The effects of fluidised bed and high shear mixer granulation processes on water adsorption and flow properties of milk protein isolate powder

The effects of fluidised bed (FB) and high shear mixer (HS) granulation processes on water adsorption and flow properties of milk protein isolate powder (MPI) were investigated and compared. The agglomerated granules were characterised by different size fractions. It was found that granules produced from the HS process adsorbed less moisture, with slower adsorption kinetics, compared to those produced from using the FB. Granulation reduced the cohesiveness of the MPI powder, with HS having a significant greater impact due to the formation of the particles with higher bulk density and larger size. Particle size played a critical role that influenced water adsorption and flowability. Granulation processes contributed to different degrees to reducing the minimum outlet diameters of hoppers based on either mass-flow or core-flow discharges. HS granules had large wall friction angles, suggesting a need for steeper hopper walls for effective discharge.