الفهرس 
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Abstract
Protein-fiber fortification of food is of current interest because of
government guidelines and policies across the globe to combat protein
energy malnutrition. In the developing countries, the problem of protein
calorie malnutrition is a wide spread serious problem. Various attempts
have been made by many researchers to enrich the diet of the people with
new food formulation using several protein-fiber sources. Protein is the
key ingredients in many food products which contributes the nutritional
value, flavor and other important functional properties to food system.
Therefore, the objectives of the present study were to investigate the
utilization of wheat germ protein products or rice bran protein products as
sources of protein-fiber at different levels of supplementation for the
preparation of biscuits, because of its acceptability in all age group,
longer shelf life, better taste and its position as snacks, it is consider as a
good product for protein fortification. The results are summarized as
follows:
5.1. Proximate composition
The proximate analysis of wheat flour (WF) and wheat germ
protein products showed that WF contained less protein (14.05%) in
comparison with wheat germ protein products, protein content ranged
between 31.85 for WGM and 73.95% for WGPC, with significant
difference (p<0.05) could be noticed.
While, the crude fiber content of WGPC was 4.65%, the DWG and WGM
contained 2.65 and 2.35%, respectively, meanwhile, the crud fiber content
of WF was 0.90%, with no significant differences (p<0.05) could be
found between WGM and DWG samples.
It could be noticed that, wheat germ protein products and rice bran
protein products were differ greatly in their protein and fiber content
which ranged between 31.85 to 73.95 and 2.35 to 4.65%for wheat germ
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SUMMARY AND CONCLUSION
Mohamed A. Aboelmakarem(2017), M.Sc. Thesis, Fac. Agric., Ain Shams Univ.
protein products and from 15.4 to 21.20 and 1.65 to 2.50% for rice bran
protein products, respectively.
5.2. Amino acid composition and protein quality
Essential amino acids (EAA) ranged from 47.2 to 49.8% from the
total amino acids in wheat flour samples supplemented with 10, 20 and
30% DRB or RBPC. Wheat flour (WF) supplemented with the above
mentioned levels of DRB contained relatively the highest concentrations
of EAA being 48.0, 48.9 and 49.8% in comparison with 47.2 in WF
included histidine, methionine, cysteine, phenylalanine and lysine, being
relatively higher than in WF. Similar observations were noticed for EAA
of wheat flour supplemented with 10, 20 and 30% RBPC, which
contained slightly the highest concentration of EAA 47.9, 48.7 and
49.5%, included with histidine, valine, methionine, phenylalanine, lysine
and theronine, being similarity or relatively higher than WF or added
DRB to WF.
The calculated protein efficiency ratio (C-PER) cleared that wheat
flour supplemented with 10, 20 and 30% DRB or RBPC had relatively
higher C-PER with values ranged between 1.32 to 1.51 in comparison to
1.25 for WF.
The essential amino acid index (EAAI) for WF and WF
supplemented with DRB or RBPC at different levels were high and varied
between 85.80 for WF-RBPC (10%) to 88.90 for WF-DRB (30%) in
comparison to 84.53 for WF. Higher biological value (B.V) irrespective
DRB when added to WF at 10, 20 and 30% for instance, the B.V reached
84.4 in WF-RBPC to 85.2 for WF-DRB at 30%, respectively.
The chemical score (CS) for the WF- supplemented with 10, 20
and 30% DRB or RBPC were 71.5, 75.6, 79.7 and 83.8, respectively, with
lower value for WF. with the first limiting amino acid, lysine in all
samples under research.
90
SUMMARY AND CONCLUSION
Mohamed A. Aboelmakarem(2017), M.Sc. Thesis, Fac. Agric., Ain Shams Univ.
5.3. Functional properties
5.3.1 Emulsification activity (EA) and emulsion stability (ES)
Three-dimension response surface cubic plot between emulsion
holding time and concentration as independent variables and the emulsion
activity index as dependent variable was established. The emulsions
prepared using the WGM had significantly (P<0.05) a high activity
indices compared to the other prepared emulsion. Increased the protein
concentration in the WGPC lead to decrease the emulsifying activity and
emulsion stability compared to other wheat germ fractions. At the same
time the emulsion that prepared by WGM was more stable compared to
other prepared emulsions.
Multiple regression coefficients of different predict cubic equation
established the obtained predicted models which recommended for
identify the optimum conditions which required to produce the strongest
stable emulsion. It was, 11.8, 14.7, 8.8 and 4.6 m2/g protein at
concentrations 1.2 %, 1.0, 1.0 and 2.0 % of WGM, DWG and WGPC,
respectively.
