Abstract:Fish bone,containing plenty of collagen,is the main offal from fish fillet processing. The collagen from Tilapia bone after removing impurities was extracted by pepsin digestion in acid medium condition. The effects of extraction medium,temperature,material to liquid ratio,pepsin addition,extraction duration on yield of collagen were investigated. The optimum conditions using lactic acid as medium to extract collagen were pH 2.6,material to liquid ratio(w/v) 1∶30,30 ℃,200 U/g pepsin addition,extraction time 24 h,and the yield of extracted collagen reached 70.28%(12.76% when compared with the initial weight of Tilapia bone). Then,the extracted crude collagen was further purified and its physicochemical property was determined by the methods of SDS-PAGE,UV and FT-IR scanning,DSC,CD and amino acid analysis. The results indicated that the extracted Tilapia bone collagen belongs to typical collagenⅠwith two α and one β chains. Furthermore,the Tilapia bone collagen contains high percentages of Gly,Pro,Hyp,Glu and Ala and its denaturation temperature was 34.5 ℃. In conclusion,the extracted Tilapia bone collagen by pepsin digestion has a higher yield and purity.
