A sustainable process for (−)-α-bisabolol extraction from Eremanthus erythropappus using supercritical CO2 and ethanol as co-solvent

•(−)-α-Bisabolol was obtained from E. erythropappus using supercritical CO2 and ethanol.•Pressure, temperature, extraction time and co-solvent percentage were evaluated.•Static and dynamic operational extraction modes were compared.•Ethanol showed essential contribution for increasing extraction yields.•The global yield was higher than the observed for steam distillation method.

Supercritical carbon dioxide (sc-CO2) extraction of Candeia (Eremanthus erythropappus) wood was studied using ethanol as a co-solvent. This tree has a great potential for producing (−)-α-bisabolol, an interesting compound for the cosmetic and pharmaceutical industries because of its properties. Using a Box–Behnken experimental design, the effects of pressure, temperature, extraction time and co-solvent percentage on the global yield were systematically evaluated. Static and dynamic extraction modes were compared. The use of ethanol as co-solvent proved itself fundamental for raising the extracted percentage of the desired compound. Both static and dynamic modes provided extracts with (−)-α-bisabolol as the major compound, although dynamic system provided the best extraction yields. In the best experimental condition, an extraction yield equal to 0.74% was achieved, which is much higher than the yields obtained using the standard steam distillation reported in the literature. Pressure showed greater influence in the obtained (−)-α-bisabolol percentage by the dynamic mode, while temperature was very important in the static system.

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