Abstract:Chu orange（Citrus sinensis Osbeck） essential oil is widely applied in food, medical, and cosmetic industries for its unique odor and antibacterial properties. However, its poor water solubility and strong volatility limit the wider application of this essential oil. In order to overcome these disadvantages, O/W Chu orange essential oil nanoemulsion was prepared with the non-ionic surfactant emulsifiers Tween 80 and Span 80. The effects of surfactant ratio, concentration and emulsification shear rate on the particle size, zeta potential, rheological viscosity and emulsion stability of Chu orange essential oil nanoemulsion were studied.The stable nanoemulsion with the particle size （135 ± 0.76） nm and the absolute vale of zeta potential （30 ± 0.36） mV was obtained under the conditions of 5%（w/w） Chu orange oil, 3% Tween 80 and Span 80（1∶2）, and shear rate of 12 000 r/min. In addition, the antibacterial activity of the Chu orange essential oil nanoemulsion was stronger than that of the pure essential oil，which suggested that nanoemulsion can efficiently improve its utilization. This opens up the possibility of expanding the application of Chu orange essential oil.
