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℃.