Effects of Irradiation on Bacterial Load and Listeria monocytogenes in Raw Chicken.

After irradiation of chickens to a dose of 2.5 kGy, the decrease in the standard plate count (SPC) was similar in air and in vacuum-packaged chickens. During storage at 4°C for 15 d, the SPC increased progressively in both types of packaged chickens. At the end of the storage period, the SPC was higher in air-packaged chicken than in vacuum-packaged chickens. In irradiated chickens, Listeria monocytogenes was only recovered from the vacuum-packaged chickens after 7 d cold storage. In unirradiated chickens, L. monocytogenes proliferated similarly in both air- and vacuum-packaged chickens.