Effect of sorbitol on solubility, heat sewing capability, and opacity of edible films from Bighead Carp fish skin gelatin

Fish skin is the bio polymer that has excellent film-forming properties. The effect of glycerol and sorbitol on various properties of gelatin films was studied. For this purpose, gelatin was extracted from Big Head Crap (Hypophthalmichthys nobilis) fish skin. The aim of this study was to determine the solubility and opacity properties; and heat sewing capability of Big Head crap skin gelatin films. The films were made with 3 g gelatin, 10% glycerol and 0-10% sorbitol based gelatin in 100 ml of distilled water (B, C, D, E, F) and a sample without glycerol and sorbitol (A). The samples were conditioned at 250C and 75±3% relative humidity for two days before analysis. Elongation at break of films increased with increasing plasticizer levels that could be attributed to increase of chain mobility of film matrix. The results showed that by increasing the sorbitol content water solubility increased, and in contrast, tensile strength, elastic modules and opacity of films decreased, significantly. The lowest and highest solubility had been observed in films containing 2.5% and 10% sorbitol based gelatin, respectively. All samples were heat sewing capabilities.