Abstract: Silver carp skin gelatin film has aroused wide attention due to its unique advantages including high safety and easy availability. However, the application of pure silver carp skin gelatin film in the food packaging industry is hampered due to its poor mechanical and barrier properties. In order to improve the properties of the film, the fish skin gelatin and sodium alginate were mixed to obtain composite films. The results showed that the composite films had a translucent appearance and could provide a shield against ultraviolet light and oil. The composite films with 20% sodium alginate had minimum water solubility and water vapor permeability and maximum tensile strength, suggesting that barrier properties and mechanical properties of the composite films were better than those of pure fish skin gelatin film. Fourier transform infrared (FT-IR) spectra and X ray diffraction results revealed a strong interaction between fish skin gelatin and sodium alginate, which may be the major cause of changes in the properties of the composite films.

Key words: silver carp skin gelatin, sodium alginate, composite film, interaction