Abstract:With Schisandra chinensis protein as the raw material，the antioxidant capacity and functional properties of neutral protease and papain for Schisandra chinensis protein before and after enzymolysis were evaluated.According to the optimal enzymolysis conditions of the two proteases，Schisandra chinensis protein was enzymatically degraded，and its structure was analyzed by scanning electron microscope，sodium dodecyl sulfate-polyacrylamide gel electrophoresis，and the determination of free sulfhydryl groups and disulfide bond content.In addition，its ability to scavenge hydroxyl radical，DPPH radical，and ABTS+ radical in vitro was determined，and its ability to chelate ferrous ions and reduce ferric ions was determined.The functional properties of water holding capacity，oil holding capacity，emulsification and emulsion stability，foaming，and foam stability of different enzymolysis products were evaluated.The results showed that the relative molecular weight of Schisandra chinensis protein decreased significantly after enzymolysis.The enzymolysis products of neutral protease had the lowest molecular weight and the highest hydrolysis degree of 26.45%，which was better than that of papain.With Schisandra chinensis protein as a reference，enzymolysis could enhance its antioxidant capacity，and the enzymolysis products of neutral protease had better antioxidant capacity than those of papain，but the enzymolysis products of papain had better reducing capacity.The solubility，emulsification and emulsion stability，foaming，and foam stability of Schisandra chinensis protein were improved after enzymolysis，and the functional properties of the enzymolysis products of neutral protease were better than those of papain.Scanning electron microscope observed that Schisandra chinensis protein produced different degrees of fragmented and stripe structures after enzymolysis by two different proteases.In addition，there were some larger flake structures in the enzymolysis products of papain，and the enzymolysis products of neutral protease showed fine and irregular fragmented structures，which were relatively loose.Meanwhile，the free sulfhydryl content of both enzymolysis products was increased compared with Schisandra chinensis protein，with the enzymolysis products of neutral protease having the smallest amount of disulfide bonds.In summary，enzymolysis can reduce the molecular weight of Schisandra chinensis protein and enhance its antioxidant activity and functional properties.