Supramolecular deep eutectic solvents as green media for efficient extraction of tea polyphenols and its application in bio-active film

Abstract

Ultrasonic-assisted supramolecular deep eutectic solvents (SUPRADESs) extraction of active ingredients from plants is a novel green extraction method. In this study, a series of SUPRADESs combined with cyclodextrins (CDs) and organic acids or polyols were synthesized and used to extract the tea polyphenols (TP). SUPRADESs, consisting of Hydroxypropyl-β-cyclodextrin (HP-β-CD) and L-lactic acid (LA) with a mass ratio of 1:5, contributed to achieving the maximum extraction efficiency of TP. Then, the extraction rate was optimized by different experimental conditions, and the optimal extraction yield of TP was (111.36 ± 2.31 mg/g). Then, the biofilms were successfully prepared using HP-β-CD/LA extract as a plasticizer for polyvinyl alcohol and chitosan. Furthermore, the antioxidant activity of extract and film containing TP was determined using biochemical kits. Finally, the synthesis process of HP-β-CD/LA and the TP extraction were investigated using molecular simulation. The findings indicate that enhanced TP yield could be attributed to an increase in non-covalent bonds between HP-β-CD and TP through the assistance of LA.