Supercritical CO2 impregnation of silica microparticles with quercetin

• Published in: The Journal of supercritical fluids 2019-01, Vol.143, p.157-161
• Main Authors: García-Casas, I., Crampon, C., Montes, A., Pereyra, C., Martínez de la Ossa, E.J., Badens, E.
• Format: Article
• Language: English
• Subjects: Chemical and Process Engineering; Engineering Sciences; Quercetin; Silica; Supercritical impregnation
• ISSN: 0896-8446; 1872-8162
• DOI: 10.1016/j.supflu.2018.07.019

Figure. Schematic process. Supercritical impregnation of silica bead with quercetin. [Display omitted] •Silica has been impregnated with quercetin using supercritical CO2.•Two methods of impregnation were developed: in batch and semi-continuous ways.•In batch process quercetin loading reached its maximum at 2 h.•The best quercetin loading was achieved at 10 MPa and 323 K during 2 h with ethanol 5% v/v as cosolvent. Supercritical carbon dioxide has been used to develop two methods for the impregnation of porous silica beads with a natural antioxidant, quercetin. These methods involved batch and semi-continuous supercritical impregnations. The first experiments performed in batch mode helped to understand the influence of pressure, temperature, duration, and the presence of a co-solvent on the impregnation efficiency. A co-solvent was added due to the low solubility of quercetin in supercritical CO2 under the operating conditions studied. In the range of temperatures and pressures studied, the best operating conditions, i.e., those that led to the highest quantity of quercetin impregnated (300 μg of quercetin per g of silica), were 10 MPa and 323 K with ethanol as co-solvent for 2 h. These operating conditions, highlighted through the batch mode experiments, were subsequently applied to the semi-continuous process. This approach provided an impregnation ratio of 240 μg of quercetin per g of silica.