Predictive modelling of Enterobacter sakazakii inactivation in bovine milk during high-temperature short-time pasteurization

A linear model was derived to describe the thermal inactivation of Enterobacter sakazakii in bovine whole milk in a high-temperature short-time pilot scale pasteurizer. Integrated lethal effect, or pasteurization effect (PE), was obtained by converting times at different temperatures in the various sections of the pasteurizer to the equivalent time at the reference temperature (72 degrees C). PE was then related, by a simple linear function, to the log(10) of the % viable counts with a power transformation of the PE values to improve linear fit. R-2 values for the three E. sakazakii trials varied from 0.941 to 0.959. Inter-trial variation was incorporated into the model using @RISK(TM) simulation software, and a comparison between models for E. sakazakii and Listeria monocytogenes revealed that L. monocytogenes was more heat-resistant. Output from simulations confirmed that treatment at 68 degrees C for 16 s can ensure (at the Ist percentile) a 5-log reduction of E. sakazakii. (C) 1999 Canadian Institute of Food Science and Technology. Published by Elsevier Science Ltd. All rights reserved.