摘要：
(-)-Epicatechin (EC) is a flavanol easily obtained through the diet and is present in tea, cocoa, vegetables, fruits, and cereals. Recent studies have shown that EC protects human health and exhibits prominent anti-oxidant and anti-inflammatory activities, enhances muscle performance, improves symptoms of cardiovascular and cerebrovascular diseases, prevents diabetes, and protects the nervous system. With the development of modern medical and biotechnology research, the mechanisms of action associated with EC toward various chronic diseases are becoming more apparent, and the pharmacological development and utilization of EC has been increasingly clarified. Currently, there is no comprehensive systematic introduction to the effects of EC and its mechanisms of action. This review presents the latest research progress and the role of EC in the prevention and treatment of various chronic diseases and its protective health effects and provides a theoretical basis for future research on EC.
摘要：
以1979-2019年WOS(Web of science)和CNKI(China national knowledge infrastructure)收录的茶叶香气品质相关文献为研究对象,采用CiteSpace文献计量方法分别从年代、作者、机构、国家、研究热点、演进趋势等方面进行归纳统计分析。结果表明,2006年以后相关研究文献呈显著增长趋势,目前已形成稳定的核心作者群,但各群体间的合作研究相对较少;在该研究领域,我国影响力最大,其次是日本和美国;热点研究内容主要集中在香气形成机理、香气物质提取方法、检测手段及关键香气物质等方面。综上结果,结合时区图谱,进一步指出茶叶香气的研究历程及目前所处的发展阶段。
期刊：
现代食品科技,2020年36(5):231-237 and 251 ISSN：1673-9078
作者机构：
[罗军武; 黄建安] Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, 410128, China;[高士伟; 龚自明; 桂安辉] Institute of Fruit and Tea, Hubei Academy of Agricultural Science, Wuhan, 430064, China;[叶飞] Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, 410128, China<&wdkj&>Institute of Fruit and Tea, Hubei Academy of Agricultural Science, Wuhan, 430064, China
通讯机构：
[Liu, ZH; Zhu, MZ; Wang, Qi-ye] H;Hunan Agr Univ, Coll Hort, Natl Res Ctr Engn Technol Utilizat Funct Ingredie, Key Lab Tea Sci,Minist Educ, Changsha 410128, Peoples R China.;Hunan Normal Univ, Coll Life Sci, Hunan Prov Key Lab Anim Intestinal Funct & Regula, Hunan Int Joint Lab Anim Intestinal Ecol & Hlth, Changsha 410081, Peoples R China.
关键词：
Dark tea;Gastrointestinal function;Gastrointestinal transit;Antibiotic;Restoration;Intestinal microbes
摘要：
Processing of dark tea varieties, such as Fu brick tea, Liupao tea, Qianliang tea, and Qing brick tea, includes solid-state fermentation involving microorganisms. In this study, we analyzed the major chemical constituents of dark tea extracts and evaluated their modulatory effect on the gastrointestinal function in normal mice, including the improvement of gastrointestinal transit and intestinal microbial, as well as the attenuation of intestinal microbial dysbiosis and intestinal pathological damage, and the adjustment of immune function in antibiotic-treated mice. Substantial differences in major chemical constituents, including total polyphenols, total organic acids, water extract content, 18 free amino acids, gallic acid, and six tea catechins, were observed among Fu brick tea, Qianliang tea, Qing brick tea, and Liupao tea extracts. Extracts from the four dark tea varieties significantly promoted gastrointestinal transit and colonization of beneficial Bifidobacterium and Lactobacillus, and inhibited the growth of harmful Escherichia coli and Enterococcus in normal mice. In addition, Qianliang tea, Qing brick tea, and Liupao tea extracts significantly accelerated the reversal of the ampicillin sodium-induced pathological damage in the ileum, intestinal bacterial dysbiosis (Bifidobacterium, Lactobacillus, E. coli, and Enterococcus), and low immunity.
