Transcript Title of Project IMPROVING THE RHEOLOGICAL PROPERTIES

Title of Project
IMPROVING THE RHEOLOGICAL
PROPERTIES & BAKING QUALITIES
OF FLOUR (BLANK) BY THE USE OF
REGULATORS AT LMLC
Presented by Sarita Khedu (Miss)
MPhil /PhD
Faculty of Science
7/16/2015
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OVERVIEW OF THE PRESENTATION
 Introduction
 Objectives of the study
Review of literature
 Research Methodology
 Statistical Design
 Results & Discussion
 Conclusions & Recommendations
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INTRODUCTION I
Wheat - primary material for bread making (BRI,
1989 ; Belitz et al., 2004),
Main ingredient - flour (Fox & Cameron, 1995
Belitz et al., 2004).
Bread and most other baked products can be
made successfully from flours having a range of
qualities.
Bread widely enjoyed, important part of a healthy
diet & enjoyed by all age groups in Mauritius
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INTRODUCTION II
Local milling industry : LMLC
 Addition of regulators to milled flour
To abide by the contract signed to standardize the
quality of flour
 To give an edge to the local and international
baking industry
Composition of regulators
Oxidising agents (ascorbic acid)
Reducing agents (L-Cysteine)
Enzymes (amylases) (Lesaffre, 2001)
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INTRODUCTION III
1993
WHO banned the use of
potassium bromate
Resulted in a great demand on food
technologists for alternatives (Cavanaugh, 2002).
local bakers cut down the required dose of
improvers in the process of bread making since the
non-bromate improvers are very expensive
Quality problems + unhappy consumers
Presently LMLC adds Regulator A
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Objectives of the Study
To study the effect of the addition of a regulator
(Reg A) on the rheological properties and baking
qualities of blank flour
To compare the effects of the addition of two
new regulators (Reg B & Reg C) with the one in
use at LMLC (Reg A) all at recommended doses
To study the effect of Regulator B at lower dose
(Reg B1) compared to the in use regulator at
recommended dose (Reg A)
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LITERATURE REVIEW I
 Bread Research Institute of Australia (1989) :
Action of α-amylase on starch
strengthening of gluten by ascorbic acid
 Confirmed by Le Saffre (2001) an increase in
dough extensibility by the addition of L-Cysteine
 Increase in bread volume by the use of ascorbic
acid (Gujral, 2002)
Lopper (1998) - malted wheat flour has a higher
proportion of enzymes - mainly of  and -amylase
It also contains protease, glucanase and other
enzymes.
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LITERATURE REVIEW II
Increase in
by the addition of L dough extensibility
Cysteine (Belitz et al.,
 flour capacity to hydrolyze
2004)
starch by α-amylase &
 volume
Jood et al. (2003) : α-amylases give softer bread crumb &
hemicellulases make dough softer as well as promote
gelatinization of starch
malt flour - rich source of maltose, soluble proteins, amylolitic
and proteolitic enzymes, and flavour substances - promote
vigorous yeast activity, accelerate dough conditioning and
contribute a distinctive flavour to the baked product - malted
wheat flour have pronounced effects on Falling Numbers
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Hruskova
et al. (2003)
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LITERATURE REVIEW III
 Regulator A : In use at LMLC
 Regulator B & C : New
 Composition of regulators
Table 1 : Composition of Regulators used
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Regulator A
Regulator B
Regulator C
Ascorbic Acid
Ascorbic Acid
Ascorbic Acid
Fungal
Hemicellulase
L-Cysteine
L-Cysteine
Wheat Flour
Malted Wheat
Flour
Malted Wheat Flour
α-amylase
Enzymes
Pure α-amylase
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Research Methodology
Treatments
Table 2 : Treatments used
1
Blank
2
Reg. A (at 0.01%)
3
Reg. B1 (0.1%)
4
Reg. B (0.15%)
5
Reg. C (0.1%)
Parameters assessed
 Rheological properties by Chopin Alveograph
 Chemical test : Falling Number
 Bake trials to assess Volume & Texture
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Statistical Design
Randomised Block Design
5 Replicates
SPSS 11.0 Software
Two Way ANOVA without replication
Tukey Honestly Significant Difference (HSD)
used to determine the best treatment
Dunnets Critical d to compare treatments with
the control
