Drying of foods under intermittent supply of microwave energy: proposal for a mathematical model

Intermittent microwave drying improves the quality of dehydrated product, because reduces effect hot spots. Mathematical modelling is essential to understand physics this process and optimize operation conditions. However, there are few studies about intermittent drying. This work proposed a mathematical model based on mass balances liquid vapor water in which non-equilibrium formulation described phase change. The heating, by Lambert’s law, was accounting as source term thermal energy conservation equation. numerical solution used finite element method, experimental potato samples validated simulated values moisture content temperature obtained showed good agreement with data. From this, it observed presence three periods kinetics: an initial heating almost without drying, follow constant rate, final decrease rate increasement. results that interior higher than surface sample, evaporation inside potato. In additional, gradients were reduced due intermittency power. redistribution could contribute improvement product during