The Galloyl Catechins Contributing to Main Antioxidant Capacity of Tea Made fromCamellia sinensisin China

Abstract

Total polyphenol content, catechins content, and antioxidant capacities of green, dark, oolong, and black teas made from Camellia sinensis in China were evaluated. The total polyphenol content of 20 samples of tea was in the range of 7.82–32.36%. Total catechins content was in the range of 4.34–24.27%. The antioxidant capacity of tea extract was determined by the oxygen radical absorbance capacity (ORAC) test and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging test. Total polyphenol content, catechins content, and antioxidant capacity decreased in the following order: green > oolong > black > dark tea. A positive correlation existed between the antioxidant capacity and total polyphenol content or catechins content (R 2 = 0.67–0.87). The antioxidant capacities of five major catechins (epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epicatechin, epigallocatechin, and catechin) were determined by online HPLC DPPH radical-scavenging; the antioxidant activity of tea was mainly attributed to the esterified catechins (EGCG or ECG).

Tea regimen, a comprehensive assessment of antioxidant and antitumor activities of tea extract produced by Tie Guanyin hybridization

“…3,4 Numerous studies have reported that drinking tea imparts various physiological and pharmacological benets which include, anti-diabetic, anti-inammatory, antioxidant, anticholesterolemic, anti-mutagenic and anticarcinogenic activities. [5][6][7][8][9][10] Jin Guanyin, also known as the no. 1 of Mingke tea (a new variety of tea that cultivated by the Tea Research Institute of Fujian Academy of Agricultural Sciences), is a new breed of clones that adopted the hybrid breeding method with the Tie Guanyin as the female parent and the golden GUI as the male from 1978 to 1999.…”

Effect of consecutive steeping on antioxidant potential of green, oolong and black tea

“…Earlier studies also reported that TPC and TFC are higher in GT than BT (Quan et al ., ; Taheri et al ., ; Carloni et al ., ; Pavlović et al ., ; Zielinski et al ., ). It was also reported that green tea contains more TPC than oolong tea followed by black tea (Zhao et al ., ). The difference in TPC is due to the variation in the manufacturing methods used to obtain different tea types (Quan et al ., ).…”

“…Although the antioxidant potential of theaflavin 3,3‐gallate is more than EGCG found in green tea, the amount is much lesser due to which black tea is less effective in scavenging radicals (Chan et al ., ). The present study is in agreement with the previous findings demonstrated similar outcomes where green tea scavenging potential was stronger than the oolong and black teas (Carloni et al ., ; Zhao et al ., ; Nadiah et al ., ).…”

UV‐C Irradiation on the Quality of Green Tea: Effect on Catechins, Antioxidant Activity, and Cytotoxicity

“…Tea catechins are well known as powerful antioxidants and they have been studied as coronary artery disease (CAD) and cancer chemopreventative agents (Deka & Vita, 2011;Kuriyama et al, 2006;Zheng et al, 2011). Health benefits including the reduced risk of CAD by consumption of green tea are attributed to the antioxidant characteristics of the catechins (Rietveld & Wiseman, 2003;Zhao, Li, Liu, & Yang, 2014). Important catechins in green tea include (+)-catechin (C), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG), (-)-gallocatechin (GC), and JFDS-2017-1898Submitted 11/20/2017, Accepted 2/23/2018 (-)-gallocatechin gallate (GCG).…”