Chemical Composition, Antimicrobial, and Repellant Properties of Lavandula stoechas and Artemisia absinthium Essential Oils Against Ephestia kuehniella

Background: Lavandula stoechas and Artemisia absinthium essential oils (EOs) were evaluated as natural antimicrobial and repellent agents. Methods: The chemical composition was determined using gas chromatography-mass spectrometry (GC-MS). The antibacterial activity was evaluated by agar diffusion method, and the minimal inhibitory concentration (MIC) values were determined for antifungal activity, while the repellent effect against mill moth was tested by fumigation. Results: Camphor was the main component in both EOs, accounting for 31.83% of L. stoechas and 41.92% of A. absinthium. In antibacterial assays, both EOs showed very good activity against Gram-positive bacteria, with inhibition zone diameters (IZDs) higher than 15 mm, and average activity against Gram-negative bacteria, with IZDs ranging from 8 to 14 mm. The EOs reduced Aspergillus niger mycelial growth by 61% to 80% for LsEO and 50% to 61% for AaEO at concentrations ranging from 1 to 3 mg/mL. The oils exhibited variation in repellent and insecticidal potential, with L. stoechas showing higher activity, while both had an impact on development and fecundity of Ephestia kuehniella. Conclusions: Thus, the two EOs may be effective as biological and sustainable alternatives to conventional chemical products for food preservation.