International Gluten Workshop, 11th; Beijing (China); 12-15 Aug 2012

1. 11Th International Gluten Workshop
Aug 12-15, 2012. Beijing, China
Gluten protein network
Reliability of gluten-related small-scale tests
to estimate dough viscoelasticity and bread
loaf volume
Roberto J Peña et al.
CIMMYT
Acknowledgements:
Carlos Guzman
Nayeli Hernandez
Gabriel Posadas
Wheat Quality Laboratory
CIMMYT

2. Outline
Introduction:
Bread making quality attributes; breeding
scheme and screening for bread making quality
Objectives
Comparison of glutenin-related small-scale tests
Rapid small-scale test study
M&M
Results & Discussion
Summary

3. Gluten quantity and quality are
the main grain factors defining:
The processing performance of
the bread making dough
• Dough mixing time; stability;
tolerance to overmixing
• Dough elasticity; viscosity;
handling properties
The quality of the final baking
product
• Bread volume; crumb texture;
freshness retention time

4. CIMMYT wheat program main breeding objective is to
combine high yield potential, disease resistance, and
desirable end-use quality attributes
Glu-1
New crosses: Parental lines selected to combine MAS Glu-3
Sec-1  x x
high yield, disease resistance and desirable quality Gli-1
(grain hardness, gluten proteins, starch)
Breeding activities Generation Yellowness Hardness (NIR), protein % and
Screening: Yield and disease resistance F1-F2 Sedimentation
(60 -80 thousand lines) F3-F4
NIRS x Discard
 Select
Screening: Yield-Disease resist.-Quality F5
(4 -6 thousand lines) F6 Mixographic Type
Screening: Yield-Disease resist..-Quality F7 x Alveograph
(2 - 3 thousand lines) F8
x
Tenacious
 gluten
x
Screening: Yield-Disease resist..-Quality F9
(>1000 lines from 3-4 environments) F10 x Weak gluten
baking  W >300
Elite Yield trials/ C Int. Nurseries. Quality
(500-1000 lines from 3-4 environments)
Yield trials in commercial fields/Quality  W >350
(10-20 lines/6-8 fields)

5. SDS-PAGE of gluten protein
Glu-1
• We examine the influence of Glu-1/Glu- Glu-B2
3/Gli-1 alleles on dough viscoelasticity and
bread making quality Glu-B3
• Crosses are made to achieve best allelic
combinations to develop wheat varieties for
diverse uses
b d d b f f b f b i,k d
• Contribution of LMW-glutenins (GLU-B3) to Gli-B1
wheat quality properties:
-Dough mixing quality: i, d, b≥, g, f, h, >b->J
-Dough extensibility: g, f, i≥, b, h, , d>b->J
-Dough strength: i, g, f, b≥ h , d>b->J

6. Instruments/tests commonly used in breeding to assess bread
making quality-related parameters:
• Mixograph. Dough mixing properties (dough
development time; stability; tolerance to over mixing
• Alveograph. Dough viscoelasticity (dough
strength, and tenacity/extensibility ratio)
• Bread baking test. Actual baking performance
(loaf volume and crumb texture)
These methods are time-consuming and therefore have limited
use in screening for quality at early stages of breeding.

7. Sodium dodecyl sulfate-Sedimentation(SDS-S)
The SDS-S test is well accepted,
particularly at early stages of
breeding, as a reliable parameter to
screen for gluten strength in Common
& Durum wheat.
Determines the volume of the flour
suspended in lactic acid-SDS solution
It is a fair-to-good estimate of gluten
strength (and extensibility?)
The SDS-value is influenced by both
protein quantity and quality, and
environmental conditions

8. The relationship between SDS-sedimentation and dough
strength parameters varies across environments. We need a
better screening tool
0.8 Elite lines under different managements/environment conditions
( Y2009-10 n=90)
SDSS vs. Mix. Time SDSS vs. W SDSS vs. P/L
0.6
0.4
0.2
0
Flat (melgas) Zero Till Beds, Red Irrig Beds, Red Drip Beds, Heat
Irrgi
-0.2
Correlation coefficients significance: r> 0.34
-0.4

9. Glutenin swells in dilute acid and SDS solutions.
Some glutenin-related small-scale methods showing potential
to screen for bread making quality:
•SDS-Sedimentation test (SDS-S). The insoluble glutenin expands
as a highly hydrated aggregate that contributes to the volume of the
sediment.
•Lactic Acid Retention Capacity (LARC). The highly hydrated
insoluble glutenin is trapped in the centrifuged pellet, and is the
main factor defining the weight gain of the tested flour
•Swelling index of glutenin (SIG). The flour is suspended in alcohol-
lactic acid. The swelling (swollen flour wt / flour wt) is directly
related to the quantity and the quality of mainly the insoluble
glutenin (Wang & Kovacs 2002; Weegels et al. 1996)

