Improper drying can damage the product. Products needs to be dried to recommended moisture content level. Optimum drying is difficult given the variability of the product being dried. Thus, proper understanding of the drying requirement and process is extremely important. Drying criteria varies from product to product, given the unique characteristics/requirement of different products. Some products are more temperature sensitive than others and hence, require special type of drying. Products, generally have surface moisture (present free on the product surface and can be removed easily) and inherit/core moisture (which is difficult to remove) and require special drying techniques. Drying is also often the largest energy consuming process, and the process needs to be understood effectively to rationalize energy needs. It is important to understand the drying techniques and technologies to reduce spoilage and enhance the quality of the product.
