Optimization of Food Thermal Processing: Sterilization Stage and Plant Production Scheduling

Abstract

Two optimization problems that have arisen in thermal process calculation are considered in this chapter. First, there is the problem of thermal process calculation where process time at a specified retort temperature must be calculated to achieve safe levels of microbial inactivation (lethality). Second, there is the problem of determining an optimized scheduling at food canneries using several autoclaves (not necessarily the same capacity), to sterilize given amounts of different canned food products with specific quality requirements. Results obtained in this research for the first problem agreed well with those previously published using more traditional approaches for similar optimization problems. Results further showed the method lent itself well to the use of a cubic spline approximation for the dynamic temperature profiles, thereby reducing significantly the number of variables and dimensional space of the problem, in contrast to other methods, while producing superior results. To demonstrate the feasibility of the mathematical model constructed for the second problem, several examples involving sterilization of different products are included. The proposed methodology is of special relevance to small- and medium-sized food canneries that normally work with many different products simultaneously.