ABSTRACT
The results of the research on apples give valuable information on the drying behavior of fruits as influenced by drying conditions and control strategy. Drying significantly increases the shelf life of easily perishable agricultural products. In convective drying, particularly in the first drying period, a product temperature is significantly lower than the process temperature due to the difference between dry- and wet-bulb temperatures. Active product temperature control is a promising alternative to standard procedures that could simultaneously increase product quality and process performance. In plant materials, most of the reactions affecting product quality occur in the cell walls and the cytoplasm. The loss of micronutrients during convection drying is a function of temperature, moisture content, duration of the process, and the presence of catalysts. Fruits are highly susceptible to browning reactions during drying and consequent storage. Enzymatic phenol oxidation and nonenzymatic browning are the two main categories of these reactions.
