摘要
开发从茶叶中分离天然儿茶素类、茶氨酸、咖啡因等有效成分的新技术,对促进茶叶资源综合利用,降低产品成本,扩大茶叶有效成分的应用范围等有重要意义。本文从儿茶素类、咖啡因和茶氨酸高效吸附剂的筛选入手,分析了不同吸附剂对目标物的吸附行为和影响因素,同时开展了洗脱剂优选,初步建立了从茶提取物中分离高纯度儿茶素类、茶氨酸和咖啡因的综合制备技术。主要研究内容及结果如下：
比较了19种吸附剂对茶提取物溶液、茶氨酸溶液、咖啡因溶液及茶氨酸和咖啡因混合溶液中目标成分的吸附情况。结果显示,PVPP和PA-6对儿茶素类吸附量大、选择性高,可用作从茶提取物中分离儿茶素类的吸附剂；HPD-400大孔树脂对儿茶素类和咖啡因的吸附量均较大,可用于去除茶氨酸粗品中的儿茶素类和咖啡因；强酸性阳离子交换树脂D001SD和ZGSPC106Na对茶氨酸吸附量大,可用作分离纯化茶氨酸的吸附剂。
研究了不同pH、温度、吸附时间、茶提取物初始浓度等因素对PVPP吸附儿茶素类和咖啡因的影响。结果显示,PVPP对儿茶素类的吸附作用强度与被吸附儿茶素分子上羟基数量关系密切,推断分子间氢键、π电子重叠和疏水交互作用是吸附主要的驱动力；咖啡因可能通过与儿茶素类互作而被PVPP间接吸附；PVPP对儿茶素类的吸附过程符合拟二级动力学模型(r2>0.99),其等温吸附可以用Langmuir方程和Freundlich方程描述,在温度20-60℃范围内,PVPP对儿茶素类的最大吸附量Qm大于630mg g-1;PVPP对儿茶素类的吸附是自发的放热过程,低温有利于吸附的进行。洗脱剂筛选实验显示,正己烷不能洗脱PVPP上吸附的咖啡因,其他实验溶剂均可将PVPP上咖啡因有效洗脱,但多数溶剂不能有效洗脱儿茶素类,只有DMF和DMSO适合于洗脱PVPP上吸附的儿茶素类。采用分步洗脱,即先用水或低浓度乙醇溶液洗脱咖啡因,再用DMSO或DMF洗脱儿茶素类,可实现咖啡因和儿茶素类的有效分离,所获产品中儿茶素类含量约95%,咖啡因含量低于0.1%。
研究了pH、温度、吸附时间、吸附质初始浓度等对D001SD和ZGSPC106Na这两种阳离子树脂吸附茶氨酸和咖啡因的影响。结果显示,在pH3.18-5.67范围内,pH对阳离子树脂吸附茶氨酸没有显著影响；但pH过高或过低均会引起吸附量下降；两种树脂对茶氨酸和咖啡因的吸附在30min内就能达到平衡,符合拟二级动力学模型；该两种树脂对茶氨酸的等温吸附可以用Langmuir和Freundlich方程描述,在20-60℃范围内,两者的最大吸附量Qm分别为481.61mgg-1和609.59mg g-1,但随温度的升高而减小；该两种阳离子交换树脂对茶氨酸的吸附过程属于自发的放热过程,而且温度对ZGSPC106Na树脂吸附茶氨酸的影响小于对D001SD树脂的影响。研究还发现,NaCl、NaH2PO4、Na2CO3溶液和氨水均能较好将吸附在阳离子交换树脂上的茶氨酸洗脱下来；为避免后续的脱盐工序,以氨水为洗脱剂为宜。
采用PA-6柱和HPD-400大孔树脂柱吸附并结合分步洗脱处理,能有效去除茶氨酸粗品(纯度30%)中的儿茶素类和咖啡因成分,将茶氨酸纯度提高至50%以上,回收率超过97%。将茶氨酸粗品(纯度30%)过ZGSPC106Na或D001SD阳离子交换树脂柱,结合水洗、醇洗和氨水淋洗,可获得纯度92%以上的高茶氨酸产品,回收率超过98%。
在上述研究基础上,开发了从茶叶原料中综合分离儿茶素类、茶氨酸和咖啡因的技术,即以PA-6柱分离茶叶提取物中的儿茶素类主体部分,透过PA-6柱的溶液经过HPD-400柱富集其中的咖啡因和剩余的儿茶素类,然后经过D001SD柱富集其中的茶氨酸。经过该综合制备过程,由PA-6柱分离的儿茶素类产品的儿茶素类总含量超过85%(回收率70%以上),咖啡因含量低于0.3%;HPD-400柱富集的咖啡因粗品中含咖啡因约50%(回收率约70%)以及儿茶素类含量约30%；D001SD柱富集的产品含游离氨基酸62%(茶氨酸含量37%,回收率71%),但儿茶素类和咖啡因均低于0.2%。
Bioactive ingredients extracted from green tea such as catechins, theanine and caffeine have a lot of health benefits and have been used widely in various neutraceuticals, pharmaceuticals, and cosmetics. Thus, the demand for these bioactive ingredients is increasing. However, considering negative effects of caffeine in some cases coupled with the requirements of the purity for pharmaceutical use, related isolation and purification techniques should be improved to remove caffeine and to get high-purity catechins or theanine. Adsorption separation methods using adsorbents to enrich bioactive ingredients from plant materials are available. Focusing on preparing high-purity catechins and theanine from tea leaves or tea extracts, this paper investigated the adsorption properties of19tested adsorbents including macroporous adsorption resins (MAR), anion exchange resins (AER), cation exchange resins (CER) for use in preparing catechins, caffeine and theanine. Those which have good adsorption capacity and selectivity were selected as adsorbents for isolation of the target ingredients. The major results can be summarized as follows:
