Preparation, Characterization and Properties of Patchouli Essential Oil Nanoemulsion

In order to improve the stability and bacteriostasis of patchouli essential oil, high-energy emulsification method was used to prepare patchouli essential oil nanoemulsion by using a mixture of tween 80, thiamine pyrophosphate and chitosan, its structure, particle size, ζ potential and polymer dispersity index were analysed. The results showed that the particle size of the newly prepared patchouli essential oil nanoemulsion was about 89.5 nm. The encapsulation rate of patchouli essential oil was 95.85%, and the retention rate remained above 85% for up to 7 days at room temperature. Furthermore, fluorescence microscopy and scanning electron microscopy demonstrated that the droplets of the emulsion were spherical and the dispersion of oil droplets was relatively uniform. It was also showed that the patchouli essential oil was encapsulated in nanoemulsion based on the Fourier transform infrared spectroscopy and X-ray diffraction experiments. The results of the antioxidation and antibacterial experiments showed that the patchouli essential oil nanoemulsion exhibited a better oxidation stability, it had a good inhibitory effect on Staphylococcus aureus and Escherichia coli within a period of 7 days. Altogether, patchouli essential oil nanoemulsion showed a better stability and bacteriostatic activity compared to pure essential oil, and had a broad application prospect in the fields of food preservation.