Study on free radical scavenging activity of proteinase hydrolysates from egg white.

Objective To determine the degree of hydrolysis (DH) and free radical scavenging activity of the hydrolysates of egg white protein (EWPHs) with pepsin, trypsin, papain, neutrase and Alcalase. Method The degree of hydrolysis of EWPH was measured by ninhydrin colorimetric method. The hydroxyl radical and superoxide anion scavenging activity was detected by the methods related to pyrogallol autoxidation and Fenton system. Results Under the optimal conditions the sequence of enzyme hydrolysis capacity was: alcalasetypsinpapainneutrasepepsin. The order of hydroxyl radical scavenging activity was: papainalcalasetrypsinneutrasepepsin and the order of superoxide radical scavenging activity was: papainalcalaseneutrasepepsintrypsin. The EWPHs with papain for 3h displayed the strongest radical scavenging activity. The values of hydroxyl radical and superoxide free radical scavenging activity were 65.63% and 38.40% respectively. Conclusion EWPHs exhibited free radical scavenging activity and the activity of scavenging hydroxyl radical were stronger than superoxide radical.