46C-22 |
Effect of ozone treatment on lipid oxidation in fish oil during storage |
S. Y. TAN, Z. M. Xu, N. R. Pavon, L. V. A. Silva, and J. M. King. Department of Food Science, Louisiana State University Agricultural Center, 111 Food Science Building, Louisiana State University, Baton Rouge, LA 70803 Fish oil is a rich source of long chain polyunsaturated fatty acids (PUFA) that have many nutritional benefits. However, strong fishy flavor deters consumers from using fish oil as a common food. Ozone treatment has been used as an effective method in eliminating unpleasant flavor. This treatment could be employed to reduce the undesirable flavor of fish oil. Because of the high levels of PUFAs, fish oil is susceptible to lipid oxidization. Since hexanal is a major oxidation product of PUFAs, it could be an index for monitoring the lipid oxidation status. The results of this study would be useful in the application of fish oil in the food industry. Our objective was to determine whether ozonation of fish oil would remove or generate new hexanal, during different storage times. Samples were treated with ozone for 0, 10 and 20 minutes at a flow rate of 20 ml/min and stored for 0, 1, 3 and 7 days at room temperature in sealed vials. Ozone was produced using electrolysis. Ethyl heptanoate was added as an internal standard. SPME/GC was utilized to analyze hexanal concentrations. SPME fibers were exposed to the samples for 15 minutes. Hexanal levels in control and treatments were not significantly different within 3 day of storage. As a secondary oxidation product, hexanal may not be significantly produced in the initial storage after treatment. Hexanal content in the control on day 0 was 0.001376 mg. However, the level in each of the controls and treatments was significantly higher after 7 day of storage, by approximately 10 times. This indicated that ozone treatment could accelerate lipid oxidation of fish oil. Fish oil treated with ozone may result in greater lipid oxidation in long-term storage due to increment in hexanal content.
Session 46C, Food Chemistry: Lipids, antioxidants and emulsifiers
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