Reliability of gluten-related small-scale tests

to estimate dough viscoelasticity and bread

loaf volume

Gluten protein network

Roberto J Peña et al.

CIMMYT

11Th International Gluten Workshop

Aug 12-15, 2012. Beijing, China

Acknowledgements:

Carlos Guzman

Nayeli Hernandez

Gabriel Posadas

Wheat Quality Laboratory

CIMMYT

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

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

Gluten quantity and quality are

the main grain factors defining:

CIMMYT wheat program main breeding objective is to

combine high yield potential, disease resistance, and

desirable end-use quality attributes

x

Mixographic Type

New crosses: Parental lines selected to combine

high yield, disease resistance and desirable quality

(grain hardness, gluten proteins, starch)

Breeding activities Generation

Screening: Yield and disease resistance F1-F2 (60 -80 thousand lines) F3-F4

Screening: Yield-Disease resist.-Quality F5

(4 -6 thousand lines) F6

Screening: Yield-Disease resist..-Quality F7

(2 - 3 thousand lines) F8

Screening: Yield-Disease resist..-Quality F9

(>1000 lines from 3-4 environments) F10

Elite Yield trials/ C Int. Nurseries. Quality

(500-1000 lines from 3-4 environments) Yield trials in commercial fields/Quality

(10-20 lines/6-8 fields)

x Discard

Select

baking

Glu-1

Glu-3

Sec-1

Gli-1

Hardness (NIR), protein % and

Sedimentation

x x

Yellowness

NIRS

W >300

W >350

Tenacious

gluten

x

x

x

Weak gluten

Alveograph

MAS

SDS-PAGE of gluten protein

• We examine the influence of Glu-1/Glu-

3/Gli-1 alleles on dough viscoelasticity and

bread making quality

• Crosses are made to achieve best allelic

combinations to develop wheat varieties for

diverse uses

• Contribution of LMW-glutenins (GLU-B3) to

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

Gli-B1

b d d b f f b f b i,k d

Glu-B2

Glu-B3

Glu-1

• 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)

Instruments/tests commonly used in breeding to assess bread

making quality-related parameters:

These methods are time-consuming and therefore have limited

use in screening for quality at early stages of breeding.

Sodium dodecyl sulfate-Sedimentation(SDS-S)

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

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.

-0.4

-0.2

0

0.2

0.4

0.6

0.8

Flat (melgas) Zero Till Beds, Red Irrig Beds, Red DripIrrgi

Beds, Heat

SDSS vs. Mix. Time SDSS vs. W SDSS vs. P/L

Elite lines under different managements/environment conditions

( Y2009-10 n=90)

Correlation coefficients significance: r> 0.34

The relationship between SDS-sedimentation and dough

strength parameters varies across environments. We need a

better screening tool

•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)

Glutenin swells in dilute acid and SDS solutions.

Some glutenin-related small-scale methods showing potential

to screen for bread making quality:

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

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)

Description Method AACC

(56-10 & 56-11)

5g flour/50 ml

Scaled-down

LARC

0.3g flour/1.5 ml

Cost 100% 0.5x of AACC

Samples

tested

100% 2x of AACC

Lower cost and higher

throughput by

scaling-down the AACC

LARC method

y = 1.3795x - 45.582 R² = 0.9359

80

100

120

140

160

180

200

80 90 100 110 120 130 140 150 160 170

Scaled-down method

AACC method Lactic Acid SRC, %

-0.40

-0.20

0.00

0.20

0.40

0.60

0.80

1.00

GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL

-0,80

-0,60

-0,40

-0,20

0,00

0,20

0,40

0,60

0,80

1,00

GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL

FLRSDS Lactic acid, Ret% SIG

Significant

(α = 0.05)

-0.40

-0.20

0.00

0.20

0.40

0.60

0.80

1.00

GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL

Significant

(α = 0.05)

Low protein: 8.8-12.3% (n = 187)

High protein: 12.6-17.0% (n = 57)

Relationship small-scale tests vs. dough parameters

Relationship small-scale tests vs. dough parameters

-0.50

0.00

0.50

1.00

GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL

-0.50

0.00

0.50

1.00

GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL

-0.50

0.00

0.50

1.00

GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL

-0.50

0.00

0.50

1.00

GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL

-0,80

-0,60

-0,40

-0,20

0,00

0,20

0,40

0,60

0,80

1,00

GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL

FLRSDS Lactic acid, Ret% SIG

Optimun Irr. (n=104)

Drip Red. Irr. (n=27)

Reduced Irr. (n=31)

Zero-till (n=49)

R> 40, significant

(α = 0.05)

R> 40, significant

(α = 0.05)

R> 40, significant

(α = 0.05)

R> 38, significant

(α = 0.05)

Relationship small-scale tests vs. dough parameters

(n = 244) -0.20

0.00

0.20

0.40

0.60

0.80

1.00

GRNHRD FLRPRO MIXTIM %TQ*MIN. ALVW ALVPL LOFVOL

FLRSDS Lactic acid, Ret% SIG FLRProt

Red line shows significant R values (α = 0.05)

Sample,

g

1st

solvent

Mix

time,

min

2nd

solvent

Mix

time,

min

Centri

fuge

time,

min

Total

testing

time,

min

Observ.

LARC 0.3 LA 5 - - 2 10 Easy

SIG 0.04 Water 10 Isopr-LA 10 5 30 Decanting

is difficult

(one short

movement)

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.

R² = 0.8391

4

4.5

5

5.5

6

6.5

3.50 4.00 4.50 5.00 5.50 6.00 6.50 7.00

SIG

FT-NIRS (Antharis) %

SIG

R² = 0.8519

80.0

90.0

100.0

110.0

120.0

130.0

140.0

150.0

160.0

90.0 100.0 110.0 120.0 130.0 140.0 150.0 160.0 170.0

LA

RC

%

FT-NIRS (Antharis) %

LARC %

NIRS-based molecular spectroscopy

Preliminary data on NIRS

calibration, using 50-70

contrasting lines (samples

spectra), indicate that

reliable calibrations for LARC

and SIG are feasible.

No validation has been

performed yet

More work is needed.

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

Thank you