Extraction and characterization of Burdock extracts (leaves, seeds and roots) with compressed solvents technologies

In this study, an advanced green extraction technique applying supercritical CO2 (scCO2) and scCO2 with co-solvent (esters, alcohols or hydroalcoholic solutions) is used to obtain value added compounds from the aerial (leaves and seeds) and underground (roots) parts of Arctium lappa, commonly known as burdock. In order to increase the yields multi-step scCO2 extraction was also tested. Thus, the highest yield of 12.78 wt % for A. lappa leaves was achieved by a six-step sequential scCO2 extraction with ethanol as а co-solvent, for A. lappa roots - 32.82 wt % by а three-step sequential scCO2 extraction with hydroalcoholic solution (methanol-water), while for the A. lappa seeds - 19.02 wt % by using scCO2 with ethanol as co-solvent. Finally, the effectiveness of the above techniques with that of a conventional Soxhlet extraction with regard to yield was compared