Title of Project IMPROVING THE RHEOLOGICAL PROPERTIES

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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

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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
WHO banned the use of potassium bromate
1993

• 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 a-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
• dough extensibility
• flour capacity to hydrolyze
• starch by a-amylase
• volume

by the addition of L-Cysteine (Belitz et al.,
2004)

• Jood et al. (2003) a-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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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 Ascorbic Acid Ascorbic Acid
L-Cysteine L-Cysteine Fungal Hemicellulase
Wheat Flour Malted Wheat Flour Malted Wheat Flour
a-amylase Enzymes Pure a-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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RESULTS I

• Bread Volume

Figure 1 Effect of the addition of regulators
on bread volume
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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 Soft Elastic
Regulator C Soft Elastic
Regulator B2 Very soft elastic
Desirable for white pan bread
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RESULTS III

• Falling Number

Figure 2 Effect of the addition of regulators
on Falling Number
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RESULTS IV

• P/ L Ratio

Figure 4 Effect of the addition of regulators
on P / L ratio
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Results V
Table 4 Summary of results
Rheological Tests Rheological Tests Rheological Tests Rheological Tests Chemical Bake Tests Bake Tests
Rheological Tests Rheological Tests Rheological Tests Rheological Tests Chemical Bake Tests Bake Tests
Tmt P L P/L FN Bread volume Texture
BLK 106 mm 71mm within range (1.3-1.5) 491 1710 cm3 Firm
Reg A ?(-) ?(-) above range outside optimum (469) ?( ) desirable
Reg B1 ??( ) ??( ) within range outside optimum (339) ??( ) desirable
Reg B ???( ) ???( ) below range Optimum (269) ???( ) not desirable
Reg C ??( ) ??( ) within range outside optimum (311) ???( ) desirable
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DISCUSSION I

• Bread Volume

Increase
ascorbic acid , L-Cysteine enzymes
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DISCUSSION II

• Action of ascorbic acid on gluten

Plate 1 Action of ascorbic acid on gluten
(Lesaffre,2001)
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DISCUSSION III

• Action of L-cysteine on gluten strands

(Lesaffre,2001)
Plate 2 - Action of L-Cysteine on gluten strands
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DISCUSSION IV
Plate 3 effect of hemicellulases on pentosans

(Lesaffre,2001)
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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 a- amylase activity, indicated
  by a low falling number (usually lt 200) will
  result in a sticky bread crumb.
• a low a- amylase activity, indicated by a high
  falling number (usually gt 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 Indication
lt 200 High a - amylase activity. Sprouted damaged wheat. Bread crumb firm and sticky
200-300 Optimum a - amylase activity. Bread crumb likely to be good
Above 300 Low a -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 a-amylase
• High bread volume Reg B C
• malted wheat flour
• Lopper (1998)- malted wheat flour consists of a
  and ß 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
Plate 3 Action of enzymes on starch
(Lesaffre,2001)
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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