Antioxidant Activities of Chicken Egg White Hydrolysates Obtained by New Purified Protease of Aspergillus avenaceus URM 6706

Abstract

Protein hydrolysates originating from egg white have already been reported to be bioactive and, among their biological activities, possess the antioxidant property that protects the body from early ageing and diseases linked to oxidation. Therefore, the objective of this work was to evaluate the antioxidant activity of hydrolysates obtained by the hydrolysis of egg white from hen poultry. The protease produced by Aspergillus avenaceus URM 6706 was purified and subsequently applied to hydrolysate the egg white, and the degree of hydrolysis was verified during the protease exposure time (4-24 h). The hydrolysis was intensified over time of exposure to the protease. It was possible to detect the antioxidant activities of eliminating the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) radical (ABTS^•+) from 97% to 99% and 2,2-diphenyl-1-picrylhydrazyl (DPPH^•) up to 27%, as well as the chelation of Cu²⁺ metal ions up to 62% and Fe²⁺ up to 54%. The elimination of ABTS^•+ radical had a positive correlation with the degree of hydrolysis; however, all the other activities tested showed a negative correlation with the degree of hydrolysis. The results obtained suggest that the egg white of hen chicken represents a food source of animal origin with potential application in the functional food industry.

Keywords:
Aspergillus; purification; ABTS; ⁺ ; DPPH; chelators