ARS | Publication request: Formation of trans Fatty Acids in Ground Beef and Frankfurters due to Irradiation

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 9, 2008
Publication Date: December 29, 2008
Citation: Fan, X., Kays, S.E. 2008. Formation of trans Fatty Acids in Ground Beef and Frankfurters due to Irradiation. Journal of Food Science. 74(2):C79-C84.

Interpretive Summary: Consumption of trans fatty acids may increase the risk of coronary heart disease. As a result, health organizations and the U.S. federal government have recommended that consumers minimize their intake of trans fatty acids. Ionizing radiation is a processing technology used to improve the microbial safety and to extend shelf life of various foods. There has been conflicting evidence about the impact of irradiation on the total trans fatty acid content of ground beef. Furthermore, the impact of irradiation on the trans fatty acid content of ready-to-eat meat products has not been reported. The objective of the present study was to investigate possible formation of trans fatty acids and changes in other fatty acids in ground beef and frankfurters due to irradiation. Our results demonstrated that ground beef and frankfurters irradiated at 5 kGy had slightly higher content of the major trans fatty acid than the non-irradiated samples and irradiation at 1 kGy had no effect on any trans fatty acid. Taking the natural variations in trans fatty acid content in meats into account, the effect of irradiation on fatty acid composition at the doses tested was minimal. The information is useful for regulatory agencies to make science-based policies and for consumers to purchase irradiated meat products.

Technical Abstract: This study was conducted to investigate possible formation of trans fatty acids due to irradiation of ground beef and frankfurters. Ground beef and frankfurter samples were irradiated at doses of 0, 1, and 5 kGy at 4 C, and stored at 4 C for 7 days (ground beef) or 3 months (frankfurters). After irradiation and storage of the samples, trans fatty acids along with other fatty acids were analyzed using a modification of AOAC Method 996.01. Results showed that 1 kGy irradiation did not induce any change in trans fatty acid content. However, 5 kGy irradiation caused a small but statistically significant (P<0.01) increase in the dominant trans fatty acid, C18:1 trans , which increased from 3.99% (of total fatty acid) for the non-irradiated ground beef to 4.05% for the 5 kGy sample, and from 1.21% for the non-irradiated frankfurter to 1.28% for the 5 kGy sample. Irradiation had no apparent effect on C16:1 and C18:2 trans fatty acids. In addition, irradiation slightly decreased the relative amount of poly-unsaturated fatty acid of ground beef and frankfurters, particularly after storage. Compared to variations in trans fatty acid content and fatty acid composition occurring naturally in meat and meat products, the changes due to irradiation were negligible.