Intensification of supercritical fluid in the extraction of flavonoids: A comprehensive review

The utilization of highly toxic, expensive, and eco-unfriendly organic solvents for the extraction process has been replaced by carbon dioxide (CO2) in its supercritical state. The most significant advantage of supercritical CO2 extraction is after the extraction process there was no trace amount of solvent present in extracted compounds since the residual CO2 can be easily depressurized and vented. Supercritical CO2 attracts interest because of its high compressibility, non-toxic, non-flammable, and physiological compatibility. This insight is a compilation of research works related to flavonoids extraction using a supercritical fluid. The significant parameters that affect the extraction process are temperature, pressure, solvent flow rate, and extraction time. These are the adjustable parameters that were optimized predominantly to improve the yield of the flavonoids extraction. The density of supercritical CO2 is attained by tuning temperature and pressure. The addition of co-solvents enhances the extraction of polar compounds. The residence time of CO2 in the extractor should be sufficient such that the solute reaches the saturation conditions in the fluid phase. This review article will give immense knowledge on the insights about the parameter that needs to be determined to scale up the extraction process.

Automated summary

Supercritical CO2 extraction, with its high compressibility and physiological compatibility, has replaced organic solvents in the extraction process. This review summarizes research on the extraction of flavonoids using supercritical fluids, including the parameters affecting the process and optimization methods.