1. Presented by Sarita Khedu (Miss) MPhil /PhD Faculty of Science
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
4/4/2019

2. OVERVIEW OF THE PRESENTATION
Introduction
Objectives of the study
Review of literature
Research Methodology
Statistical Design
Results & Discussion
Conclusions & Recommendations
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3. Main ingredient - flour (Fox & Cameron, 1995 Belitz et al., 2004).
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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4. Local milling industry : LMLC
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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5. 1993 INTRODUCTION III 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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6. 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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7. strengthening of gluten by ascorbic acid
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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8. LITERATURE REVIEW II Increase in dough extensibility
flour capacity to hydrolyze
starch by α-amylase &
volume
by the addition of L-Cysteine (Belitz et al., 2004)
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 Hruskova et al. (2003)
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9. Regulator A : In use at LMLC Regulator B & C : New
LITERATURE REVIEW III
Regulator A : In use at LMLC
Regulator B & C : New
Composition of regulators
Table 1 : Composition of Regulators used
Regulator A
Regulator B
Regulator C
Ascorbic Acid
L-Cysteine
Fungal Hemicellulase
Wheat Flour
Malted Wheat Flour
α-amylase
Enzymes
Pure α-amylase
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10. Research Methodology Treatments Parameters assessed
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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11. 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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12. Figure 1 – Effect of the addition of regulators on bread volume
RESULTS I
Bread Volume
Figure 1 – Effect of the addition of regulators on bread volume
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13. Table 3 – Effect of the addition of regulators on bread crumb texture
RESULTS II
Texture
Table 3 – Effect of the addition of regulators on bread crumb texture
Treatment
Result
Blk
Firm
Regulator A
Soft & Elastic
Regulator B1
Regulator C
Regulator B2
Very soft & elastic
Desirable for
white
pan bread
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14. Figure 2 – Effect of the addition of regulators on Falling Number
RESULTS III
Falling Number
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Figure 2 – Effect of the addition of regulators on Falling Number

15. Figure 4 – Effect of the addition of regulators on P / L ratio
RESULTS IV
P/ L Ratio
Figure 4 – Effect of the addition of regulators on P / L ratio
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16. Table 4 – Summary of results
Results V
Table 4 – Summary of results
Rheological Tests
Chemical
Bake Tests
Tmt P L
P/L FN
Bread volume
Texture
BLK
106 mm
71mm
within range ( )
491
1710 cm3
Firm
Reg A
↑(-)
↓(-)
above range
outside optimum (469)
↑( +)
desirable
Reg B1
↓↓( +)
↑↑( +)
within range
outside optimum (339)*
Reg B
↓↓↓( +)
↑↑↑( +)
below range
Optimum (269)
not desirable
Reg C
outside optimum (311)*
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17. DISCUSSION I Bread Volume Increase ascorbic acid , L-Cysteine
& enzymes
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18. Plate 1 – Action of ascorbic acid on gluten
DISCUSSION II
Action of ascorbic acid on gluten
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Plate 1 – Action of ascorbic acid on gluten
(Lesaffre,2001)

19. Plate 2 - Action of L-Cysteine on gluten strands
DISCUSSION III
Action of L-cysteine on gluten strands
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(Lesaffre,2001)
Plate 2 - Action of L-Cysteine on gluten strands

20. Plate 3 – effect of hemicellulases on pentosans
DISCUSSION IV
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Plate 3 – effect of hemicellulases on pentosans
(Lesaffre,2001)

21. 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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22. Table 4 - Interpretation of the different Falling Numbers
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DISCUSSION VI
Falling Number
Table 4 - Interpretation of the different Falling Numbers
Falling Number
Indication
< 200
High α - amylase activity. Sprouted damaged wheat. Bread crumb firm and sticky
Optimum α - amylase activity. Bread crumb likely to be good
Above 300
Low α -amylase activity. Bread crumb is likely to be dried. And a reduced bread volume is obtained.
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23. DISCUSSION VII Three regulators used contained added α-amylase
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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24. Plate 3 – Action of enzymes on starch
DISCUSSION VIII
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Plate 3 – Action of enzymes on starch
(Lesaffre,2001)

25. 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
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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26. 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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