الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Snack foods have become an important part of the diet for the world’s population, especially children for being cheap and ready to eat products. Extrusion process has a great importance for improving digestibility by denaturing protein, gelatinizing starch and deactivating undesirable compound such as antinutrients, but these corn snacks do not satisfy the nutritional needs of health consumers especially protein and iron. With prevalence anemia among Egyptian children where FAO (2008) reported that anemic Egyptian children were 2,707,000 children among 9 million and the high price of animal iron sources, it must be search for other natural source of iron with low cost. Therefore, the aims of this study were:
1- Study the effect of germination at room temperature for 72 hr. on antinutrients, in-vitro protein digestibility and iron bioavailability of chickpea and pea seeds.
2- Determination of the chemical composition, antinutrients, mineral content and antioxidant activity of corn flour, germinated and dehulled chickpea, germinated and dehulled pea, tomato pomace powder and skimmed milk powder.
3- Using germinated and dehulled chickpea and pea flours as a source of protein and iron at levels of 10, 20 and 30% as well as 5% tomato pomace powder as a by-product rich in antioxidants and 5% skimmed milk powder as a source of animal protein for preparing healthy corn snacks.
4- Evaluation these extrudates chemically, nutritionally as well as their physical, functional and sensory properties.
5- Study the effect of storage at room temperature for 3 months on physical, functional, microbial and sensory properties as well as their antioxidant activity.
6- Study the effect of feeding rats with these selected extrudates on anemia parameters (Hemoglobin, Hematocrit, Red blood cells, MCV, MCH, MCHC) as well as bioavailability of iron for these extrudates.
Results can be summarized in the following points:
First: Effect of germination for 72 hr. on antinutrients, in-vitro protein digestibility and iron bioavailability of chickpea and pea seeds.
1- Germination of chickpea and pea seeds for 72 hr. caused a dramatic reduction in phytic and tannic acid contents. Reductions in phytic acid were 69.40 and 63.72 % and in tannic acid were 54.02 and 53.12 % for chickpea and pea seeds, respectively. In-vitro protein digestibility of chickpea and pea seeds was improved resulting of the germination by 19.96 and 18.06%, respectively.
2- Germination caused a significant (P≤ 0.05) increase in bioavailable iron of both of seeds by 81.75 and 70.27 %, respectively.
Second: Chemical composition of raw materials used for preparing the healthy snacks.
1- Results showed that there were significant differences in chemical constituents of raw materials. It was found that skimmed milk powder contained the highest protein (37.13%) and ash (7.10%) contents, while corn flour contained the lowest ones (9.40 and 0.79%, respectively). Also, corn flour contained the highest carbohydrates content (85.58%) while tomato powder had the lowest value (47.67%). On contrary, tomato powder had the
highest contents of fiber (20.41%) and fat (7.54 %) while skimmed milk powder contained the lowest fat (1.84%) content.
2- With respect to mineral contents of raw materials, skimmed milk powder was rich in sodium, calcium and potassium, while corn flour had the lowest contents of sodium, calcium, potassium and zinc. Tomato powder contained the highest potassium content. Germinated chickpea and pea flours recorded the highest content of iron (9.40 and 8.73 mg ∕ 100g), while skimmed milk powder recorded the lowest content.
3- Concerning antinutrients of raw materials, no significant difference was found in phytic acid content between corn and germinated pea flours which contained the highest content (2.24 and 2.28 mg ∕ g, respectively) followed by germinated chickpea flour(1.72 mg ∕ g) then tomato powder (1.28 mg ∕g). Also, germinated pea contained higher content of tannic acid (1.84 mg ∕g) than germinated chickpea (1.21 mg ∕ g), while skimmed milk powder was free in both acids. There was a negative correlation (r= -0.73) between phytic acid and in-vitro proyein digestibility where skimmed milk powder recorded the highest in-vitro protein digestibility (98.34%), while corn flour recorded the lowest value (63.51%). Also, there was no significant difference between germinated chickpea, pea and tomato powder.
