Abstract:Angiotensin-converting enzyme（ACE）inhibitory peptide was prepared from Penaeus albinus by complex enzymatic hydrolysis. On the basis of the traditional enzymatic hydrolysis method，the proteases with high enzymatic hydrolysis efficiency were screened and combined，and the shrimp head protein was hydrolyzed by complex enzymatic hydrolysis of double enzymes. With ACE inhibition rate and hydrolysis degree as indexes，the preparation process was optimized by single factor and response surface tests，and the combination，ratio，and other process parameters of complex protease were determined.The optimal enzymatic hydrolysis conditions to obtain ACE inhibitory peptides from shrimp head protein were as follows：solid-liquid ratio of 1∶7（g/mL），enzyme dosage of 400 U/g，initial pH value of 7.5，enzymatic hydrolysis temperature at 50 ℃，complex enzyme ratio（mass ratio of trypsin to flavor protease）of 2.29∶1（U/U），and enzymatic hydrolysis time of 2.17 h.Under these conditions，the hydrolysis degree of shrimp head protein reached 71.48%，and the ACE inhibition rate reached 83.57%. The enzymatic hydrolysis efficiency was increased by 35.05% compared with the enzymatic hydrolysis of a single enzyme before optimization. The results showed that the head of Penaeus albinus had higher ACE inhibition activity after enzymatic hydrolysis by trypsin and flavor protease.