Rosemary is a perennial herb with fragrant evergreen needle-like leaves that are commonly used to add flavor when cooking. It is widely grown in the Mediterranean region and in much of southern Europe. It has been found to act both as a stimulant and as a mild analgesic, and it has been used as a traditional herbal medicine to treat headaches, epilepsy, poor circulation, and many ailments for which stimulants are typically prescribed. Rosemary extracts have been incorporated into drugs and cosmetics and used for their flavor and fragrance in foods. (1)
Extraction of dried, ground rosemary leaves was performed in supercritical CO2 with 10% co-solvent ethanol added. Operating conditions of 5,000 psi. and temperatures of 40, 60, and 80C, were investigated to help optimize the extraction efficiency. Runs consisted of a one-hour static soak followed by a one-hour dynamic extraction at a flow rate of 1.0ml/minute. The extracts were collected into a 20ml vial that was pre-filled with acetone and maintained at 4C during the extraction to trap the volatile extract. (2)
The optimum conditions for this extraction were found to be 80C at 5,000 psi. This yielded 5.3% extract, in which five major active compounds were identified by liquid chromatography/mass spectrometry (LC/MS): Rosmarinic acid, carnosol, 12-methoxycarnosic acid, carnosic acid, and methyl carnosate. The carnosic acid and carnosol exhibit non-toxic, potent anti-tumor bioactivity, and the remaining active ingredients were found to be effective in anti-inflammatory therapy in low dosages.
Supercritical Fluid Technologies Manufactures a wide range of supercritical fluid extractors. For early-stage experimentation, the SFT-120 SFE is a moderately priced laboratory SFE that covers a full range of temperatures and pressures that are more than adequate for the majority of supercritical extractions performed on natural products. To learn more about this versatile sc-CO2 extractor, please see: https://www.supercriticalfluids.com/products/supercritical-fluid-extraction-products/sft-120/
(1) Aruoma, O. I., Spencer, J. P., Rossi, R., Aeschbach, R., Khan, A., Mahmood, N., Munoz, A., Murcia, A., Butler, J., and Halliwell, B., An evaluation of the antioxidant and antiviral action of extracts of rosemary and Provenc¸al herbs. Food Chem. Toxicol., 34, 449–456. (1996).
(2) Chiung-Huei PENG, Jeng-De SU, Charng-Cherng CHYAU, Tzu-Ying SUNG, Shin-Shien HO, Chiung-Chi PENG, and Robert Y. PENG. Bioscience, Biotechnology, and Biochemistry 71 (9), 2223–2232, 2007