Oxidative fate of lipid structures in food and during digestion – possible metabolic significance

Although excessive lipid consumption should be avoided, dietary lipids are now recognized as having various beneficial nutritional effects, especially regarding the need for a balanced supply in both omega-6 and omega-3 polyunsaturated fatty acids (PUFA). Improving the lipid profiles through an increase of PUFA supply also increases risks of (per)oxidation with possible negative consequences for food technological, sensory and nutritional properties. Food lipids exhibit various molecular and supra-molecular structures that interact with the other constituents of the foods. These structures and interactions evolve during processing, storage and digestion. They modulate or induce the formation in the food and in the digestive tract of potentially hazardous molecules. This short review concerns the links between the structures of lipids in foods, their oxidation and the metabolic fate and significance of lipid oxidation products. The actual data concerning: (ii) oxidation of dietary lipids, especially when dispersed as oil-in-water emulsions, during process including digestion, (iii) the absorption of primary and secondary, lipid oxidation (especially hydroperoxides and the two hydroxyalkenals : 4-hydroxy-2-nonenal and 4-hydroxy-2-hexenal) and their consequences on metabolic oxidative stress are briefly summarized. We conclude that innovative food formulations should integrate an adequate structuration of lipids so that their metabolism could be oriented toward their nutritional benefits, limiting the risks linked to peroxidation of the unsaturated fatty acids in the food and during digestion