CO2-supercritical extraction, hydrodistillation and steam distillation of essential oil of rosemary (Rosmarinus officinalis)

Essential oil of rosemary was obtained by supercritical CO2-extraction (SCE), hydrodistillation (HYDRO), and steam distillation (SD). Quantity of oil, antioxidant activity, and chemical composition (gas chromatography-mass spectrometry, GC -MS) of the essential oils were evaluated. For SCE, oil was obtained at two temperatures (40 and 50 degrees C) and two pressures (1034 and 17.24 MPa) using a rosemary particle size of 600 +/- 50 mu m. The yield was between 1.41 and 2.53 g essential oil (EO) 100 g(-1) of dry rosemary (% wow). The antioxidant activity values were in the range 29.67-37.55 mg equivalent of Trolox (ET) g(-1) of EO or 22.66-30.81 mg ascorbic acid (AA) g(-1) of EO. Yields of essential oil were between 0.35 and 2.35%. The antioxidant activity was found in the range 1.73-2.60 Mg ET g(-1) of EO or 1,50-2.20 mg AA g(-1) of EO. Camphor, eucalyptol, beta-caryophyllene, and borneol acetate were the main chemicals detected by GC -MS in EO. (C) 2017 Elsevier Ltd. All rights reserved.