ABSTRACT
Drying reduces the water activity, thus preserving foods by avoiding microbial growth and deteriorative chemical reactions. The heating effects on microorganisms and enzyme activity are also important in the drying of foods. In the case of foods to be preserved by drying, it is important to maximize microorganism and/or enzyme inactivation for preventing spoilage and enhanced safety, and to reduce the components causing dried foods’ deterioration. On the other hand, in the case of drying bacterial cultures, enzymes, or vitamins, minimum inactivation of the microorganism and/or enzyme is required. Thus, the detrimental effects of drying may be desirable or undesirable depending on the purpose of the drying process. Initial freshness plays an important role in determining the quality of dried foods. The fresher the raw material, the better the stability and quality of the dried products. Suitable varieties or species of produce with desired maturity should be used to achieve the desired product with the best possible quality [1]. The quality characteristics of dried foods can be grouped as microbial, chemical, physical, and nutritional (Table 28.1). Quality Characteristics of Dried Foods https://www.niso.org/standards/z39-96/ns/oasis-exchange/table"> Microbial Chemical Physical Nutritional Pathogens Browning Rehydration Vitamin loss Spoiling Oxidation Solubility Protein loss Toxin Color loss Texture Functionality loss Aroma development Aroma loss Fatty acid loss Removal of undesired components Porosity Shrinkage Pores’ characteristics Crust formation Structure
