Nano-emulsification of Osmanthus essential oil: Characterizations, stability and molecular interactions explaining antibacterial activity

The practical usage of Osmanthus essential oil (OEO) in foods is limited due to its poor solubility in water, higher volatility, and instability. This research aimed to prepare OEO nano-emulsion (OEO-NE) by high-pressure homogenization technique and characterize its nano-form (particle size, zeta potential, structure, FTIR, and thermodynamic stability). The antibacterial activity of OEO was researched using network pharmacology and molecular docking. Furthermore, the antibacterial and antioxidant activities of OEO-NE and OEO were researched. The OEO-NE exhibited long-term storage stability compared to the OEO, with particle size changing to 40.90 nm ∼ 68.09 nm and zeta potential changing to −38.37 mV ∼ −35 mV over 31 storage days at 4 °C and 25 °C. Dihydro-β-ionone and linalool oxide showed better binding affinity for S. aureus TyrRS than E. coli 24 kDa. In addition, nano-emulsification effectively stabilizes the antibacterial and antioxidant activity of OEO. Therefore, OEO-NE is an effective strategy to enhance stability and bioavailability. •Nano emulsified Osmanthus essential oil is prepared and investigated.•The nano-emulsion stands long-term stable under wide range of PH and temperature.•The emulsion shows anti-bacterial activity and the key components are identified.•Molecular docking study is conducted to help revealing the underlying mechanisms.