Application of the thermal inactivation model to model risk to human health from consumption of VTEC O157 in beef burgers

<p>"The purpose of this study was for RIVM to investigate the impact of heat transfer within beef burgers of different sizes on the log inactivation of VTEC O157. The RIVM thermodynamic model divides the burger into a number grid cells dependent on its thickness and width and simulates the heat flow through these cells as it is cooked and the resulting inactivation of bacteria within each cell. The outputs from the thermodynamic model include the time to reach a desired internal cooking temperature and the overall inactivation of VTEC O157 within the burger A number of scenarios were tested to reach different cooking preferences of the consumer. The thermodynamic inactivation model is able to show the time taken to reach the preferred cooking style with a defined internal temperature. The following variables were tested to identify the time taken to reach these scenarios: Thickness / height of the burger – 1 cm for small burgers, 2.5 cm for regular burgers and 5cm for gourmet burgers. Cooking Preference – rare (54.4°C), medium (62.7°C), well done (68.3°C), well done +2 minutes, 4 log inactivation and 6 log inactivation. Following this analysis, the findings of the inactivation of VTEC O157 across different cooking preferences are then input to the APHA risk assessment model to provide the number of human infections of VTEC O157 per 100,000 servings."</p>