(1) Screening of candidate adsorbents
Polyvinylpolypyrrolidone (PVPP) and polymide-6(PA-6) displayed strong and selective adsorption characteristics for catechins due to their capacity to form hydrogen bonds between their amide group and the phenolic hydroxyl group of catechins, and they adsorbed little caffeine and theanine, indicating PVPP and PA-6can be used to isolate catechins from caffeine or theanine.Among the tested MARs, HPD-400had good adsorption capacity for caffeine in solution, but had weak adsorption for theanine. It can be used for decaffeination of crude theanine product.The tested CER had an excellent adsorption capability to theanine, among which ZGSPC106Na had higher adsorption capacity than D001SD, while D001SD had better adsorption selectivity to theanine. Both ZGSPC106Na and D001SD can be used to enrich theanine from tea extract.
(2) Adsorption behaviors of PVPP to catechins and caffeine
The adsorption behaviors of PVPP to catechins and caffeine were investigated by static adsorption testing. The results showed that catechins rather than caffeine were preferred to adsorb onto PVPP. The adsorption was driven by hydrogen bonds between the proton donor from the catechins and the carbonyl group from PVPP, together with π-bond overlap and hydrophobic interactions between the aromatic ring of the catechins and the pyrrolidone ring of PVPP, among which hydrogen bond appeared was the major driving force. The adsorption of catechins onto PVPP fitted the pseudo-second-order model. The results also showed that the adsorption capacity of catechins and caffeine decreased with an increase in temperature, and that both Freundlich and Langmuir models were suitable for describing the isothermal adsorption of catechins, but not suitable for caffeine. The predicted maximum monolayer adsorption capacity of total catechins by PVPP was671.77mg g-1at20℃. The thermodynamics analysis showed that the adsorption of catechins onto PVPP was a spontaneous and exothermic physisorption process, and decreasing temperature was favorable for the adsorption of catechins. Elution tests showed that the desorption rates of caffeine and catechins were higher than91%and99%by water eluting stage and dimethyl sulfoxide/ethanol (DMSO/EtOH) solution eluting stage, respectively, resulting in the final catechins product containing more than95%catechins and less than0.1%caffeine. PVPP was considered to be an excellent alternative adsorbent for preparing high-purity catechins from tea extracts.
