A Critical Review on the Microencapsulation of Bioactive Compounds and Their Application

Microencapsulation is an effective method to incorporate environmentally sensitive bioactive compounds into small capsules to increase stability and bioavailability. The morphological properties, microencapsulation efficiency and release kinetics are important features of final microcapsules. A systematical review of state-of-the-art microencapsulation methods of bioactive compounds is necessary for the food industry to compare the strengths and weaknesses of technologies, and it can enlighten future researchers to explore a new and promising approach in microencapsulating bioactive compounds. This article discussed the differences in the structures and release kinetics between two types of microparticles (reservoir-system and matrix-system), collected the information of bioactive compounds and compared the physicochemical properties of microparticles produced by six microencapsulation methods (spray drying, freeze-drying, fluidized bed coating, extrusion, supercritical fluids, and electrospinning). Main factors including microencapsulation techniques, working conditions, wall materials and the interaction between the wall and bioactive compounds should be noticed by researchers to produce microparticles with desirable characteristics.