Acta Pharm. 49 (1999) 51-57

Comparison of essential oils obtained from Mentha piperita L. using supercritical
carbon dioxide extraction and hydrodistillation

SLAVCO ALEKSOVSKI,^*1   HELENA SOVOVA,²  FILIMENA A. POPOSKA,¹
SVETLANA KULEVANOVA,³ and   MIHAILO RISTIC⁴

¹Department of Chemical and Control Engineering,  Faculty of Technology and Metallurgy,  91000 Skopje,  Republic of Macedonia
²Institute of Chemical Process Fundamentals,  Academy of Sciences CR Prague,  Czech Republic
³Institute of Pharmacognosy,  Faculty of Pharmacy,  91000 Skopje,  Republic of Macedonia
⁴Institute for Medicinal Plant Research,  »Dr. J. Pancic«,  11000 Belgrade,  FR Yugoslavia

Extraction of peppermint oil was performed with supercritical and liquid carbon dioxide at 9–12 MPa and 25–50 °C. Rate of extraction was dependent on the extraction pressure and temperature and on the amount of carbon dioxide passed through the extractor. Under experimental conditions, the extraction rate did not depend on the CO₂ flow rate nor on particle size of the plant material. Using analytical GC and GC-MS technique, the extracts were compared with the peppermint oil obtained by hydrodistillation. The main oil components were menthol, menthone, menthyl acetate and menthofuran. In addition to the essential oil, the CO₂ extracts contained cuticular wax. Only minor differences in the essential oil composition between the extracts and the distillates have been found, and no effect of the different extraction conditions on the oil composition has been observed.

Keywords: Mentha piperita, supercritical fluid extraction, hydrodistillation, essential oil, menthol, menthyl acetate, menthone