The application of a log‐logistic model to describe the thermal inactivation of Clostridium botulinum 213B at temperatures below 121.1°C

Abstract

In this work, the death of Clostridium botulinum 213B was measured at temperatures between 101 degrees C and 121 degrees C. It was found that at all temperatures tested, survivor curves deviated from log-linearity which prevented their description using traditional first order kinetics. The survivor curves were better described using a vitalistic approach and the log-logistic transformation proposed by Cole et al. (1993). A single equation was derived to describe all survivor curves over the temperature range tested and a comparison of predicted and measured data showed good correlation. The implications of the use of the vitalistic approach to the validity of the 'minimum botulinum cook' is discussed.

Heat resistance of Lactobacillus spp. isolated from Cheddar cheese

“…Anderson et al (1996) used a log/logistic method to interpret the data, while a log/linear method was used by Turner et al (1986), Adams et al (1989) and Waiter et al (1995). When equations of best fit were applied to the present data, the linear model gave r 2 values ×0·91 and calculations were based on this model.…”

A model of non‐isothermal degradation of nutrients, pigments and enzymes

“…Although van Boekel's analysis focused on microbial cells, there is clear evidence that the survival curves of several bacterial spores of food safety concern can also be described by the same model. 4,5,7 The heat inactivation of bacterial cells and spores is obviously a more complex process than the degradation of a single chemical compound or the denaturation of a single enzyme. Nevertheless, both processes are manifested in similar 'survival curves', ie a plot of the fraction of surviving cells or spores versus time in the first case and the fraction of intact or active molecules versus time in the second.…”

Thermische Inaktivierung von Mikroorganismen: Zur Modellierung temperaturabhängiger Prozesse

“…Man siehe dazu z. B. den sehr umfassenden Artikel von Pardey et al [1] und die dort zitierte Literatur, weiterhin Kopf et al [2], Peleg et al [3], Moats et al [4], Anderson et al [5], Stephens et al [6] sowie die Arbeiten der Verfasser [7 -11]. Die zu Grunde liegende Fragestellung lässt sich -für den Fall der thermischen Inaktivierung -wie folgt formulieren: Eine Probe mit Anfangskeimzahl N 0 wird ab einem Zeitpunkt t = 0 einer keimtötend hohen Temperatur T (in Grad Celsius) ausgesetzt.…”