Chicken skin gelatin films with tapioca starch

Abstract

Chicken skin gelatin-based films with tapioca starch used to induce crosslinking reactions improved the quality of food packaging films made from the two biopolymers. The composite films were prepared with differing starch concentrations (0–25%) using a casting technique. The physical and mechanical properties of each film were evaluated. The addition of tapioca starch increased the thickness and improved the water resistance of the films (p < 0.05). The addition of tapioca starch at >5% did not improve water barrier properties, but did increase water vapor permeability (p < 0.05). Ultraviolet light shielding increased, along with a decrease in the visible light transmission and transparency. The increase in Tm values of the composite films indicated that the thermal stability of the films was increased by the addition of tapioca starch. SEM micrographs showed that the composite films had a smoother surface and improved internal structure over pure gelatin films, while X-ray diffraction analysis showed increasing crystallinity of the films as a function of tapioca starch content. The films also showed higher tensile strength and elongation at break values, with no effects on Young's modulus (p ≥ 0.05) found after the addition of tapioca starch. Overall, chicken skin gelatin with 10% tapioca starch was found to be the optimal formulation, since it had the highest values for both tensile strength and elongation at break.