Sensitivity of bacteria to irradiation on poultry meat under various atmospheres

The sensitivity of seven bacterial species inoculated on to sterile poultry meat and irradiated under various atmospheres (air, CO2, vacuum and nitrogen) was investigated. The irradiation sensitivities of Streptococcus faecalis and Staphylococcus aureus were unaffected by atmosphere. The other micro-organisms (Pseudomonas putida, Salmonella typhimurium, Escherichia coli, Moraxella phenylpyruvica and a Lactobacillus sp.) were more sensitive (their D10 values decreased) when irradiated in atmospheres other than air. In general, a vacuum or CO2 atmosphere during irradiation was found to have the most lethal effect. Plating media were found to have a significant effect on the recovery of irradiated E. coli and Salm. typhirium.