Abstract: Collagens were extracted from fish scale of grass carp with pepsin and the effects of extraction media, pretreating, stirring, extract times and time on the yield of collagen were studied. The results indicated that the optimum extracted conditions are 1% citric acid as extraction solutions with a magnetic stirrer during the whole process, being extracted three times and 48 hours each time after removing impurity by microwave and decalcifing with 10% citric acid. Purified collagens were analyzed by SDS-PAGE and FT-IR, compared with calf tendon type Ⅰ collagen. The results confirmed that the extracted collagens are typical typeⅠ collagen and of electrophoretic purity.

Key words: fish scale, collagen, technology, SDS-PAGE, FT-IR