Formation of Acrolein in the Autoxidation of Triacylglycerols with Different Fatty Acid Compositions

Abstract

Fish, echium, linseed, and soybean oil triacyglycerols (TAGs) were oxidized at 50 or 60 °C to determine the effect of the polyunsaturated fatty acid composition on the volatile product formation. The analysis of the oxygen consumption and total volatile formation demonstrated that the soybean oil TAG had the highest oxidative stability followed by linseed, echium, and fish oil TAGs. Our results were in agreement with the expected average number of bis-allylic positions of each TAG. Higher quantities of acrolein (2-propenal) and propanal were detected using the static headspace gas chromatography method at the early stages of oxidation of echium and fish oil TAGs; however, a considerable amount of propanal and only a small amount of acrolein were found in the oxidized linseed oil TAG. The peak area ratios of acrolein to propanal were 0.115, 0.569, and 2.554 after the 8-h oxidation of linseed, echium, and fish oil TAG, respectively, suggesting the preferential formation of acrolein, especially during the fish oil TAG oxidation. The acrolein quickly increased during the first stage of oxidation, but thereafter it either did not change or slightly decreased during the fish oil oxidation. Because fish oil induces flavor deterioration from the very early stage of the oxidation, the acrolein formation observed in the present study may be important for fish oil deterioration.