Conjugate Heat and Moisture Transfer During a Dynamic Thermal Treatment of Food

This work concerns the thermal decontamination of the surface of a food by hot air with the objective of inactivating the bacteria located at the surface. This heat treatment is considered to be intense and short, compared to more conventional drying processes. In order to predict the surface temperature, a coupled heat and mass transfer model was developed taking into account convective and diffusive mechanisms, evaporation, and shrinkage. A pragmatic alternative between Eulerian and Lagrangian formalisms was used in order to perform an efficient model. It was shown that this thermal decontamination process was governed by convection in a first stage, whereas mass diffusion was the limiting phenomenon in the second period. An inverse method was carried out in order to optimize the parameters of the mass diffusivity law.