Extraction and Identification of Collagen from Tilapia Tail

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.