Vol. 23, March/April 2011 Journal of Essential Oil Research/45 Rec: June 2010 Acc: July 2010 Characterization of Oils from the Fruits, Leaves and Flowers of the Bitter Orange Tree Giovanni Dugo, Ivana Bonaccorsi*, Danilo Sciarrone, Rosaria Costa, Paola Dugo and Luigi Mondello Dipartimento Farmaco-chimico, Università di Messina, V.le Annunziata, 98168 – Messina, Italy Luca Santi Dipartimento di Biologia, Università di Roma Tor Vergata, Rome, Italy Hussein A. Fakhry A. Fakhry & Co. 1081, Corniche El-Nil Cairo 11451, Egypt Abstract The bitter orange tree is used to obtain different products: essential oil cold pressed from the peel of the fruit, the neroli distilled from the flowers, the petitgrain distilled from the leaves and twigs, and different other products obtained by solvent extraction or by hydrodistillation. All these products are much appreciated for their odor proper- ties. Their analytical characterization is important for the identification of quality parameters, and considering their commercial value, it is important to determine their composition. This study is meant to determine differences be- tween Italian and Egyptian cold-pressed, neroli and petitgrain oils, and gives useful information on the composition of the essential oil obtained from the whole crushed fruits. The composition of all the samples was studied by different analytical techniques to determine the volatile fraction, the enantiomeric distribution of some volatiles (by GC, GC/ MS and esGC, respectively) and the oxygen heterocyclic fraction by RP-HPLC. Key Word Index Citrus aurantium L., essential oil, neroli, petitgrain, composition, enantiomeric distribution, oxygen heterocyclic compounds, GC, GC/MS-LRI, chiral GC, RP-HPLC. 1041-2905/11/0001-045$14.00/0—© 2011 Allured Business Media *Address for correspondence: bonaccor@pharma.unime.it Introduction The different products obtained from the tree of bitter orange are well appreciated in perfumery and are present on the international market at high cost. The most important among them are: Cold-pressed oils, obtained from the peel of the fruits; Petitgrain bigarade oil, obtained by steam distillation of the leaves and twigs from the pruning of the trees at different times throughout the year; and Neroli oil obtained from the steam distillation or hydro- distillation of the flowers. In addition to those listed above, one should also mention bitter orange flower water absolute, obtained by extraction with hexane from the water solution (i.e. hydrolate or floral water) after separation of neroli; and the concrete of bitter orange flowers, obtained by solvent extraction (usually hexane or light petroleum), from which it is possible to obtain the bitter orange flower absolute by extraction with alcohol, winteriza- tion, filtration, and concentration. The oils and extracts obtained from the bitter orange tree are much appreciated for their odor characteristics, and com- mercial value, and those of high quality are used in perfumery and in the food and alcoholic beverage industries. As reported by the “world map showing production center of essential oil” produced by Treatt PLC and attached to the recent volume edited by Baser and Buchbauer (1) the produc- ing countries of essential oils from the bitter orange tree are Spain, Italy, France, Egypt, Tunisia, Morocco, Uganda, Ivory Coast, Paraguay, Brazil, Argentina, and China. Recently, different advanced techniques in the field of chromatography have been applied to the analysis of essential oils in GC as enantio-GC/MS [2], fast-GC/MS and fast-GC-FID [3-6], multidimensional GC-GC [7,8], GC x GC [9] and GC-C- IRMS [10], while in LC, different approaches were reported as LC/MS [11] and LC x LC [12]. The composition of the volatile fraction and of the oxygen heterocyclic fraction of bitter orange oil, of petitgrain and of neroli have been revised respectively by Dugo et al. (13), Dugo and McHale (14), Dugo et al. (15) C. aurantium