Effect of tea polyphenols on the properties and antioxidant activity of defatted soybean meal films

The natural tea polyphenols(TP)with antioxidant function were added to the film-forming solution prepared by defatted soybean meal(DSM).The tensile strength,water vapor permeability and carbondioxide permeability were tested.At the same time,the antioxidation and reducibility of the film-forming solution were measured.The TP-DSM film-forming solution was used to coat apple surface in order to test the browning index.The addition of tea polyphenols significantly increased the TP-DSMF tensile strength by 15.69% and water vapor permeability decreased by 18.49%.The carbon dioxide permeability was reduced 43.10% than the film which was prepared by defatted soybean meal dry basis. The DPPH free radical scavenging and Ferric reducing antioxidant power had been developed by addition of the tea polyphenols.The TP-DSM film-forming solution had taken effect as an antioxidant role which could make the browning degree of the apple slices slow down.