A food grade approach for the isolation of major alkylresorcinols (ARs) from rye bran applying tailored supercritical carbon dioxide (scCO2) extraction combined with HPLC

Tailored supercritical carbon dioxide (scCO2) extraction of alkylresorcinols (ARs) from rye bran resulting in pre-purification of ARs already during extraction process. The pre-purification was achieved by splitting the extraction process in 2 steps.. In both steps, the CO2 pressure was set at 25 MPa with a flow rate of 10 g/min. The first step was carried out at 70 °C, 0.06% of ethanolic co-solvent for 2 h, followed by the second step at 45 °C using 10% of ethanolic co-solvent for 4 h, resulting in a pre-purified ARs extract. From the pre-purified scCO2 extract, chromatographed on C8 column, were obtained pure ARs homologues of C17, C19 and C21 (68% of total) eluting separately in a linear gradient of ethanol. Additionally, a rapid method for the isolation of high purified pools of ARs homologues using a disposable solid phase extraction SPE-C18 column and a step gradient of ethanol was developed.