Influences of Fermentation Time, Hydro-distillation Time and Fractions on Essential Oil Composition of Damask Rose (Rosa damascena Mill.)

Damask rose (Rosa damascena Mill.) is known for its high quality oil, used in the perfumery industry. The aim of this Study was to determine the influences of fermentation time, hydro-distillation time and fractions with sequential intervals on essential oil composition. particularly on methyl eugenol content of Damask rose. Essential oil of the rose flowers was produced by hydrodistillation using a Clevenger-type apparatus. Six fermentation times (6, 12, 18, 24, 30 and 36 h at 25 degrees C in sack), 6 distillation times (30, 60, 90, 120, 150 and 180 min.) and 7 fractions (0-15, 16-30, 31-60, 61-90, 91-120, 121-180, and 181-240 min.) during a hydro-distillation were used. The components in the essential oils were analyzed by GC-FID and GC-MS. Rose oil was characterized by high percentage of acyclic monoterpene alcohols. represented particularly by citronellol. geraniol and nerol, and long-chain hydrocarbons represented particularly such as nonadecane. nonadecene and heneicosane. The oil yield started to decrease through the fermentation (from 0.55 to 0.025%) Fermentation increased the citronellol and methyl eugenol contents in opposition to the content of geraniol and nerol. Each one of hydrocarbons increased their percentages nearly two times and more during the fermentation. Extending of distillation time up to 150 min increased the essential oil yield. The longer distillation time gave a higher methyl eugenol concentration, whose content increased steadily up to last distillation time (from 0.69 to 1.65%) Contents of monoterpene alcohols decreased, whereas the hydrocarbons steadily increased LIP to late fractions.