الفهرس 
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Abstract
SUMMARY
Bakery products such as bread, cake and biscuit are an
important staple food consumed all over the world; wheat (Triticum
aestivum) flour of both hard and soft wheat classes has been the major
ingredient of bread and other bakery products for many years. Therefore,
the aim of the current study was to produce some bakery products using
sorghum or chickpea flour to produce good products. Sorghum or
chickpea flour was used as a replacement for wheat flour by 5, 10, 15 and
20% levels and studies their effect on chemical composition, rheological
and baking properties, as well as, the acceptability of the produced bread,
cake and biscuit. The obtained results could be summarized in the
following points:
1- Proximate chemical composition:
- The proximate chemical composition of both wheat flours (72%
extraction), sorghum and chickpea flour (100% extraction) used in current
study were determined. Strong or weak wheat flours (72% ext.) contained
moisture 12.83 and 13.25 %; crude protein 13.04 and 9.58% ; crude lipid
0.81 and 0.72%; crude fiber 0.78 and 0.73 ; ash 0.55 and 0.48 % and NFE
84.82 and 88.49 %, respectively. On the other hand, whole sorghum and
chickpea flour contained moisture 11.21 and 9.33%; crude protein 9.75
and 23.26%; crude lipid 3.00 and 6.20%; crude fiber 1.97 and 2.45%; ash
1.34 and 1.91% and NFE 83.94 and 66.18%, respectively.
- Chemical composition of wheat flour blends with different levels of
whole sorghum or chickpea flour used in current study were determined.
The results revealed that, lipid, crude fiber and ash contents was increased
gradually with increasing the replacement level of wheat flour with
sorghum flour, while crude protein gradually decreased. On the other
hand, it could be noticed that crude protein, lipids, crude fiber and ash of
wheat flour was gradually increased as the level of substitution with
chickpea flour increased, while NFE gradually decreased.
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SUMMARY AND CONCLUSION
Ahmed M. Abouelazm, M.Sc., 2015
2- Rheological properties of the produced dough:
Farinograph parameter:
- Water absorption of strong wheat flour was gradually decreased with
increasing the level substitution of wheat flour by sorghum flour which
decreased to 59.1 and 57.0% for wheat flour dough’s replaced with 5 and
20% of sorghum flour, respectively in compared to 59.7% for the control
wheat flour dough. But, the replacement of wheat flour by chickpea flour,
water absorption was increased gradually with increasing the level
substitution of wheat flour by chickpea flour.
- The arrival time was not affected with the increasing of replacement of
sorghum flour in compared to the control sample (100% wheat flour),
while, when chickpea flour was added it could be observed that the arrival
time was decreased about 33.0% for all substitution levels of chickpea
flour.
- The stability time of wheat flour dough was gradually decreased with
increasing the level of substitution with sorghum or chickpea flour. On
the contrary, both of mixing tolerance index and dough weakening were
increased.
- Generally, replacement of strong wheat flour (72% ext.) with chickpea
flour was more successful rather than using sorghum flour.
- Water absorption was increasing gradually with increasing the level of
substitution of weak wheat flour (72% ext.) by sorghum or chickpea flour.
On the contrary, both of dough stability and dough weakening were
decreased.
Extensograph parameter:
- Concerning extensograph test the results indicated that replacement of
strong wheat flour (72% extraction) by 15% chickpea flour was the only
level which improved the extensibility of the resulted dough. The same
ratio of chickpea flour replacement (15%) increased the extensibility at
maximum elasticity. On the other hand, all of the applied sorghum flour
replacement ratios didn’t improve the dough extensibility. This parameter
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SUMMARY AND CONCLUSION
Ahmed M. Abouelazm, M.Sc., 2015
was reduced to be less than the control sample (100% wheat flour 72%
extraction).
- It is interest to record that both of sorghum or chickpea flour didn’t
improve the dough elasticity. The dough elasticity reduced from 26.15 to
44.62 or from 23.8 to 40% for wheat flour replacement with different
concentration of sorghum or chickpea flour, respectively compared with
control sample. The higher proportional number was calculated when 5%
of both sorghum and chickpea flours used.
