Factors Influencing the Instant Solubility of Milk Powders

Abstract

High concentrations of milk solids in the aqueous phase in contact with dissolving milk powder particles render part of their constituents insoluble. This effect has been studied by measuring the amount of milk powder dissolved by volumes of water swept through mixed beds of sand and milk powder as well as beds of sand, water, and milk powder. From a consideration of the increases in solubility occurring as the spatial concentration of powder particles in the beds was decreased, and the decrease in solubility when the water content of the powders in the beds was increased, it was concluded that maximum solubility by self-dispersion can be obtained only with milk powders having bulk densities of less than 0.4 g/ml. Higher bulk densities seem incompatible with instant self-dispersion. Milk solids rapidly lose solubility if their moisture content ranges from approximately 15 to 38%. This unstable range broadens with the increase in the time the milk solids are in contact with the water. © 1963, American Dairy Science Association. All rights reserved.