Whey powder rehydration is expected to be closely linked to both denaturation and lactosylation of the proteins. This study investigated the relation between the forced imbibition rate of spray-dried milk serum protein/lactose powders and the particle morphology and how it is related to the insoluble and lactosylated protein fraction, respectively. Despite extensive variation in protein denaturation, aggregation and lactosylation, only comparably small effects on the forced imbibition rate of the powders and the particle morphology could be observed. A possible explanation for this rather limited effect on the rehydration properties and particle morphology might be that the surface composition of the powder particles is rather similar and dominated by native proteins. These insights have relevance for the formulation of whey powders with improved rehydration properties.
