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

Abstract

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.

Keywords:

• Evaporation
• Forced convection
• Heat diffusion
• Inverse method
• Mass diffusion
• Modeling

ACKNOWLEDGEMENTS

The authors thank the European Community for the financial support of this project, and the associated partners, FRPERC for the rig development and Dr A. Kondjoyan (INRA) for his fruitful collaboration.

This study was carried out with financial support from the Commission of the European Community, FP5, Specific Programme “Quality of life and management of living resources,” Key Action 1: Food, Nutrition and Health, QLK1-CT-2001-01415 BUGDEATH. It does not necessarily reflect its views and in no way anticipates the Commission's future policy in this area. The authors thank the associated partners, FRPERC for the rig development and Dr A. Kondjoyan (INRA) for his fruitful collaboration.