SUPERCRITICAL-FLUID EXTRACTION OF ESSENTIAL OIL FROM TURKISH LAVENDER FLOWERS

Abstract

Essential oil was extracted from Turkish lavender flowers by supercritical carbon dioxide. A statistical experimental design based on ''Second Order Central Composite Design'' was planned fixing the extraction period at four hours. Parameters such as pressure, temperature, carbon dioxide flow rate, and particle size coded as x(1), x(2), x(3), and x(4), respectively, were used. These parameters were investigated in five levels (-2, -1, 0, 1, and 2). The dependent variable Y-1 was taken as the relative overall essential oil yield. The effects of operating conditions of supercritical fluid extraction on the relative overall yields were calculated with respect to steam distillation. The optimum conditions to obtain Y greater than or equal to 80% were about x(1) = 85.77 bar, x(2) = 36.58 degrees C, x(3) 10. 11 L h(-1), and x(4) = -2143 mu m, after some modifications for third order-like model. The components of lavender essential oil such as fenchone, camphor, linalool, linalyl acetate, bornyl acetate, and cadinene were detected by GC-MS chromatography. Fenchone and camphor were determined as the major components. Besides, the essential oil samples extracted and trapped in alcohol for each experiment were analyzed qualitatively by gas-liquid chromatography. Then, the same response surface methodology was used for components of essential oil such as fenchone (Y-2) and camphor (Y-3).