Abstract: In this research, medium-chain triglyceride (MCT) and zein were used respectively as internal oil phase (core) and external shell to prepare MCT/zein microcapsules with core-shell structure by the anti-solvent method. Based on the macro-morphology, micro-morphology and size distribution of microcapsules, the optimum preparation conditions were determined as follows: 0.5% gum arabic (GA) as emulsifier, emulsification speed 800 r/min, zein precipitation with a mixture of 30 mL of water and 100 mL of GA solution added at a rate of 6 mL/min. Scanning electron microscopy, confocal laser scanning microscopy and laser particle size analyzer were used to characterize the structure and size properties of freeze-dried MCT/zein microcapsules. It turned out that the MCT/zein microcapsules had a typical core-shell structure with homogenous size distribution and good storage stability. In conclusion, the anti-solvent method was simple, practical and suitable for the preparation of MCT/zein microcapsules with core-shell structure for application in the encapsulation and protection of various lipophilic bioactive components.

Key words: microcapsule carrier, core-shell structure, anti-solvent method, medium chain triglyceride (MCT), zein