(3) Adsorption behavior of the theanine onto cation exchange resins
Two cation exchange resins, i.e. D001SD and ZGSPC106Na, were used to test their adsorption capacity to theanine in static adsorption test using model solution of theanine and caffeine respectively. The effects of adsorption time, temperature and pH on resin exchange capacity were investigated. Between pH3.18and pH5.67, pH had little effect on the adsorption of the tested resins to theanine. However, as the solution acidity was below pH3.18or above pH5.67, the adsorption capacity decreased. It was proposed that the adsorption process should be carried out at natural pH level of tea extract. The adsorption equilibrium of theanine onto the two CER was obtained in30min of adsorption time, among which equilibrium time of ZGSPC106Na was shorter than that of D001SD. The adsorption process was fitted to the pseudo-second-order kinetics model, and the equilibrium parameters could be calculated using both the Langmuir model and the Freundlich model. As temperature ranging293K to323K, the adsorption capacity of the resins to theanine decreased with increase in temperature, suggesting that lowering temperature favored the adsorption capacity. However, resin ZGSPC106Na was less sensitive to temperature than resin D001SD.
Effects of NaCl, NaH2PO4and Na2CO3and ammonia at various pH levels and ionic strength levels on the elution of theanine were investigated. Ammonia solution was confirmed to be good eluant to elute theanine from the cation exchange resins, which avoided the salt-leaching process.
(4) Isolation of catechins and caffeine from crude theanine
An adsorption separation method was developed to isolate catechins and caffeine from crude theanine extract (theanine content being30%) using PA-6or HPD-400as adsorbents. It showed that PA-6adsorbed catechins specifically but HPD-400adsorbed both catechins and caffeine. As the extract was passed through the PA-6or HPD-400column, most of catechins and caffeine were retained in the column. When the the theanine extract solution was sequentially loaded onto the PA-6or HPD-400column, catechins and caffeine were retained in the columns. As the effluent which was passed through the columns was concentrated and freeze dried, the product contained theanine more than50%, withy a recovery rate>97%. The catechins and caffeine retained in the PA-6or HPD-400columns could be recovered by eluting using80%(v/v) aqueous ethanol.
The above abtained crude theanine was further purified by CER column (packed with ZGSPC106Na or D001SD) chromatography using stepwise elution process, i.e.1) sequentially elution using water and80%(v/v) aqueous ethanol to wash away catechins and caffeine;2) elution using0.5M ammonia solution. The ammonia solution eluate which contained theanine was collected, concentrated and freeze dried, by which a refined theanine powder was obtained. This theanine level in the product was more than92%, and the theanine recovery rate was upto98%.
(5) Simultaneous preparation of catechins and theanine from tea leaves
Based on above study, a method for simultaneous preparing catechins and theanine from tea extract was developed. Green tea extracts was loaded on a PA-6column and washed sequentially with water and80%aqueous ethanol. The ethanol eluate was collected, concentrated and freeze dried, resulting in a product with total catechins concentration being854.08mg g-1and caffeine less than2.53mg g-1. The effluent passed through the PA-6column and the previous water eluate fraction was combined and further passed through a HPD-400resin column and then washed using water and80%ethanol. The ethanol eluate was collected, concentrated and freeze dried, by which a product with total catechins being352.14mg g-1and caffeine399.76mg g-1was obtained. The effluent was then loaded on D001SD cation exchange resin column and eluted using water and ammonia solution. The ammonia solution eluate was concentrated and freeze dried, by which a product containing more than37%theanine was obtained. By this process, three products were separated from a material of tea leaf.
引文
白云峰,丁玉,张海燕.2007.氨基酸分离纯化的研究进展[J].食品研究与开发,28(2)：175-178.
陈丛瑾.2010.大孔吸附树脂分离纯化黄酮类化合物的研究进展[J].化学与生物工程,27(11)：1-4.
陈建新,兰先秋,范新年,丁平平,宋航.2005.茶多酚工业提纯方法的比较研究[J].四川化工,8(2)：41-44.
陈日春.2011.用响应面法优化超临界CO2脱除绿茶咖啡因工艺研究[J].河南工业大学学报(自然科学版),32(3)：45-50.
陈荣义,张新申,申金山,谢君.2005.茶叶中有效成分综合提取的研究[J].食品科学,26(4)：174-177.
陈秀兰,李炎,黄雪松.2006.离子交换树脂分离合成茶氨酸[J].食品与发酵工业,32(4)：126-129.
陈移姣,周兴国,李桂玲.2005.悬浮聚合法制备咖啡因分子印迹聚合物微球及其性能研究[J].中草药,36(5)：692-695.
