A two-dimensional axial symmetric simulation model for continuous ohmic heating of hazelnut cream and carrot puree

Technology in the food industry has moved towards reduction of mechanical and thermal damage, increase of hygienic safety and a choice of preservation methods based on physical principles, leading to improvement in quality. Ohmic heating is one of these preservation techniques. Two different food products, a hazelnut cream and a carrot puree, were treated using an ohmic heater. The treatment of both these products was simulated with a computational fluid dynamic (CFD) code using finite element methods (FEM), adopting user-defined functions for Joule effect equations (Comsol Multiphysics 3.3a). It was observed that the model and experimental data reached a good agreement: the model tended to predict temperature distribution and, in particular, final temperature of the ohmic heater. The two dimensional model also permitted, identification of velocity, electrical conductivity and dynamic viscosity distribution. A two-dimensional axial symmetric model has been adopted to reduce the computational time, although keeping a good level of detail.