Controlling milk protein interactions to enhance the reconstitution properties of whole milk powders – A minireview

Abstract

Spray-dried milk powders are widely used in recombined milk products and processed foods. The interactions of the specific components in milk, i.e. casein micelles, whey proteins and fat globules, dictate how milk will behave during processing and the functional properties of the powder in different applications. The manufacture of milk powders involves heat treatments, evaporation, homogenisation and spray drying. The major effect of heat treatment is the denaturation of whey proteins and their association with casein micelles. During evaporation, the casein micelle size increases due mainly to the aggregation of some of the micelles and increased association of the whey proteins with the micelles. During whole milk powder manufacture, there are also considerable changes in the size of fat globules and the protein composition of the milk fat globule membrane (MFGM). This modified composition and the consequent reactivity of the MFGM play a major role in determining the functionality of whole milk powders, in particular its reconstitution properties.