绿茶提取物的功能和发展状况

饮茶有益健康,不仅在中国,现今西方发达国家对茶叶功能成分,也有较多的研究。特别是儿茶素和表没食子儿茶素没食子酸酯(EGCG),普遍认为儿茶素和EGCG具有抗氧化、抑菌、抑制肥胖等功效。作为功能配料和膳食补充剂的绿茶提取物,已大量出口到日夲、德国、法国、美国等国。作者简单介绍了国内外儿茶素及EGCG的发展状况。     

茶叶活性成分的抗炎作用及其机制研究进展

茶叶中主要活性成分如茶多酚、茶氨酸、茶黄素具有较好的抗炎作用,且茶多酚效果最佳。虽然茶多酚的抗氧化作用被世界公认,但这并不是其发挥抗炎作用的唯一机制,其机制应与抑制炎症因子、调节相关炎症信号通路、抗氧化等综合作用有关。本文综述了茶叶及茶叶成分茶多酚、茶氨酸、茶黄素的抗炎作用及其机制,其中重点阐述了主要儿茶素组分表没食子儿茶素没食子酸酯(epigallocatechin gallate,EGCG)的抗炎机制,为茶叶抗炎作用的深入研究提供参考,为健康饮茶和茶叶抗炎功能产品的研发提供理论依据。     

儿茶素类的保健作用及机制

茶是二十一世纪风靡全球的健康饮料。茶叶中含有多种保健功能成分, 尤其是儿茶素类物质。儿茶素 具有诸多医疗保健功能和一些特殊性质, 不仅被应用于经口服的膳食补充剂、保健食品、保健饮料等产品, 还应用于化妆品、日化用品等外用型的健康产品, 具有良好的市场开发潜力。本文综述了内服和外用两种方式下儿茶素类物质的保健作用及其作用机制。     

茶叶中表儿茶素对映光学立体异构体的生化功能

综述了对茶叶加工过程中所形成表儿茶素对映的光学立体异构体药理等相关功能最新研究进展,表儿茶素与其对映的光学立体异构体在机体内清除自由基与药理功能方面没有显著差别,对映的光学立体异构体反而在某些方面所发挥的功能强于表儿茶素。因此,对儿茶素立体异构体的研究和认识可以提高和改善茶叶的质量与品质。     

南通大学科技成果展示

正项目名称:基于草本精华的纺织品保健功能面料开发项目简介:抗菌抗紫外消臭自洁复合功能面料的制备方法(ZL 201410556751.1);抗皱柔软透气、无污染的复合功能面料的制备方法(ZL 201610429549.1);茶多酚对棉织物的吸附及抗菌消臭处理方法(ZL 201610201992.3)。成果简介:采用天然植物提取的草本汉方和环保型助剂,结合现代纳米技术,对纺织品进行抗菌消臭、吸湿排汗、防螨驱蚊、远红外保暖、凉感柔软、舒适调温、负离子保健功能整理,提高纺织品附加值。相关技术获中国纺织工业联合会科技进步奖和南通市科技进步奖。     

儿茶素衍生物合成及药理作用研究进展

儿茶素是茶叶中多酚类的主要成分,具有多种药理功能,广泛用于食品、医药及日用化工等领域。但其脂溶性及稳定性差,生物利用率低等缺点使其应用范围受到限制。因此对儿茶素的结构修饰应运而生。本文重点综述儿茶素衍生物主要合成方法--酶法和化学法,简述其生理活性,并对其前景作出展望。     

黄烷醇类化合物的药理活性研究进展

黄烷醇类化合物是一类常见的天然植物多酚类化合物包括儿茶素类、花色素类及黄酮类等化合物,大部分存在于多种木本植物组织中,如山楂、葡萄、可可粉、苹果及草莓等,与日常的饮食有着非常密切的联系。近年以来,国内外许多学者对黄烷醇类化合物进行了研究,多项研究结果表明黄烷醇类化合物具有多种保健功能及生物活性作用,如清除自由基、抗氧化、抗肿瘤、抗炎、抗真菌、降血脂、保护肝脏、保护心血管等,也已被很多的药物科学研究所证实,并成为当今开发研究的热点。本文主要对天然黄烷醇类化合物的来源及多种药理活性等作用进行了综述,并对我国黄烷醇类化合物开发的应用前景提出了一些建议,对黄烷醇类化合物取代合成药物应用于保健食品等行业提供了较好的参考。     

沙枣功能成分及药理活性研究进展

沙枣为胡颓子属植物,在我国西北干旱地区生长面积较大,是西北地区具有开发利用前景的重要资源.沙枣果实含多种功能保健成分,其药理活性已成为近年来研究的重点 . 本文主要探讨了沙枣功能成分及药理活性研究现状,为沙枣的开发利用提供一定的依据,在此基础上提出了沙枣功能成分及药理活性研究的发展策略.     

