1. 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

2. Grain quality and end-usesGrain quality and end-uses

3. Why Grain Quality?Why Grain Quality?
Quality for :
 Breeder
 Farmer
 Primary processors
(Flour millers)
 Secondary processors
(bakers, biscuit, etc)
 Marketing agencies

4. Bread wheat
Flat breads
Steamed bread
leavened bread
Tandyr
Mandazi
Injera
Porridge
Cakes
Cookies/Biscuits
etc
Diverse end usesDiverse end uses
Durum wheat
• Pasta
products
(macaroni,
spaghetti)
• Causcaus
• Local bread
• Injera
Triticale
• Bread
• Morning
cereals
• Injera
• etc
To meet Urban and local needs !!

5. Wheat quality characterizationWheat quality characterization
 Kernel (grain) characteristics
 Milling and flour characteristics
 Dough/baking (rheological)
 End product characterization

6. 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

7. Milling and flour characteristicsMilling and flour characteristics
Flour yield (%)
Ash (%)
Color
Semolina quality
Starch damage
Flour water absorption
Flour protein concentration
Flour chemical composition (%)
SDS sedimentation test
Wet gluten content
Gluten index

8. Dough/baking (rheological) parametersDough/baking (rheological) parameters
 Farinograph
 Alveograph
 Extensigraph
 Mixograph
Farinograph
Mixogram
Alveograph

9. End product characterizationEnd product characterization
Bread
Volume
Weight
Texture (internal and external texture)
Internal characteristics
Biscuits:
Diameter
Texture
taste
• Flat bread
• Pasta products
• etc

10. Wheat Quality Improvement in KenyaWheat Quality Improvement in Kenya
Objectives
1.Identify main wheat end-uses and grain quality
requirements
2.Understand the genetic and G x E factors
influencing wheat quality attributes and end-use
quality.
3.Apply quality characterization/screening to:
oWheat breeding lines
oUsing efficient and high throughput screening tools.

11. Interactions on Development of superiorInteractions on Development of superior
quality wheat at KALROquality 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)
Farmers
Milling companies

12. Development of superior quality breadDevelopment of superior quality bread
wheat at KALROwheat at KALRO
 Breeding activities : F1-F2
 Screening for yield and disease resistance : F3-F4
(40 -60 thousand lines)
o Screening: Yield, Disease resistance & Quality : F5
o (2 -6 thousand lines) F6 NIR Test
o Screening: Yield, Disease resistance & Quality :F7
o (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/Alveograph
PYT/AYT: Quality (200-500 lines) (6-7 sites) A. Amylase
NPT trials: Quality (5-10 lines) NIR
Baking

13. Parameters Considered in Breeding forParameters Considered in Breeding for
QualityQuality• 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)

14. Quality parameters used by bread wheat breeders for qualityQuality parameters used by bread wheat breeders for quality
screening in thescreening in the United StatesUnited States,, EuropeEurope and atand at CIMMYTCIMMYT
Location 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

15. 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

16. Near Infrared Spectroscopy(NIR)Near Infrared 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 variation
o Geographical origin, growing season,
etc. when developing a NIR calibration.

17. FarinographTestFarinographTest
Measures: 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)

18. 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)
.

19. Weak/Soft Flour
Strong /Hard Flour

20. LINK BETWEEN ENDOSPERM TEXTURE, STARCH GRANULE SHAPE& SIZE,
PACKED CELL VOLUME AND PROTEIN BODY ULTRASTRUCTURE
SEM

21. 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

22. MixographMixograph

23. Alveograph (Chopin) TestAlveograph (Chopin) Test
Measures the extensibility,
strength and deformation
Measures: Extensibility, strength,
P/L ratio and deformation energy
for gluten

24. 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).

