Supercritical carbon dioxide extraction of carrot fruit essential oil: Chemical composition and antimicrobial activity Sandra B. Glis ˇic ´ a , Dus ˇan R. Mis ˇic ´ b , Marko D. Stamenic ´ a , Irena T. Zizovic a, * , Ruz ˇica M. As ˇanin b , Dejan U. Skala a,c a Faculty of Technology and Metallurgy, Department of Organic Chemical Technology, Belgrade University, Karnegijeva 4, 11020 Belgrade, Serbia and Montenegro b Faculty of Veterinary Medicine, Department of Microbiology, Belgrade University, Bulevar Oslobodjenja 18, 11000 Belgrade, Serbia and Montenegro c Texas A&M at Qatar, Qatar Support Office, College Station, TX, 77844 USA Received 21 June 2006; received in revised form 23 October 2006; accepted 29 November 2006 Abstract Isolation of carrot fruit (Daucus carrota L., cultivar ‘‘Chanteney”) essential oil by supercritical carbon dioxide was investigated from the pretreatment of herbaceous matrix and extraction conditions to the chemical composition of obtained extract and its antimicrobial activity. The qualitative and quantitative analyses of the supercritical extract, as well as of the essential oil obtained by hydrodistillation, were done by GC/FID and GC/MS methods. Antimicrobial properties of both samples were investigated against ten species of micro- organisms. Experimental results showed that the particle size had no influence on the extraction process. The highest yield was obtained at 40 °C and 10 MPa. The main component of the supercritical extract, as well as of the essential oil was carotol. The supercritical extract was characterized by the presence of heavier molecular weight compounds, while some lighter compounds, e.g. pinenes, were not detected. The supercritical extract and the essential oil were the most effective against Gram-positive bacteria. Ó 2006 Elsevier Ltd. All rights reserved. Keywords: Carrot fruit; Carotol; Supercritical fluid extraction; Essential oil; Antimicrobial activity 1. Introduction Essential oils may have great potential use as food fla- vours and preservatives. The antimicrobial activity of essential oils and their components has long been recog- nized. Spices, which are added as flavouring agents to foods, are present in insufficient quantities for their antimi- crobial properties to be significant. Moreover, spices are often contaminated with bacterial and fungal spores, due to their volatile oil content being enclosed within oil glands with antimicrobial activity (Dorman & Deans, 2000). Therefore, essential oils, which often contain the main aro- matic and flavouring components of herbs, when added as flavours to food, would also retard microbial contamina- tion. Carrot fruit essential oil is widely used as a flavour ingredient in most major food categories, and as a fra- grance component in perfumes, cosmetics, and soaps (Law- less, 2002). It is the source of sesquiterpenic alcohols, carotol and daucol, and the sesquiterpene b-caryophyllene. The conventional method for carrot essential oil isolation is steam-distillation of dried fruits. Claimed properties of the oil include antibacterial (Giraud-Robert, 2005; Kili- barda, Nanusevic, Dogivic, Ivanic, & Savin, 1996; Stanis- zewska, Kula, Wieczorkiewicz, & Kusewicz, 2005), fungicidal (Batt, Solberg, & Ceponis, 1983; Dwivedi, Dwiv- edi, Pandey, & Dubey, 1991; Giraud-Robert, 2005; Stanis- zewska et al., 2005), hepatocellular regenerator, general tonic and stimulant, lowering of high cholesterol and cic- atrisant (Giraud-Robert, 2005). Traditional uses are for hepatic and renal insufficiency and skin disorders, e.g. burns and furuncules (Bergonzelli, Donnicola, Porta, & 0308-8146/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodchem.2006.11.062 * Corresponding author. Tel.: +381 11 3303 795; fax: +381 11 3370 387. E-mail address: zizovic@tmf.bg.ac.yu (I.T. Zizovic). www.elsevier.com/locate/foodchem Food Chemistry 105 (2007) 346–352 Food Chemistry