Extraction and characterization of gelatin from different fresh water fishes as alternative sources of gelatin

Gelatins from the skin of four different species of fresh water fish, namely pangas catfish (Pangasius pangasius), Asian redtail catfish (Hemibagrus nemurus), striped snakehead (Channa Striata), and Nile tilapia (Oreochromis niloticus) have been successfully extracted by citric acid. The gelatin from pangas catfish was found to possessed the highest rheology properties compared to the others. It had the following properties: gel strength of 273.58 g, viscosity of 36.5 cP, melting point at 32oC, gelling temperature at 12oC, melting temperature at 29oC and total amino acid content of 754.47 mg/g. The gelatin from fresh water fish had lower physicochemical and rheological properties compared to the commercial gelatin, though total amino acid were 699.86 mg/g for pangas catfish and 734.94 mg/g for striped snakehead, respectively. The fishes investigated in this study were potential alternative sources of gelatin.