Volatile Oil Constituents of Rosa canina L.: Quality As Affected by the Distillation Method

The volatile oils of R. canina flowers were isolated by hydrodistillation (HD) and traditional dry distillation (DD) and analyzed by HRGC-FID and GC-MS. Compared to HD, DD at 50°C leads to the isolation of high quality oil which contains the highest content of oxygenated compounds (83%). The main components are the 2-phenethyl alcohol and eugenol. The percentage of the 2-phenethyl alcohol, a highly desirable component in rose oil, was significantly higher (58.4%) in DD extract when compared to that of HD one (13.6%). As temperature increased (100°C) during DD, the oil quality decreased. The most significant changes were observed in 2-phenethyl alcohol percentage (4.5%). Moreover, an increase of alkanes/alkenes and the production of furan derivatives were observed. So, DD at moderate temperature (50°C) seemed more suitable to improve the volatile oil quality and hence, to make more value of R. canina.