Characterization of milk protein concentrate solubility using focused beam reflectance measurement

Milk protein concentrate (MPC) is a newly developed dairy powder with high protein content (40–90 wt%). MPC is known to have relatively poor dissolution properties, rendering traditional testing methods ineffective for characterizing their functionality. To date, various techniques have been used to quantitatively measure the properties of MPC. Mostly, they are conducted offline with considerable sample preparation that influences the reproducibility of the measurement. Here, a methodology to characterize the solubility of MPC using Focused Beam Reflectance Measurement (FBRM) is presented. FBRM provides the ability to monitor in situ the changes in chord length with time over a wide range of suspension concentrations, which directly reflects the solubility of MPC in this case. Faster rate of the chord length reduction implies a better solubility, as more particles break down and dissolve in solution. In this study, the effect of water temperature was investigated for MPC powders. A characteristic dissolution profile for different MPC powders was subsequently established.