Gramza-Michałowska Anna, Sidor Andrzej, Reguła Julita, Kulczyński Bartosz
Department of Food Service and Catering, Poznań University of Life Sciences, Poland.
Department of Human Nutrition and Hygiene, Poznań University of Life Sciences, Poland.
Acta Sci Pol Technol Aliment. 2015 Oct-Dec;14(4):331-341. doi: 10.17306/J.AFS.2015.4.33.
Plant polyphenols are known for their limiting of adverse effects on reactive oxygen species (ROS) in biological systems. The photochemiluminescence (PCL) assay allows to evaluate the antiradical activity of a compound in the presence of a superoxide anion-radical (O •-), which is one of the ROS directly associated with the human body. In this work, determination of the superoxide anion radical scavenging activity of different tea extracts using the PCL assay was performed.
Investigations were conducted on different tea leaves extracts. The study included five kinds of tea leaves subjected to aqueous and ethanol extraction procedure. Catechins content was evaluated using HPLC. Antiradical activity of the samples was conducted with use of Photochem assay.
Analysis of total catechins content in tea aqueous extracts enabled them to be arranged as follows: yellow > green > white > red > black, while for ethanol extracts it was: yellow = green > white > red > black. The examined tea extracts were ranked from highest to lowest water-soluble antioxidative capacity (ACW) values as follows: yellow > green > white > red > black. The results of lipid-soluble antioxidative capacity (ACL) values for aqueous extracts were similar; however, were approximately 50% lower than those presented as ACW. The second examined group were ethanol extracts, which ranked for ACW values: yellow > green = red = white > black, while ACL values ranked as follows: yellow > white = black = red > green. PCL assay results were correlated with total catechin content in aqueous extracts.
Antiradical activity of different tea leaves extracts in PCL assay, showed that the highest activity was found in extracts of yellow tea; the lowest, however, was identified in black tea extracts.
植物多酚以其对生物系统中活性氧（ROS）的不良影响的限制作用而闻名。光化学发光（PCL）测定法可用于评估化合物在超氧阴离子自由基（O•-）存在下的抗自由基活性，超氧阴离子自由基是与人体直接相关的活性氧之一。在这项工作中，使用PCL测定法对不同茶叶提取物的超氧阴离子自由基清除活性进行了测定。
对不同茶叶提取物进行了研究。该研究包括对五种茶叶进行水提取和乙醇提取。使用高效液相色谱法（HPLC）评估儿茶素含量。使用光化学测定法进行样品的抗自由基活性测定。
对茶叶水提取物中总儿茶素含量的分析使它们按以下顺序排列：黄茶＞绿茶＞白茶＞红茶＞黑茶，而乙醇提取物的顺序为：黄茶 = 绿茶＞白茶＞红茶＞黑茶。所检测的茶叶提取物按水溶性抗氧化能力（ACW）值从高到低排列如下：黄茶＞绿茶＞白茶＞红茶＞黑茶。水提取物的脂溶性抗氧化能力（ACL）值结果相似；然而，比ACW值低约50%。第二个检测组是乙醇提取物，其ACW值排列为：黄茶＞绿茶 = 红茶 = 白茶＞黑茶，而ACL值排列如下：黄茶＞白茶 = 黑茶 = 红茶＞绿茶。PCL测定结果与水提取物中的总儿茶素含量相关。
不同茶叶提取物在PCL测定中的抗自由基活性表明，黄茶提取物的活性最高；然而，黑茶提取物的活性最低。
