A novel CO2-sensitive in situ deep eutectic solvent system: Efficient extraction of polyphenol phytochemicals

In the present study, monoethanolamine (MEA) was applied as a solvent for the extraction of polyphenols from lingonberry (Vaccinium vitis-idaea L.) pomace. In addition to solvent extraction an in situ DES could be formed with the secondary metabolites to obtain higher extraction yield. FT-IR, DSC, and TGA were used to validate MEA-based in situ DESs with reference compound. And the reusability of the solvent system still reached about 70.2% after the fifth cycles. The Box-Behnken experimental design method was used to determine the extraction efficiency under optimal conditions in practical applications, and the highest extraction yields of polyphenols increased 1.06–1.21 folds higher than that of traditional solvents. In addition, the extraction mechanism was studied using density functional theory. In summary, this study proposed a green and sustainable strategy to replace traditional solvents for targeted extraction of polyphenols from plants.