| In order to obtain the optimal preparation conditions of antioxidant peptide from defatted rice bran, the progress characteristics of enzymatic hydrolysis with Trypsin， Pepsin， Neutrase， Alcalase and Papain and the effect of enzymatic hydrolysis conditions on antioxidation activity of antioxidant peptide from defatted rice bran were investigated. The best protease was chosen from these proteases and the effects of substrate concentration, enzyme dosage, pH, temperature and time on the degree of hydrolysis and the scavenging rate on ABTS radical were studied by single factor experiment. Based on single factor experiment, response surface methodology was designed with the scavenging rate of hydrolysate on ABTS radical as indicator. The results showed that Alcalase was the optimal protease for preparation of antioxidant peptide from defatted rice bran and the optimal enzymatic hydrolysis conditions were obtained as follows: enzyme dosage 1.8%, temperature 50℃, time 276 min, pH 9.0, substrate concentration 5%. Under these conditions, the antioxidant peptide from defatted rice bran exhibited strong scavenging activity on ABTS radical and the scavenging rate reached up to 71.85%. |
