Journal of Chromatography A, 1192 (2008) 306–318 Contents lists available at ScienceDirect Journal of Chromatography A journal homepage: www.elsevier.com/locate/chroma Isolation of Indonesian cananga oil using multi-cycle pressure drop process Magdalena Kristiawan ∗ , Vaclav Sobolik, Karim Allaf University of La Rochelle, Pole Sciences, LEPTIAB, Avenue Michel Cr´ epeau, 17042 La Rochelle, France article info Article history: Received 4 February 2008 Received in revised form 18 March 2008 Accepted 19 March 2008 Available online 28 March 2008 Keywords: Cananga odorata forma macrophylla Cananga oil isolation Instantaneous controlled pressure drop DIC Response surface methodology abstract New process, instantaneous controlled pressure drop (DIC) was applied on Cananga odorata dry flowers with the aim to isolate essential oil. DIC is based on high temperature, short time heating followed by an abrupt pressure drop into a vacuum. A part of volatile compounds is carried away from flowers in the form of vapor (DIC direct oil) that evolves adiabatically during the pressure drop (proper isolation process) and the other part remains in the DIC-treated flowers (DIC residual oil). In the present paper, the effect of DIC cycle number (1–9) and heating time (4.3–15.7min) on the availability of oil compounds was investigated at three levels of steam pressure (0.28, 0.4 and 0.6MPa). The availability was defined as the amount of a compound in direct or residual oil divided by the amount of this compound in the reference oil extracted from non-treated flowers by chloroform during 2 h. The total availability and yield of volatiles in the direct oil increased with pressure and cycle number. At a higher pressure, the effect of heating time was insignificant. The amount of oxygenated monoterpenes and other light oxygenated compounds (i.e. predominantly exogenous compounds) in the residual flowers was lower than in the direct oil and this amount decreased with cycle number. On the other hand, the availability of oxygenated sesquiterpenes and other heavy oxygenated compounds (i.e. predominantly endogenous compounds) in residual flowers exhibited a maximum for about five cycles and their quantity at this point was three times as much as in the direct oil. The total availability of each compound at 0.6MPa was higher than one. The rapid DIC process (0.6 MPa, 8 cycles, 6 min) gave better results than steam distillation (16 h) concerning direct oil yield (2.8%dm versus 2.5%dm) and content of oxygenated compounds (72.5% versus 61.7%). © 2008 Elsevier B.V. All rights reserved. 1. Introduction Besides its long utilisation as fragrance component in per- fumery, the application of cananga or ylang–ylang essential oils as flavoring agent in candies, icings, frozen dairy, pudding, baked goods, soft drinks and chewing gums have increased in the recent years [1–4]. Cananga refers to plant species of Cananga odorata forma macrophylla whereas ylang–ylang is belonging to forma gen- uina. These oils have been approved as food additives by US Food and Drug Administration (FDA) and have been determined to be safe (GRAS) for food uses by Flavor and Extract Manufacturers Association (FEMA) and the International Organisation of Flavor Industries (IOFIs) [5,6]. Burdock et al. [5] reported that the present consumption level of cananga or ylang oil (0.1 g/(kg day), which is estimated using per capita daily intake method) from food flavoring does not pose human health effects. ∗ Corresponding author. Current address: University of Surabaya, Department of Chemical Engineering, Jalan Raya Kalirungkut, Surabaya 60293, Indonesia. Tel.: +62 81 61516 5510; fax: +62 31 298 1178. E-mail address: magdanana@yahoo.com (M. Kristiawan). The cananga and ylang oils are mostly obtained by steam dis- tillation of fresh mature flowers and rarely by solvent extraction [1,4]. Losses of some volatile compounds, long processing time, low-isolation efficiency, compounds degradation and toxic solvent residue in the extract may be encountered using these conven- tional essential oil isolation methods [7,8]. The modern process such as supercritical fluid extraction, mainly using carbon dioxide, allows us to obtain a high-quality extract, but the high-fixed cost limits its application to high-added value products [9,10]. More- over, this process is less convenient for polar compounds and it extracts also culticular waxes and lipids [11,12]. The green tech- nologies for extraction of essential oil from aromatic plants, such as vacuum microwave hydrodistillation (VMHD) and solvent-free microwave hydrodistillation (SFME), have been successfully devel- oped [13–19]. They consist in combination of microwave heating and dry distillation, performed at atmospheric pressure (SFME), and followed by slow pressure drop rate into vacuum (VMHD), without added any solvent or water. These processes yielded the better quality extracts (more oxygenated compounds) with faster kinetics extraction than the conventional ones. However, Klima [20] reported the presence of non-uniformity of material tem- perature due to non-homogeneity of electromagnetic field during microwave heating. 0021-9673/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.chroma.2008.03.068