Optimization of process for preparation of antioxidant peptides by enzymatic hydrolysis of protein prepared from peony seed meal

The protein prepared from peony seed meal was subjected to hydrolysis to prepare the antioxidant peptides in order to providing a theoretical basis for the deep processing of peony seed meal.Firstly,the type of proteases was screened then alcalase was selected to hydrolyse the protein isolated from peony seed meal by alkaline-solubilization and acid-precipitation method. Then hydrolysis degree and DPPH free radical scavenging capacity were used as the response values to investigate the effects of single-factors including substance concentrations, hydrolysis time, enzyme dosage, enzymolysis temperature and pH on the activity of prepared antioxidant peptides. The optimal parameters for the preparation of antioxidant peptides from peony seed meal protein through response surface analysis were obtained as follows:substance concentration 0.7%,hydrolysis time 2 h, enzyme dosage 4.60%, enzymolysis temperature 56℃ and pH8.0, with a DPPH radical scavenging ratio of 52.49% for the prepared antioxidant peptides from peony seed meal protein.The analysis of amino acid composition of 17 kinds of hydrolysis showed that the essential amino acids accounted for 32.24% of the total amount of amino acids hydrolyzed, and the peony peptides have a high nutritional value.