Antioxidant activity and properties of gelatin films incorporated with tea polyphenol-loaded chitosan nanoparticles

BACKGROUND: Gelatin film is widely used for the protection of food quality. In order to improve its antioxidant activity, natural antioxidant tea polyphenol-loaded chitosan nanoparticles (TPCN) were prepared and incorporated into gelatin film. The antioxidant effect of TPCN against the oxidation of fish oil was investigated, as well as the release of TP from nanoparticles in the film. RESULTS: The incorporation of TPCN greatly decreased the tensile strength and oxygen permeability but increased the water vapour permeability and affected the transparency of gelatin film. Scanning electron microscopy images indicated that extensive interference was embedded with TPCN in the film microstructure. The peroxide value of fish oil packaged with films incorporated with TPCN was lower than that of fish oil packaged with control films during the incubation period. The radical-scavenging activity of films incorporated with TPCN was higher than that of control films, and increasing radical-scavenging activity of the former was observed during the storage period. CONCLUSION: The antioxidant activity and properties of gelatin film were affected by TPCN incorporation and storage time. Also, the oxidation of fish oil was retarded. The addition of TPCN could improve the antioxidant activity of gelatin film, and the release of TP from nanoparticles in the film was achieved during the storage period. (C) 2009 Society of Chemical Industry