Extraction of essential oils from damask rose using green and conventional techniques: Microwave and ohmic assisted hydrodistillation versus hydrodistillation

Abstract

Damask rose is cultivated as the main species used in the production of rose water and relevant essential oils (EOs) of rose for its fragrance and therapeutic applications. Since the flowers are highly perishable, the extraction of oil should be done rapidly in order to produce rose EO successfully and optimally. Solvent free microwave-assisted extraction (SFME) and ohmic assisted hydrodistillation (OAHD) are advanced and green distillation techniques, which utilize microwave, and ohmic heating processes respectively for the extraction of EOs. In this study, SFME and OAHD of EOs were performed on fresh flowers of damask rose, and the findings were compared with the traditional hydrodistillation (HD). The findings of EO analysis indicated considerable alterations in EOs compounds extracted by SFME and OAHD methods compared with the traditional HD. To reach the desirable temperature of extraction (nearly 100 °C) and to get the first EO droplets’ evaporation with steam, the mixture was heated for 2.50 ± 0.29 min in SFME and for 17.33 ± 0.33 min in OAHD, while for the HD the heating had to take more than 40 min (42.66 ± 0.32 min). The total extraction time of EOs extracted from damask rose by using the green extraction procedures (SFME and OAHD) were compared with HD extraction method. Extraction by SFME occurred much earlier than extraction by OAHD. Also in this study, the analysis of EOs indicated that the chemical profile of damask rose may fluctuate quantitatively with respect to the constituents and structure of the extracted molecules. This would depend on the system of extraction that influences the characteristics of the EOs.