Extraction of essential oil from Eucalyptus leaves by combination of hydro-distillation and ultrasound-assisted extraction techniques

Abstract

Eucalyptus is a plant that its leaves contain valuable oil with potential significant medical applications. In this work, Eucalyptus oil was extracted via the most common hydro-distillation (HD) and the advanced combination of HD and ultrasonic-assisted extraction (UAE). The best conditions of extraction parameters particularly different liquid to solid (L:S) ratio, extraction time, extraction temperature, and speed of agitation, were investigated in particular ranges in this study. The oil yield was calculated based on the volume of the extracted oil per 100 g of the powdered Eucalyptus leaves as a feed material. The maximum oil yield in the HD method was only 3.85 mL/100 g, which is obtained at the extraction temperature of 100 °C, extraction time of 160 minutes, liquid to solid ratio of 6:1, and agitation speed of 500 rpm. The yield attained 4.1 mL/100g in the HD-UAE approach with the same extraction temperature and solid to liquid ratio but with an extraction time of 80 minutes and no agitation. The error of our data was determined from reiterating of experiments that have been arbitrarily selected to be around 4%.