Caking behaviour of spray-dried powders: using scanning probe microscopy to study nanoscale surface properties

Spray drying is widely used to manufacture many powdered products, with the drying process parameters having significant influence over the final powder’s surface properties and propensity for unwanted caking. In most cases caking experiments are performed on bulk powders, but especially in multi-component powders, it is often difficult to interpret these results, where interaction effects between particles can be complex. Here we use the technique of scanning probe microscopy to characterise the nanoscale properties of spray dried model milk powders in order to investigate the surface properties of the powders.