Changes in the component composition of <i>T</i><i>hymus vulgaris</i> L. essential oil depending on the method of distillation

Abstract

The objective of the work was to identify changes in the amount and component composition of essential oil in the raw material of Thymus vulgaris L. (common thyme) when using different distillation methods. The object of the study was two samples of thyme-thymol and linalool chemotypes. Essential oil was obtained from freshly harvested raw materials (inflorescences in the mass flowering phase) by the following methods: hydrodistillation method on Clevenger apparatuses and steam extraction method on the installation for the production of essential oil and intermediates "Alpha-Ether Compact". The component composition of volatile substances was determined by gas chromatography-mass spectrometry. In the composition of volatile compounds of plant essential oil, 29 components for the thymol chemotype were identified, and 18 components for the linalool chemotype were identified. It was found that the use of the hydrodistillation method allows extracting 40-50% more essential oil. Significant differences were found between the mass fraction of extracted essential oil components using different methods and the content of the mass fraction of essential oil in the raw material of Th. vulgaris and found that depending on the method of obtaining essential oil, the proportion of volatile terpene hydrocarbons and oxygen-containing compounds changes. The method of steam distillation leads to a deterioration of the component composition of the essential oil, reducing the content of the dominant components of both chemotypes (thymol and linalool).