ABSTRACT
Drying of foods and agricultural materials refers to the removal of water by mechanical expression, evaporation at atmospheric or reduced pressures, freezing the water and subliming ice directly to water vapour without passing through the liquid phase, and application of heat to drive off moisture. By drying, water content of food materials can be reduced to below 10% which makes the micro-organisms inactive thus prolonging storage and shelf life of the food. Methods of drying where thermal properties of the material are significant factors in design and analysis are heated air drying and drying by sublimation or freeze drying.
