Abstract: Thermal treatment techniques for fruit juices have been extensively investigated, primarily to improve the control of process variables and ensure the preservation of product quality. Among these techniques, ohmic heating stands out due to its high energy efficiency, as it generates thermal energy directly within the material through an applied electrical potential. However, maintaining product quality requires precise temperature control capable of adapting to variable conditions. This study characterizes the thermal performance of a bench-scale ohmic cell and presents the experimental results of applying on-off, Fuzzy, and a proposed cascaded Fuzzy control techniques to regulate the temperature of an orange juice solution. The results indicate that the proposed cascaded Fuzzy controller proved to be more robust by combining primary and secondary controllers, maintaining the temperature stability of the cell even when subjected to thermal disturbances, while also reducing energy consumption. These findings reinforce the potential of Fuzzy control for industrial applications.

Keywords: food heat treatment, cascade control, energy efficiency, Joule effect