Abstract: For soybean oil added with arachidonic acid (AA) emulsion stabilized by whey protein, the effects of iron concentration, chelator and antioxidant on lipid oxidation during accelerated oxidation were examined in this paper. Lipid oxidation determined by TBARS indicated that iron was an important lipid oxidation catalyst in emulsion and the oxidation rate was greatly affected by chelating agent - sodium citrate. The preventive effect of antioxidant on oxidation obviously occurred in the latter oxidative process to eliminate oxygen produced during the oxidative chain reaction. The cooperative effects of both chelator and antioxidant on both the oil-in-water emulsion and the formula powder could greatly prevent the lipid oxidation of fatty acids during preparation and storage.

Key words: emulsion, lipid oxidation, whey protein, iron, chelator, antioxidant