Physicochemical, Chemical, and Antibacterial Characterization of Lavandula angustifolia Essential Oils Cultivated in Çankırı, Türkiye

The present study investigates the physicochemical, chemical, and antibacterial properties of essential oils obtained from the flower (LF-EO) and stem-leaf (LSL-EO) fractions of Lavandula angustifolia cultivated under the semi-arid continental conditions of Çankırı, Türkiye. The essential oils were extracted by hydrodistillation using a Neo-Clevenger apparatus and characterized in accordance with ISO 3515:2002 and related standards. The physicochemical parameters of LF-EO, including density (0.8937 g mL⁻¹), refractive index (1.4566), optical rotation (-9.50°), and ester value (55.04 mg KOH g⁻¹), were consistent with the ISO specifications for high-quality lavender oil. GC-MS analysis identified 98.11 % (LF-EO) and 98.42 % (LSL-EO) of total volatile constituents, revealing β-linalool (44.77 % and 34.55 %) and linalyl acetate (12.94 % and 6.60 %) as the major compounds, alongside camphor, borneol, and 1,8-cineole. The compositional profile of LF-EO corresponded to the French Maillette chemotype defined by ISO 3515:2002.Both oils exhibited notable antibacterial activity against Gram-positive and Gram-negative bacteria. LF-EO demonstrated strong inhibition against Bacillus cereus and Listeria monocytogenes (30 mm), while LSL-EO showed moderate activity against Escherichia coli (20 mm) and Salmonella typhimurium (17 mm). The enhanced antimicrobial performance of LF-EO was attributed to its high content of oxygenated monoterpenes and esters, which contribute to membrane permeability and destabilization effects.Overall, the results confirm that Lavabdula angustifolia cultivated in Çankırı produces a French-type lavender oil of superior physicochemical and biological quality, suitable for pharmaceutical, cosmetic, and aromatherapeutic applications