Influence of heat processing and calcium ions on the ability of EDTA to inhibit lipid oxidation in oil-in-water emulsions containing omega-3 fatty acids

The nutritional benefits of omega-3 fatty acids make them excellent candidates as functional food ingredients if problems with oxidative rancidity can be overcome. Oil-in-water emulsions were prepared with 2% salmon oil, stabilized by 0.2% Brij 35 at pH 7. To determine the effects of heating (50-90 degrees C), ethylenediammetetraacetic acid (EDTA), and calcium on the oxidative and physical stability of salmon oil-in-water emulsions, particle size, thiobarbituric acid reactive substances (TBARS), and lipid hydroperoxides were measured. The heat-processed emulsions showed no significant difference, in particle size, TBARS or hydroperoxides during storage, from unheated emulsions. Above 2.5 mu M, EDTA dramatically decreased lipid oxidation in all samples. Addition of calcium to emulsions containing 7.5 mu M EDTA significantly increased both TBARS and hydroperoxide formation when calcium concentrations were 2-fold greater than EDTA concentrations. These results indicate that heat-processed salmon oil-in-water emulsions with high physical and oxidative stability could be produced in the presence of EDTA. (c) 2005 Elsevier Ltd. All rights reserved.