摘要：Drying is one of the most complicated food proce sses which include simultaneous heat and mass transfer. It is generally defined as the removal of moisture from food. The microbial and enzyme activity in dry food products are quite low due to reduced water activity. Therefore, drying is widely preferred in long term storage of foods. The drying mechanism, common drying techniques used in industry and thin layer drying models were summarized in this review. Thin layer drying models can be classified as theoretical, semi-theoretical and empirical. Theoretical models can be applied to all process conditions. However, due to their practical inconvenience, semi-t heoretical and empirical models are widely preferred in drying studies. Among the models studied in food drying, semi-theoretical models, Page and Midilli, were found to be the best fit ting models. In addition, the effective diffusion coefficie nt calculated from Fick's Second Law and the activation energy, which is determined using Arrhenius equation, give valuable information regarding drying. The effective diffusivities and activation energy values in foods were reported in the range of 10 -7 -10 -1 1 m 2 /s and 10-80 kJ/mol, respectively.
