The aim of this study is to evaluate and optimize the influence of process conditions on the microencapsulation of DHA algal oil by spray drying, while using whey protein isolate (WPI) and maltodextrin (MD) as wall material. Emulsion stability was analyzed. Microencapsulation efficiency, surface oil content and moisture content are evaluated with the change of five independent variables, including the ratio of WPI and MD, the ratio of core and wall material, total solid content, inlet air temperature and centrifugal disk speed. The morphology of the microcapsules was observed using scanning electron microscopy (SEM). Particle size distribution was measured using high Resolution Laser Particle Size Analyzer. The microencapsulation process was finally optimized at 2.5 of WPI/MD, 0.2 of core/wall material, 0.5 of total solid content, inlet air temperature of 180°C and centrifugal disk speed of 32000 rpm. The produced microcapsules with spherical shape exhibited smooth and free of pores, cracks and surface indentation, which indicated the emulsification and encapsulation of DHA with above process was feasible.
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