基于自组装技术的EGCG多层乳液的制备及其微胶囊化

针对表没食子儿茶素没食子酸酯(EGCG,Epigallocatechin gallate)稳定性差、易氧化降解的问题,采用层层自组装技术对其进行包载,建立EGCG稳态体系的制备工艺,并对产品微观形态及离心稳定性进行考察,进而通过喷雾干燥对其微胶囊化包埋,得到了粒径均一、稳定性较好的EGCG微胶囊。结果表明:在辛烯基琥珀酸淀粉钠(SSOS,sodium starch octenyl succinate)添加量70.0 g、水相油相比8:1 (g/g),剪切速率9000 r/min,剪切时间3 min条件下制备EGCG单层乳液,其离心稳定性系数可达0.138;在阿拉伯胶浓度15%,9000 r/min剪切3 min条件下,进一步制备而得的EGCG多层乳液稳定性较高。经喷雾干燥所得微胶囊的粒径在1~10 μm,其包封率达53.5%±0.5%,呈表面有褶皱无裂痕的椭球状,具有较好热力学稳定性。本研究为提高茶多酚稳定性,拓宽茶多酚产品应用领域提供了理论参考。

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 selfassembly 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 1~10μm,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.