EFFECT OF SOME FACTORS ON QUANTITY AND COMPOSITION OF FLOWER ESSENTIAL OIL IN DAMASK ROSE

Rose oil is an important basic material for flavor and fragrance in medical and food industries. In this study, effects of harvesting time (April 25, May 1, 7 and 13, 2007), planting site (Meimand and Shiraz, two regions in southern Iran) and flower drying on quantity and composition, such as linalool, phenyl ethyl alcohol, citronellol, geraniol, eugenol, nonadecan and monoterpenes alcohol, of essential oil in Damask rose were assessed. The experiment was conducted as a split-plot-in-time design with three replications. Quantity and composition of essential oil were determined by GC and GC-MS methods, respectively. Harvesting time, affected percentage of oil content, phenyl ethyl alcohol, citronellol, eugenol, nonadecan and monoterpenes alcohol. The highest monoterpenes alcohol in fresh flowers was obtained when flowers were harvested on May 7, 2007 in Meimand and Shiraz (44.76 and 53.36%, respectively). The highest oil content (0.41%) was observed in fresh flowers harvested on May 1 and 7, 2007 in Meimand and Shiraz, however, oil content was decreased in first and fourth of harvesting time. Similarly in dried flowers, the highest linalool contents were found in flowers harvested on 25 April in Meimand and Shiraz (1.73 and 1.36%, respectively). Planting site had significant effects on eugenol content in fresh flowers but not on other compositions. In dried flowers, composition of linalool, citronellol, geraniol, nonadecan and monoterpenes alcohol was significantly affected by planting site. When flowers were dried, extraction efficiency of essential oil and quantity of citronellol, geraniol and monoterpenes alcohol were decreased, however, linalool content was increased.