Reliability of gluten-related small-scale tests to estimate dough viscoelasticity and bread loaf...
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Transcript of Reliability of gluten-related small-scale tests to estimate dough viscoelasticity and bread loaf...
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