Effect of sodium citrate on properties of chitosan / soybean protein isolate composite films

A composite films was prepared by chitosan( CS) and soybean protein isolate( SPI),with sodium citrate as cross- linker.The structure of films was characterized by FT- IR.The influence of sodium citrate on the mechanical properties,water vapor barrier properties and antioxidant property of CS / SPI composite film were evaluated.The results showed that the molecular interaction of composite film was increased by sodium citrate.The mechanical properties and water vapor barrier properties of composite film was improved,water solubility was decreased,and the antioxidant property of composite film was improved by 0.03%( w / v) sodium citrate,meanwhile the DPPH radical scavenging activity was 1.72 times that of the control.