4- Regarding total phenolic content and antioxidant activity of raw material, there was a relationship between phenolic content and antioxidant activity. Tomato powder had the highest contents of total phenolic (41.62 mg GAE ∕ g sample) and antioxidant activity (80.39%), whilst skimmed milk powder recorded the lowest values (1.73 mg GAE ∕g sample and 20.53%, respectively).
Third: Chemical evaluation of the corn extrudates fortified with germinated chickpea and pea.
1. Chemical composition of the legumes – corn blends:
1.1. Concerning the chemical composition of the germinated chickpea – corn extrudates, blend 3 (30% germinated chickpea) recorded the highest contents of protein (15.15 and 14.81%), fat (4.81 and 4.27%), fiber (2.39 and 2.41%) and ash (3.13 and 3.31%). At the same time, this blend contained the lowest contents of carbohydrates (74.50 and 75.28%) and caloric value (401.97 and 398.85 Kcal) compared with blends 1, 2 and control.
1.2. With regard to germinated pea – corn extrudates, blend 6 (30%germinated pea) recorded the highest contents of protein (15.94 and 15.30%), fiber (2.36 and 2.41%) and ash (3.23 and 3.44%) while it contained the lowest contents of fat (3.37 and 2.88%), carbohydrates (75.08 and 75.95%) and caloric value (394.5 and 391 Kcal) compared with blends 4, 5 and control.
1.3. With respect to germinated chickpea and pea mixture – corn extrudates, blend 9 (15% germinated chickpea + 15% germinated pea) had the high contents of protein (15.51 and 14.89%), fat (4.14 and 3.53%), fiber (2.34 and 2.49%) and ash (3.14 and 3.31%) while it contained the lowest content of carbohydrates (74.86 and 75.76%) and caloric value (399.16 and 394.42 Kcal) compared with the other blends and control. Generally, extrusion process caused significant decreases in moisture, protein, fat contents and caloric value while it caused an increase in carbohydrates. Fiber and ash contents were not affected.
2. Antinutrients of the legumes – corn blends:
2.1. Concerning antinutrients contents of germinated chickpea - corn blends, extrusion process led to a significant decrease in phytic and tannic acid contents while in-vitro protein digestibility increased. Blend 3 recorded the highest decrease in phytic acid (46.51%) compared with control (40.604). Reduction in tannic acid ranged between 40.46% for blend 3 and 43.61% for blend 1. In-vitro protein digestibility was improved after extrusion by 9.53 – 6.37%.
2.2. With regard to germinated pea - corn blends, blend 5 had the highest decrease in phytic acid (45.40%) compared with control (40.604). Reduction in tannic acid ranged between 37.86 % for blend 6 and 42.48% for control. Extrusion process caused an increase in in-vitro protein digestibility by 12.30 – 7.28%.
2.3. With respect to germinated chickpea and pea blends, blend 8 recorded the highest decrease in phytic acid (41.64%) while blend 9 had the lowest decrease (38.79%). Reduction in tannic acid ranged between 38.40 % for blend 9 and 42.48% for control. Extrusion process led to increase in-vitro protein digestibility by 11.84–7.35%.
3.Total phenolic and antioxidant activity of the legumes – corn blends
3.1. Regarding total phenolic content and antioxidant activity of germinated extrudates. Total phenolic content and antioxidant activity increased with increasing germinated chickpea or pea level up to 30% as well as tomato powder. In germinated chickpea - corn blends, blend 3 had the highest contents of total phenolic (10.30 mg GAE/g sample) and antioxidant activity (55.26%) compared to control (7.17 mg GAE/g and 41.57%). Extrusion process caused a significant increase in
total phenolic content and antioxidant activity by 1.92 – 7.94% and 1.94 – 9.42%, respectively.
