Efficiency of a reheating step to inactivate Clostridium perfringens vegetative cells: How to measure it?

Clostridium perfringens is responsible for foodborne diseases often associated with processed meats in institutions. This study investigated the behavior of C. perfringens in beef-in-sauce products in a French hospital. In the studied process, the final reheating step makes the inactivation of C. perfringens vegetative cells possible. The aim of this study was thus to combine microbial, thermal and dose response modeling to propose, for this reheating step, three new control measures which are as efficient as current French regulation while also being easier to apply. These measures were based on thermal process duration (DA53), final temperature in food (FTF) and sum of temperatures-minutes above 53 °C (ST53) required to achieve food safety. A criterion was defined to describe the ability of the proposed control measures to lower the risk of foodborne illness related to the consumption of products with high populations of C. perfringens vegetative cells before reheating. imate acceptable values of DA53, FTF and ST53, variability and uncertainty were taken into account separately. A two dimensional Monte Carlo simulation enabled the definition of 14 measure thresholds which made sure with a 97.5% confidence that less than 20%, 10% or 5% of exposed consumers in a specified population would experience diarrhea. The three proposed control measures, single and combined, were then compared by estimating the duration required to reach control measure thresholds. This required duration differs significantly from a control measure to the other, with the lowest duration for the combination of FTF and DA53.