Antioxidant and Free Radical-Scavenging Activities of Goby (<i>Zosterisessor ophiocephalus</i>) Muscle Protein Hydrolysates Obtained by Enzymatic Treatment

Abstract

Antioxidant activities of protein hydrolysates prepared from goby muscle by treatment with various bacterial alkaline proteases from Bacillus mojavensis A21, Bacillus subtilis A1, Bacillus pumilus A26, and Bacillus licheniformis NH1 and Alcalase were investigated. All hydrolysates showed different degrees of hydrolysis. The antioxidant activities of protein hydrolysates at different concentrations were evaluated using various in vitro antioxidant assays, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical method, reducing power assays, β-carotene bleaching, and DNA nicking assay. All protein hydrolysates showed varying degrees of antioxidant activity. The hydrolysate prepared using A26 proteases showed the strongest DPPH radical-scavenging activity, followed by NH1 and A21 hydrolysates. Moreover, NH1 hydrolysate exhibited notable effects against the discoloration of β-carotene. A1, A21, and alcalase protein hydrolysates exhibited high protection against hydroxyl radical induced DNA breakage.