Assessment of Mutagenic Activity in Thermally Processed, Frozen, Electron-Irradiated, and Gamma-Irradiated Beef Using the Ames Salmonella/Mammalian Microsome Mutagenicity Assay

摘要

Studies were undertaken to determine the mutagenic activity of beef that had been thermally processed, frozen, electron-irradiated, and gamma-irradiated. The Ames Salmonella/mammalian microsome mutagenicity assay, with several modifications, was used. Considerable difficulties in performing the test and interpreting the results were encountered. Experiments conducted showed that on some occasions up to 80% of the apparent revertants were not true revertants. The meats contained water-soluble growth factors, particularly histidine, which apparently supported greater than normal growth and macrocolony formation. Subsequently, the level of histidine in the media was reduced by an amount equal to that contributed by the meats. Also, extracts of the meat were substituted for whole meats as test material for evaluation. Particulate matter from the whole meats made automated colony counting impossible and complicated manual counting. Data collected failed to demonstrate that any of the meats or processing techniques produced mutagens. It was concluded that the test had limited applicability to whole food items and that the use of thermally, frozen, electron-irradiated, and gamma-irradiated processing does not induce mutagenic potential in beef. (Author)