茶酒的保健作用

以茶类产品为主要原料,进行微生物发酵得到的茶酒,内含丰富的茶多酚、咖啡碱、氨基酸、固形物等成分,具有营养、保健、医疗3大功能。主要从茶多酚、咖啡碱、茶氨酸这3种主要营养成分分析茶酒的保健作用。     

L-茶氨酸合成新方法

介绍了一条新的合成茶氨酸的路线,即由价格低廉且易得的L-谷氨酸加保护基团邻苯二甲酰基(pht),使L-谷氨酸分子内脱水生成N-pht-L-谷氨酸酐后,与乙胺二氧六环溶液反应生成中间产物N-pht-L-茶氨酸,最后脱去保护基团得到L-茶氨酸.该法简单、经济、高效.     

茶氨酸联合γ-氨基丁酸改善CUMS大鼠抑郁症状的研究

目的:观察L-茶氨酸和γ-氨基丁酸(γ-aminobutyric acid,GABA)联合干预对慢性不可预知温和刺激(CUMS)模型大鼠抑郁症状的缓解作用。方法:采用CUMS法建立抑郁症大鼠模型,不同剂量L-茶氨酸和GABA混合物或西酞普兰连续灌胃45 d,期间持续CUMS刺激。另设对照组,常规饲养。监测大鼠体重变化、糖水偏好程度、以及旷场实验水平运动、垂直运动等行为学指标,测定大鼠血清及脑组织中五羟色胺(5-HT)、多巴胺(DA)、白介素-6(IL-6)、脑源性神经营养因子(BDNF)、β-内啡肽(β-EP)的水平。结果:与对照组比较,CUMS大鼠体重、糖水消耗百分比、旷场水平和垂直运动显著降低(P<0.05);与模型组比较,茶氨酸联合GABA干预可显著增加大鼠体重增量、糖水消耗百分比,运动距离和站立次数(P<0.05),抑郁大鼠血清及脑组织中5-HT、DA以及BDNF、β-EP的含量增加(P<0.05),降低IL-6的水平(P<0.05)。结论:L-茶氨酸和GABA联合干预对CUMS诱发的抑郁症有一定改善作用,且高剂量的作用更为显著。     

OPA柱前衍生高效液相色谱法测定茶氨酸的研究

研究了OPA柱前自动衍生-紫外检测茶汁中茶氨酸的 HPLC法,色谱条件为:Hypeml ODS C18柱,洗脱液为醋 酸钠和甲醇混合液,采用梯度洗脱,流速为1.0mL／min. 检测波长为338nm。茶氨酸在0.05-1.00mg／mL范围内浓 度与峰面积线性关系良好,线性相关系数为0.9998,平均 回收率为98.85％,RSD小于1％(n=5)。     

液相色谱法测定茶氨酸提取物中咖啡因的含量

目的建立一种快速、简便测定茶氨酸提取物中咖啡因的液相色谱方法。方法样品经过前处理,以1-癸烷磺酸钠溶液(1.22 g→850 m L)+乙腈+磷酸=850+150+1(V:V:V)为流动相,流速1.0 m L/min,柱温40℃,进样量10μL,等度洗脱,经Agilent C18柱分离,于280 nm波长处检测,以外标法定量。结果用本方法进行检测,能很好的分离咖啡因,在浓度0.001 mg/m L至0.05 mg/m L之间呈现良好的线性关系,方法的相关系数可达1.000,平均回收率为100.2,在95%~105%之间,相对标准偏差(RSD)为1.0%,定量限为92.78μg/g,检出限为29.03μg/g。结论该方法耗时短、操作简便、准确、重现性好、分离效果明显。可以应用于茶氨酸提取物中咖啡因含量的测定。     

7种茶氨酸类似物的合成及清除自由基活性

以L-谷氨酸为起始原料,经邻苯二甲酸酐保护、酰化开环、肼解脱保护等反应合成了7种茶氨酸类似物,结构经EA、IR、1HNMR、13CNMR和MS进行了确认,并测定了其清除DPPH自由基和羟自由基活性。结果表明:2-氨基-5-氧代-5-[(4-羟基苯基)氨基]戊酸清除自由基活性最强,0.002 mol/L时清除DPPH自由基率为90%,0.004 mol/L时清除羟自由基率达95%;2-氨基-5-氧代-5-[(4-氨基苯基)氨基]戊酸次之。由此可见,茶氨酸类似物中5位连有苯基或所连苯基对位有供电子基团时,可提高其清除DPPH自由基和羟自由基活性,且随对位所连基团供电性的提高,清除活性增强。     

