A comparison between different techniques for the isolation of rosemary essential oil

Traditional hydrodistillation (HD), supercritical fluid extraction (SFE), organic solventextraction (SE), and water microwave assisted hydrodistillation (MAHD) techniqueswere compared and evaluated for their effectiveness in the isolation of rosemaryessential oil. The microwave assisted hydrodistillation technique was optimized interms of both delivered power and time duration. The extracts/distillates were analyzedby GC and GC-MS. Microwave distillation, which exploits the physical action ofmicrowaves on plants, showed a series of advantages over the other approaches:low cost, use of water in sample pre-treatment step, greatly reduced isolation time,and attainment of high quality essential oil distillate. Moreover, the absence of environmentalimpact of this innovative technique was also emphasized.