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

Antibacterial andantioxidant activity of the rocky shore crab, Grapsus albolineathus, protein hydrolysate (CPH), with differentdegree of hydrolysis (DH)preparedusing alcalasewas investigated. The results showedthat by increasing DH with reaction timeup to 90 min, the DPPH radical scavenging activity ofthe hydrolysates raise,followed by a decrease in the next stages from 90 to 180 min.Interestingly, ABTS radical scavengingofthehydrolysates increase up to 120 min,and CPH120show the highest activity withno significant difference with CPH90and CPH180.The degree of hydrolysis applieda significantinfluence on the antibacterialactivity of crab hydrolysatesagainst gram-positive bacteria, with a significant increase up to 90 min. The maximum zone of inhibitionswas recordedagainst Listeria monocytogenefor CPH90:14.55mm.The results suggest that the alcalasehydrolysis of rocky shore crab can produce bioactive peptides with potent antioxidant and antibacterial activitiesas affectedby the degreeof hydrolysisup toa certainlevel.