Ability of chelators to alter the physical location and prooxidant activity of iron in oil-in-water emulsions

Our research determined whether chelators could influence physical location and prooxidative activity of lipid-phase iron in oil-in-water emulsions. Corn oil saturated with ferric ions was used to produce polyoxyethylene 10 lauryl ether-stabilized oil-in-water emulsions. Continuous-phase iron concentrations increased with increasing chelator concentrations (10 to 100 muM and storage time (1 to 7 d). At pH 3.0, the concentration of continuous-phase iron was higher in the presence of EDTA and sodium tripolyphosphate (STPP) than citrate. STPP and EDTA were more effective than citrate at inhibiting lipid oxidation at pH 3.0. These results indicate that chelators can increase the transfer of iron in lipid to the aqueous phase, thus altering its prooxidant activity in oil-in-water emulsions.