Subcritical water extraction of essential oils from Zataria multiflora Boiss.

Essential oil of Zataria multiflora Boiss, cultivated in Iran, was extracted by subcritical water extraction (SCWE) and compared with two conventional methods including hydrodistillation and Soxhlet extraction. The extraction efficiencies of different temperatures (100, 125, 150 and 175 o C), mean particle sizes (0.25, 0.50 and 1 mm), and water flow rates (1, 2 and 4 ml/min) were investigated. Separation and identification of the components were carried out by GC–FID and GC–MS. The best operating conditions for the SCWE of Zataria multiflora Boiss. Were determined to be 150 o C temperature, 0.50 mm mean particle size and 2 mL/min flow rate for 150 min extraction time. In this paper, we brought out information about effect of different temperatures on efficiency of the Thymol and Carvacrol. The SCWE method provides a more valuable essential oil (with higher amounts of oxygenated compounds and no significant presence of terpenes).

Keywords:

Subcritical water extraction , Hydrodistillation , Soxhlet , Zataria multiflora Boiss , Essential oil