RELATIONS BETWEEN ANTIOXIDANT EFFECT OF α-TOCOPHEROL AND EMULSION STRUCTURE

A lipid oxidation analysis of lecithin based oil-in-water emulsions shows that the antioxidant effect of α-tocopherol solubilized in multilayers of lecithin outside the oil is much higher than the antioxidant effect of the same amount of α-tocopherol solved in the soybean oil. When α-tocopherol is located in the lecithin membranes, the antioxidative effect increases with the antioxidant concentration up to a concentration of about 0.02% (w/w). Higher α-tocopherol levels decrease the protection towards lipid oxidation until a plateau is reached at a level of about 0.09% (w/w) α-tocopherol (calculated on the amount of emulsion). All emulsions studied contain 5% oil, 1% lecithin and 94% (w/w) water.