Preparation of EGCG Multilayer Emulsion Based on the Self-assembly Technology and Its Microencapsulation

In view of the poor stability and oxidative degradation of EGCG(Epigallocatechin gallate),the layer-by-layer self-assembly technology was used to encapsulate EGCG. The EGCG steady-state emulsion was prepared by optimization experiment,and the microscopic morphology and centrifugal stability of the samples were also investigated. Based on the preferred parameters,the EGCG microcapsules with uniform particle size and good stability were prepared by spray drying. The results indicated that the centrifugal stability coefficient of EGCG single-layer emulsion reach up to 0.138,which was prepared under the conditions of 70.0 g SSOS,water-oil ratio of 8:1 (g/g),and shear rate 9000 r/min for 3 min. And the EGCG multilayer emulsion with higher stability was prepared under the conditions of 15% gum arabic and shearing at 9000 r/min for 3 min. The ellipsoidal microcapsules with wrinkles and cracks on the surface were obtained by spray drying. The particle size of the microcapsules distributed within 1~10 μm,and the encapsulation efficiency achieved 53.5%±0.5%. This study provided a theoretical reference for improving the stability of tea polyphenols and broadening the application of tea polyphenols.