Abstract:  After hydrolysis with mixed protease the hydrolysates of scallop skirt was purified by hollow fiber ultrafiltration（UF）．The processing parameters for the manufacture of liquid-HAP in good quality were investigated．Results show that the content of polypeptides peptides and free amino acids in the liquid-HAP is largely increased by using flavorzyme after4h pre-hydrolysis with A．S．1．398neutral subtilisin．And that permeation flux was affected by operating pressure temperature pH value of hydrolysates and the ratio of volume to concentration （RVC）． Optimal operative condition which might prolong working time of the device with high permeation flux minimize pollution of membranes and raise separating efficiency is pH7．0～7．5at 43℃ under0．10MPa and the membranes rinsed repeatedly for2minutes after every operating for10minutes．These results suggest that sense index of fractionated hydrolysates is superior to that of the original hydrolysates． 

Key words: hydrolyzed animal protein, scallop skirt, enzymatic hydrolysis, hollow fiber ultrafiltration