CHARACTERIZATION OF A HEAT-STABLE ANTIOXIDANT COPURIFIED WITH THE SUPEROXIDE-DISMUTASE ACTIVITY FROM DRIED PEAS

Heat-stable antioxidant activity co-purified with the pea superoxide d ismutase (SOD) activity is believed to be due to bound phenolic compou nds. Digestion with trypsin showed that the native SOD protein structu re was not required for the expression of the thermostable antioxidant activity. Part of the bound phenolic compounds can be removed from th e SOD protein by alkaline hydrolysis. The dissociated phenolic fractio n was able to inhibit the autoxidation of linoleic acid by more than o ne week. Incubation of the phenolic fraction with bovine SOD (BSOD) an d serum albumin (BSA) resulted in the transfer of thermostable antioxi dant activity to the SOD protein but not to serum albumin. The results indicate that pea SOD can act as a carrier for certain pea phenolic c ompounds and thus facilitate a protein-bound thermostable antioxidant.