Variable retort temperature optimization benefit in scheduling for retorts of different capacities in food canneries

摘要

In the majority of small- to medium-sized canneries, retorting is carried out in a battery of retorts asa batch process. For such canneries, the unloading and reloading operations for each retort are laborintensive;therefore, a well-designed and well-managed plant should be utilized in order to optimize thewhole sterilization process. In other words, it is necessary to develop a suitable mathematical model for theoperation of the whole plant and to determine the optimal values of its decision variables. The result of such amodel involves the quantities of each product to be loaded onto the retorts for each of the batches, and theoptimal solution provides an optimum scheduling. On the other hand, it is well-known that variable retorttemperature processing can be used for reducing the sterilization processing time required for sterilizationusing the traditional constant retort temperature processing. Therefore, the objective of this researchconsisted of utilizing a variable retort temperature processing in developing a mathematical model forscheduling at food canneries for the case of retorts of different capacities. The developed model was based onmixed-integer linear programming and simultaneous sterilization based on variable retort temperatureprocessing. The adaptive random search algorithm coupled with penalty functions approach, and the finitedifference method with cubic spline approximation are utilized in this study to obtain the simultaneoussterilization vectors to be processed under time-variable retort temperature. The proposed in this studymethodology can be useful for small- and medium-sized food canneries, which work with many differentproducts simultaneously.