Production and study on antioxidant activity of protein hydrolysate from whey protein

In this study, protein hydrolysate was prepared from whey protein concentrate with Alcalase 2.4 L. The effects of temperature (40, 45, 50 and 55 °C), time (30, 60, 90, 120, 150, 180 and 210 min) and enzyme/substrate ratio (30, 60 and 90 Anson unit), on antioxidant activity of the product were investigated in a completely randomized design. The antioxidant activity of protein hydrolysate was studied using reducing power and Fe2+ chelating activity. The highest Fe2+ chelating activity (87.2%) was observed in temperature 50 ºC, enzyme activity of 60 Au/kg and hydrolysis time of 90 min. The highest reducing power (0.435) of protein hydrolysate was observed in temperature of 40ºC, enzyme activity of 90 Au/kg and hydrolysis time of 210 min which showed 57.08% reducing power compared to 100 ppm ascorbic acid. The results indicate that the antioxidant peptides can be used as a natural antioxidant in food formulations, as well as a pharmaceutical composition.