Abstract: To improve the stability of sweet orange oil emulsion emulsified by tea saponin,the effect of sweet orange oil content and ester gum content on emulsion properties were investigated. Sweet orange oil nanoemulsion was prepared by high-pressure microfluidization and characterized by laser particle size analyzer,spectrophotometer and gas chromatography-mass spectrometer (GC-MS),which contained mean droplet size (MDD),polydispersity index(PDI),turbidity, turbidity loss rate and d-limonene oxidation rate. Besides, the response surface methodology was used to optimize the preparation process. The results showed that the optimal sweet orange oil nanoemulsion process was as follows: sweet orange oil mass fraction was 4.05% and ester gum mass fraction was 2.17%. Under these conditions and using high-pressure microfluidization, the MDD, PDI, turbidity, turbidity loss rate and d-limonene oxidation rate of sweet orange oil nanoemulsion were (130.8±1.4) nm, (0.178±0.010), (0.322±0.001), (0.007 2±0.002 3) A/d and (0.69±0.00)%, respectively. The particle size distribution of the nanoemulsion showed good dispersion. The MDD was less than 140 nm and PDI was less than 0.3 when the nanoemulsion was stored at 4 ℃ for 60 days. It showed good dynamic stability. The research provides references for the preparation and application of sweet orange oil nanoemulsion stabilized by tea saponin.
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