Changes in the essential oil content and composition of pelargonium graveolens l’hér with different drying methods

In this study, the effect of various drying methods (fresh plant, shade-drying, sun-drying, and oven-drying at 30 and 60 °C) on the essential oil (EO) composition of rose-scented geranium were determined. Essential oil samples were extracted by hydrodistillation and analyzed by GC and GC-MS systems. The highest EO contents were obtained in the fresh plant (1.98%), followed by shade-drying (1.34 %) and oven-drying at 30 °C (1.20 %). The main components were citronellol (23.99-39.87%), geraniol (4.15-17.09%), menthone (4.48-8.34%), linalool (1.96-7.42%), β-caryophyllene (2.63-4.32%), geranyl tiglate (0.99-4.52%), citronellyl butyrate (0.53-5.31%) and cis-rose oxide (0.71-3.15%). The drying methods showed a marked impact on the constituents of the EO samples. The results demonstrated that drying the aerial parts of fresh geranium, and shade-drying and oven-drying at 30 °C were the best optimal methods to obtain the highest oil yield, and citronellol, geraniol, and linalool contents in the oil.