Modelling the hygienic processing of foods - A global process overview

A modelling approach has been developed to predict the implications of processing for microbial growth in food production, storage and distribution. Models based on mass and energy balances together with simple microbial kinetics have been incorporated into a commercial simulation package. The process is evaluated from raw materials through to consumption and as a result a prediction of the contribution of each individual process stage to the microbial level in the product is made. The model is a valuable tool to assist decision making on the operation of existing processes as well as in the process design of new product lines. The system output is a quantitative estimate used as a guide to identifying key process steps rather than a high precision solution to a fully defined problem. This can help to identify critical areas of a process line for which more dedicated programs and microbial kinetics can be used for a more detailed assessment. The model is thus a valuable tool for a HACCP team by providing a more quantitative basis on which to base decisions and set critical limits. The system is a framework within which various models can be combined. An initial test of the model has shown its value in identifying bottlenecks and setting limits for several processes, including both batch and continuous systems.