Changes in Polyphenols and Antioxidant Activities of Yingshan Yunwu Tea during Digestion in Vitro.

[Objectives] To explore the change rule of polyphenol content and antioxidant activity of coarse old leaves of Yingshan Yunwu Tea in the process of human digestion. [Methods] The coarse and old leaves of Yunwu tea in Yingshan, Huanggang, Hubei Province were selected as the research object, and their digestion in vitro was simulated. The total polyphenol content was determined by Folin-phenol reagent colorimetric method, and the DPPH radical scavenging activity and total antioxidant activity were determined. [Results] After simulated gastrointestinal digestion in vitro, the polyphenol content and antioxidant activity of coarse old leaf tea soup showed a downward trend. After gastrointestinal digestion, the polyphenol content in tea infusion separately decreased by 31.8% and 8.5%; the scavenging rate of DPPH free radical was 97% before digestion, decreased to 92% after gastric digestion and 65% after intestinal digestion, which decreased by 5% and 27%, respectively ; after gastrointestinal digestion, the total antioxidant capacity of tea soup decreased by 4.7% and 3.1%, respectively. [Conclusions] This study provided a reference for the development and application of coarse old leaves of Yingshan Yunwu tea, and provided a reference for the nutritional value evaluation and comprehensive utilization of coarse old leaves, so as to make the best use of coarse tea leaves and reduce the waste of resources. [ABSTRACT FROM AUTHOR]