COSMO-SAC-supported evaluation of natural deep eutectic solvents for the extraction of tea polyphenols and process optimization

To reduce the environmental pollution caused by organic solvents and improve the extraction efficiency, a range of natural deep eutectic solvents (NADESs) was explored for the extraction of green tea polyphenols (TPs). The use of the NADESs, especially ChCl/EG (Choline chloride/Ethylene glycol, molar ratio 1:2), can increase extraction efficiency when comparing with the traditional solvents. Then response surface methodology (RSM) was used for the optimization of TPs extraction with ChCl/EG. The perfect regression prediction model was generated and the highest TPs extraction yield of 20.12% was achieved, highlighting the potential of NADES for TPs extraction.