The effects of drying and distillation methods on essential oil content and composition of Eucalyptus largiflorens

In this research, the fresh leaves of Eucalyptus largiflorens were collected in the middle of spring from Kashan in Isfahan province. After drying the plant materials in oven 30°C, 40°C, 50°C, sun and shade, their essential oils were obtained by hydro-distillation. In addition, the essential oil of shade-dried sample was obtained by two other distillation methods (water and steam distillation and direct steam distillation). The oils were analyzed by GC and GC/MS. Oil yields (w/w) of the oven-dried 30°C, 40°C, 50°C, sun-dried and shade-dried sample were 1.37%, 1.58%, 1.59%, 1.31% and 1.32% respectively. 1,8-cineole (25.0%, 26.2%, 40.6%, 29.7% and 24.6%), P-cymene (17.2%, 17.4%, 20.3%, 20.5% and 17.1%) and α-pinene (16.2%, 12.6%, 14.4%, 7.2% and 9.9%) were identified as the main components in oven-dried 30°C, 40°C, 50°C, sun-dried and shade-dried sample, respectively. On the other hand, the oil yields were 0.92% and 0.77% in water and steam distillation and direct steam distillation. In different drying methods the result showed the oil yield and 1,8-cineole percentage were higher in oven-dried 50°C sample and in different distillation the oil yield in hydro-distillation was higher and the highest percentage of 1,8-cineole was obtained by water and steam distillation.