Optimization of enzymolysis technology for preparation of antioxidant peptides from dandelion seeds- derived proteins by response surface methodology

The aim of this study was to optimize the hydrolysis technology of preparation of antioxidant peptides from dandelion seeds protein using response surface methodology( RSM). The protein extracted from dandelion seeds was hydrolyzed by alcalase and antioxidant activity of the hydrolysates was evaluated by DPPH radical scavenging activity. Effects of p H,substrate concentration,enzyme / substrate ratio and temperature on DPPH scavenging activity of hydrolysates were evaluated. Based on the results of the single factor experiments,a procedure optimized using the response surface analysis with three factors( p H,enzyme / substrate ratio and hydrolysis time) was conducted in order to obtain the optimal enzymolysis condition. The quadratic term model of the enzymatic preparation technology was established and the reliability was verified.The interaction effects of p H,enzyme / substrate ratio and time were investigated,and the optimal hydrolysis condition was obtained and checked out experimentally.The results indicated that the effect order of the three factors on antioxidant activity of protein hydrolysates was p H > enzyme / substrate ratio > hydrolysis time,and the optimal enzymolysis conditions were time of 4.90 h,p H8.5 and enzyme / substrate ratio of 7.80%. Under the optimal enzymolysis conditions,DPPH radical scavenging rate of the hydrolysates was 79.13%,which indicated that the protein hydrolysates possessed strong antioxidant activity.