Assessment of Thermal Resistance of Hot Water in Pasteurization

Pasteurization is a process that eliminates microorganisms and minimizes nutrient loss in fruit juices, thus extending their shelf life. It is effective for juices with a pH range of 3.5-4.6. It involved three computational domains: the bath fluid, the thickness of the container, and the juice-filled container. The temperature-dependent properties of real fruit juices were converted into experimental model equations. They were incorporated into the computational fluid dynamics (CFD) simulation. The governing equations were solved simultaneously in each domain. We activated conjugate heat transfer, allowing heat transport between domains through fluid-solid and solid-fluid interfaces. Simulation results were validated with experimental measurements of time-temperature history at the can's center. Three CFD formulations were used to investigate the thermal resistance of hot water in pasteurization. Three domains were simulated simultaneously in the first approach. In the second method, the bath temperature was directly specified on the inner wall of the sealed container. During the third approach, we deactivated natural convection in a juice-filled container suspended in hot water. The findings indicate that using hot water as a heat source extends the duration by 10 min compared to isothermal conditions on the inner wall, regardless of the type of juices filled in the container.