Manufacture of Milk and Whey Products: Whole and Skim Milk Powder

Abstract

Dehydration is used to manufacture milk powders and to stabilize milk constituents for storage, transport and subsequent use. Dehydration by spray drying using hot air is one of the most convenient techniques for water evaporation in the production of milk powders and for stabilizing the majority of milk constituents. Before spray drying, the milk undergoes several processes such as heat treatment, fat separation, membrane processes, vacuum evaporation, and/or homogenization. The physical-chemical, nutritional, functional, and microbiological properties of milk powders are influenced by a number of factors such as processing and storage conditions. This article provides the reader with an overview of the manufacture of whole and skim milk powders, including the key unit process of spray drying, and provides an overview of modeling and water transfer simulation (drying and rehydration). The article also provides an overview of the critical physical-chemical and functional properties of dairy powders, including powder particle properties, rehydration (wettability, sinkability, dispersibility, solubility) characteristics, hygroscopicity, heat stability, emulsifying properties, glass transition temperature, water activity, and stickiness and cakiness.