Integrated and sustainable separation of chlorogenic acid from blueberry leaves by deep eutectic solvents coupled with aqueous two-phase system

Abstract

In this work, deep eutectic solvent (DES), as a green solvent, coupled with the aqueous two-phase system (ATPS) for the Negative pressure cavitation extraction and enrichment of chlorogenic acid (CGA) from blueberry leaves (NPCE-DES-ATPS) was developed and optimized for the first time. Eight DESs were synthesized and applied, and ChCl-1,3-Butanediol exhibited the best extraction ability. Under the negative pressure of −0.07pa, the influencing parameters, temperature, liquid–solid ratio, and extraction time, were optimized by response surface methodology (RSM). The RSM results revealed that optimized conditions are liquid/solid ratio 17.01mL/g, extraction temperature 59.03°C, extraction time 24.12min. Subsequently, an aqueous two-phase system (ATPS) formed by DES extract and salt was developed for the enrichment of CGA. Influence factors on the ATPS system were optimized using single factor experiments and the optimal conditions was ChCl-1,3-Butanediol concentration 26.72% (w/w) and K2HPO4 concentration 35.11% (w/w), pH 3 and temperature 35°C. After the integrated and sustainable extraction and enrichment process, the recovery of CGA by DES-ATPS achieved 96.18%, and the purity could reach 74.5%. This green and efficient NPCE-DES-ATPS method has great potential to extraction and purification of CGA and other compounds in pilot or large-scale operations.