Single droplet drying of dairy-based systems at spray drying like temperature–time trajectories

Upon spray drying of dairy powders, the distribution of components within the droplets can become nonuniform. In this study, the influence of the composition on the drying behaviour, morphological development and surface composition were studied using single droplet drying. The addition of fat was found to result in an earlier locking point (1.1 instead of 1.8 s). The fat content did not influence the morphological development, but the protein and lactose ratios did influence whether the dried particle was smooth or wrinkled. Confocal Raman microscopy revealed that the initial fat, lactose and protein contents influenced the dry surface composition. For example, fat was found on the surface of emulsions that were either rich in fat or in whey protein.