大豆分离蛋白-茶皂素复合乳化剂制备山茶油纳米乳液及其性质研究

为提高山茶油稳定性、减少化学合成乳化剂使用量,本研究主要采用微射流高压均质技术,利用大豆分离蛋白(Soy Protein Isolate,SPI)与茶皂素(Tea Saponin,TS)作为复合乳化剂制备山茶油纳米乳液。研究了茶皂素与大豆分离蛋白比例、复合乳化剂质量分数、山茶油质量分数、均质压力对山茶油纳米乳液的平均粒径、多分散性指数(Polydispersity Index,PDI)、ζ-电位、浊度等性质的影响。结果表明,山茶油纳米乳液的最佳制备工艺参数为:茶皂素与大豆分离蛋白比例为2:1,复合乳化剂质量分数为3%,山茶油质量分数为10%,均质压力为100 MPa,得到山茶油纳米乳液的平均粒径为(198.800±1.558) nm,PDI为(0.140±0.017),ζ-电位为(-53.600±0.497) mV,浊度为(3661.224±45.996) cm-1。透射电镜观测结果表明,山茶油被包埋于复合乳化剂中且均匀分布在乳液体系中。流变特性研究表明,山茶油纳米乳液具有良好的动力学稳定性。储存稳定性表明,复合乳化剂稳定的山茶油纳米乳液在4、25、50 ℃下具有良好的储藏稳定性。

Preparation of Camellia Oil Nanoemulsion by Soy Protein Isolate-Tea Saponin Compound Emulsifier and Properties of Nanoemulsion

In order to improve the stability of camellia oil and reduce the use of chemical synthesis emulsifier, this study mainly adopted high-pressure microjet homogenization technology to prepare camellia oil nanoemulsion using soybean protein isolate (SPI) and tea saponin (TS) as compound emulsifier. The ratio of tea saponin to soy protein isolate, the concentration of complex emulsifier and camellia oil, and the homogenization pressure were studied. The results showed that the optimal preparation parameters of camellia oil nanoemulsion were as follows:The ratio of tea saponin to soybean protein isolate was 2:1, the mass fraction of compound emulsifier was 3%, the mass fraction of camellia oil was 10%, and the homogenization pressure was 100 MPa.The mean particle size of the nanoemulsion of camellia oil was (198.800±1.558) nm, PDI was (0.140±0.017), ζ-potential was (-53.600±0.497) mV and the turbidity was (3661.224±45.996) cm-1. It was observed by transmission electron microscopy that camellia oil was embedded in the composite emulsifier and evenly distributed in the emulsion system. The rheological properties of the camellia oil nanoemulsion showed good kinetic stability. The storage stability showed that the compound emulsifier-stabilized camellia oil nanoemulsion had good storage stability at 4, 25, and 50℃.