Antioxidant and Enzyme Inhibitory Activities of Metapenaeusmonoceros By-Product Hydrolysates Elaborated by Purified Alkaline Proteases

This study investigated the antioxidant potential and enzymatic inhibitory power of shrimp by-product protein hydrolysates (hyd) prepared using two purified serine alkaline proteases namely; alkaline protease from Anoxybacilluskamchatkensis strain M1V (SAPA) and alkaline protease from Aeribacilluspallidus strain VP3 (SPVP). The characterization of their molecular weights showed the presence of peptides less than 15 kDa. SAPA-hyd displayed the highest reducing power activity. Likewise, SAPA-hyd was found to be active against angiotensin I-converting enzyme (ACE), tyrosinase (Tyr), and amylase (Amy) enzymes with IC50 values of 10.01, 6.13, and 4.11 µg/mL, respectively. SPVP-hyd revealed the highest radical scavenging power, β-carotene protection, and ferrous chelating activity with EC50 values of 11.79, 3.69, and 0.61 µg/mL, respectively. After fraction nation, all fractions displayed a high inhibitory potential against ACE. Only fractions F2 and F3 from SAPA-hyd showed the highest anti-tyrosinase activity with IC50 values of 25.10 and 12.5 ng/mL, respectively. These results suggest that a simple, clean, economic, and controllable bioprocess for the utilization of shrimp by-product was investigated. This study gives an unprecedented report on the anti-Tyr activity of the protein hydrolysate from fish bio-waste. Additionally, two peptide hydrolysates with multifunctional biological activities were elaborated from Metapenaeusmonoceros by two bacterial purified proteases.