Extraction and physicochemical characterization of greater Lizardfish (Saurida tumbil) skin and bone gelatin

Type A gelatins were extracted from skins and bones of lizardfish and analyzed to determine their functional and chemical properties. Lizardfish skin gelatin had ash content of 2.2 +/- 0.3% while bone gelatin had ash content of 12.2 +/- 0.2%. Gel strength was 159.1 +/- 14 and 135 +/- 7.9 g, respectively, for skin and bone gelatins compared to 224.3 +/- 7.7 g for porcine gelatin. Gelatin from skin exhibited higher viscosity and lower setting time than bone. Skin gelatin had higher imino acid content than bone gelatin. The total imino acid content was 21.71% and 19.83% for skin and bone, respectively. Both skin and bone gelatins contained more alpha chains than beta and gamma components. Both bone and skin gelatins also contained low molecular weight (< alpha) peptides. The differences in functional properties between the skin and bone gelatins appeared to be related to differences in amino acid composition and molecular weight distribution of the gelatins.