Review of Some Thermal Methods in Drying and Roasting Processes

Thermal processing is a routine procedure in food science, with two important methods being drying and roasting. During thermal processing, simultane-ous heat and mass transfer occur, where the distribution of heat and humidity depends on effective diffusivity. Various methods exist for achieving this, each differing in efficiency and energy consumption. The conventional method of thermal processing involves hot air (HA) or convection, which typically requires sig-nificantly more energy and time (at least 25%).

However, there are newer thermal processing methos based on radiation, each with their own advantages and disad-vantages. Nevertheless, all radiation-based methods generally consume less time and energy compared to the HA method. Different thermal processing methods have been studied and reviewed with regard to their energy consumption and effective diffusivity. In summary, while HA remains the routine method in indus-tries, it demands considerably more energy and time compared to radiation-based methods. Radiofrequency is a non-thermal method that can also be employed to enhance the efficiency of various processing techniques.