Chemical Components and Biological Activities of Essential Oils of Mentha × piperita L. from Field-Grown and Field-Acclimated after In Vitro Propagation Plants

In this work, we studied in vitro propagation of three cultivars of Mentha × piperita L. Murashige and Skoog medium (MS) supplemented with 0.5 mg·L−1 BAP was the most optimal medium for micropropagation of the cultivars studied. The ability of peppermint plants field-acclimated after in vitro micropropagation to produce essential oils (EOs) was investigated. EO was obtained by hydrodistillation from dried leaves and flowering shoots from control (field grown) plants and plants acclimated in field conditions after in vitro propagation. The samples were collected at the first and second year of vegetation, and their chemical composition was investigated using gas chromatography-mass spectrometry (GC-MS). Differences were observed in the yield, as well as in the quantitative and qualitative composition of the EOs extracted from the control plants and field-acclimated plants after in vitro propagation. Menthol was the main component of the EO in control plants, while pulegone and menthone were dominant in the EO pattern in field-acclimated in vitro regenerants in the first year of the growing season. However, in the second year of vegetation, the content of the main EO components in field-acclimated peppermint plants was approximately the same as in control plants. The antioxidant activity of EOs extracted from field-acclimated after in vitro micropropagation plants was found to be the same as in control field-grown M. × piperita plants.