Ascorbic Acid Contents and In-Vitro Antioxidant Activities of Newly Developed Isolated Soya Protein

Soy protein ingredients have been accredited a number of beneficial effects on preventing obesity, lowering blood cholesterol levels, have evidence for a beneficial role in preventing diseases (cancer, osteoporosis, menopausal disorders and cardiovascular diseases) The aim of the study was to evaluate the quantity of various phenolic compounds, ascorbic acid and in-vitro antioxidant activities of developed isolated soy protein (ISP). In vitro antioxidant models like the total antioxidant capacity, 2, 2diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and reducing power are studied by using UV-VIS spectrophotometer (analytikjena,specord-205). The contents of Phenolics, flavonoids, proanthocyanidins and ascorbic acid are 170±4.68 mg tannic acid equivalent, 135.75±3.98 mg catechin equivalent, 86.06±3.96 mg catechin equivalent and 12.28±2.54 mg in 100 gm ISP respectively. The total antioxidant capacity is 243.02±5.26 mg ascorbic acid equivalent and IC 50 value of ISP in DPPH assay is 35.40 mg/ml whereas IC 50 of standard ascorbic acid in DPPH assay is 3.37 μg/ml. IC 50 value of ISP and ascorbic acid in reducing power assay are 35.40 mg/ml and 31.12 micro gm/ml respectively. The results suggested that besides protein content, the phenolic, flavonoids, proanthocyanidins and ascorbic acid contents should be also considered as an important characteristic features of ISP, and as a potential selection criterion for antioxidant activity in ISP.