Research on extraction of total flavonoids from green tea with deep eutectic

Abstract

Objective: This study aimed to optimize the extraction technology of total flavonoids from green tea with Deep Eutectic Solvents (DESs) and evaluate the antioxidant activity of total flavonoids extracted from green tea under optimal conditions. Methods: The extraction rate of total flavonoids was taken as the index, with the ratio of liquid to solid, extraction temperature and extraction time taken as the influencing factors, and the extraction process parameters were optimized by orthogonal test, followed by the antioxidant activity evaluating with DPPH free radical inhibition. Results: The optimal extraction conditions for extraction of total flavonoids from green tea with DESs were 80% acetylcholine-lactic acid solution (acetylcholine∶lactic acid =1∶1), with ratio of liquid to solid 30∶1 （mL/g）, extraction at 90 ℃ for 75 min. Under the control of these conditions, the extraction yield of total flavonoids was 1.84%, and the concentra-tion of total flavonoids was 65.8 mg/mL. The research on antioxidant activity showed that in a certain concentration range, the antioxidant activity of total flavonoids extract from green tea was stronger than that of vitamin C. Conclusion: Under the control of the optimal technological conditions, the total flavonoids extracted from green tea with 80% acetylcholine-lactic acid solution as eutectic solvent had certain antioxidant activity.

Keywords

• dess
• extract
• green tea
• total flavonoids
• antioxidant activity