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 Bread Volume
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RESULTS I
Figure 1 – Effect of the addition of regulators on bread volume
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Texture
RESULTS II
Table 3 – Effect of the addition of regulators on bread crumb texture
Treatment
Result
Blk
Firm
Regulator A
Soft & Elastic
Regulator B1
Soft & Elastic
Regulator C
Soft & Elastic
Regulator B2
Very soft & elastic
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Desirable for
white
pan bread
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RESULTS III
Falling Number
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Figure 2 – Effect of the addition of regulators on Falling Number
 P/ L Ratio
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RESULTS IV
Figure 4 – Effect of the addition of regulators on P / L ratio15
Results V
Table 4 – Summary of results
Rheological Tests
Chemical
Bake Tests
FN
Bread
volume
Texture
Firm
Tmt
P
L
P/L
BLK
106
mm
71m
m
within range
(1.3-1.5)
491
1710
cm3
above
range
outside
optimum
(469)
↑( +)
desirable
within
range
outside
optimum
(339)*
↑↑( +)
desirable
below
range
Optimum
(269)
↑↑↑( +)
not
desirable
within
range
outside
optimum
(311)*
Reg A
Reg
B1
Reg B
↑(-)
↓(-)
↓↓( +) ↑↑( +)
↓↓↓(
+)
↑↑↑(
+)
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Reg C
↓↓( +) ↑↑( +)
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↑↑↑( +)
desirable
DISCUSSION I
Bread Volume
Increase
ascorbic acid ,
L-Cysteine
& enzymes
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DISCUSSION II
Action of ascorbic acid on gluten
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Plate 1 – Action of ascorbic acid on gluten
(Lesaffre,2001)
DISCUSSION III
 Action of L-cysteine on gluten strands
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(Lesaffre,2001)
Plate 2 - Action of L-Cysteine on gluten strands
DISCUSSION IV
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Plate 3 – effect of hemicellulases on pentosans
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(Lesaffre,2001)
DISCUSSION V
Bread crumb texture
Reg A, B1 and C - soft and elastic (desirable)
Reg B - not desired by consumers since slicing problems
 added enzymes which are responsible
The proportion of enzymes
 a high level of α- amylase activity, indicated by a low
falling number (usually < 200) will result in a sticky bread
crumb.
a low α- amylase activity, indicated by a high falling
number (usually > 400) yields in a dry and firm texture
(Operation Manual 8600).
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DISCUSSION VI
Falling Number
Table 4 - Interpretation of the different Falling Numbers
Falling
Number
< 200
200-300
Above 300
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Indication
High α - amylase activity. Sprouted
damaged wheat. Bread crumb firm
and sticky
Optimum α - amylase activity. Bread
crumb likely to be good
Low α -amylase activity. Bread crumb is
likely to be dried. And a reduced bread
volume is obtained.
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DISCUSSION VII
 Three regulators used contained added αamylase
High bread volume – Reg B & C
malted wheat flour
Lopper (1998)- malted wheat flour consists of α
and β –amylases and many other enzymes.
Hruskova et al. (2003) - amylases from malted
wheat flour do have a pronounced effect on
Falling Numbers
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DISCUSSION VIII
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Plate 3 – Action of enzymes on starch
(Lesaffre,2001)
DISCUSSION IX
Overpressure ‘P’ gives an indication of the dough
to resistance to deformation (Faridi & Rasper,
1987).
The ‘L’ value is usually used to determine the
dough extensibility (Faridi & Rasper, 1987).
Ideal P/L values - 1.3-1.5.
ineffectiveness of the in-use regulator (regulator
A) in giving desired P/L value is noted, which is
very well outside range
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Conclusions & Recomendations
 The in use regulator, regulator A did not give good
rheological properties and baking qualities.
 Regulator C gave best results in all the parameters
assessed followed by B1
 RECOMENDATIONS
 To improve flour quality the mill can replace
Regulator A by Regulator C.
 Very soft and elastic structure which is highly
desirable for burgers and rounders – opt for
Regulator B
Option between regulator B1 OR C – Financial analysis
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