Abstract: The remove of lipid-soluble pigments and extraction of collagen from tilapia tails were studied. In addition, collagen purity and type were analyzed. The highest pigment removal rate, 2.85% (calculated on wet basis), was obtained after 36 h of treatment with a mixture of chloroform, methanol and water (1:2:0.8, V/V) at a material-to-liquid ratio of 1:1.5 (g/mL). The optimal conditions for collagen extraction, as determined by orthogonal array optimization, were guanidine hydrochloride concentration 3 mol/L, pepsin dose 3.0% (calculated based on crude protein weight), material-to-liquid ratio 1:50 (g/mL), and twice repeated extraction for 72 h each time. Under these conditions, the extraction efficiency of collagen was 4.96% (calculated on wet basis). In tilapia tails, collagen accounted for 40.39% of total crude protein. The extract obtained contained 94.63% of collagen and displayed the characteristics of collagen typeⅠ.

Key words: collagen, pigment, extraction, identification