EFFECT OF OXIDIZED LIPID AMINO-ACID REACTION-PRODUCTS ON THE ANTIOXIDATIVE ACTIVITY OF COMMON ANTIOXIDANTS

The antioxidative activity of mixtures of oxidized lipid/amino acid re action products (OLAARPs) and common antioxidants were evaluated to de termine the role of OLAARP formation in the antioxidative activity obs erved for common antioxidants in foods, 1-(5-Amino-1-carboxypentyl)-py rrole, l-4-pentyl-1,4-dihydropyridine-3,5-dicarbaldehyde, nzyloxy)-1(3 )-[1'-(formylmethyl)hexyl]-L-histidine dihydrate, [3'-carboxy-2'(E)-pr open-1'-yl]-4-pentylpyridinium betaine, butylated hydroxytoluene, alph a-tocopherol, and mixtures of them were added at 50-200 ppm to soybean oil which was oxidized under air in the dark at 60 degrees C. Oil per oxidation was evaluated by the thiobarbituric acid-reactive substances (TBARS) assay. Both OLAARPs and common antioxidants increased the ind uction period of the oil and exhibited an additive effect when tested in mixtures. For most samples the percentage of synergistic efficiency was within the +/-20% range. These results suggest that the antioxida tive activity observed for common antioxidants in protein-containing f oods may be increased by the antioxidative activity of the OLAARPs pro duced during the oxidative process.