|Title of host publication||Reference Module in Food Science|
|Place of Publication||Amsterdam Netherlands|
|Number of pages||11|
|Publication status||Published - 2017|
The formation of the chemical surface composition in convectively dried milk droplets has been investigated from a range of experimental and numerical studies. The process is complex and of particular importance for the functional properties of spray-dried milk powder, as its surface composition has been found to differ considerably from its bulk composition. The surface of milk powder is usually characterized by a distinct accumulation of fat and, in case of milk emulsions with low fat content, a less-pronounced overrepresentation of protein in comparison with the bulk composition. Based on experimental studies on the drying process of milk powder using various analysis techniques of its surface composition, a number of different concepts have been proposed in literature to explain this segregation mechanism. Furthermore, numerical models of increasing complexity have been developed over the years to contribute toward a better understanding of the segregation process and to predict the powder properties as a function of drying and feed conditions applied.