ORIGINAL PAPER Extraction of Essential Oils From the Seeds of Pomegranate Using Organic Solvents and Supercritical CO 2 Hajar Abbasi Æ Karamatollah Rezaei Æ Ladan Rashidi Received: 3 July 2007 / Revised: 15 October 2007 / Accepted: 18 October 2007 / Published online: 15 November 2007 Ó AOCS 2007 Abstract In this study, essential oils from pomegranate seeds of the Malas variety from Shahreza, Iran, were extracted using hexane and petroleum benzene applying four extraction methods: normal stirring, soxhlet, micro- wave irradiation, and ultrasonic irradiation. Also, supercritical fluid extraction (SFE) using CO 2 under dif- ferent conditions was used for comparison. Different methods of extraction with organic solvents (normal stir- ring, soxhlet, microwave irradiation, and ultrasonic irradiation) showed significant differences in the extraction yields. However, no differences were found when a given method (e.g., microwave irradiation) was applied using different organic solvents. On the other hand, different extraction conditions from the various runs of SFE resulted in different extraction yields, all of which were lower than those of the other extraction methods using organic sol- vents. No significant differences were observed in the fatty acid compositions of the extracted oils using organic sol- vents. However, the fatty acid compositions of the oils extracted under different conditions of the SFE system indicated significant differences among several fatty acids including unsaturated fatty acids. Keywords Essential oils Á Fatty acid composition Á Pomegranate seed oil Á Punicic acid Á Supercritical fluid extraction Introduction Pomegranate (Punica granatum L.) is one of the oldest edible fruit and belongs to the Punicacea family [1]. Pomegranate is extensively cultivated in the Mediterranean area and most Near- and Far East countries [2]. Iran is a native land of pomegranate. The total pomegranate pro- duction in Iran was reported at 665,000 tons for the year 2003 [1]. The edible part of pomegranate is called aril and constitutes about 52% (w/w) of the total fruit and com- prises of 78% juice and 22% seeds [3]. Pomegranate seeds contain high amounts of oil, in which in some Iranian varieties the total lipid content on a dry basis ranged from 66 to 193 g in one kg of the fruit [1]. Pomegranate seed oil consists of 65–80% conjugated fatty acids, the most important of which is 9-trans, 11-cis, 13-trans, octadecatrienoic acid, the so-called punicic acid. Pomegranate seed oil was reported to inhibit the upstream eicosanoid enzyme phospholipase A 2 expressed by human prostate cancer cells [4]. In addition, pomegranate seed oil can decrease the leukotriene production from arachidonic acid, which plays a major role in the occurrence of asthma in children, skin inflammation and platelet aggregation associated with cardiovascular diseases [2]. The objectives of this work were to extract the essential oils from pome- granate seeds using various extraction methods and to determine the fatty acid compositions of the extracted oils. Materials and Methods According to a previous report, ‘‘sour–sweet’’ varieties of pomegranate seeds contain more oil than do other varieties [1]. Therefore, the pomegranate selected for this study was from the Malas variety obtained from Shahreza, in the H. Abbasi Á K. Rezaei (&) Department of Food Science and Engineering, Faculty of Biosystem Engineering, The University of Tehran, P.O. Box: 31587-78659, Karaj, Iran e-mail: krezaee@ut.ac.ir L. Rashidi Institute of Standard and Industrial Research of Iran, Karaj, Iran 123 J Am Oil Chem Soc (2008) 85:83–89 DOI 10.1007/s11746-007-1158-x