Study on the preparation of antioxidant activity peptide from walnut protein hydrolyzed by papain

The technique of papain hydrolyzed walnut residueto polypeptide of anti oxidative activity was studied.Box-Behnkentodesign response surface was used to optimize the experiment.Scavenging rate of hydroxyl radical and superoxide anion free radicals were the targetindexes.The best hydrolyzedconditions were:pH 6,temperature 50 C,hydrolysis time 3h,substrate concentration 3%.Under the above conditions,the scavenging rate of hydroxyl free radicals and superoxide anion free radicals were 32.7% and 24.6% respectively.The result showedthat the peptide from walnut protein by papain hydrolysis has certain antioxidant activity.Compared with VC,its reduction was 37.9% of VC.