Manufacture and properties of dairy powders

Abstract

Due to the high intrinsic perishability of milk, strategies for its preservation by partial or almost complete removal of water have been studied and used commercially for over a century. Today, milk-based powders (e.g., whole and skim milk powders) represent a very large sector of dairy commodity production and export trade, and demand for these products, for a range of applications, is increasing. The technology of production of these powders, based around pre-concentration of milk by multi-stage thermal evaporation followed by spray drying in a range of related dryer types, which vary in terms of design, method of atomisation and number of drying stages, is today very sophisticated. Key properties of milk powders, such as their ability to fl ow, remain stable on long-term storage, and reconstitute on addition to water, are infl uenced by drying parameters. Understanding these relationships allows processes to be manipulated in order to yield tailored functionality for each application. The technology of drying milk to produce the principal dairy powders is reviewed in this chapter, along with the principal changes to milk constituents induced by such processes, and the potential for use of these powders in applications such as cheese and yoghurt manufacture