- Dough elasticity (resistance to extension) and proportional number
values were gradually decreased as a result to replacement of weak wheat
flour by 10 and 15% sorghum or chickpea flour. Concerning to the
energy, all treatments were lower in comparison to control, except the
blend contained 10% chickpea flour had higher energy value than that
found in control dough.
- Generally, it could be seen that the deleterious effect of adding sorghum
flour to wheat flour on the rheological properties was more pronounced
than that happened when chickpea flour was added.
3- Wet gluten, Dry gluten, gluten index and sedimentation test:
- The wet gluten content of strong wheat flour was found to be 31.2%, the
incorporation with 5, 10, 15 and 20% sorghum or chickpea flour resulted
in decreasing the amount of wet gluten gradually to (30.82 or
28.84),(30.46 or 27.91),(29.33 or 26.97) and (27.54 or 26.00),
respectively. It was noticed that dry gluten decreased in increasing the
amount of sorghum or chickpea flour. Furthermore, the gluten index
decreased as the percentage of sorghum or chickpea flour increased. The
lowest gluten index 91.54% was obtained from 20% sorghum flour: 80%
wheat flour as compared with 97.88% for the control. For the gluten
absorption ratio, the obtained results recorded that, the gluten absorption
ratio for wheat flour replacement with 5% sorghum flour gave the lowest
results, while the incorporation at 15% chickpea flour gave the highest
one.
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SUMMARY AND CONCLUSION
Ahmed M. Abouelazm, M.Sc., 2015
- Sedimentation test values for strong wheat flour replacement by
different concentration of sorghum or chickpea flour caused gradually
decreased at level of replacement increased. The sedimentation values for
wheat flour gave the highest result, while the incorporation at 20%
sorghum flour gave the lowest one.
4- Falling number:
- Wheat flour falling number had the highest value (332), while chickpea
flour gave the lowest one (260). The addition of sorghum or chickpea
flour at different levels to strong wheat flour decreased the falling number
gradually. On the other side, liquefaction number was gradually increased
as the level of substitution with sorghum or chickpea flour increased
which reached to (21.90, 22.14, 22.73 and 22.73) or (22.64, 23.35, 23.35
and 24.39) for wheat flour dough’s replaced with 5, 10, 15 and 20% of
sorghum or chickpea flour, respectively in compared to 21.27 for the
control wheat sample.
5- Chemical composition of bread samples:
- The results revealed that, crude protein, lipid, ash and crude fiber
contents of prepared bread had gradually increased with increasing the
replacement level with chickpea flour in comparison to prepared
contained 100% wheat flour (control). On the other hand, crude protein
content of bread had gradually decreased, while lipid, ash and crude fiber
contents of bread had gradually increased with increasing the replacement
level with sorghum flour.
6- Physical measurements of bread:
- The weight of pan bread was increased as substitution level with 10%
chickpea flour, but the weight of bread was decreased a substitution level
with 10% sorghum flour. On the other hand, replacement of wheat flour
with 10 and 15% sorghum or chickpea flour caused gradually decreased
in bread volume by increasing levels of substitution in compared to
control sample.
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SUMMARY AND CONCLUSION
Ahmed M. Abouelazm, M.Sc., 2015
- Specific volume of all bread loaves replacement with sorghum or
chickpea flour was reduced compared to control. The largest specific
volume index was remote by the control sample followed by bread
produced from wheat flour blends with 5% sorghum or chickpea flour,
meanwhile, bread prepared by replacement with 15% sorghum flour
recorded the lowest specific volume index.
7- Oranoleptic properties:
- When sorghum and chickpea flour were used as replacement media to
process pan bread, taste and aroma showed a real significant differences
than the other sensory parameters; on the other hand, there were no
significant differences between control sample and pan bread samples
which substituted with 10% sorghum flour for aroma.
