[Aim] The industrial washing process of harvested products, like fruits and vegetables, is often performed through a flume washing tank. In this kind of operation, a certain level of disinfectant concentration is required to guarantee bacterial inactivation under security thresholds in wash water, which implies avoiding cross contamination and ensures food quality. Additionally, high levels of organic matter and chlorine-based disinfectant in wash water produces hazardous byproducts. In this study, we seek to establish an optimal setup for the washing process, ensuring the attainment of a bacterial threshold level while avoiding the formation of byproducts. [Method] A convection-diffusion-reaction model has been used to simulate the disinfection process in a washing tank, describing the evolution of species present in the washing water in the system. The species considered were a chlorine-based disinfectant, organic matter identified by chemical oxygen demand, and bacterial concentration, taking E. coli O157:H7 as a case study. We propose a reduction of the system to a one spatial dimension problem, to facilitate and allow optimization other way not possible. The objective of the optimisation problem is to minimise the disinfectant added through the injection ports while guarantee certain maximum bacteria concentration and the model dynamics. [Results] Optimal disinfectant profiles were achieved, meeting the requirements set by the optimization problem, were the constraints of the optimization problem as well as the cost function definition have their foundations by findings from prior studies. It was determined that with constant incoming concentrations of organic matter and bacteria into the tank, the injection port that is closest to the entrance, must have the higher concentration of disinfectant added. Additionally, subsequent additions will assist in adjusting bacterial levels to gradually reach the safety threshold. [Conclusion] A methodology has been developed to optimize the disinfectant dosages of the washing process for fruits and vegetables in industrial tanks. The quantity of disinfectant added at each injection port has been optimised to ensure food safety and minimize the maximum concentration of free chlorine in the system, therefore reducing the formation of hazardous byproducts

38th EFFoST International Conference 2024. Future Food Systems: Innovation through Progress at Scientific Interfaces, 12-14 November 2024. Bruges, Belgium

Peer reviewed