Ability of surfactant micelles to alter the partitioning of phenolic antioxidants in oil-in-water emulsions.

In oil-in-water emulsions, the physical location of antioxidants can be an important determinant in their activity. Surfactants can potentially influence the physical location of antioxidants in oil-in-water emulsions by causing solubilization of lipid-soluble antioxidants into the aqueous phase. Excess Brij micelles in an oil-in-water emulsion were found to increase the partitioning of phenolics into the continuous phase with polar antioxidants (propyl gallate) partitioning more than nonpolar antioxidants (butylated hydroxyltoluene). Solubilization of propyl gallate was rapid coming to equilibrium in less than 5 min. Increasing surfactant micelle concentrations from 0.3 to 2.8% increased the solubilization of propyl gallate by 2.3-fold. Solubilization of phenolic antioxidants into the aqueous phase by Brij micelles did not alter the oxidative stability of salmon oil-in-water emulsions, suggesting that surfactant micelles influenced oxidation rates by mechanisms other than antioxidant solubilization.