is
indirectly estimated by testing the paste viscosity of whole meal and refined flour
• During the test:o The flour-water slurry is
heated gradually allowing for optimum T for enzymatic hydrolysis.
• Low FN values (60-150 seconds) correspond to high levels of alpha amylase activity.
AVERAGE STANDARDS OF BREAD AVERAGE STANDARDS OF BREAD WHEATWHEAT
Parameter Basic Grain Quality Standards
Protein Content 12 %
Specific Weight 76 kg/hl
Falling Number >250
Thousand kernel mass >40
Farinograph mixing time 3-6 min (optimum 4 min)
Flour extraction 76 %
Alveograph P/L ratio 0.5-0.8 (optimum 0.8)
Flour color (as measured by color grader series III)
Cake (-2.5 to 1); white bread flour (1.5-4.5); brown bread(9-14)
Wheat end-usesWheat end-uses Main wheat-based food types
Breads (leavened, flat, steamed) Noodles, Biscuits, Alimentary pasta (spaghetti, etc.) Regional dishes (cous-cous, burghul, porridge).
A wheat variety suitable for one end-use may not be suitable for a different one.
Quality differences result mainly from the grain compositional traits: oGrain hardness oProtein quantity and quality (gluten protein
composition) o Starch pasting properties (amylose / amylopectin
Ratio)
SOFT MEDIUM HARD T. Durum
15
14
13
12
11
10
9
Pro
tein
con
ten
t %
Grain hardness
Biscuits,Cakes, Pastry, Puddings
Noodles & Steamed bread
Pasta
Flatbread
Pan breads
Leavened breads
Couscous
Tandyrbread
Main Wheat-based products
Glu
ten
str
engt
h
SOFT MEDIUM HARD T. Durum
15
14
13
12
11
10
9
Pro
tein
con
ten
t %
Grain hardness
Biscuits,Cakes, Pastry, Puddings
Noodles & Steamed bread
Pasta
Flatbread
Pan breads
Leavened breads
Couscous
Tandyrbread
Main Wheat-based products
Glu
ten
str
engt
h
Pan BreadPan BreadMechanized pan bread is
important in Kenya urban areas
Main wheat quality requirements: Hard to medium-hard
grain High protein content
(>12.5%) Strong and extensible
glutenSoft wheat with weak
gluten not suitable for this baking process
Colour Index
Flat breadsFlat breadsFlat breads (Chapatis) are
very important in rural and urban in Kenya
Main wheat quality requirements:Soft wheat with weak gluten Intermediate protein content
(10-12%)Medium-strong and extensible
gluten
Biscuits and CakesBiscuits and CakesDesirable to avoid the
development of gluten visco-elastic properties.
Achieved by including:High levels of fat and sugar
(30-40% of total formula)Air, water vapor and chemicals
are the main leavening agentsAll acting at the oven stage
Durum wheat productsDurum wheat products
Durum wheat-based products breads are consumed as alimentary pasta globally
Main wheat quality requirements:o Large vitreous grainoHigh yellow pigment
contentoHigh protein content
(>12.5%)oStrong gluteno Low lipoxygenase activity
Biotechnology ApproachBiotechnology Approach Double Haploids Techniques
◦Improvement of protein and Gluten content Mutants (photo)
Increasing Resistant starch and TocopherolIncreasing Zinc and Iron contents Reduced phytic acid content (Photo)
Molecular TechniquesIdentification of Gluten (Glutenins and Gliadins)
MAS helps selecting parental lines with desirable quality genes /alleles in short time
Molecular tools for screening Molecular tools for screening (Inherent quality)(Inherent quality) Bread wheat
(HMW glutenin subunit)
Durum wheatB-LMW glutenins and γ-gliadin
…………Humans and NutritionHumans and Nutrition
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
Over 60 percent of the world’s 7 billion people are:Iron deficient and over 30 percent are zinc deficient.
…………HUMANS AND NUTRITIONHUMANS AND NUTRITIONIn addition, protein, calcium and magnesium deficiencies are common in
developed and developing countries including Kenya.
2B people are nutritionally hungry in worldResistant starch (RS) is known to have healthy benefits for human
Should be encouraged to form part of daily diet
Presence of antinutrients eg phytic acid in wheat
Micronutrient malnutrition (Hidden Micronutrient malnutrition (Hidden hunger)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
Methodologies for Nutrition Methodologies for Nutrition analysisanalysis
Atomic Absorption spectrophotometry for Minerals analysis
Phytic acid AssayMegazyme kit for
Resistant starch analysis
NIR/Kjedhal apparatus for protein analysis
Value additionUse of induced
mutation
Achievements/ ChallengesAchievements/ ChallengesKALRO Njoro cereal chemistry lab has
contributed to the release of170 commercial high quality varieties since 1920s
Recently contributed to release of 10 varieties
Screened 20 commercial varieties for nutritional profile
Trained Millers on wheat grading and qualityOther crops quality analysisAchievements/awardsEquipments
ConclusionsConclusions• To succeed in quality improvement it is
important to:Identify main end uses in targeted areasDetermine main grain traits affecting
processing qualityUse efficient, high throughput quality
screening toolsDetermine end-product quality and shelf life
attributesUnderstand genetic control of quality traits Determine G x E factors influencing end-use
quality