Synergistic action of vitamin C and amino acids on vitamin E in inhibition of the lipoperoxidation of linoleic acid in disperse systems

The synergistic effect of some amino acids (L-tryptophan, L-cysteine, L-alanine and glycine), glutathione, n-butylamine and of vitamin C on the antioxidant effect of vitamin E on the lipoperoxidation of linoleic acid in sodium dodecylsulphate micellar solutions and oil in water emulsions was examined at pH 5.0 and 7.0. The antioxidant activity of vitamin E, measured by oxygen consumption, was similar in both emulsions and micellar solutions. The addition of vitamin C produced only a slight synergistic effect at pH 5.0 and none, or a prooxidative effect, at pH 7.0. The amino acids studied exerted a synergistic effect only at pH 5.0, and their effectiveness was partially related to their lipophilicity. (C) 1997 Elsevier Science B.V.