Effect of temperature abuse on frozen army rations: Part 2: Predicting microbial spoilage

- Growth rates of different microorganisms on beefsteak were modeled.
- Microbial kinetics was incorporated with a heat transfer numerical model.
- Two real-time temperature abuse scenarios were simulated.
- Extent of temperature abuse that would still ensure microbial safety was predicted.

Numerically simulated heat transfer model of frozen US military rations was combined with microbial kinetics to predict the microbial spoilage of the food products, during two possible temperature abuse scenarios. An army breakfast menu box containing five different food items was selected for conducting this research. One of the food item in the menu box, beefsteak, was chosen for detailed microbial study. A microbial predictive tool was used to identify and evaluate the kinetics of the most prone microorganism that can grow in a beefsteak. Numerical predictions suggested that the food items exposed to external temperatures ranging from 20 °C to 40 °C can be allowed to stay at those temperatures for maximum times of 28.7 h to 11.9 h, respectively. The food items can be allowed to stay inside the broken freezer for a maximum time of 186 h, to ensure microbial safety in the case of freezer failure.