10. Objectives
1. To scale-down the LARC method, attempting to
increase the throughput of the test
2. To compare the three small-scale tests (SDS-S;
LARC; SIG) with respect to their relationship with:
• Dough mixing properties; dough strength and
extensibility; and bread loaf volume
• Compare the relationship of the small-scale
tests under different environmental conditions

11. Materials
Wheat advanced lines (242); various elite yield trials (CIMMYT, Mexico Y. 2010-11)
No N-fertilizer limitations
Testing conditions: Optimum irrigation; Drip reduced irrigation;
Reduced irrigation; Zero-till
Genotypes represented wide variability in quality traits (grain hardness; dough visco
elasticity; and bread making loaf volume.
Methods
Protein (NIRS); Mixograph (DDT and % Torque); Alveograph (W and P/L); and bread
loaf volume, according to AACC methods
-SDS-sedimentation test (FLRSDS-S), ml/1g flour, according to Peña et al. (1990)
-Lactic acid retention capacity (LARC), %, AACC method 56-11 (& scaled-down
version)
-Swelling index of glutenin (SIG), weight of residue/40 mg flour, according to Wang and
Kovacs (2002)

12. Lower cost and higher Description Method AACC Scaled-down
(56-10 & 56-11) LARC
throughput by 5g flour/50 ml 0.3g flour/1.5 ml
scaling-down the AACC
Cost 100% 0.5x of AACC
LARC method
Samples 100% 2x of AACC
tested
AACC method Lactic Acid SRC, %
200
y = 1.3795x - 45.582
R²= 0.9359
180
160
140
120
100
80
80 90 100 110 120 130 140 150 160 170
Scaled-down method

13. Relationship small-scale tests vs. dough parameters
1.00
Low protein: 8.8-12.3% (n = 187)
0.80
0.60
0.40
Significant
0.20 (α = 0.05)
0.00
GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL
-0.20
1,00
-0.40
1.00 0,80
0,60
High protein: 12.6-17.0% (n = 57)
0.80
0,40
0.60 Significant
0,20 (α = 0.05)
0.40
0,00
GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL
0.20
-0,20
0.00 -0,40
GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL
-0.20 -0,60
-0.40 -0,80
FLRSDS Lactic acid, Ret% SIG

14. Relationship small-scale tests vs. dough parameters
1.00
R> 38, significant Optimun Irr. (n=104)
(α = 0.05)
0.50
0.00
GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL
-0.50
1.00
R> 40, significant Drip Red. Irr. (n=27)
0.50 (α = 0.05)
0.00
GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL
-0.50
1,00
1.00
R> 40, significant Reduced Irr. (n=31)
0,80 (α = 0.05)
0.50
0,60
0.00
0,40 GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL
-0.50
0,20
1.00 Zero-till (n=49)
0,00 R> 40, significant
0.50 (α = 0.05)
GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL
-0,20
0.00
-0,40
GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL
-0.50
-0,60
-0,80
FLRSDS Lactic acid, Ret% SIG

15. Relationship small-scale tests vs. dough parameters
1.00
FLRSDS Lactic acid, Ret% SIG FLRProt
0.80
0.60
0.40
0.20
0.00
GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL
(n = 244)
-0.20
Red line shows significant R values (α = 0.05)

16. Over all observed quality-predicting value:
SIG>LARC>SDS-S
The SIG test is difficult to perform; requires consistent, one-
single, decanting step (flour-gel residue tends to flow down)
The scaled-down LARC test is very simple and easy to
perform. But, higher throughput is desirable.
Sample, 1st Mix 2nd Mix Centri Total Observ.
g solvent time, solvent time, fuge testing
min min time, time,
min min
LARC 0.3 LA 5 - - 2 10 Easy
SIG 0.04 Water 10 Isopr-LA 10 5 30 Decanting
is difficult
(one short
movement)

17. NIRS-based molecular spectroscopy
LARC %
160.0
Preliminary data on NIRS 150.0
R²= 0.8519
calibration, using 50-70 140.0
130.0
LARC %
contrasting lines (samples 120.0
spectra), indicate that 110.0
100.0
reliable calibrations for LARC 90.0
and SIG are feasible. 80.0
90.0 100.0 110.0 120.0 130.0 140.0 150.0 160.0 170.0
FT-NIRS (Antharis) %
SIG
No validation has been 6.5
R²= 0.8391
performed yet 6
5.5
SIG
5
More work is needed. 4.5
4
3.50 4.00 4.50 5.00 5.50 6.00 6.50 7.00
FT-NIRS (Antharis) %

18. Summary
• The efficiency of SDS-Sedimentation to predict dough strength-related
parameters varies with different environmental conditions
• SDS-S is still generally efficient but LARC and SIG have shown better
relationship with dough-strength parameters and bread making
• SIG showed better prediction value of bread making quality under
various different environment and protein levels.
• However, the single decanting step of the SIG test is difficult to master
• LARC is easy to handle, although the number of samples /day is not
as large as what can be handle with SDS-S
• Attempts to develop NIRS calibration for SIG and LARC are highly
promising

19. Thank you