Behaviour of Listeria monocytogenes under combined chilling processes


    loading  Checking for direct PDF access through Ovid

Abstract

The behaviour of Listeria monocytogenes under chilling processes was investigated. Growth kinetics were measured at 7 °C in TSBYE culture medium as a function of pH (7.2 and 6.2), pre-incubation temperatures (4 or 7 °C), cooling (0.05 or 0.1 °C min−1) and freezing (0 and −5 °C) treatments. Growth curves generated were fitted by Gompertz and Baranyi functions. The Baranyi function gave better parameter estimation values than the Gompertz equation which over-estimated the specific growth rate values. Listeria monocytogenes grew at 7 °C without a lag phase, except when the sub-culture was performed at 37 °C, whereas the specific growth rate was affected by the chilling processes. In fact, L. monocytogenes grew slightly faster at 7 °C when a 4 °C pre-incubation treatment was applied than with a 7 °C pre-incubation treatment. These results suggest that to mimic the processes of contamination in industry, predictive microbiology studies with L. monocytogenes should be performed with organisms cultured at low temperatures.

    loading  Loading Related Articles