Abstract
Comparisons were made of the effects of oxidized fatty acids (OFA, fatty substances insoluble in petroleum ether) and dimers (polymerized fatty acid fraction), and their secondary products (SP) of fatty acids separated from heated soybean oil, on the decomposition of tocopherol, several amino acids (valine, methionine, tryptophan, histidine, cysteine and arginine) and ascorbic acid in ethanol solution during oxidation at 60 or 20±2°C. The decomposition of tocopherol, amino acids (especially cysteine and histidine) and ascorbic acid was apparently promoted by OFA and SP. The decomposition ratio of these components increased with further addition of OFA and SP. The effect of SP on the decomposition of tocopherol, amino acids and ascorbic acid was similar to that of OFA. As reduction of nitroblue tetrazolium was observed upon addition of SP or OFA, it was considered that the oxidation of tocopherol, amino acids and ascorbic acid by OFA and SP might be attributable to the production of superoxide anion.
