Spray drying of food: principles and applications

Drying has been historically one of the most practical inventions among others to preserve food for longer periods. It has been known that removing water from food and dairy could preserve their taste, smell, and nutritional values while easing their transportation, storage, and application. Spray drying has been one of the most frequently used techniques for transforming food and dairy into powder products with desirable properties. Spray drying not only facilitates the drying process due to the atomization process but also leads to the development of powders with superior properties such as enhanced flowability, morphology, and size. These capabilities make spray drying a unique method that also complies with continuous manufacturing principles. This chapter aims to introduce spray drying, its fundamental working principles, and its applications in drying food and dairy. In order to provide a deeper understanding of the spray drying process, an overview of the current single droplet drying models and experimental techniques has been provided. The impact of spray drying on carbohydrates, fats, vitamins, proteins, minerals, and antioxidants has been comprehensively reviewed. The reasons for the loss of nutrients during spray drying and the strategies for minimizing the loss have been presented. Moreover, the use of spray drying for processing dairy has been explored, and the impact of process conditions on the properties of the final powder has been investigated. A final remark has been made on the future of technologies used for drying food and dairy and their contribution to improving the quality of the produced powders.