Antioxidant and antibactrial properties of protein hydrolysate from Persian Gulf Crab (Grapsus albacarinous) as affected by progress of hydrolysis

Antibacterial and antioxidant activity of the rocky shore crab, Grapsus albolineathus, protein hydrolysate (CPH), with different degree of hydrolysis (DH) prepared using alcalase was investigated. The results showed that by increasing DH with reaction time up to 90 min, the DPPH radical scavenging activity of the hydrolysates raise, followed by a decrease in the next stages from 90 to 180 min.Interestingly, ABTS radical scavenging of the hydrolysates increase up to 120 min, and CPH120 show the highest activity with no significant difference with CPH90 and CPH180. The degree of hydrolysis applied a significant influence on the antibacterial activity of crab hydrolysates against gram-positive bacteria, with a significant increase up to 90 min. The maximum zone of inhibitions was recorded against Listeria monocytogene for CPH90:14.55 mm. The results suggest that the alcalase hydrolysis of rocky shore crab can produce bioactive peptides with potent antioxidant and antibacterial activities as affected by the degree of hydrolysis up to a certain level.