Effects of Ionizing Radiation on Microbiological Contaminants of Foods

Abstract

Ionizing radiation can be used in food industry in order to control the number of microbiological contaminants, among others. The sources of irradiation allowed to be used in this respect are: high-voltage electron beams up to 10 MeV, X – rays up to 5 MeV and gamma rays produced from the radioisotopes 60Co and 137Cs. One of the most important properties of irradiation is inactivation of microorganisms, especially pathogens. Gram-negative pathogen bacteria are very sensitive to radiation. As expected bacterial spores are more resistant to ionizing radiation than vegetative cells are. Irradiation also reduces the number of mould populations. Yeasts on the other hand are more radio-resistant than bacteria and moulds and can become the dominant flora of irradiated foods. In what viruses are concerned, ionizing radiation must be accompanied by other treatments in order to be an efficient inactivation method. In conclusion, ionizing radiation can be used, at acceptable doses, as a control method in preserving the innocuity of foods.