No abstract

The chemical composition and physical properties of the rose absolute produced from rose concretes and the extract, supplied by three different companies, were determined by GC and GC-MS. It was found that rose absolute consists mainly of β β β β β-phenylethyl alcohol, citronellol, geraniol, nerol, eugenol, methyl eugenol, geranyl acetate, benzyl alcohol, nonadecane, nonadecene and farnesol. The solid residue, which is the by-product of absolute production, was further divided on a silica gel column into three fractions by solvents having different polarities (n-hexane, 5% diethyl ether in n-hexane, and diethyl ether alone). A fraction eluated with n-hexane was analysed directly by GC and GC-MS. Two other fractions, after saponification, were converted to their methyl ester derivatives and then analysed by GC and GC-MS. It was observed that the solid residue contains mainly straight-chain saturated hydrocarbons with high molecular weight (C 15 -C 31 ) and the esters of carboxylic acids and a homologous series between them exists. It was also concluded that the extract obtained by solvent extraction from the residue of rose flower (Rosa damascena Mill.) which was subjected to steam distillation is also a valuable raw material.

Rose absolute was produced from rose concrete at two temperatures ( 25°C, 20°C) using two concentrations (96%, 80%) of ethanol as solvent. Chemical composition of the absolute was determined by GC and GC-MS and then some properties of it such as refractive index and density were examined. It was found that the absolute mainly consists of phenylethyl alcohol, citronellol, geraniol, nerol, 1-nonadecene, methyl eugenol, eugenol, nonadecane, benzyl alcohol. The amounts of these compounds were found to depend largely upon the conditions of production of absolute and the concentration of the ethanol used. The yields of absolute were found to be in the range of 58-64%.

No abstract