Also, emulsification activity and stability of wheat flour, RBM,
DRB and RBPC were studied using Three-dimension response surface
method. There was a significant (P<0.05) relationship between the
holding time and the emulsion stability in all cases. At the same time
DRB significantly (P<0.05) had the highest emulsification activity index
compared to the other tested samples.
the obtained predicted models are recommended for identify the
optimum conditions which required to produce the strongest stable
emulsion. It was, 11.8, 15.9, 22.7 and 7.4 m2/g protein at concentrations
1.2 %, 1.0, 2.0 and 1.75 % of wheat flour, RBM, DRBM and RBPC,
respectively.
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SUMMARY AND CONCLUSION
Mohamed A. Aboelmakarem(2017), M.Sc. Thesis, Fac. Agric., Ain Shams Univ.
5.3.2. Water and oil binding capacities
Data showed that WG protein products had WBC ranging from 3.6
to 4.6 g/g sample or 6.4 to 12.2g/g protein, compared to 3.2 g/g of WF
sample or 25.6 g/g protein. Significant differences (P>0.05) in WBC of
WF and WG protein products was obtained. No significant observations
in OBC and WOBI of WF and WG protein products g/g samples was
noticed.
Non-significant differences (P>0.05) were observed between the
mean values of wheat flour, RBM and DRB. RBPC had significantly the
lowest water binding capacity value. The wheat flour appeared
significantly (P<0.05) the highest oil binding capacity. RBM, DRB and
RBPC came in the second order. In conclusion, rice bran protein products
exhibited higher water-oil binding capacity in comparison with wheat
germ protein products.
5.3.3. Foaming capacity (FC) and stability (FS)
DWG exhibited higher FC descendingly at 2, 1.5, 1.0%, followed
by WF and WGM, but the poorest FC was noticed by the WGPC. DWG
exhibited higher FS till 50min descendingly at concentrations 2.0, 1.5and
1.0%.
It was cleared that the wheat flour had the highest foam volume
compared to all the rice bran protein products. Also, the foaming capacity
of WF increased with increased its concentration. The foaming ability in
all rice bran products was low in the following order DRB > RBM >
RBPC
5.4. Physical characteristics of biscuit samples
5.4.1. Farinograph parameters
The water absorption (WA) increased when DWG was added at
10 to 30%, it ranged between 56.5% for control sample to 63.1% for
sample containing 30% DWG. On the other side, WA decreased to 54.6%
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SUMMARY AND CONCLUSION
Mohamed A. Aboelmakarem(2017), M.Sc. Thesis, Fac. Agric., Ain Shams Univ.
when WGPC at 30% was added. No differences were observed in arrival
time between doughs with DWG or WGPC at different level of
supplementation. Control dough and dough containing 10% WGPC had
peak time (development time) 2.0 min. However, development time did
not vary for doughs incorporated with 10, 20 and 20% DWG or WGPC,
respectively, which being 2.5 min. On the other hand, dough with 30%
DWG or WGPC recorded a higher peak time, which was 6.5 or 9.5 min,
respectively.
It was noticed that the use of 10, 20 and 30% DWG or WGPC
decreased the dough stability, which varied between 8.0 to 8.5 min for
dough containing DWG or ranged between 2.0 to 10.5 min for dough
containing WGPC, respectively, compared with control dough (13.5 min).
Degree of softening data in (B.U) showed slight weakening of the
dough with increasing the level of DWG, except the dough containing
30% DWG. Whereas, the extent of weakening was relatively higher in the
case of WGPC, especially at 30% level of supplementation which was
100 B.U.
The DRB had a relatively lower water absorption (WA) which
was 55.5, 54.0 and 53.2%, at 10, 20, 30% respectively in comparison with
WF, 56.5%. Similar finding is recorded for RBPC which recorded 54.6,
54.0 and 53.3% at 10, 20, 30%, respectively. No differences were
observed in arrival time and peak time between dough with DRB or
RBPC at the different levels of supplementation which being 1.5 min and
2.0 min, respectively, except WF-RBPC, WF-DRB at 10% and WFRBPC
at 30% level of supplementation which recorded slightly higher 2.0
min and 2.5 min, respectively, than other samples.
It was observed that dough stability decreased with increasing
levels of DRB to 30 min.
