STUDIES ON SOME NEW PRODUCTS PREPARED FROM CEREALS AND VEGETABLES BLENDS BY EXTRUSION

Abstract

This study was carried out to use germinated chickpea and pea for 72 hr. as a source of protein and iron at levels of 10, 20 and 30% as well as tomato pomace powder as a source of antioxidant for preparing healthy snacks for anemic patients. These extrudates were evaluated chemically, nutritionally as well as their antioxidants activity and physical properties. Also, effect of storage for 3 months on their different properties as well as biological evaluation of iron bioavailability was studied. Results showed that germination of chickpea and pea caused a significant decrease in antinutrients while in-vitro protein digestibility and bioavailable iron improved. Significant differences were found in chemical constituents of raw materials, germinated chickpea and pea had higher contents of iron (9.40 and 8.73%). Tomato pomace powder recorded the highest antioxidant activity. Addition of germinated chickpea and pea in corn extrudates led to increase their protein, fat, fiber, ash, mineral and antioxidant activity while carbohydrates decreased. Extrusion process caused a significant decrease in moisture, protein, fat and mineral contents while carbohydrates increased. Fiber, ash, Fe and Zn contents were not affected. Also, phytic acid decreased by 38.79 – 46.51% and tannic acid by 37.86 – 43.61% while in-vitro protein digestibility improved by 6.37 - 12.30%. Extrusion process caused significant increases in total phenolic content and antioxidant activity of chickpea extrudates by 1.92 – 7.94% and 1.94 – 9.42% and pea extrudates by 2.43 – 13.56% and 9.42 – 30.87%. On contrary, total phenolic and antioxidant activity of chickpea and pea together extrudates reduced by 7.05 – 19.8% and 7.61 – 9.79%, respectively. Concerning physical properties, with increasing germinated chickpea or pea level in the extrudates, expansion ratio, porosity and water solubility index decreased while bulk density, apparent density and water absorption index increased in contrast with control. Organoleptic evaluation showed that germinated chickpea and pea flours can be added successfully in corn snacks up to 20% with slight changes that not affected in acceptability of the extrudates. The selected extrudates contained higher essential amino acid except lysine and sulphur amino acid. Storage of extrudates did not affect their physical, sensory and microbial properties while antioxidant activity affected. All rats groups fed the selected extrudates showed high values of anemia parameters as well as RBV of iron which were 86.01 % for blend 3, 79.11% for blend 1 and 75.62% for blend 2. Therefore, germinated chickpea and pea flours can be added up to 20% and tomato powder for preparing healthy corn snacks.