Abstract:

In order to obtain polypeptides from pig bone collagen as much as possible, the enzymolysis process of bone collagen was optimized. On the basis of one-factor and double-factor interaction tests, according to Box-Behnken central  composition design principle, the method of response surface analysis with 3 factors (substrate concentration, Protamex-compound protease concentration and hydrolysis time) and 3 levels combined with Minitab14-statistical data analysis software was adopted to built a quadratic regression equation with pig bone polypeptide yield as the function, and with pig bone polypeptide yield as the response value, the response surface and contour were plotted. According to the above results, the optimum enzymolysis conditions were obtained as follows: substrate concentration 15%, pH 7.5, enzyme concentration 0.25%, hydrolysis temperature 55 ℃ and time 13 h. Under these conditions, the polypeptide yield is up to 121.45 mg/g pig bone powder.

Key words: polypeptide, enzymatic hydrolysis, pig bone powder, response surface methodology (RSM), hydrolysis condition, optimization