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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 91 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. 92 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% 93 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. 94 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 96 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 |