Unusual antioxidant effects in multiphase and complex systems

Abstract

In recent years, a number of studies have produced evidence that the multiphase and boundary effects in the systems containing surfactants, have to be taken into account for the development of innovative antioxidant technologies of lipid containing products. This report presents some unusual antioxidant effects, which occur only in multiphase complex systems due to the influence of surfactants (S). Hydroperoxides (LOOH), the primary oxidation products, form mixed micelles with surfactants (S) {nLOOH…mS}. In the case of cationic surfactants (S+), an accelerated hydroperoxide decomposition resulted in free radical generation occurs. Moderate magnetic field affects the free radical escape from mixed micelles {nLOOH…mS+} into bulk solution; it can result in inhibiting of lipid oxidation in micellar system. Nonionic S can inhibit the catalyzed lipid oxidation by solubilization of the hydrophilic catalyst and spatial separation of the catalyst and substrate. Anionic surfactants alkylsulfates and alkylphosphates are effective antioxidants for alkylaromatic hydrocarbons due to the catalytic heterolytic decomposition of hydroperoxides into carbonyl compound and phenol which scavenges peroxyl radicals.Practical applications: Some antioxidant effects caused by surfactants, which occur only in multiphase systems, are presented. Hydroperoxides (LOOH), the primary oxidation products, form mixed micelles with surfactants (S) {nLOOH…mS}; in the case of cationic surfactants (S+), accelerated hydroperoxide decomposition resulted in free radical generation occurs. So, the mixture of cationic surfactants with hydroperoxides can be used as free radical initiators at moderate temperatures; anionic surfactants (S−) inhibit such processes. Alkylsulfates and alkylphosphates are effective antioxidants for alkylaromatic hydrocarbons due to the catalytic heterolytic decomposition of the alkylaromatic hydroperoxides into phenol and carbonyl compound. Nonionic surfactants can inhibit the catalyzed oil oxidation by solubilization of the hydrophilic catalyst and spatial separation of the catalyst and substrate. Moderate magnetic field decreases the free radical escape from mixed micelles {nLOOH…mS+} into bulk solution; it can result in the inhibition of oil oxidation in the micellar system.External static magnetic field, SMF, 60–150 mT, reduces the yield of radicals in the decomposition of hydroperoxides in mixed micelles with cationic surfactants and acetylcholine chloride (ACh); by this reason SMF can retard lipid oxidation in the presence of ACh and cationic surfactants.