Effect of different acetic acid concentration on physicochemical characteristics of gelatin from starry trigger fish skin (Abalistes stellaris)

Starry trigger fish skin (Abalistes stellaris) is generally considered as waste from fish processing industry, especially in the traditional smoked fish industry. The purpose of this study was to determine the effect of different acid concentrations, used in the immersion process, on the physicochemical characteristics of starry trigger fish skin gelatin. Various concentration of acetic acid (0.2 M; 0.4 M; and 0.6 M) was applied during the gelatin soaking process. The experiment was done in triplicate. The extraction process was carried out for 4 hours at temperature of 55C. The results showed that different concentration of acetic acid used in the soaking process had a significant effect (p<0.05) on the water, protein, and ash contents, yield, viscosity, gel strength, gelling point, and melting point. The results showed that the higher concentration of acetic acid used during the soaking process would affect the physical and chemical characteristics of gelatin from starry trigger fish skin (Abalistes stellaris).