Effects of different protease hydrolysis patterns on walnut protein peptide and its antioxidant activity

Single protease hydrolysis on walnut protein was conducted through using seven proteases,respectively,and the results were compared with double protease hydrolysis,the effects of different protease hydrolysis patterns on hydrolysis degree,peptide yield and antioxidant activity of hydrolysis products were explored.The re-sults show that,the treatment of single alcalase,which hydrolysis degree and peptide yield got 18.94% and 76.37%,respectively,while the IC50 value of DPPH scavenging rate reduced to 3.23mg/mL,was superior to other treatments.When combined al-calase with other single proteases to hydrolyze walnut protein,both the hydrolysis degree and the peptide yield of hydrolysis product were improved,in which the treatment combined alcalase with papain were enhanced to 28.36%and 85.62%,respectively.The effects of double protease hydrolysis on improving the clearance rate of DPPH radical and.OH radical were not significant.However,the treat-ments combined alcalase with neutral proteinase or papain could significantly enhance the scavenging rate of superoxide anion.