Characterisation of Snakehead Fish, Channa striata (Bloch, 1793), Byproduct and Its Gelatin Properties

This study aims to identify the characteristics of skin, bones, and scales as a biomaterial byproduct of snakehead fish, Channa striata (Bloch, 1793) before and after the extraction process into gelatin, based on 36 fresh snakehead fish samples. The biomaterials were identified, including their proximate composition (by weight of protein, fat, moisture, ash) collagen, amino acids. The physicochemical properties of gelatin in terms of yield, gel strength, viscosity pH, and functional groups were determined for scales, skin and bones. Combined, these biomaterials made up about 47.74 % of the total byproduct by weight of snakehead fish that would usually be discarded. Moisture and protein content of the skin was higher than that of scales and bone (P < 0.05), and fat content was higher in bone than in skin and scales (P < 0.05). The lowest ash content was in skin (<1 %), compared to scales and bone (P < 0.05). The collagen content of scales was higher than that of skin and bone (P < 0.05). Glycine and proline in the three biomaterials were nearly equal and highest in skin, scale, and bone, respectively. There were significant differences in viscosity and gel strength of the three types of gelatin (P < 0.05), the highest viscosity was in skin gelatin while the best gel strength was in scale gelatin, while pH was not significantly different (P > 0.05). The application of the same method and solvent can produce different properties and characteristics of gelatin, and the presence of functional groups helps determine the occurrence of changes in the secondary structure of gelatin from the three biomaterials.