Analytica Chimica Acta 555 (2006) 157–160 Microwave accelerated steam distillation of essential oil from lavender: A rapid, clean and environmentally friendly approach F. Chemat a,∗ , M.E. Lucchesi a , J. Smadja a , L. Favretto b , G. Colnaghi b , F. Visinoni b a Laboratoire de Chimie des Substances Naturelles et des Sciences des Aliments, Facult´ e des Sciences et Technologies, Universit´ e de La R´ eunion, B.P. 7151, 15 Avenue Rene Cassin, F-97715 Saint Denis Messag Cedex 9, La R´ eunion, France b MILESTONE srl, Via Fratebenefratelli, 1/5, I-24010 Sorisole, Bergamo, Italy Received 8 April 2005; received in revised form 12 July 2005; accepted 22 August 2005 Available online 19 October 2005 Abstract A new process design and operation for microwave accelerated steam distillation (MASD) of essential oils was developed. A packed bed of lavender flowers (Lavandula angustifolia Mill., Lamiaceae) sits above the steam source generated by microwave heating. Only steam passes through it without the boiling water mixing with vegetable raw material, as is the case in hydro-distillation. MASD has been compared with a conventional technique, steam distillation (SD), for the extraction of essential oil from lavender flowers. Extraction of essential oils from lavender with MASD was better than SD in terms of energy saving, rapidity (10 min versus 90 min), product yield, cleanliness and product quality. © 2005 Elsevier B.V. All rights reserved. Keywords: Microwave; Steam distillation; Essential oil; Lavender flowers 1. Introduction Lavender is one of the most useful medicinal plants. Com- mercially, the lavender provides several important essential oils to the fragrance industry, including soaps, colognes, perfumes, skin lotions and other cosmetics. In food manufacturing, laven- der essential oil is employed in flavouring beverages, ice cream, candy, baked goods and chewing gum. The essential oils of Lavandula species are obtained by steam distillation of the fresh flowering spikes. Oil quality is assessed by oil chemical com- position and by the organoleptic opinion of the flavourists [1,2]. In general, an analytical procedure for essential oils or aro- mas from plants or spices comprises two steps: extraction (steam distillation, hydro-distillation, simultaneous distillation– extraction, ...) and analysis (gas chromatography (GC), gas chromatography coupled to mass spectrometry (GC–MS)). Whereas the last step is finished after only 15–30 min, extraction takes at least several hours. It is frequently done by a prolonged heating and stirring in boiling water. Much more attention has been given to the application of microwave dielectric heating ∗ Corresponding author. Tel.: +262 262 938182; fax: +262 262 938183. E-mail address: chemat@univ-reunion.fr (F. Chemat). in analytical chemistry because of the reducing analysis time, simplified manipulation and work-up, and higher purity of final product [3–5]. Up to now, however, there are only a few reports in the literature that mentioned the acceleration of essential oil extraction by microwave irradiation [6–10]. The aim of this work was to develop a new method, “microwave accelerated steam distillation”, for the extraction of essential oils, and compare the results with those obtained by conventional techniques, in order to introduce this advanta- geous alternative in the analytical or production of essential oils in food, cosmetic and pharmaceutical industry. To investigate the potential of MASD, comparisons have been made with conventional steam distillation for the extraction of essential oils from Lavandula angustifolia flowers. We intend to make appropriate comparison in term of extraction time, yield and aromatic composition. 2. Experimental 2.1. Plant material Lavender flowers (L. angustifolia Mill., Lamiaceae) were col- lected in June 2003 in Bergamo province (Northern Italy) and let dry on a bench in the shade. 0003-2670/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.aca.2005.08.071