Oxidation Products from Omega-3 and Omega-6 Fatty Acids During a Simulated Shelf Life of Edible Oils

Nutritional guidelines recommend reduced intake of saturated fatty acids to prevent cardiovascular disease. Polyunsaturated fatty acids (PUFA) are proposed as substitutes for saturated fats. PUFA, however, are more susceptible to lipid peroxidation resulting from environmental free radical than saturated fats. We hypothesize that toxic lipid peroxidation products could be generated during shelf storage in dietary sources of PUFA prior to consumption. Therefore, the oxidative stability of six edible oils rich in omega-3 and omega-6 PUFA was evaluated by simulating transport, storage and consumption conditions that these oils typically receive. 2-Propenal (acrolein); 2-butenol; (E,E)-2,4-heptadienal; (E,E)-3,5-octadien-2-one; (Z,Z)-3,6-nonadienal and (E,E)2,4-decadienal were identified as potentially toxic products resulting from the oxidation of PUFA in omega -3 rich oils from marine sources while propan-2-one; 2-butanol; (E,E)-2,4-heptadienal; (E,E)-3,5-octadien-2-one and (E,E)-2,4-decadienal were identified in omega-3 PUFA rich oils from vegetable sources. Hexanal, (E)-2-heptenal, (E,E)-2,4-neptadienal, nonanal and 2-undecenal were identified from omega-6 rich oils. All samples showed increased oxidation with some lipid oxidation products exceeding recommended limits at the time of consumption. These findings highlight the importance of examining the oxidative stability of commercially available edible oils. The physiological implications of the chronic intake of reactive aldehydes, such as acrolein, through the consumption of dietary oils deserve further investigation.