26. GROUP 1:
RED WEAK WHEAT
LOW PROTEIN

27. GROUP II:
STRONG STABLE RED WHEAT
MEDIUM PROTEIN

28. GROUP III:
•STRONG EXTENSIBLE
•RED/WHITE WHEAT
•HIGH PROTEIN

29. GROUP IV:
SOFT /WHITE WHEAT
LOW PROTEIN

30. Classes of wheatClasses of wheat
USA: 6
principal
classes
USA: 6
principal
classes

31. 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.

33. STANDARDSSTANDARDS
 National standards
(KEBS)
 Factory based standards

34. AVERAGE STANDARDS OF BREAD WHEATAVERAGE STANDARDS OF BREAD WHEAT
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)

35. 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)

36. SOFT MEDIUM HARD T. Durum
15
14
13
12
11
10
9
Proteincontent%
Grain hardness
Biscuits,
Cakes,
Pastry,
Puddings
Noodles & Steamed bread
Pasta
Flat
bread
Pan breads
Leavened breads
Couscous
Tandyr
bread
Main Wheat-based products
Glutenstrength
SOFT MEDIUM HARD T. Durum
15
14
13
12
11
10
9
Proteincontent%
Grain hardness
Biscuits,
Cakes,
Pastry,
Puddings
Noodles & Steamed bread
Pasta
Flat
bread
Pan breads
Leavened breads
Couscous
Tandyr
bread
Main Wheat-based products
Glutenstrength

37. Pan BreadPan Bread
Mechanized 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 gluten
Soft wheat with weak gluten
not suitable for this baking
process
Colour Index

38. Flat breadsFlat breads
Flat 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

39. Biscuits and CakesBiscuits and Cakes
Desirable 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 agents
All acting at the oven stage

40. Other Types of BreadsOther Types of Breads

41. Durum wheat productsDurum wheat products
 Durum wheat-based
products breads are
consumed as alimentary
pasta globally
 Main wheat quality
requirements:
o Large vitreous grain
o High yellow pigment content
o High protein content (>12.5%)
o Strong gluten
o Low lipoxygenase activity

42. Biotechnology ApproachBiotechnology Approach
 Double Haploids Techniques
◦ Improvement of protein and Gluten content
 Mutants (photo)
Increasing Resistant starch and Tocopherol
Increasing Zinc and Iron contents
Reduced phytic acid content (Photo)
 Molecular Techniques
Identification of Gluten (Glutenins and Gliadins)
 MAS helps selecting parental lines with desirable
quality genes /alleles in short time

43. Molecular tools for screening (InherentMolecular tools for screening (Inherent
quality)quality)
 Bread wheat
 (HMW glutenin subunit)
Durum wheat
B-LMW glutenins and -γ
gliadin

44. Humans and NutritionHumans and Nutrition

45. …………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.

46. …………HUMANS AND NUTRITIONHUMANS AND NUTRITION
In addition, protein, calcium and
magnesium deficiencies are common in
 developed and developing
countries including Kenya.
2B people are nutritionally hungry
in world
Resistant 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

47. Micronutrient malnutrition (Hidden hunger)Micronutrient malnutrition (Hidden hunger)
Source: World Health Organization

48. 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

49. Methodologies for Nutrition analysisMethodologies for Nutrition analysis
Atomic Absorption
spectrophotometry for
Minerals analysis
Phytic acid Assay
Megazyme kit for
Resistant starch analysis
NIR/Kjedhal apparatus
for protein analysis
Value addition
Use of induced
mutation

50. Achievements/ ChallengesAchievements/ Challenges
KALRO 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 quality
Other crops quality analysis
Achievements/awards
Equipments

52. ConclusionsConclusions
• To succeed in quality improvement it is important
to:
Identify main end uses in targeted areas
Determine main grain traits affecting processing quality
Use efficient, high throughput quality screening tools
Determine end-product quality and shelf life attributes
Understand genetic control of quality traits
Determine G x E factors influencing end-use quality

54. Thank you…

55. (Return)

56. Selection of KM14 M2 mutantsSelection of KM14 M2 mutants
(Return)