3.2. With respect to germinated pea - corn blends, blend 6 contained the highest contents of total phenolic (12.84 mg GAE/g sample) and antioxidant activity (58.03%) compared to control. Extrusion process caused a significant increase in total phenolic content and antioxidant activity by 2.43 - 13.56% and 9.42 - 30.87%, respectively.
3.3. With regard to germinated chickpea and pea - corn blends, blend 9 had the highest contents of total phenolic (13.39 mg ∕ GAE ∕ g sample) and antioxidant activity (65.04%) compared to control. These extrudates followed a different trend for effect of extrusion on total phenolic and antioxidant activity. Extrusion process caused a decrease in total phenolic content and antioxidant activity of these extrudates by 7.05 - 19.80% and 7.61 – 9.79%, respectively.
Fourth: Physical and function properties of the extrudates.
1. Addition of germinated chickpea or pea alone or together as well as tomato powder and skimmed milk powder in corn snacks led to a significant reduction in expansion ratio (ER), porosity (PO) and water solubility index (WSI) while bulk density (BD), apparent density (AD) and water absorption index (WAI) increased. Blend 3 recorded the lowest values of ER, PO and WSI (2.57, 0.59 and 10.90%, respectively) and the highest values of BD, AD and WAI (0.23 g∕ cm3, 0.57 g ∕cm3 and 5.05 g gel ∕g sample) compared with control which contained the highest values of ER (3.22), PO (0.74) and WSI
(15.60%) and the lowest values of BD (0.08 g cm3), AD (0.30 g cm3) and WAI (4.31 g gel ∕g sample).
2.Regarding the physical properties of germinated pea - corn extrudates, Blend 6 recorded the lowest values of ER, PO and WSI (2.52, 0.61 and 10.54%, respectively) and the highest values of BD, AD and WAI (0.20 g cm3, 0.53 g cm3 and 5.01 g gel ∕g sample) compared with control.
3.With respect to the physical properties of germinated chickpea and pea - corn extrudates, blend 9 had the lowest values of ER (2.67), PO (0.60) and WSI (11.27%) and the highest values of BD (0.21 g/cm3), AD (0.53 g/cm3 ) and WAI (5.02 g gel/g sample) compared with control.
Fifth: Sensory evaluation of the extrudates prepared for anemic.
Results showed that it could be added germinated chickpea or pea alone or together up to 20% as well as tomato pomace and skimmed milk powder with slight changes in sensory properties while texture (crispness) improved compared with control. At level of 30% of added germinated legumes, color, taste and flavor values were affected and texture became hard. Therefore, blends 2, 5 and 8 were selected for storage and biological evaluation.
Sixth: Amino acids and chemical score of the selected extrudates.
Results showed that the selected extrudates contained higher percent of essential amino acids compared to the reported values by FAO and WHO (33 g/16 g protein). Blend 2 had the highest essential amino acid content (38.96 g/16g protein), followed by blend 1 (37.86 g/16g protein) then blend 3 (35.94 g/16g protein) except for lysine which was decreased by 30.17, 34.65 and 33.96% and sulphur amino acids by 22 ,
24.4 and 23.6% for the three selected extrudates, respectively. With regard to chemical score of the extrudates, results showed that lysine was the first limiting amino acid in all products where chemical scores were 69.84, 65.34 and 66.03% for the three extrudates, respectively.
Seventh: effect of storage on physical, sensory, microbial properties as well as antioxidant activity of the selected extrudates.
1.Total phenolic content and antioxidant activity of stored extrudates were affected during the storage period where they decreased by 30.12 – 36.46 and 11 – 18 % at the end of the storage, respectively.
2. Physical properties of the stored extrudates were not affected through storage period (3 months) except for bulk and apparent density of blend 1which increased at the end of storage by 10.52 and 9.43%, respectively.
3. Concerning effect of storage on functional properties of the extrudates, no significant difference in WAI was observed of blend 1 through storage period, while there were significant increases in WAI of blend 2 and 3 at the end of storage period by 26.3 and 28.1 %, respectively. There was no significant difference in WSI of blend 2 through storage period. WSI of blend 1 increased by 17.76 % while WSI of blend 3 decreased by 15.60% at the end of storage.
