Composition of rose (Rosa damascena Mill.) essential oils from various geographic origins

Rosa damascena Mill. (Rosaceae) requires temperate climate as well as alkaline soil pH during flowering to attain high oil contents. It is usually cultivated at an altitude between 300 – 1500 m ASL. Having favorable edaphic and climatic conditions, Turkey and Bulgaria are the main rose oil producers in the world, followed by Morocco, Iran and a couple of a few other countries producing smaller quantities [1].

Different agrometeorological and technological conditions in these countries result in varying chemical compositions of the respective rose oils [2]. In the present study the chemical composition of 154 batches, originating from Turkey, Bulgaria, Iran, Ethiopia and Afghanistan, were evaluated. Essential oil composition was analyzed by GC-FID using surface-bonded polyethylene glycol as stationary phase.

Major constituents of the eleoptene fraction were found to be the acyclic monoterpene alcohols β- citronellol, geraniol and nerol. While β-citronellol content was similar in all the oils investigated (30.3%-32.6%), geraniol and nerol contents were highest in oils from Afghanistan (23.7% and 12.7%, respectively) but lowest in Ethiopian oil (16.6% and 7.2%, respectively). The stearoptene fraction predominantly consisting of the aliphatic hydrocarbons nonadecane (C₁₉) and heneicosane (C₂₁) was highest in Ethiopian rose oils (19.8% for C₁₉ + C₂₁), followed by rose oils from Iran (14.4% for C₁₉ + C₂₁). Since the roses in Ethiopia and Iran grow at much higher altitudes the higher stearoptene content in these oils could be explained by a thicker cuticular wax layer preventing rose petals from evaporation of water and volatiles upon solar radiation.

• References

• 1 Gunes E. Turkey Rose Oil Production and Marketing: A Review on Problem and Opportunities. J Appl Sci 2005; 5: 1871-1875.
• 2 Gochev V, Wlcek K, Buchbauer G, Stoyanova A, Dobreva A, Schmidt E, Jirovetz L. Comparative Evaluation of Antimicrobial activity and composition of Rose Oils from various geographic origins, in particular Bulgarian rose oil. Nat Prod Commun 2008; 3: 1063-1068.