5.5. Extraction with supercritical CO2 modified with ethanol/water

The extraction with supercritical CO2 modified with water in different proportions is carried out to obtain bioactive compounds of high polarity, because as mentioned above, CO2 is an


Table 7. Published studies about carotenoid extraction using CO2


Table 8. Published studies about fatty acids extraction using CO2


Table 9. Phenolic compounds extracted with supercritical CO2 modified with ethanol/water.

non-polar molecule and does not have "power" to solubilizate polar substances as is the case of the phenolic compounds (phenolic acids and flavonoids) [105, 106]. As previously mentioned, parameters of processes, such as temperature and pressure, can influence the extraction of bioactive compounds. Besides these two parameters, anthocyanins are also important for the extraction of phenolic compounds. Solvent flow rate, percentage of co-solvent, co-solvent type (ethanol or water), and extraction time are parameters that directly implicate the yield of these substances at the end of the extraction process [107].

Further examples of extraction of phenolic compounds using supercritical CO2 modified with co-solvents can be analyzed in the studies [106, 108, 109]. They extracted various flavonoids like quercetin, catechin, epicatechin from cranberry, blueberry, and raspberry. Table 9 presents some studies in which supercritical CO2 modified with ethanol/water were used to extract chemically active phenolic compounds.