4. With respect to effect of storage on sensory properties, there were no significant effects on the sensory properties of blends through storage period except texture which was affected at the end of storage. In spite of this, these blends were organoleptically acceptable through storage period.
5. Microbiology evaluation showed that the stored extrudates contained less than 1000 cells of microorganisms per gram where these stored samples contained 4×102, 5×102 and 3×102, respectively at the end of the storage period. Also, these stored samples were free yeast and mold during storage period except blend 1 which contained 3 cells/gram at the end of the storage period.
Eighth: Biological effects of the extrudates on anemia parameters:
1. Results showed that all rats groups fed these extrudates prepared for anemic showed increases in anemia parameters through the repletion period (28 days). At the end of the repletion period, increase in hemoglobin values ranged from 49.4% for control to 71.02% for blend 1 (20% germinated chickpea). Increase percentages in RBC ranged between 9.77% for control and 26.2% for blend 2 while increase in hematocrit ranged between 26.6% for control and 41% for blend 1.
2. MCV, MCH and MCHC values increased at the end of the repletion period. Control group had the highest values of MCV and MCH (95 FL and 30.25 g/dl) while group fed blend 2 had the lowest values (81.75 FL and 25 g/dl, respectively). There was no significant difference in MCHC values between the blends and control groups
3..Concerning bioavailability of iron, blood volume, Hb-Fe pool, HRE and RBV values of all groups increased throughout the repletion period. At the end of the repletion period, group fed blend 3 contained the highest values of blood volume and Hb-Fe pool (7.08 % and 7.66 mg) while group fed blend 2 recorded the lowest values (6.28 % and 6.26 mg, respectively). HRE values ranged between 23.5 % for blend 2 and 31.11% for control. Also, the three blends showed higher biological values of iron, blend 3 has the highest value of RBV (86.01%) followed blend 1 (79.11%) then blend 2 (75.62%).
We have previously said, it was educed that these extrudates prepared from germinated chickpea and pea alone or together as a source of protein and iron as well as tomato powder rich with antioxidant activity satisfy with the nutritional needs especially, protein and iron. Also, these products are considered acceptable and safe throughout the storage period.
We concluded that using these extrudates for feeding children and research for other natural sources of iron and protein to combat this serious problem. Also, nutritive and safety consciousness should be pronounced among women in which reflects on our children health.
2. Mineral contents of the legumes – corn blends.
2.1. Regarding mineral contents of germinated chickpea - corn extrudates, blend 2 had the highest contents of sodium (353.52 and 324.87 mg ∕100g), calcium (96.45 and 113.20 mg∕100g) while blend 3 contained the highest contents of potassium (538.89 and 497.69 mg ∕100g), iron (11.02 and 10.75 mg ∕100g) and zinc (3.43 and 3.27 mg ∕100g) compared to the other blends and control which recorded the highest phosphorus content (539.25 and 447.18 mg/100g).
2.2. Concerning mineral contents of germinated pea - corn extrudates, blend 6 had the highest contents of sodium (428.80 and 417.84 mg/100g), calcium (149.43 and 113.86 mg/100g), potassium (619.66 and 579.62 mg/100g), iron (9.19 and 9.12 mg/100g) and zinc (4.03 and 3.94 mg/100g) compared to the other blends and control.
2.3. With respect to mineral contents of germinated chickpea and pea extrudates, blend 9 had the highest contents of sodium (417.88 and 396.70 mg/100g), calcium (120.61 and 85.86 mg/100g), potassium (638.68 and 577.62 mg/100g), iron (10.94 and 10.34 mg/100g) and zinc (3.61 and 3.56 mg/100g) compared to the other blends and control. In general, extrusion process caused a significant decrease in mineral contents of extrudates except calcium in germinated chickpea extrudates while iron and zinc were not affected. Although, these blends had a sufficient amounts of minerals compared with the reported values.