Variations in the essential oil composition from different parts of Coriandrum sativum L. cultivated in Tunisia.

Essential oils obtained by hydrodistillation from different organs (flowers, leaves, stems and roots) of Tunisian coriander (Coriandrum sativum L.) was analyzed. GC and GC-MS analysis enabled us to identify 64 compounds and revealed great qualitative and quantitative differences between the analyzed parts. In all organs, the main compound was (E)-2-dodecenal, followed by (E)-2-tridecenal, gamma-cadinene, (Z)-myroxide, neryl acetate and eugenol. Multivariate analysis (PCA) revealed a high similarity in the essential oils composition between upper leaves and flowers in one hand and basal leaves, roots and stems on the other hand. Further, it has been reported an organ-dependant distribution of essential oil compounds.

Comparison of pistachio hull essential oils from different Tunisian localities.

Pistachio (Pistacia vera L.) fruit is well known for its oleaginous and edible seed. Less information is available about the hull constituted by the epicarp and the mesocarp. This part of the fruit contains an essential oil that can be valorized. Tunisia is one of the countries cultivating pistachio trees. This work presents essential oil composition of pistachio hulls (Mateur variety) from different geographical localities: Grombalia (North-East), Kairouan (Middle) and Sfax (Middle-East). Yields were more important in Sfax samples (0.53% on a dry weight basis). Alpha-terpinolene was the major compound for Grombalia fruits (35.7%), whereas Kairouan and Sfax samples where characterized by alpha-pinene (42.5 and 43.8% respectively). For all samples, monoterpene hydrocarbons predominated (more than 79.8% of the essential oil).

Volatile constituents of two Hypericum species from Tunisia.

The chemical composition of the essential oils obtained by hydrodistillation from the aerial parts of the Tunisian Hypericum perforatum and H. ericoides ssp. roberti was elucidated by a combination of GC and GC-MS analyses. The main constituents of the oil of H. perforatum were alpha-pinene (11.8%), alpha-ylangene (10.4%), germacrene-D (9.5%), n-octane (6.5%) and alpha-selinene (5.9%). The oil of H. ericoides ssp. roberti exhibited a higher amount of aliphatic and branched hydrocarbons and the main constituents were n-octane (29.1%), alpha-pinene (10.9%), pulegone (7.7%) and acetophenone (7%). Both qualitative and quantitative differences were observed between the studied oils. This chemical variability seems likely to result from the genetic variability, since samples of both species were collected at the same location and processed under the same conditions.