The objective of this research was to study the co-encapsulation of Coenzyme Q(10) (CoQ(10)) and vitamin E (VE) using single droplet drying (SDD) and micro-fluidic-jet spray drying (MFJSD), to study the particle formation-structure- function relationships of the microcapsules. Single droplets of selected CoQ(10) and VE-containing emulsions were studied for their particle formation under convective drying (at 70 and 90 degrees C for 10 min) and rehydration processes using the SDD device. The emulsions were also spray-dried (at 160 and 190 degrees C) by MFJSD to form monodisperse microcapsules, followed by analyses of powder properties and functionalities. Results from SDD showed emulsion droplets with 30% w/w solids content were associated with earlier crust formation (30 s faster) and less particle shrinkage during drying compared to those with 10% w/w solid content. Comparing the spray-dried microcapsules produced from the emulsions containing 30% and 10% w/w solids content, the former gave larger particle size (172-175 mu m vs. 116 mu m), higher microencapsulation efficiency (ME) (98-99% vs. 96%), lower tapped density (0.532-0.599 g/cm(3) vs. 0.406-0.502 g/cm(3)) and better flow properties (Carr's index of 22.06-29.19% vs. 22.70-40.64%). Overall, the CoQ(10) and VE retention, antioxidant capacities and colour of the microcapsules were relatively stable when spray-dried at 190 degrees C than at 160 degrees C.