作者机构：
湖南农业大学茶学教育部重点实验室,湖南 长沙 410128;国家植物功能成分利用工程技术研究中心,湖南 长沙 410128;湖南省植物功能成分利用协同创新中心,湖南 长沙 410128;[周方; 欧阳建] Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, 410128, China<&wdkj&>National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, 410128, China;[黄建安; 刘仲华] Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, 410128, China<&wdkj&>National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, 410128, China<&wdkj&>Hunan Co-Innovation Center for Utilization of Botanical Functional Ingredients, Changsha, 410128, China
作者机构：
[程晓梅; 李永迪] Tea Key Lab of the Ministry of National Teaching of Hunan Agricultural University, Changsha, 410128, China;National Research Center of Engineering Technology for Utilization of Botanical Functional Ingredients, Changsha, 410128, China;Hunan Co-Innovation Center for Utilization of Botanical Functional Ingredients, Changsha, 410128, China;[杨培迪] Tea Research Institute, Hunan Academy of Agriculture Sciences, Changsha, 410128, China;[李勤; 刘仲华] Tea Key Lab of the Ministry of National Teaching of Hunan Agricultural University, Changsha, 410128, China<&wdkj&>National Research Center of Engineering Technology for Utilization of Botanical Functional Ingredients, Changsha, 410128, China<&wdkj&>Hunan Co-Innovation Center for Utilization of Botanical Functional Ingredients, Changsha, 410128, China
摘要：
Epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3 '' Me) in tea (Camellia sinensis (L.) O. Kuntze) is a major source of O-methylated catechin and renowned for a wide range of health effects. However, the transcriptional regulation mechanisms of EGCG3 '' Me biosynthesis remain unclear. In the present work, the basic Helix-Loop-Helix (bHLH) transcription factor, designated as CsbHLH62, belonging to GBOF group of bHLH families, was isolated and characterized from Camellia sinensis. CsbHLH62 contains an Open Reading Frame of 1662 bp and encodes a polypeptide of 553 amino acids. Subcellular location and transcriptional activity analysis showed it as a nucleus protein and possessed transcriptional inhibition activity. Furthermore, the expression of CsbHLH62 was decreased during EGCG3 '' Me accumulation. More importantly, E-box motifs (5'-CANNTG-3') were found in the promoters of CCoAOMT, CsLAR, and CsDFR, and further transient expression assays showed that CsbHLH62 repressed the transcription of CCoAOMT, CsLAR, and CsDFR. Collectively, these results suggest that CsbHLH62 acts as a transcriptional repressor that might be negatively affecting the accumulation of EGCG3 '' Me. These findings provide novel insights into the regulatory mechanism of EGCG3"Me biosynthesis, which might help to breed high EGCG3 '' Me-content tea plants.
摘要：
To better understand the effects of bacteria on the characteristics of Fu brick tea, we investigated bacterial community structure as well as the predicted functions of identified bacteria and their correlations with chemical compounds during the manufacturing process. Overall, Klebsiella species dominated during the initial stage of processing, but were quickly replaced by Pseudomonas, Lactococcus, Stenotrophomonas, Enterococcus, and Bacillus species, which remained stable until the end of the manufacturing process. Network analysis identified 11 bacterial genera as keystone taxa, which contributed to the stabilization of the microbial community in the co-occurrence network. Bacterial taxa were grouped into eight modules, with the dominant genera mainly distributed amongst modules I and , which were involved in metabolism of carbon and flavor compounds in the Fu brick tea ecosystem. Using bidirectional orthogonal partial least squares analysis, 19 bacterial genera were identified as core functional genera linked to the metabolism of chemical compounds during the manufacturing process, while three genera, namely Klebsiella, Lactococcus, and Bacillus, also dominated the Fu brick tea fermentation process. These findings provide new insights into Fu Brick tea bacterial community variation and increased our understanding of the core functional bacterial genera involved in the manufacture of Fu brick tea.
摘要：
Abstract The antioxidant effects of tea catechins (TC) on the shelf life of raw minced duck meat were investigated by measuring the levels of lipid peroxidation, globulin precipitation, and TC residues during refrigeration (4 °C). TC was added to the raw minced duck meat at 0 (T0), 300 (T300), 500 (T500), 800 (T800), or 1000 (T1000) mg/kg. Treated samples were stored in a refrigerated (4 °C) display cabinet under aerobic conditions for 10 d. The levels of lipid peroxidation (thiobarbituric acid reactive substances), globulin precipitation, and TC residues were measured every 2 d. TC-treated duck meat displayed significantly lower (P < 0.05) lipid peroxidation compared with the control under refrigerated aerobic conditions, indicating that the TCs have antioxidant activity. As the TC concentration increased, globulin precipitation decreased under aerobic conditions. At the same time, the level of TC residues first increased and then decreased. These results showed that addition of TC improved the lipid stability, decreased globulin precipitation, and decreased the level of TC residues in minced duck meat. Therefore, TCs are a promising additive for inhibiting the oxidation of duck meat, and could be used to maintain food product quality.
