Rehydration and powder functionality are important quality parameters in industrial applications, either as ingredients added in dairy applications or used in dry blend products as infant formulas or performance products. Thus, improving powder functionality, particularly the rehydration characteristics, is becoming critically important. Rehydration is essential as most powders must be completely dispersed and dissolved to fully present their functional properties.

This study investigates how the dissolution rate of spray-dried powders on a microscopic level is related to the formulation and properties of the components in the formulation. Milk serum protein concentrate and lactose in varying ratios were used. To study the dissolution rate of the spray-dried powders, a newly developed flow cell-based method with a controlled liquid flow was used. The dissolution of the powders was recorded and the obtained data was analyzed by image analysis. The results indicate that the powder dissolution on a microscopic level is a function of the protein. By characterizing the properties and the dissolution behavior of dairy powders, the production of powders with improved rehydration properties and functionality that are easily dissolved may be possible. This could improve the production efficiency of powders and increase the overall quality of dairy powders.