Supercritical carbon dioxide extraction of caraway essential oil

Abstract

Caraway seeds were extracted with liquid and supercritical carbon dioxide at 23–40°C and 90–100 bar. The extracts were analyzed for carvone and limonene, and compared with essential oil obtained by steam distillation. Slight fractionation was observed during the extraction. The effect of process parameters, such as temperature, pressure, and solvent flow rate and direction, on essential oil recovery was described using a simple model with mass transfer between a liquid mixture of essential and fatty oils and the solvent, and with diffusion resistances both in the liquid mixture and in the walls of caraway cells.