Fractionating of java (Cymbopogon winterianus) essential oil by vacuum distillation and evaluation of bioactivities of fractions

Abstract

Java citronella essential oil (Cymbopogon winterianus) is a natural product with many biological activities and is commonly used in the food and cosmetics industries. This work aims to evaluate the use of vacuum fractional distillation to separate Java essential oil compounds, producing essential oil fractions containing high citronellal and rhodinol (mixture of citronellol and genariol) content. The effect of process parameters, namely vacuum pressure and type column on the fractionation time, content, and recovery of citronellal and rhodinol in the fractions, was investigated. The fractions were then evaluated for their antioxidant and antibacterial properties. The fractionation of Java oils successfully provided four fractions, i.e., fraction 1 (F1), fraction 2 (F2), fraction 3 (F3) and fraction 4 (F4). GC-MS (Gas Chromatography-Mass Spectrometry) spectra showed that the main compound contained in F2 fractions was citronella. Meanwhile, F4 was the main fraction for rhodinol recovery. The optimal conditions of the fractional distillation system included a column height of 400 mm, and pressure of 40 mbar. These conditions correspond to the highest total citronella content of 80.2%, with a recovery of 92.8% at the F2 fraction and the highest total rhodinol content of 71.2%, with a recovery of 81.3% at the F4 fraction. Different Java essential oil fractions show different anti-oxidant and anti-bacterial properties. Fraction 4 with main components including citronellol and genariol showed the highest antioxidant capacity (7.0186 ± 0.0254 mg AAE/mL EO). Meanwhile, the F2 fraction with the main ingredient citronella showed the best antibacterial ability among the fractions and the original essential oil.