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SUMMARY AND CONCLUSION
Mohamed A. Aboelmakarem(2017), M.Sc. Thesis, Fac. Agric., Ain Shams Univ.
5.4.2. Extensograph parameters
The extensibility and extensibility at maximum elasticity in mm
decreased with the increase in the levels of DWG or WGPC up to 30%
which being 150, 110 and 80 mm; 105, 45 and 50 mm, respectively.
Maximum resistance to extension and relative resistance of extension in
B.U. of blends decreased sharply from 540 to 220 and 280 B.U. when
supplemented with 10 and 20% DWG, respectively..
Extensibility in (mm), maximum resistance to extension in (B.U.)
and energy cm2 gradually decreased with increment level of
supplementation with DRB or RBPC.
5.5. Proximate analysis of biscuit samples
Moisture content of biscuit samples ranged from 2.75 for biscuit
containing 30% WGPC to 5.10% for samples incorporated with 30%
DWG.
Similar trends were obtained for protein content of biscuit
samples. Biscuit samples incorporated with 30% WGPC or DWG
recorded the highest protein content being 20.80 and 19.25%, followed by
samples containing 20% WGPC or DWG which contained 17.3 or
15.05% protein, respectively, meanwhile, the lowest protein content was
noticed for control biscuit samples, being 8.90%.
Data cleared that, no significant differences (P<0.05) in total lipid
and crude fiber of all biscuit samples. The use of DWG or WGPC
enhanced the nutritional characteristics of prepared biscuits.
Significant differences (P<0.05) in protein content of biscuit
samples containing 20, 30% or 10 and 20% DRB or RBPC, respectively
and other biscuit samples containing 100% WF, 10% DRB and 30%
RBPC.
95
SUMMARY AND CONCLUSION
Mohamed A. Aboelmakarem(2017), M.Sc. Thesis, Fac. Agric., Ain Shams Univ.
Generally, biscuit samples containing DRB or RBPC can be
considered the most suitable by-product for food utilization which
characterized by high nutritional value.
5.6. Physical characteristics of biscuit samples
Data showed that significant differences in weight of biscuit was
noticed between samples containing 20 and 30% DWG or WGPC and
biscuit containing 100% WF.
Significant differences (P<0.05) in height (mm) of biscuit samples
containing 10 and 20% DWG and those containing WGPC at all levels of
supplementation. Similar observation could be noticed for diameter (mm)
and spread ratio of biscuit samples containing 100% WF, 10, 20 and 30%
DWG and biscuit samples containing 10, 20 and 30% WGPC.
No significant observation (P<0.05) in weight (g)of biscuit samples
containing 10, 20 and 30% DRB or RBPC could be recorded between all
samples under research, with average varied from 6.6 to 7.10g.
The spread ratio (D/H) of biscuit samples prepared by using 100
WF (control) and supplemented with 10, 20 and 30% DRB or RBPC,
increased from 8.66 for control samples to 9.93 for biscuit samples
incorporated with 30% RBPC.
5.7. Texture profile
No significant variation (P<0.05) in maximum force (N) was be
noticed between biscuit samples prepared by using 10, 20, 30 or 10 and
20% of DWG or WGPC, respectively.
The energy to break (J) and energy to peak (J) of biscuit samples
indicated that no significant differences (P<0.05) between all the samples.
No significant differences (P<0.05) in maximum force (N)
between biscuit samples containing 10, 30; 10 and 20% DRB or RBPC,
respectively, also, no significant differences (P<0.05) in energy to break
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SUMMARY AND CONCLUSION
Mohamed A. Aboelmakarem(2017), M.Sc. Thesis, Fac. Agric., Ain Shams Univ.
(J) between samples containing 10, 30 or 10 and 20% DRB or RBPC, as
well as 100% WF.
5.8. Sensory evaluation of biscuit samples
Significant differences were observed (P<0.05) in appearance and
overall acceptability of biscuit samples containing 10% DWG and those
containing 100% WF, 30% DWG and 30% WGPC.
The mean values of sensory scores for color, odor, taste,
crispiness, appearance and overall acceptability of biscuit samples
significantly (P<0.05) increased, in all sensory characteristics of biscuit
samples prepared with 100% WF and other samples containing DRB or
RBPC at different levels of supplementation.
In conclusion, the results of this study indicate that, biscuit could
be produced by supplementation of wheat flour by DWG, WGPC, DRB
and RBPC up to 30% level with high protein-fiber contents