Enzymatic hydrolysis and extraction of ginsenoside recovered from deep eutectic solvent-salt aqueous two-phase system.

Rare ginsenoside CK was recognized as a popular functional food because of superior pharmacological activity, but it is restricted by further applications by the difficulty in preparation. In this study, deep eutectic solvent (DES)-based aqueous two-phase system (ATPS) was established to transform and extract ginsenoside CK in situ for the first time. The phase formation conditions for preparing ATPS using choline chloride-based DES were studied, and the optimal conditions for extractive bioconversion were explored using conventional single-factor experiments. The conditions for ATPS establishment were as follows: 31.9% (w/w) DES (ChCl-ethylene glycol)/24.5% (w/w) K2HPO4, 55 °C, pH 5.0. Under the optimal conditions, 75.79% product and 61.14% β-glucosidase were recovered from the top and bottom phase, respectively. In addition, DES and β-glucosidase can be recovered and recycled again for the next extractive bioconversion of CK. These results indicated that this green and efficient method exhibited considerable value in integrated production and extraction processes, and demonstrated the potential for obtaining highly recycled functional foods and similar products.