Abstract: In order to improve the stability of emulsions, gelatin (GE), soybean protein isolate (SPI), chitosan (CS) and gum arabic (GA) were modified with 3.000% nano-SiO2 and used separately as a stabilizer to prepare camellia oil emulsions. The effect of nano-SiO2 on emulsion properties was investigated by considering emulsifying activity, emulsion stability, centrifugal stability, average particle size, rheological properties, microstructure and oil droplet distribution. The results showed that nano-SiO2 enhanced the stability of emulsions. The comprehensive properties of GE-nano-SiO2 composite emulsion were the best. Addition of nano-SiO2 significantly enhanced the emulsifying activity and emulsion stability (P < 0.05), and reduced the centrifugal stability by 68.444%. The resulting emulsion had the smallest particle size and uniform particle size distribution with an average particle size of 8.472 μm, and the emulsion particles were spherical with smooth surface. The emulsion was rheologically characterized as a typical weak gel with good stability. The results of this study could provide a practical basis for the preparation and application of nano-SiO2-modified natural macromolecules in emulsions.

Key words: nano-SiO2; emulsion; macromolecular materials; camellia oil; stability