Microwave energy-assisted extraction of bioactive polyphenols with green technology based on magnetic ionic liquid and their stability under different conditions

Abstract

In recent years microwave-assisted extraction has been proved as a more rapid and energy-efficient technique than conventional ways, here it was employed in this study and a kind of magnetic ionic liquid (C3MIMFeCl4) was used as green medium for tea polyphenols (TP). Due to the strong polarity of the ionic liquid, it can quickly absorb microwave energy and increase the temperature; thus the extraction time will be greatly shortened. As the result, it was found when microwave power was set at 200 W, solid-liquid ratio was 1:20 and extraction time was 7 min, the highest extraction efficiency of 0.8 mol/L C3MIMFeCl4 could be obtained as 159.8 mg/g. Compared with ultrasonic-assisted mode used in previous study, the extraction time was shortened significantly from 300 min to 7 min. Moreover, magnetic ionic liquid can be easily recovered by external magnetic field. Finally, stability of TP was further investigated under related conditions by spectroscopic characterization meanwhile related intermolecular interactions; it was found IL could provide greater stabilization energy for these extracted objects in this study at some extent. The results of above research are expected to provide useful references for large-scale application of green technology based on ILs and TP production.

A comprehensive review of nano-delivery system for tea polyphenols: Construction, applications, and challenges

“… UV–Vis the highest extraction efficiency of 0.8 mol/L C 3 MIMFeCl 4 could be obtained as 159.8 mg/g Z. Guo et al, 2019 green tea ultrasonic extraction method the TPC value was 243 ± 7 mg, when the liquid-to-solid ratio was 36:1, the ultrasonic power was 461.5 W, and the ultrasonic time was 21 min. HPLC deep eutectic solvents (DESs) and ultrasound-assisted extraction method (UAE) is a good method for extracting antioxidant polyphenols from green tea with promising applications.…”