Nanoemulsion of Satureja battandieri L. Briq essential oil: antioxidant and biological activities for food preservation

This study investigates the formulation, stability, and multifunctional bioactivity of Satureja battandieri essential oil-based nanoemulsions (SbEO-NE), highlighting their enhanced antifungal, antibacterial, antioxidant, anti-inflammatory and toxicity profiles compared to pure SbEO. Gas chromatography-mass spectrometry (GC-MS) analysis identified thymol (45.49 %) and carvacrol (30.11 %) as the predominant constituents, both known for their potent bioactivities. Nanoemulsions were prepared using high-energy ultrasonication with three different concentrations of Tween 80 "1 %, 2 %, and 3 %", with 2 % providing optimal colloidal stability and submicron droplet size (PDI <0.3). In vitro assays demonstrated that SbEO-NE exhibited superior antimicrobial efficacy compared to pure SbEO, with a stronger inhibition of Fusarium oxysporum spore germination was observed (delayed by 64.2 h at 1.3 mg/mL) and significantly lower minimum inhibitory concentrations (MICs) against Escherichia coli and Listeria monocytogenese. Antioxidant activity, assessed by DPPH assay, was notably higher in SbEO-NE, likely due to improved dispersibility and bioavailability of phenolic compounds. In vivo anti-inflammatory effects, evaluated using a xylene-induced ear edema model in mice, showed that SbEO-NE reduced edema by 64 %, compared to 32 % with pure SbEO, indicating enhanced therapeutic potential. Acute oral toxicity assessments revealed no adverse effects, supporting the safety of SbEO-NE for potential food applications. These findings suggest that nanoemulsification significantly enhances the bioactive properties and stability of SbEO, positioning SbEO-NE as a promising natural alternative to synthetic additives in food preservation and bioactive food packaging, with assured biocompatibility and consumer safety.