Optimization of the extraction process and hypoglycemic activity of Tieguanyin tea polyphenols

In this study, the extraction process of Tieguanyin tea polyphenols was optimized and its hypoglycemic activity was tested. The response surface method was used to design the experiment to optimize the extraction process and explore the best extraction conditions. The extract was purified by AB-8 macroporous resin, and its hypoglycemic activity was studied by the inhibition rate of two enzymes (alpha-glucosidase and alpha-amylase). The optimum conditions of ultrasonic-assisted extraction of Tieguanyin tea polyphenols were as follows: material-to-liquid ratio of 40 mL/g, ultrasonic power of 240 W, and ultrasonic time of 30 min. The extraction rate of tea polyphenols was 13.82%, which was consistent with the predicted value of 13.78%. The purification experiment results showed that the purity of tea polyphenols was 50.62%. The IC50 of Tieguanyin tea polyphenol extract on alpha-glucosidase and alpha-amylase was 1.93 x 10-8 mg/mL and 7.65 x 10-11 mg/mL, respectively, indicating that it could inhibit both of them. In this study, the optimum extraction process of Tieguanyin tea polyphenols was optimized and confirmed, and it was confirmed that Tieguanyin tea polyphenols had strong hypoglycemic activity.