Isolation and characterization of the volatile aroma compounds from the concrete headspace and the absolute of Jasminum sambac (L.) Ait. (Oleaceae) flowers grown in Egypt.

摘要

Flowers from Jasmninum sambac are used as a flavouring in teas. The composition of the volatile fraction of Egyptian J. sambac flowers picked in July (the climax of the flowering season), was studied using GC/MS. Headspace volatiles were obtained from dried hexane extracts of the flowers by solid phase microextraction (SPME) and by extraction with ethanol (ET). The main volatile constituents of the SPME and ET fractions, respectively, were: benzyl acetate (23.7 and 14.2%), indole (13.1 and 13.4%), E-E- alpha-farnesene (15.9 and 13.1%), Z-3-hexenyl benzoate (4.9 and 9.4%), benzyl alcohol (7.7 and 8.4%), linalool (10.6 and 6.3%) and methyl anthranilate (5.0 and 4.7%). The major volatile constituents of Egyptian J. sambac absolute were almost qualitatively similar but quantitatively different from those of flowers grown in other geographical regions. Proportions of some major volatile constituents observed in this investigation were also different from those reported in a previous study. Results also suggested that headspace SPME with equipped with a polydimethylsiloxane fibre is an effective technique for directly determining the composition of some of the major volatile constituents of J. sambac, e.g. indole, methyl anthranilate and E-E- alpha-farnesene.