A high concentrate viscosity indicates a greater
degree of water bound to milk proteins and less efficient rate of
moisture transfer to air (Baldwin et al., 1980). Moreover, Baldwin
et al. (1980) showed that the viscosity and the total solids of the
concentrate do not have the same impact on powder properties:
viscosity has a marked effect on the rate of moisture transfer
whereas total content of solids greatly influences the mean particle
size of the powder. In both cases, the resulting large, compact droplets
are more susceptible to unequal drying and local overheating.
The resulting powders have lower solubility indices, and higher
bulk density and mean particle diameter (Fergusson, 1989).