浙江地区茶叶中有毒有害元素溶出特性及形态分析调查研究报告

调研的背景和意义 茶是世界三大天然饮料之一,具有药理和保健功能,可防病治病,强身健体。茶叶除含有纤维素、维生素、茶多酚、蛋白质等有机物外,还含有较丰富的微量元素,已有研究表明饮茶可防病治病、强身健体。茶叶是浙江省具有明显优势的大宗传统农业主导产业,在全省农村经济、农民收入和出口创汇中占有重要地位。     

表没食子儿茶素没食子酸酯纳米化研究进展

摘要: 表没食子儿茶素没食子酸酯(EGCG)是茶叶中的主要活性成分,具有抗炎抗氧化等诸多生物活性。然而,体内、体外实验结果与流行病学研究存在较大差异。主要原因是EGCG不稳定,生物利用度低等原因。EGCG口服后只有极少数能被肠道所吸收,难以发挥其药理特性。EGCG的诸多缺陷严重阻碍了EGCG相关医药和膳食产品的开发。随着科技的发展,纳米化技术不仅能够提高EGCG稳定性,改善EGCG生物利用度。还能够在纳米颗粒上添加靶向分子定向输送到特定部位,提高EGCG药理特性。纳米化EGCG在食品、医药领域具有广阔前景。因此,本文综述了EGCG吸收,代谢及纳米化EGCG研究进展,以期为EGCG进一步的开发利用提供借鉴。     

Isolation of Green Tea Catechins and Their Utilization in the Food Industry

Tea is a rich source of catechins, which are well-known antioxidants. Tea consumption has been found to promote human health; however, only drinking tea may not provide a sufficient level of catechins to achieve health benefits. Thus, the utilization of catechins in foods is an alternative way to supplement catechin consumption. Furthermore, catechins can prevent lipid oxidation and improve color and flavour of foods; hence, addition of catechins can also prolong the shelflife of foods. Therefore, catechins have recently been isolated from green tea for utilization in food products to enhance their shelflife and health benefits. This article outlines several methods for the isolation of catechins from green tea, discusses the challenges involved, and reviews the utilisation of catechins in the food industry.     

Comparison of extraction and isolation efficiency of catechins and caffeine from green tea leaves using different solvent systems

Catechins from green tea (Camellia sinensis L.) have received considerable attention due to their beneficial effects on human health, such as antioxidant and anticancer activities. Optimisation of extraction conditions of the catechins from green tea leaves was performed using different solvents (ethanol or distilled water), different extraction methods (ultrasound‐assisted, room temperature or reflux extractions) and various extraction times (0.5–24 h). The optimal extraction conditions were determined using 40% ethanol with ultrasound‐assisted extraction method for 2 h at 40 °C. In addition, two isolation methods for the recovery of catechins from green tea extracts were compared using different solvent combinations (chloroform/ethyl acetate versus ethyl acetate/dichloromethane). The results showed that the ethyl acetate/dichloromethane system could achieve much higher content of catechins than the other isolation approaches, indicating the method that extract catechins first with organic solvent such as ethyl acetate before removing caffeine is much effective than removing caffeine first when organic solvents are used for the recovery of catechins without caffeine from green tea extracts.     

儿茶素对鸡肉的抗氧化保鲜作用

通过在肉鸡饲料中添加一定量的儿茶素 ,来研究体内儿茶素对鸡肉的抗氧化保鲜作用效果。体内儿茶素明显提高了鸡肉的氧化稳定性能 ,具有延长保鲜期的潜力 ,鸡腿肉的效果比鸡胸肉的效果更加明显 ,鸡肉的氧化稳定性能随着儿茶素添加量的增多而改善 ,儿茶素 3 0 0mg/kg的抗氧化作用效果与VE2 0 0mg/kg的相近。结果表明 ,儿茶素可以代替VE 作为肉鸡饲料中的抗氧化添加剂 ,以提高鸡肉的氧化稳定性及延长其保鲜期     

Overview of antibacterial, antitoxin, antiviral, and antifungal activities of tea flavonoids and teas

Tea leaves produce organic compounds that may be involved in the defense of the plants against invading pathogens including insects, bacteria, fungi, and viruses. These metabolites include polyphenolic compounds, the six so-called catechins, and the methyl-xanthine alkaloids caffeine, theobromine, and theophylline. Postharvest inactivation of phenol oxidases in green tea leaves prevents oxidation of the catechins, whereas postharvest enzyme-catalyzed oxidation (fermentation) of catechins in tea leaves results in the formation of four theaflavins as well as polymeric thearubigins. These substances impart the black color to black teas. Black and partly fermented oolong teas contain both classes of phenolic compounds. A need exists to develop a better understanding of the roles of polyphenolic tea compounds in food and medical microbiology. This overview surveys and interprets our present knowledge of activities of tea flavonoids and teas against foodborne and other pathogenic bacteria, virulent protein toxins produced by some of the bacteria, virulent bacteriophages, pathogenic viruses and fungi. Also covered are synergistic, mechanistic, and bioavailability aspects of the antimicrobial effects. Further research is suggested for each of these categories. The herein described findings are not only of fundamental interest, but also have practical implications for nutrition, food safety, and animal and human health.     

