Effects of Enzymatic Hydrolysis on the Antioxidative and Antihypertensive Activities from Red Tilapia Fish Protein

Abstract

In this research, activities of antioxidative and antihypertensive peptides, derived from Red Tilapia meat protein (Oreochromis niloticus) by alcalase and thermolysin enzymes were evaluated. The hydrolysis process was performed from 0-4 hours at 37 degrees C, pH 7.4. Two hours of hydrolysis with thermolysin and alcalase resulted in degree of hydrolysis of 76.29% and 63.49%, respectively. Hydrolysates obtained after 1 hour and 2 hours hydrolysis were chosen for further study on the bioactive activities. Results showed that thermolysin enzyme yielded higher antioxidant activities than alcalase enzyme based on ABTS and reducing power assays, before and after ultrafiltration for concentrated cut-off interval of hydrolysates. For antihypertensive assay, thermolysin enzyme yielded higher inhibition of ACE enzyme activities after 1 hour hydrolysis while alcalase enzyme yielded higher inhibition activities after 2 hours hydrolysis. Chosen cut-off interval of hydrolysates showed that, thermolysin hydrolysates have a strong inhibition effects towards ACE enzyme than alcalase hydrolysates. Based on SDS-PAGE test, the hydrolysates obtained by alcalase appeared as a smear and have concentrated the most with molecular weight within range