Optimisation of oil extraction from lemongrass leaves (Cymbopogan citratus) with steam distillation using Box-Behnken Design

The demand for lemongrass essential oils is on the rise as consumers become more aware of their benefits. In Malaysia, the leaves are underutilised after harvesting. The two conventional techniques employed for commercial purposes of oil extraction are steam distillation and hydrodistillation, with steam distillation being preferable. The main objective of this study is to determine the optimum parameters of steam distillation: extraction time, solvent-solid ratio, and power using Response Surface Methodology to achieve maximum oil yield from the lemongrass leaves. Results showed that a solvent-solid ratio of 2:1, extraction time of 90 minutes, and a power of 1800 W were the optimal steam distillation conditions for achieving 0.0473% of the lemongrass oil yield. Steam distillation yields an average of 0.0458%, which was higher than hydrodistillation (0.0358%). Therefore, steam distillation proved to be a better extraction method for lemongrass oil from its leaves as a means of waste management.