Flavonoids and essential oils containt in peppermint (Mentha x piperita L.) raw materials grown in organic farming

The study of the medicinal plant quality indicators is an urgent task in the organic raw materials production. Peppermint (Mentha x piperita L.) is one of the most popular medicinal crops in the world, which is used to obtain mint leaves, essential oils, to produce herbal teas, where organic products occupy a separate segment. The pharmacologically significant compounds in mint are essential oil and phenolic compounds (including flavonoids and tannins). The aim of the work was to estimate the content of essential oil, the sum of phenolic compounds, flavonoids, and tannins in the leaf of 5 varieties of peppermint, which were grown under organic culture condition. Materials and Methods. The varieties of Mentha x piperita Mitcham, Apelsinovaya, Kubanskaya 6, Tik-Tak, and Multimentha were selected as objects. Productivity was determined in the flowering phase. The yield was determined in the flowering phase. The essential oil content was determined by the Clevenger hydro distillation method, component composition - by gas chromatography, the sum of phenolic compounds and tannins - according to the Folin-Ciocalteu method in a water-alcohol extract in terms of gallic acid. Determination of flavonoids was carried out by the aluminum chloride method in terms of rutin. Results. The content of essential oil, depending on the variety, ranged from 0.89 to 2.91% over 2 years, while the menthol content of the menthol varieties varied from 25, 99 to 50, 36%. The mint raw material is characterized by a high content of the total phenolic compounds (from 9.33% for the Mitcham variety to 10.77% for the variety Multimentha). The flavonoids content, depending on the variety, ranged from 2.25% by the variety Kubanskaya 6 to 4,22% by the variety Apelsinovaya. The average content of tannins for two years did not exceed 1,5%. Conclusion. Growing peppermint in organic culture allows to obtain raw materials with a high content of phenolic compounds, including flavonoids, and essential oil.