Extraction and isolation of Salvia desoleana and Mentha spicata subsp insularis essential oils by supercritical CO2

Dried and ground leaves of different endemic plants of Sardinia (Italy), such as mint, Mentha spicata ssp. insularis, and sage, Salvia desoleana, were used for supercritical extraction with carbon dioxide to isolate the corresponding essential oils. The vegetable fragrances were isolated by supercritical CO2 extraction coupled to a fractional separation technique. GC-MS analysis of the extract allowed the identification of constituents of the oils. The process was carried out by operating at 90 bar and 50 degreesC in the extraction vessel, at 90 bar and below -5 degreesC in the first separator to selectively precipitate the cuticular waxes, and at a pressure of 15-20 bar and temperatures in the range 15-21 degreesC in the second separator to recover the volatile oil. In the case of Salvia desoleana, a comparison with the product obtained by hydrodistillation is also given. Copyright (C) 2001 John Wiley & Sons, Ltd.