Lipid oxidation in emulsified food products

Most lipids in food exist as colloidal dispersions stabilized by surface active agents that slow down the gravitational separation of oil and water. The surface active agents in emulsion create an oil-water interface that has major impacts on the distribution of the components in foods that impact lipid oxidation. This includes location and reactivity of prooxidative factors such as transition metals, lipid hydroperoxides and minor lipid components and antioxidants such as free radical scavengers and metal chelators. Understanding of how the physical properties of the lipid-oil interface in food emulsions impacts the chemistry of lipid oxidation has lead to new strategies to inhibit oxidation such as creating charged surfaces that electrostatically repel metals and thick interfaces that inhibit lipid-prooxidant interactions. As food formulations continue to move towards inclusion of more polyunsaturated fatty acids and the use of traditional antioxidants becomes more limited due to increased consumer demand for all natural foods, it is important to have a better understanding of the mechanisms of lipid oxidation in foods dispersion so that novel antioxidant technologies can be developped.