46C-14 |
Ability of lipid hydroperoxides to partition into surfactant micelles and alter lipid oxidation rates in oil-in-water emulsions |
C. D. NUCHI1, P. Hernandez2, D. J. McClements3, and E. A. Decker3. (1) Nestlé Product Technology Center and formerly, University of Massachusetts, 201 Housatonic Avenue, New Milford, CT 06776, (2) Dpto. de Produccion Animal y Ciencia de los Alimentos, Universidad Cardenal Herrera-CEU, 46113 Moncada, Valencia, Spain, (3) Department of Food Science, University of Massachusetts, Chenoweth Laboratory, Amherst, MA 01003 Lipid hydroperoxides are important factors in lipid oxidation due to their ability to decompose into free radicals. In oil-in-water emulsions, the physical location of lipid hydroperoxides could impact their ability to interact with prooxidants such as iron that can promote their decomposition. The objective to this research was to test the ability of surfactant micelles to remove hydroperoxides from oil-in-water emulsion droplets and thus influence the oxidative stability of food emulsions. Corn oil-in-water emulsions containing different concentrations of Brij 76 micelles and lipid hydroperoxides from linoleic acid, methyl linoleate or trilinolein were prepared by sonication. The continuous phase of the emulsion was separated by centrifugation and its lipid hydroperoxide concentration was determined using a spectrophotometric method. Interfacial tension measurements show that linoleic acid, methyl linoleate and trilinolein hydroperoxides are more surface-active than their non-peroxidized counterparts. In oil-in-water emulsions containing surfactant (Brij 76) micelles in the continuous phase, linoleic acid, methyl linoleate and trilinolein hydroperoxides were solubilized out of the lipid droplets into the continuous phase. Brij 76 solubilization of the different hydroperoxides was in the order of linoleic acid > trilinolein ³ methyl linoleate. Brij 76 micelles inhibited lipid oxidation in corn oil-in-water emulsions with greater inhibition of oxidation occurring in emulsions containing linoleic acid hydroperoxides. These data indicate that surfactant micelles can solubilize surface-active lipid hydroperoxides out of the emulsion droplets. Surfactant solubilization of lipid hydroperoxides could be responsible for the ability of surfactant micelles to inhibit lipid oxidation in oil-in-water emulsions.
Session 46C, Food Chemistry: Lipids, antioxidants and emulsifiers
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