UV-irradiated gelatin-chitosan bio-based composite film, physiochemical features and release properties for packaging applications.

In this study, Chitosan-Gelatin biodegradable films loaded with Gallic acid (GA) were developed. Ethanol, tween, and β-Cyclodextrin (β-CD) were used to enhance the distribution of GA in the film forming solutions. The effect of the exposure time of UV irradiation on the color, mechanical properties (TS, %E), water vapor permeability (WVP) microstructure and release rate of GA to fatty food simulants investigated. UV irradiation reduced darkness of the films markedly and increased the release rate of the GA. Among the non-irradiated samples the highest and lowest release rate were obtained for the films containing β-CD and ethanol respectively. On the other hand incorporation of β-CD could reduce the increasing effect of UV light on release rate. The UV irradiation for 10 min reduced mechanical strength and barrier properties of the film against water vapor. Microscopic analysis, showed the consistent and uniform microstructure. However, long-term radiation caused some cracks in the films network. The UV irradiation weakened the _OH bending and enhanced the amide I amide II.