PREDICTIVE MODEL OF THE EFFECT OF CO2, PH, TEMPERATURE AND NACL ON THE GROWTH OF LISTERIA-MONOCYTOGENES

The growth responses of L. monocytogenes as affected by CO2 concentrat ion (0-100% v/v, balance nitrogen), NaCl concentration (0.5-8.0% w/v), pH (4.5-7.0) and temperature (4-20 degrees C) were studied in laborat ory medium. Growth curves were fitted using the model of Baranyi and R oberts, and specific growth rates derived from the curve fit were mode lled. Predictions for specific growth rate, doubling time and time to a 1000-fold increase could be made for any combination of conditions w ithin the matrix. Predictions of growth from the model were compared w ith published data and this showed the model to be suitable far predic ting growth of L. monocytogenes in a range of foods packaged under a m odified atmosphere. (C) 1997 Elsevier Science B.V.