Impact of Extraction Methods on the Yield and Quality of Essential Oil from Oregano (Origanum Vulgare, Subsp. Vulgare)

The research investigated the effects of different extraction methods on the yield and chemical composition of essential oil obtained from the flowers, leaves, and stems of Origanum vulgare subsp. Vulgare (Oregano). The study employed hydrodistillation, Soxhlet extraction, and ultrasonic extraction using n-hexane and 70% ethanol as solvents. Ultrasonic extraction with n-hexane yielded the highest amount of essential oil (1.35% of sample weight), while hydrodistillation with toluene produced the lowest yield (0.25%) from stem samples. Chemical composition analysis revealed sabinene as the dominant component of the essential oil, with its concentration varying based on the extraction method and solvent used, reaching 100% with ultrasonic extraction using 70% ethanol. In stem samples, terpinen-4-ol (20.3%) was notably abundant following hydrodistillation, while in the flowers and leaves sample group, the highest terpinene content (34.3%) was observed using the Soxhlet method. The results underscore the importance of optimising extraction methods and solvent selection to maximise yield while preserving the qualitative composition of essential oils. The above data confirm that ultrasonic extraction is superior in terms of both efficiency and preservation of the chemical composition. Future research should focus on optimising ultrasonic extraction parameters, including solvent type and temperature, to further enhance the yield of key essential oil components while preserving their quality.