Water removal by spray-drying solutions is a common engineering practice. By decreasing water content and water activity, spray-drying is generally used in food industry to ensure a microbiological stability of products, avoid the risk of chemical and/or biological degradations, reduce the storage and transport costs, and finally obtain a product with specific properties like instantaneous solubility for example. The spray-drying process has been developed in connection with the manufacture of dried milk. However, when milk is spray-dried, the process can be considered as a microencapsulation one; milk fat is being the core material that is protected against oxidation by a wall material consisting of a mix of lactose and milk proteins. In this
mix, the carbohydrates provide structure through glass formation
whereas the proteins provide emulsification and
film forming properties