Abstract:

This research focused on the steady state protection factors of the antioxidant peptide derived from egg white protein which was hydrolyzed both by Alaclase and flavorenzyme at the pilot scale. The DPPH scavenging activity of antioxidant peptide from egg white was selected as the index to investigate the effects of temperature, pH, food ingredients and metal ions on the stability of antioxidant activity. The results show that antioxidant activity of peptide derived from egg white protein was very strong and the IC50 of DPPH free radical reached to 1.07 mg/mL. The scavenging activity got to 94.34% when its concentration was 5 mg/mL. The antioxidant peptide from egg white treated for 1 h to 3 h has a strong heatresistant ability at 25~40 ℃. And it can keep high activity at pH 2～10. Sucrose had no significant effect on it (P>0.05).Glucose and NaCl changed the activity significantly (P<0.05), and NaCl concentration relatived to DPPH antioxidant activity positively. K+, Ca2+, Mg2+, Fe2+, Zn2+ ions all improved the antioxidant activity of it in which Fe2+, K+, Zn2+ could enhance the activity significantly (P<0.01 or P<0.05 ), while Ca2+, Mg2+ had no significant effect on it(P>0.05).

Key words: Antioxidant peptide derived from egg white protein, DPPH clearance, stability