Malonaldehyde from the Autoxidation of Methyl Linolenate

Abstract

THE pink colour obtained when 2-thiobarbituric acid (TBA) reagent is heated with foods or tissues has often been used as an index of lipid oxidation. It has been assumed that malonaldehyde (MA) is responsible because the colour obtained with oxidized food or fat has the same absorption spectra as that from MA^1,2. Recently, however, Saslaw et al.³ and Saslaw and Waravdekar⁴ irradiated fatty acids in air, separated by thin-layer chromatography several different substances which reacted positively with TBA, and suggested that none of these was MA, thus casting some doubt on the previous assumption. The present experiments show that the principal TBA-reactive substance produced during the air oxidation of methyl linolenate is indeed MA.