The aim of this study was to determine the effects of ultrasound on the dissolution properties of milk protein concentrate (MPC) powders. A high intensity ultrasound (20 kHz; power 70.2 W) was used to dissolve MPC powder and the dissolution rate was compared to conventional methods of dispersion (e.g., stirring). Rehydration of MPC by stirring at 50 degrees C complied with the 2-step dissolution model whereby the disappearance of larger particles coincided with the formation of smaller ones over time. MPC dispersal by sonication dramatically accelerated this process, achieving >90% levels of powder solubilisation. Temperature rise (>70 degrees C) during sonication causes protein denaturation and aggregation, but this can be alleviated using thermal dissipation. Overall, the use of a combination rehydration process for MPC powders involving (i) conventional dissolution (stirring) for 10 min at 50 degrees C followed by (ii) ultrasonication (<50 degrees C) for 1 min (energy density 21.1 J/mL) can achieve rapid powder dissolution. (C) 2013 Elsevier Ltd. All rights reserved.