Synergism between -Tocopherol and Amino Compounds in the Inhibition of the Autoxidation of Fatty Acid Methyl Esters

Abstract

Factors affecting synergism between γ-tocopherol (γ-Toc) and amino compounds in the inhibition of the autoxidation of methyl esters of fatty acids, mainly linoleate, were investigated in order to clarify the conditions exhibiting their synergism.Tri-n-octylamine (TOA) and trimethylamine oxide (TMAO) themselves used as synergists were pro-oxidative, but they, especially TOA, remarkably synernized with γ-Toc when higher concentration of γ-Toc was present. Lecithin and cephalin showed no pro-oxidative activity under these conditions. Out of the reducing dimers of γ-Toc, γ-Toc ether dimer showed synergism with TOA and TMAO, but γ-Toc biphenyl dimer didn't. It was found, therefore, that the synergistic effects required limited factors such as temperature, concentration, the composition of fatty acids, etc. when purified methyl linoleate was used as a substrate.As TMAO served as a potent synergist for a small amount of Toc in inhibiting the autoxidation of lard, however, remarkable synergism could be expected by a combination of Toc and more than two kinds of amino compounds containing at least a substance which compensates pro-oxidative actions of synergists such as TMAO and strongly draws forth their synergistic abilities.