Abstract:  The enzymatic hydrolysis action of protein in silver carp bone by Alcalase and Flavorzyme were investigated,and step hydrolysis conditions of protein in Silver Carp bone were optimized by orthogonal experiment. The optimum reaction temperature and pH value of Alcalase and Flavorzyme were 55℃ and 50℃,7.5 and 6.0,respectively. Hydrolysis degree,30.05%,and nitrogen recovery ratio,79.80% could be reached by hydrolyzing protein with 1500U/g Alcalase at the solid-liquid ratio of 1:4(W/V),initial pH8.0 for 2 hours at 55℃,and then with 1500U/g Flavorzyme for another 2 hours. Compared with those of hydrolyzing with Alcalase or Flavorzyme alone,hydrolysis degree were increased by 10.05% and 10.07%,and nitrogen recovery ratio were increased by 4.54% and 12.54%,respectively.

Key words: fishbone, protein, Alcalase, Flavorzyme, step hydrolyze