Antioxidant Protection of an Omega-3 Fatty Acid Fortified Dairy-Based Beverage
Skim, butter-derived aqueous phase, anhydrous milk fat, and fish oil were used to formulate ultra high temperature (UHT) processed extended shelf-life omega-3 fatty acid fortified dairy-based beverages with fat contents mimicking whole milk (3.25%). Oxidation of the lipids in the formulated beverages was investigated during storage for 35 days at 4 °C using GC/MS analysis, conjugated diene analysis, and headspace solid phase micro-extraction GC/MS (SPME-GC/MS) analysis of headspace. Omega-3 fatty acid fortified dairy-based beverages were produced that mimicked the physical properties of 3.25% fat whole milk. Oxidation resulted in only small changes in omega-3 lipid content and sensory analysis by an untrained panel indicated that the overall aroma was no different than that of commercially available UHT processed milk. An omega-3 fatty acid fortified dairy-based beverage was produced that delivered 440mg of omega-3 fatty acid per 8oz serving. When consumed daily, the beverage could provide the equivalent amount of omega-3 fatty acids recommended by the American Heart Association, and the equivalent amount of omega-3 fatty acids found in two fatty fish meals over the period of one week.
Antioxidants were added to the lipid phase, immediately prior to processing, of additionally produced formulations to determine if a reduction in omega-3 lipid oxidation was observed. No overall reduction in oxidation was observed, as indicated by GC/MS and SPME-GC/MS analysis. Sensory analysis indicated that oxidative aromas increased during storage for the antioxidant and omega-3 fatty acid fortified dairy-based beverage. Ascorbyl palmitate was determined to have a pro-oxidative effect on the formulated omega-3 fortified dairy-based beverages. Antioxidants present in the commercial grade fish oil used for fortification were effective in controlling oxidation in the formulated omega-3 fatty acid fortified dairy-based beverages.