Microencapsulation of fermented noni juice via micro-fluidic-jet spray drying: Evaluation of powder properties and functionalities

Abstract

This study investigated the microencapsulation of fermented noni juice (FNJ) via a novel pilot scale micro-fluidic-jet-spray-dryer (MFJSD). Different concentrations of maltodextrin (M1, 10–13 DE; M3, 17–20 DE) and gum acacia (GA) were used as wall materials. The physicochemical properties, microstructure, droplet-to-particle formation process and bioactives stability of the powders produced by the MFJSD were examined. Results showed that the M1 powders with 28% solid content (M1, 28%) exhibited better bulk density, particle size, glass transition temperature and hygroscopicity than the other three powders produced (namely the M1 (21%), M3 (28%) and GA (21%) powders). The FNJ powders underwent five different stages during the drying process, from isotropical drying, crust formation, solidification and buckling to final particle formation. The external surface morphology of the powders was obviously influenced by the wall materials selected. However, the drying and wall material type have limited effect on the stability of bioactives in the FNJ powders after microencapsulation and during storage. This study provided insight into the micro-fluidic-jet spray drying of FNJ, and evaluated the properties and stabilities of the powders produced.