Optimization of preparation process of collagen oligopeptide from puffer fish skin

The best preparation process of collagen oligopeptide from puffer fish skin by two- step enzymatic hydrolysis was studied.Taking hydrolysis degree and molecular weight as indices,the hydrolysis conditions were optimized by the single factor experiments and orthogonal tests. The results showed that the first- step optimal enzyme was fish scale collagen hydrolysis special enzyme or trypsin and the second- step optimal enzyme was acid protease.The optimal hydrolysis conditions of acid protease were found to be reaction at 50℃ and p H of 4.5for 8h with protease concentration of 2%.The molecular weight of prepared collagen oligopeptide ranged from 100 u to 600 u.The collagen peptide,ash and water content of the lyophilized sample was respectively 94.0%,0.71%,and5.2%.