The Effect of Chitosan Type on Biodegradable Films from Gelatin Extracted from Huso Huso Skin Patches and Their Specifications and Characteristics

Film forming capabilities of gelatin as well as chitosan have been used as edible films with suitable physical and mechanical properties in the packaging and food preserving industry. In this study, the effect of various chitosans (water-soluble, acid-soluble, oligosaccharide) was investigated with ratio of 50:50 chitosan-gelatin. The latter was extracted from farmed Huso huso</em> skin. In order to evaluate the effect of chitosan kinds in combination with gelatin extracted from the fish, physical, mechanical experiments, and then optical and infrared spectroscopic tests, and thermal characteristics of the films were assessed. In this study, the highest tensile strength and elongation at break point was obtained in films containing 100% gelatin and 50-50% soluble chitosan and gelatin one, respectively. In the chitosan oligosaccharide film, the highest moisture and solubility was observed while in the pure gelatinous film the lowest amounts of them were portrayed. Regarding swelling rate results, all films (soluble in gelatin / chitosan) were dissolved, while the lowest percentage of swelling rate was found in the pure gelatinous film. The results of the water vapor permeability of the films showed that the gelatinous films combined with the acid-soluble and oligosaccharide chitosan showed the lowest and the highest permeability to water vapor, respectively. The optical properties and transparency of the films showed a significant difference. The results of the infrared spectroscopy indicated that the gelatin- chitosan oligosaccharide film due to the less breaking process and the stronger absorption of band in amide 1, demonstrated better properties. In addition, the thermal stability and the weighted remainder of the combined films were more than that of the pure gelatinous film, which can be attributed to the incorporation of chitosans in the film matrix.