PREPARATION AND CHARACTERIZATION OF MUSSEL (MYTILUS EDULIS) PROTEIN HYDROLYSATES WITH ANGIOTENSIN-I-CONVERTING ENZYME (ACE) INHIBITORY ACTIVITY BY ENZYMATIC HYDROLYSIS

The hydrolysis of mussel (Mytilus edulis) protein in the presence of six different proteases was investigated. The results showed that Alcalase 2.4 L catalyzed the hydrolysis most efficiently among the tested proteases. In addition, the highest protein recovery was achieved in the case of Alcalase hydrolysate which possesses the strongest angiotensin-i-converting enzyme (ACE) inhibitory activity. Moreover, response surface methodology (RSM) was applied to optimize the hydrolysis conditions. The optimum values for enzyme/substrate ratio (E/S), pH and temperature were found to be 1.64%, 9.12 and 57C, respectively. Under the optimal condition, the mussel protein hydrolysate (MPHs) was prepared by Alcalase. Furthermore, the distribution of the relative molecular weight was examined by HPLC and the result showed that the oligomeric peptides peptides with molecular weight below 1,000 Da account for 78.4% of MPHs. It has been demonstrated that MPHs could serve as a source of peptides with ACE inhibitory activity and the short peptides below 1,000 Da might mainly attribute the activity to it.