Effects of Deamidation and Fragmentation on Antioxidative Activity of .ALPHA.-Zein

The effcts of deamidation of fragmentation on the antioxidative activity of α-zein were investigated individually. Heat treatment at 70°C in 70% ethanol-0.05M HCl caused deamidation of α-zein without fragmentation. Antioxidative activity of α-zein was improved by this deamidation. α-Zein with deamidation treatment for 12 hours protected 80% of docosahexaenoic acid ethyl ester from autoxidation until 7 days. Model peptide of α-zein had a lower antioxidative activity than α-zein. Fragmentation by N-btromosuccinimide decreased the antioxidative activity of α-zein.