Essential oil composition of Damask rose (Rosa damascena Mill.) distilled under different pressures and temperatures

Experiments were conducted on field distillation unit to distil rose oil and rose water from the fresh flowers of Damask rose (Rosa damascena Mill.) under different pressures and temperatures to study and compare the essential oil composition by GC-FID. The monoterpene hydrocarbons and esters were found to be in traces, and stearoptene content was found to be higher in the oil distilled under high pressure, as compared to oil produced under atmospheric pressure. In general, the percentage of total alcohols (55.25-83.41%) in rose oil increased with the increase in pressure and temperature of the distillation. Physicochemical properties of rose oil distilled at varying level of temperatures and pressures are discussed. A comparative study was also conducted of rose oil constituents from dichloromethane-extracted rose water and redistilled rose water under atmospheric and higher pressure. At higher pressure early-eluting components in the GC column were present in traces and decrease in total alcoholic content was observed. It can be concluded that distillation conducted under pressure does not yield good quality oil. However, dichloromethane-extracted rose oil from rose water carries a higher amount of 2-phenylethyl alcohol. The total rose alcohol content present in rose water was higher than in rose oil. Copyright (C) 2002 John Wiley Sons, Ltd.