NEW MODIFIED SQUARE-ROOT AND SCHOOLFIELD MODELS FOR PREDICTING BACTERIAL-GROWTH RATE AS A FUNCTION OF TEMPERATURE

A new modified Square Root model and two new modified Schoolfield models were evaluated for their ability to predict the growth rate of Yersinia enterocolitica as a function of temperature. The new Square Root model fits the data better than both the original Square Root model and the Zwietering Square Root model. Both new Schoolfield models, a six- and a four-parameter equation, fit the data better than the original Schoolfield model. The new four-parameter Schoolfield model was developed by removing the term describing low temperature inactivation from the new six-parameter Schoolfield model. Inclusion of the two extra parameters in the new six-parameter Schoolfield model (F = 318) did not significantly improve the fit compared to the new four-parameter Schoolfield model (F = 488).