- The sensory properties of external characteristics (bloom / crust color or
summitry of form), the results indicated that there were no significant
differences between control bread samples and bread samples contained
10% levels of substitution with sorghum or chickpea flour.
- Generally it could be concluded that, the pan bread produced by
substitution with 10% sorghum or chickpea flour gave bread loves more
sensory acceptable rather than the bread produced by added 15% sorghum
or chickpea flour.
8- Staling of pan bread :
- There was a gradual decrease in AWRC% value for all different bread
samples during storage period.
- The partial replacement of wheat flour by sorghum or chickpea flour is
not improving the rate of bread staling in comprising to control sample.
The freshness of pan bread decreased from 100% for control sample after
baking (zero time) to 90% freshness after storage 24 hours for all
treatments. On the other hand, the freshness of pan bread decreased to
75% for bread produced by added both sorghum or chickpea flour with
15% to wheat flour after storage 72 hours.
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SUMMARY AND CONCLUSION
Ahmed M. Abouelazm, M.Sc., 2015
9- Chemical composition of cake samples:
- from the results, it could be observed that, protein content from
different cake samples was increased as the percentage of sorghum or
chickpea flour increased. On the other hand; lipids, ash and crude fiber
contents of cake samples were increased as increasing the replacement
level of wheat flour by sorghum or chickpea flour.
10- Physical measurements of cake samples:
- The weight of sponge cake produced from the flour samples under
research weak flour (72% ext.) was slightly decreased as a percentage
replacement of wheat flour by sorghum or chickpea flour increased.
While the volume and specific volume of prepared cake samples was
increased by increasing the replacement of wheat flour with 10%
chickpea flours. Also from the data, it could be concluded that, the
sorghum and chickpea flour successfully replace wheat flour with 10%
sorghum flour or 10% and 15% chickpea flours to produce cake without
any unfavorable change, for physical characteristics of cake especially for
the cake produced by added 1% cake improver.
11- Sensory evaluation of cake:
- No significant differences in color, flavor and texture could be observed
between the control cake samples and cake prepared by substituted with
10% sorghum or chickpea flour, for cake produced with or without cake
improver. Concerning the taste and overall acceptability were no
significant differences between the control cake samples and cake
prepared by substituted with 10% chickpea flour, for cake produced
without cake improver. On the other hand, the taste and overall
acceptability were no significant differences between the control cake
samples and cake produced from wheat flour replacement with 10%
sorghum flour or 10 and 15% chickpea flours, for cake produced by
added 1% cake improver.
- Generally, it could be concluded that, chickpea flour successfully
replace wheat flour with 10 or 15% in produced sponge cake without any
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SUMMARY AND CONCLUSION
Ahmed M. Abouelazm, M.Sc., 2015
unfavorable change especially for the cake produced by added cake
improver.
12-Chemical composition of biscuit samples:
- The results revealed that, crude protein, fat, ash and crude fiber contents
of prepared biscuit had gradually increased with increasing the
replacement level with sorghum or chickpea flour in comparison to
prepared biscuit contained 100% wheat flour (control).
13-Physical measurements of biscuit:
- The weight of the biscuit samples was gradually increased as
substitution level by sorghum or chickpea flour increased, but gradually
decreased in both of biscuit volume, specific volume and thickness were
noticed for biscuit samples which prepared by substitution of wheat flour
with sorghum or chickpea flour compared to control sample. Also, from
the results it could be noticed that there were no significant differences
between the thickness and spread ratios of 100% wheat flour biscuit
(control) compared to that of sorghum or chickpea – wheat composite
flour biscuit.
14-Sensory evaluation of biscuit :
- The control sample and biscuit containing 10 and 15% chickpea flour
had maximum total score, whereas biscuit containing 15% sorghum flour
were found to be unacceptable to the panelists. Generally it could be
concluded that replacement of wheat flour with chickpea flour gave
biscuit more sensory acceptable rather than those of sorghum flour.