Study on Preparation Process and Antioxidant Activity of Polypetide Prepared by Enzymes from Peony Seed Meal

In order to explore the possibility of peony seed meal peptides as antioxidant functional food components, this study optimized the preparation process of peony seed meal antioxidant peptides with peony seed meal protein as raw materials. Firstly, the hydrolysis degree (DH) and the free radical scavenging rate of 1,1-diphenyl-2-nitrophenylhydrazine (DPPH) were used as indexes, and the effects of hydrolysis temperature, time, enzyme concentration, pH and substrate concentration on the degree of proteolysis and antioxidant activity of peony seed meal were determined by single factor test. On this basis, L 9 (3 4 ) orthogonal test with four factors and three levels was used to optimize the optimal preparation process of antioxidant peptides. The results were as follows: enzymatic hydrolysis time 2 h, pH 9.5, enzymatic hydrolysis temperature 60˚C, substrate concentration 10%, enzyme concentration 1.3%. Then, the peony seed meal polypeptide was simulated for digestion in vitro to explore the effect of digestion on its antioxidant activity. It was found that the scavenging capacity of 2,2'-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium (ABTS + ) was not significantly different, the scavenging rate of superoxide anion ( 2 O − ) radical and reducing power were increased by 13.40 and 14.79%, respectively, indicating that the antioxidant functional peptide of peony seed meal could not be damaged by gastrointestinal digestion. This study provides theoretical support for the application of peony seed meal peptides in food system.