Abstract
The effects of packaging atmosphere, storage temperature and oregano essential oil (EO) on growth of Listeria monocytogenes on ready-to-eat smoked turkey were studied. Smoked turkey slices were inoculated with a strain of Listeria monocytogenes Scott A (5.95, 5.28 and 5.26 log CFU/g) then vacuum packaged (VP), modified atmosphere packaging (MAP: 40% CO2 and 60% N-2) and MAP with oregano essential oil (MAPEO), respectively. The treated slices were then stored at 0, 5, 10 and 15 degrees C for 179.88days and the L. monocytogenes Scott A's growth and microbial shelf life were monitored. The combination of MAP or MAPEO and storage temperature did not allow growth of L. monocytogenes higher than log 1CFU/g during all storage periods. While in VP temperature combinations, the multiplication of bacteria were1 log CFU/g. In VP, MAP and MAPEO smoked turkey, the growth of L. monocytogenes increased regardless of storage temperature. In MAPEO samples the inoculum in the product was suppressed by ca. 5log CFU/g at 0, 10 and 15 degrees C at 180, 117 and 81days of storage, respectively. The inhibition of L. monocytogenes in ready-to-eat smoked turkey by the combinations of MAP and MAPEO was enhanced by storage at 0 or 5 degrees C. The MAPEO system can be used effectively to control growth of pathogen in processed food when maintaining fixed temperature measures is difficult.