The galloyl catechins contributing to main antioxidant capacity of tea made from Camellia sinensis in China.
The galloyl catechins contributing to main antioxidant capacity of tea made from Camellia sinensis in China.
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DOI：
10.1155/2014/863984
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发表时间：
2014
影响因子：
--
通讯作者：
Yang L
中科院分区：
文献类型：
--
作者：
Zhao C;Li C;Liu S;Yang L
对中国茶树绿茶、黑茶、乌龙茶和红茶的总多酚含量、儿茶素含量和抗氧化能力进行了评估。 20个茶叶样品的总多酚含量在7.82%~32.36%之间。总儿茶素含量在4.34-24.27%范围内。通过氧自由基吸收能力（ORAC）测试和1,1-二苯基-2-三硝基苯肼（DPPH）自由基清除测试测定茶提取物的抗氧化能力。总多酚含量、儿茶素含量、抗氧化能力依次降低：绿茶>乌龙茶>红茶>黑茶。抗氧化能力与总多酚含量或儿茶素含量呈正相关（R 2 = 0.67-0.87）。通过在线 HPLC DPPH 自由基清除法测定五种主要儿茶素（表没食子儿茶素没食子酸酯 (EGCG)、表儿茶素没食子酸酯 (ECG)、表儿茶素、表没食子儿茶素和儿茶素）的抗氧化能力；茶的抗氧化活性主要归因于酯化儿茶素（EGCG或ECG）。
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).