Effects of metal ions, catechins, and their interactions on prostate cancer

Prostate cancer is threatening human health heavily, for its causes are related to diet, genetic factors, and lifestyle. Metal ions, which are necessary to our health, are important factors inducing many diseases including prostate cancer in the condition of absence or excess. Epidemiological and laboratory studies provide convincing evidence that green tea prevents and cures prostate cancer. Practically, interactions of catechins, which are the main bioactive components in green tea or GTP, with metal ions have a new aspect to investigate their mechanism in preventing and curing prostate cancer. In the present paper, we summarize some research about the effects of catechins with metal ions related to prostate cancer and their interactions on prostate cancer.     

乌龙茶加工过程中儿茶素的稳定性及化学变化

研究半发酵乌龙茶加工对活性化学成分儿茶素的影响。采摘的鲜叶立即在严格控制的加工条件下进行加工,分析每道加工工艺操作所制茶叶的儿茶素总量和各种儿茶素单体(－)-儿茶素、(－)-表没食子儿茶素、(＋)-儿茶素、(－)-表儿茶素、(－)-表没食子儿茶素没食子酸酯、没食子儿茶素没食子酸酯、(－)-表儿茶素没食子酸酯、(－)-儿茶素没食子酸酯的含量。研究表明,在乌龙茶加工过程中,儿茶素总含量略有下降,约为10%;儿茶素单体变化不一。在加工工艺中,做青、杀青和干燥对儿茶素含量影响较大。为使乌龙茶中儿茶素的潜在健康效益最大化,这3 道工艺应在茶叶生产中加以考虑并做到最优化,以期为乌龙茶加工研究提供一定的参考依据。     

贮藏时间对武夷岩茶金锁匙生化成分及感官品质的影响

以轻火、中火武夷岩茶金锁匙为实验材料,研究不同贮藏时间对其生化成分及感官品质的影响,为武夷岩茶的科学品饮、储藏、运输、营养保持等提供理论参考。结果表明:贮藏过程中轻火、中火金锁匙茶多酚、儿茶素、咖啡碱、水浸出物含量(生化成分与干物质质量比)均呈下降趋势,水分含量呈上升趋势,氨基酸含量呈先增加后减少的趋势。贮藏12个月轻火、中火金锁匙茶多酚、儿茶素、酯型儿茶素、非酯型儿茶素、咖啡碱含量分别降低21.03%、19.48%；21.87%、17.24%；30.58%、26.76%；10.25%、6.45%；17.60%、13.36%。轻火金锁匙贮藏6个月氨基酸含量最高,达2.32%；中火金锁匙贮藏8个月氨基酸含量最高,达2.25%。贮藏前期,轻火、中火金锁匙火气逐渐退去,感官品质得到提升；贮藏后期,其滋味变得更加甘醇,但香气鲜锐度略有下降,因此感官品质得分先增加后略有降低。轻火金锁匙贮藏6个月感官品质得分最高,中火金锁匙贮藏8个月感官品质得分最高。研究结果表明,合理贮藏有利于提高武夷岩茶的感官品质。     

Factors affecting the levels of catechins and caffeine in tea beverage: estimated daily intakes and antioxidant activity

Increased public awareness of health benefits of green tea is generally based on the high polyphenol content of tea leaves and the resulting beverage. A number of factors, such as species, season, agronomic condition and age of the leaves, are known to affect the composition of commercial teas. In the present study the effects of factors associated with domestic preparation and analytical methods, such as brewing time, concentration, solvent and type of tea product, on levels of catechins and caffeine, antioxidant activity and estimated daily intakes were investigated. There were large variations in the levels of total catechins: 43 and 117 mg g^?1 dry matter (DM) (brewed for 30 s and 5 min respectively); 72 and 161 mg g^?1 DM (extracted in boiling water and 50% acetonitrile respectively); 72 and 117 mg g^?1 DM (a tea bag and tea leaves respectively). The effects on caffeine content were comparatively smaller. These variations consequently led to considerable variations in estimated daily intakes based on three cups (600 ml), ranging between 538 and 2014 mg g^?1 DM of total catechins and between 103 and 466 mg g^?1 DM of caffeine. The antioxidant activity was highest (26 680 µmol g^?1 DM) for tea leaves brewed for 5 min and lowest (10 110 µmol g^?1 DM) for a tea bag product brewed for 1 min. Copyright © 2005 Society of Chemical Industry