Study on the stability of supercritical fluid extracted rosemary (Rosmarinus Offcinalis L.) essential oil

The aim of this study was to examine the influence of storage conditions and duration on compo- sition and antioxidant activity of supercritical fluid (SCF) extracted essential oil of rosemary (Rosmarinus officinalis L.). Supercritical extraction was carried out sequentially by using SCF carbondioxide in the first two steps and with 5% ethanol as entrainer in the third step. The compositions of the extracts were determined by gas chromatography/mass spectrometry. The total phenolics were analyzed using Folin-Ciocalteau assay. Antioxidant activities of the extracts were tested by ß-carotene-linoleic acid bleaching method. The extracts stored at 4°C in the dark for 14 weeks were associated with slight changes in their composition. However, storage under indirect day light at room temperature caused considerable changes in the composi- tions of the oils due to the chemical transformations in some of their components. Both the total phenolic contents and the antioxidant activities were significantly decreased after storage. © Pleiades Publishing, Ltd., 2010.Çukurova ÜniversitesiACKNOWLEDGMENTS This work was financially supported by Çukurova University (Project no. FEF2007BAP12). The authors are thankful to Dr. Yesim Özogul from Faculty of Fisheries in Çukurova University for her support in providing their GC MS instrument for analysis