This chapter describes and discusses some results obtained through the study of the microencapsulation of açai juice by spray drying using different carrier agents. Initially, the influence of process conditions on the moisture content, process yield and anthocyanin retention was evaluated using a central composite design. From the conditions selected in this first section (inlet air temperature of 140oC, feed flow rate of 15 g/min and 6% of carrier agent), particles were produced using four types of carrier agents: maltodextrin 10DE, maltodextrin 20DE, gum Arabic and tapioca starch. These particles were then characterized with respect to water activity, bulk and absolute density, porosity, particle size distribution and morphology. The samples produced with maltodextrin 20DE and with gum Arabic exhibited the highest water activity and the lowest particles size, while those produced with tapioca starch were the less porous, with the lowest bulk density and highest mean diameter. Then, physical stability of particles, when exposed to different relative humidities, was evaluated through the construction of sorption isotherms and determination of the glass transition temperature. The samples produced with maltodextrin 10DE exhibited the highest critical water activity, being considered as the most stable powder. Glass transition temperature decreased with increasing moisture content, confirming the plasticizant effect of water on this property. Finally, anthocyanin stability of powders stored at different temperatures and relative humidities was evaluated. The increase of both these parameters resulted in higher anthocyanin degradation. Maltodextrin 10DE was the carrier agent that showed the best pigment protection, for all the conditions studied.