The Effects of Amino Acids on the Oxidation of L-Ascorbic Acid in Food (Preliminary Report)

The effects of amino acids upon the autoxidation and the photoxidation of L-ascorbic acid were studied, obtaining the following results. 1) L-Glutamic acid restrained the oxidation of L-ascorbic acid most remarkedl y. L-Na-glutamate sho wed the same effect. 2) L-Aspartic acid and L-methionine also restrained the oxidation. 3) L-Tryptophan accelerated the oxidation of L-ascorbic acid most strikingly, particularly under ultraviolet rays.L-Phenylalanine also showed the same effect. 4) L-Threonine, L-serine and L-hydroxyproline seemed to accelerate the oxidation. 5) L -Histidine-HC1 restrained the oxidation of L-ascorbic acid in the dark, while it accelerated the oxidation under ultraviolet rays. 6) Other amino acids (glycine, L-alanine, L-valine, L-leucine, L-isoleucine, L-proline, L-arginine-HC1 etc.) did not show such an effect.