Peptide extracted from quinoa by pepsin and alcalase enzymes hydrolysis: Evaluation of the antioxidant activity

摘要

Defatted quinoa flour, as the extracted protein, was hydrolyzed with pepsin and alcalase enzymes. Twelve pretreatments (T_(1–12)) were prepared with different temperatures, periods of time, and the ratio of enzyme to substrate to determine the optimum hydrolysis condition and evaluate their ability to inhibit ABTS free radicals. The increase in temperature, enzyme activity levels, and time caused a significant increase in the degree of hydrolysis (DH) while T_(12) with enzyme ratio 90 AU/kg and temperature of 55°C for 210 min displayed the highest DH. The highest ability to neutralize ABTS radicals (21.35% and 21.67%) were assigned to T_7 (enzyme/substrate ratio 60, the temperature of 50°C) and T_(11) (enzyme/substrate ratio 90, the temperature of 50°C) for 150 min, respectively. The quinoa proteins as a potential source of antioxidant peptides could be applied as a useful food ingredient in the food industry.