Physicochemical characteristics and thin layer chromatography of the essential oil of spearmint: Mentha spicata L, from western Algeria

The species chosen for this study is sweet mint, Mentha spicata L, harvested in the wilaya of El Bayadh in Algeria. The aim of this work is to highlight the plant's identification criteria, its yield in essential oil, the various physico-chemical parameters and the composition of the essential oil using different techniques (determination of several chemical indices and establishment of the list of constituents of the essential oil using chromatographic methods). The botanical study showed the presence of two types of "Lamiaceae" type secretory hairs. These secretory hairs are the histological support for the production and storage of essential oils. A study of the kinetics of the extraction yield shows that distillation is rapid from 0 to 120 minutes, when the yield reaches an optimum (1.08%). The organoleptic characteristics and physico-chemical indices obtained are in line with the standards given in the bibliography. Thin layer chromatography revealed the presence of several constituents through the appearance of several spots of different colour and Rf, three of which were identified by comparison with controls, namely menthol, cineol and carvone.