Physicochemical Properties of Biodegradable Tilapia Skin Gelatin Film and Gelatin-Polysaccharide Based Composite Films

Abstract

The present study was to investigate the film forming properties of tilapia skin gelatin as affected by the addition of 2%, 5% Arabic gum or pectin (g/g gelatin), as well as 1%, 2% glutaraldehyde (GTA) (g/g gelatin) in an attempt to improve gelatin film properties. Tensile strength (TS) and transparency of gelatin film were improved 36.6% and 30.3% by the addition of Arabic gum, respectively, while the water vapor permeability (WVP) was not affected. The addition of pectin had less effect on the film tensile strength and transparency, but led to 41.7% of increase in WVP. Tensile strength and WVP of gelatin-arabic gum composite film cross-linked with 2% GTA were better than those of 1% GTA cross-linked composite film, though the extensibility and transparency were slightly weak. The FTIR spectra of gelatin films showed that both Arabic gum and pectin formed cross-linkages with gelatin protein molecules, while GTA facilitated the formation of intermolecular bonds, resulting in more stable films.