茶叶中有效成分综合提取的研究

以绿茶为原料，采用ZJL大孔离了交换树脂和ZJX大孔吸附树脂从茶叶的浸提液中提取茶氨酸、咖啡因、茶多酚和茶多糖。通过对树脂的静态、动态吸附性能的实验研究，确定了咖啡因、茶氨酸、茶多酚及茶多糖联合分离提取的工艺。研究结果表明：该工艺能有效的从茶叶中提取咖啡因、茶氨酸和茶多酚，提取的咖啡因纯度达83．23％，提取率为1．9％，茶氨酸纯度达85．43％，提取率为0．94％，提取的茶多酚纯度达95．62％，提取率为12．35％，且茶多酚中的咖啡因含量低于0．7％，茶多糖的纯度达51％，提取率为1．1％。     

Epidemiological Evidence Linking Tea Consumption to Human Health: A Review

Tea has been widely consumed around the world for thousands of years and drinking tea is a daily habit for people of all ages. Tea is a major source of flavanoids, which have become well known as antioxidants. Tea also contains caffeine and theanine, which have been found to associate with health benefits. Many animal and epidemiological studies have been conducted to investigate the link between tea consumption and human health. However, common questions that arise about tea consumption include: whether all teas are the same, why drinking tea is linked with health benefits, how do the different ways of tea preparation impact on availability of tea components, how much and how long a person should consume tea to obtain health benefits, and whether there is any negative health effect associated with drinking tea. To answer these questions, this paper outlines the tea components and their link to human health, discusses major factors affecting availability of tea components in a tea cup, and reviews the latest epidemiological evidence linking tea consumption to human health.     

Valorisation of theanine from decaffeinated tea dust in bakery functional food

Nowadays, consumers appreciate the positive properties of decaffeinated tea for their well‐being. During decaffeination process, a very fine tea dust powder is obtained as by‐product, which contains the same quantity of bioactives as decaffeinated tea: the antioxidant polyphenols and the amino acid theanine. The aim was to add value to theanine gained from black tea powder dust and to develop theanine‐enriched bread. A theanine containing powder was obtained by column separation of decaffeinated tea dust extract and spray‐drying using carrier supports. This powder contains also the very polar compounds from decaffeinated tea such as amino acids, sugars and minerals. Breads with 110, 220 and 330 ppm of theanine, respectively, were prepared with the theanine powder. Physical properties, theanine and total polyphenolic content in bread were analysed. Bread and other bakery food serve as good products to add value to bioactive tea dust ingredients.     

4种功效物质对视疲劳的缓解作用研究

将4种功效物质(茶氨酸、γ-氨基丁酸、β-胡萝卜素和葡萄籽提取物)添加到巧克力糖果中,通过问卷调查、视力测试、注意力测试、记忆力测试以及脑电波测试,研究其在30d内对102位受试者视疲劳症状的改善作用。结果表明:样品组眼部不适和全身不适症状的总积分和各单项症状(视物模糊、异物感、畏光、主观记忆力减退、主观注意力减退和失眠)积分均低于0d值,视疲劳引起的眼部不适和全身不适症状得到明显改善,如7d后视物模糊积分降低了0.21,主观记忆力减退积分降低了0.46;视力测定结果显示样品组受试者视力提高有效率明显增加,左眼和右眼视力分别由0.89和0.90显著提高至1.00和0.99;注意力测试和记忆力测试结果显示:样品组受试者注意力和记忆力显著提高,分别具有累积效应和短时效应,即苏尔特方格用时和脑年龄分别降低5.09s和2.49;在脑电波测试中,样品组P4和O2导联的反映大脑放松度的α波功率值、α波功率值谱百分比和α/β波功率值谱百分比比值均增加,其中P4导联分别增加了7.69,0.04,0.50,O2导联分别增加了9.90,0.04,0.73。因此,含有茶氨酸、γ-氨基丁酸、β-胡萝卜素和葡萄籽提取物的巧克力糖果产品对视疲劳具有一定的缓解作用。