Supercritical fluid extraction of Z-sabinene hydrate-rich essential oils from Romanian Mentha hybrids

The green solvent SC­CO 2 was used to extract the volatile part, rich in thermolabile compounds, Z-sabinene hydrate and its acetate, from a Romanian mint hybrid. The best yield, 2.26%, was obtained at 92­94 bar, 50 °C (SFE 2). Kinetic study of SC­CO 2 extraction and hydrodistillation and monitoring by gas chromatography (GC) and gas chromatography mass spectrometry (GC­MS) analysis established optimal conditions for SC­CO2 extracts with a high content of Z-sabinene hydrate (43.5%) and its acetate (19.15%) and flavor similar to plant material (P = 90­100 bar, T = 50 °C). Only at the beginning of hydrodistillation was it possible to obtain a high content of Z-sabinene hydrate (37.3%, after 70 min), but a high content of its acetate never could be reached. This study suggests a way to obtain Z-sabinene hydrate from a natural source and reveals the importance of mild conditions to keep what is valuable in nature.