Abstract: The hydrolyzings of tilapia meat by means of papain proteinase, neutral proteinase, acid proteinase, alkaline hydrolase or bromelain proteinase respectively to prepare hydrolyzed animal protein were studied, and the degree of hydrolysis (DH) were assayed during the hydrolyzing. According to the results, one neutral proteinase was selected and the methods to control hydrolyzing were studied. In order to improve the degree of hydrolysis and to choose one kind of proteinase for the hydrolyzing, the results of hydrolysis by two kinds of proteinases (neutral proteinase and acid proteinase)were studied. Then the optimum materials of decoloring and removing bitterness and fishy smell from enzymed liquid of tilapia meat were selected from yeast powder, flavourease, active carbon and fucose. The results indicated that active carbon and the fucose were the optimum materials, the decoloring effect of active carbon was better than fucose, while the bitterness and fishy smell removing effect of fucose was better than active carbon.

Key words: tilapia, enzymatic hydrolysis, degree of hydrolysis, hydrolyzed animal protein(HAP), active carbon, fucose