Effect of the Type of Enzyme and Degree of Hydrolysis on the Antioxidant Properties of Paste Shrimp Protein Hydrolysates Prepared by Varying in Vitro Enzymatic Process

Protein hydrolysates from Paste Shrimp (Acetes spp.) were produced using four commercial proteolytic enzymes (alcalase, papain, trypsin, and pepsin) independently. The degree of hydrolysis (DH) from 5 to 30% was standardized using a linear regression plot viz. DH (%) against the duration of hydrolysis (min). In the present study, the influence of DH on antioxidant and antihypertensive properties, such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2 2′-azino-bis-3-ethylbenzothiazoline sulfonic acid (ABTS) radical scavenging activity, metal chelating activity, and angiotensin converting enzyme (ACE) inhibition activity, was investigated. Papain-mediated hydrolysate displayed the highest DPPH radical scavenging activity while trypsin-mediated hydrolysate showed the highest ABTS radical scavenging activity at 30% DH. The highest metal chelating activity was obtained at 20% DH in alcalase mediated hydrolysate. The highest ACE inhibiting activity was detected in Alcalase-mediated hydrolysates at 30% DH, and the activity increased with rising DH. This study revealed that the increase in the extent of hydrolysis with a suitable enzyme can significantly enhance the bioactive properties of the Acetes protein hydrolysate.