The extraction of essential oils from patchouli leaves (Pogostemon cablin Benth) using a microwave air-hydrodistillation method as a new green technique (Publication with Expression of Concern)

Nowadays, patchouli oil extraction in Indonesia is generally carried out using conventional methods, although such methods require large amounts of energy, solvents in significant amounts, and quite a long time. Therefore, in this study, patchouli oil extraction was done using a microwave hydrodistillation method. In addition to optimizing the extraction process of patchouli oil, this study used a development of the microwave hydrodistillation method, microwave air-hydrodistillation. Based on this research, it can be seen that patchouli oil extraction using the microwave air-hydrodistillation method is faster, produces a better yield and a higher accumulation of recovery than extraction using the standard microwave hydrodistillation method. A gas chromatography-mass spectrometry analysis of the composition of the compounds in the patchouli oils shows that the heavy fraction components obtained by microwave air-hydrodistillation are more numerous than those obtained using the microwave hydrodistillation method. Furthermore, an analysis of the electric consumption and the environmental impact of the microwave air-hydrodistillation method for patchouli oil extraction indicates that this method can be considered a new green technique.