46C-4 |
Influence of heat processing and EDTA on lipid oxidation in salmon oil-in-water emulsions |
J. ALAMED1, D. J. McClements, and E. A. Decker. (1) Department of Food Science, University of Massachusetts, Chenoweth Lab, Amherst, MA 01003 The nutritional benefits of n-3 fatty acids make them excellent candidates as functional food ingredients if problems with oxidative rancidity can be overcome. The objective of this research was to establish the effects of heating time, holding temperature, and ethylendiaminetetraacetic acid (EDTA) on the susceptibility of salmon oil-in-water emulsions to lipid oxidation. Oil-in-water emulsions were made by blending 2% salmon oil with 98% aqueous phase (0.2% Brij 35, 10mM acetate/imidazole buffer, pH 7.0) followed by homogenization using an APV homogenizer at 5,000 psi. EDTA (0-167 µM) and calcium (0-62.5 µM) were added to the emulsions after homogenization. Emulsions were heated to 30-90 °C for 10 minutes and then stored at 20 °C in the dark. Particle size was measured by laser light scattering and lipid oxidation was tracked with thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides. Emulsions exposed to temperatures from 30-90 °C showed no difference in particle size, TBARS or lipid hydroperoxides during storage for up to 8 days. EDTA dramatically decreased lipid oxidation in all samples. EDTA added to samples before heat treatments had lower lipid hydroperoxides and TBARS than samples where EDTA was added after heating. Addition of calcium to emulsions containing 7.5 µM EDTA increased both TBARS and lipid peroxide 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. However, the effectiveness of EDTA can be diminished by the presence of calcium. These emulsions could be an excellent source of oxidatively stable n-3 fatty acids that could be used as a functional food ingredient.
Session 46C, Food Chemistry: Lipids, antioxidants and emulsifiers
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