Chapter 5Dehydration: Spray Drying—Freeze Drying

Drying or dehydration of foods is an extremely important food-processing operation used to preserve foods for extended periods of time. Although both these terms are applied to the removal of water from food, drying usually refers to natural desiccation, such as spreading fruit on racks in the sun, and dehydration designates drying by arti“cial means, such as a blast of hot air. The distinguishing features between drying and concentration are the “nal level of water and nature of the product. Concentration leaves a liquid food, whereas drying typically produces product with water content suf“ciently low to give solid characteristics.