The encapsulation of curcumin in whey protein microparticles by spray drying was done to improve solubility and thus, the bioavailability of curcumin. In solution, curcumin formed soluble complexes with whey protein isolate (WPI) via hydrophobic interactions and its solubility increased linearly with WPI concentrations. Solutions of WPI-curcumin complexes were spray-dried as uniform microparticles via a microfluidic jet spray dryer. Nearly 100% curcumin was retained in amorphous state and the microparticles could be easily rehydrated as transparent dispersions irrespective of the drying temperature. Antioxidant properties of these microparticles were studied by DPPH test, showing a higher DPPH radical scavenging activity for curcumin-loaded microparticles compared to that of WPI particles as benchmark. The ability to generate easily dissolved powders containing water-insoluble ingredients such as curcumin is a beneficial approach for pharmaceutical and functional foods applications. (C) 2015 Elsevier Ltd. All rights reserved.