Subcritical water extraction of essential oils from coriander seeds (Coriandrum sativum L.)

Subcritical water extraction (SCWE), hydrodistillation and Soxhlet extraction were compared for the extraction of essential oil from coriander seeds (Coriandrum sativum L.). The extraction efficiencies of different temperatures (100, 125, 150 and 175 °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 results showed that the optimum temperature, mean particle size, and flow rate were 125 °C, 0.5 mm, and 2 ml/min. The SCWE was compared with both conventional methods in terms of the efficiency and the essential oil composition. Hydrodistillation and Soxhlet extraction showed higher extraction efficiencies, but the SCWE resulted to the essential oils more concentrated in valuable oxygenated components.