Viola odorata: Influence of supercritical fluid extraction on the efficiency of ultrasound- and microwave-assisted extraction of bioactive compounds

Abstract

This study aimed at examining the effect of supercritical carbon dioxide (ScCO2) extraction on the subsequent extraction of the Viola odorata polar bioactive components. The raw material was firs submitted to ScCO2 extraction for the extraction of the lipophilic fraction. Then the exhausted raw material was subjected to ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) in order to extract the polar components. ScCO2 extraction was performed under the pressure of 300 bar and at a temperature of 40 °C for 4 hours. In order to see the effect of ScCO2, the UAE and MAE (50% aqueous ethanol solution as solvent) were conducted on both exhausted (residue-after the ScCO2) and unexploited raw materials. Also, the impact of the various UAE and MAE conditions was tested. The UAE was conducted on two different temperatures (40 and 50 °C) at the constant extraction time (40 and 20 min).