Determination of Amino Acid Composition and Evaluation of Melting Point and Viscosity of Gelatin Extracted from Phytophag's Skin

Gelatin is polypeptide with high molecular weight which is derived from collagen of connective tissue, skin, bone and tendons. The most common source of gelatin in the world is skin and bone of cow and pig. However, spreading BSE and other related animal diseases made many consumers of these products concern about using related products. In this regard, fish gelatin has gained a lot of consideration as a valuable source of gelatin in comparison with cow skin and bone or other related wastes. One of the most important factors related to fish gelatin is its lower melting point in comparison with commercial source of gelatin. For this reason, it is useful for application in products which are used and served at cold temperature. In this study, amino acid composition of Phytophag's fish skin gelatin was determined. Also, the effects of different alkali and acid concentrations (0.05, 0.33, 1.025, 1.71 and 2 N) along with extraction temperature (45, 51, 65, 79 and 85 ˚C) on melting point and viscosity of Phytophag's fish skin gelatin were studied using CRCD with 5 levels and 4 replicates of central point. Results showed significant effects of different temperature and acid/alkali concentrations on viscosity, while no significant effects were observed for melting point.