Comparative Analysis of Selected Extraction Methods for Essential Oils from Cymbopogon citratus and Eucalyptus Leaves

Abstract

This study evaluates and compares different extraction techniques for isolating essential oils from lemongrass (Cymbopogon citratus) and Eucalyptus leaves to support the development of sustainable botanical bio-pesticides. Using a locally fabricated steam distillation still, a 2.0 kg charge of plant tissue was processed at a regulated boiling temperature of 100 0C. The rising steam systematically disrupted glandular plant structures, volatilizing the essential oils into a gas phase that was liquefied within a water-cooled condenser. Biphasic separation yielded an upper essential oil phase and a lower aqueous hydrosol. To benchmark this process, alternative techniques including organic solvent extraction, supercritical carbon dioxide (scCO2) extraction, maceration, and classical enfleurage were comparatively analysed based on extraction conditions, thermolabile component preservation, and infrastructure requirements. The findings indicate that while advanced techniques like scCO2 preserve high-purity volatile fractions, localized steam distillation offers an eco-benign, highly cost-effective, and operationally viable methodology for producing plant secondary metabolites intended for sustained-release agricultural matrix applications.