Abstract: This paper has studied the extraction of collagen from porcine skin by trypsin, papain and pepsin. There have been found to contain 24.59% protein, and 2.3% hydroxyproline, respectively of porcine skin. Collagen from porcine skin was extracted by three kinds of enzymes. After extraction it was purified further by dialyzing, condensing and lyophilizing. The results showed: Among the collagens extracted by three kinds of enzymes, the extraction rate of trypsin is the highest, but the structure of collagen is severely destroyed, while the structure of collagen by papain is the best, and also the whiteness was the highest among the collagens extracted, but the extraction rate is the lowest.

Key words: collagen, enzymatic hydrolysis, hydroxyproline, extraction