Study the Effect of Pretreatment Conditions on Yield and Gel Strength of Phytophag's Skin Gelatin

Gelatin is widely used in foods as an important functional biopolymer. Yield of extraction and other quality parameters like gel strength vary according to pretreatment conditions. Also, these parameters are affected by source and type of collagen. In this project, 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 gel strength and extraction yield of Phytophag's fish skin gelatin were studied using CRCD which consists of 5 levels and 4 replicates of central point. The effect of different alkali concentration and temperature on yield of extraction was significant. However, different acid concentration and extraction temperature had no significant effect on yield. Mutual effects of alkali and acid concentrations showed significant effects on extraction yield but their effects on gel strength showed that by increase in alkali concentration, no changes observed in gel strength, while gel strength showed an increasing trend by increase in acid concentrations. The effects of different extraction temperature and acid/alkali concentrations on gel strength were significant.