陈瑛,陶文沂.1998.几种激素对茶愈伤组织合成茶氨酸的影响[J].无锡轻工大学学报,17(1)：76-79.
陈瑛,钟俊辉,陶文沂.1998.离子交换法提取茶氨酸的研究[J].氨基酸和生物资源,20(1)：31-34.
陈宗懋.2003.茶多酚类化合物抗癌的生物化学和分子生物学基础[J].茶叶科学,23(2)：83-93.
崔湘兴,龚雨顺,黄建安,刘仲华,杨志辉,李娟.2008.717阴离子交换树脂吸附茶氨酸的热力学研究[J].湖南农业大学学报(自然科学版),(5)：601-603.
大须博文,竹尾忠一,戴素贤.1991.用柱层层析法除去乌龙茶浸出液中的咖啡碱[J].广东茶业,(4)：43-45.
大须博文,竹尾忠一.1990.用柱分离法使乌龙茶浸出液脱咖啡碱[J].日本农业化学会志,64(1)：35-37.
丁勇,周坚,罗仲兴.2011.茶产业的发展现状、需求及趋向[J].广东茶业,(1)：8-12.
龚雨顺,黄建安,刘仲华,杨志辉,李娟.2008.HD-8大孔强酸型树脂对茶氨酸的吸附行为研究[J].茶叶科学,28(4)：273-276.
龚雨顺,刘仲华,黄建安,王坤波,刘硕谦,张盛.2005.大孔吸附树脂分离茶儿茶素和咖啡因的研究[J].湖南农业大学学报(自然科学版),31(1)：50-52.
韩佳宾,陈静,王静康,封顺祥.2003.超临界二氧化碳萃取咖啡因的研究进展[J].现代化工,23(3)：25-27.
韩佳宾,王静康.2003.咖啡因在水和乙醇中介稳区的测定[J].天津大学学报,36(6)：765-768.
何炳林,黄文强.1995.离子交换与吸附树脂[M].上海科技教育出版社.
何春雷,杜晓.1994.茶叶成份综合提取技术研究——Ⅰ影响茶多酚、咖啡碱、叶绿素抽提条件的初探[J].四川农业大学学报,12(3)：448-450.
花王株式会社.含有咖啡因的儿茶素类组合物的脱咖啡因的方法：CN1708238[P].
黄健涵,徐满才,黄可龙,刘素琴,罗琼.2007.大孔交联聚(对乙烯基苄基苯基醚)树脂对苯酚的吸附机理[J].化学学报,65(17)：1907-1910.
贾晓波,刘引青,彭伟烈,卢素玲.2003.用阳离子铵型树脂分离苯丙氨酸[J].氨基酸和生物资源,(2)：63-65.
江春柳,孙云,岳鹏翔.2009.茶氨酸的制备及应用研究进展[J].茶叶科学技术,(1)：11-15.
江和源,蒋迎,刘栩.2004.超临界流体技术脱除绿茶中咖啡因和儿茶素的研究[J].食品工业科技,25(2)：95-97.
晋江市恒源科技开发有限公司,复旦大学.一种综合分离提取茶多糖、茶氨酸、茶多酚和咖啡因的方法：CN101798355A[P].
雷启福,钟世安,向海艳,周春山,于典.2005.儿茶素活性成分分子印迹聚合物的分子识别特性及固相萃取研究[J].分析化学,33(6)：857-860.
李海航,龚莉红,张宗耀.2007.茶资源及其生物活性成分综合开发进展[J].科技导报,25(7)：51-56.
李海霞,陈榕,周丹,吴良.2011.咖啡因的合成及其药理作用的研究进展[J].华西药学杂志,26(2)：182-187.
李平,宛晓春,张正竹.2004.生物合成茶氨酸的研究进展及构建基因工程菌合成茶氨酸的可行性探讨[J].食品与发酵工业,30(1)：71-75.
李平,张效林,亢茂德.1999.茶叶茶多酚、咖啡碱提取及超滤-吸附综合分离纯化过程研究[J].现代化工,19(11)：21-24.
李振武,张效林,张卫红,高晓明,王同宝.2006.茶叶活性成分综合提取过程研究[J].化学工程,34(10)：46-50.
梁慧玲,梁月荣,陆建良,叶俭慧,唐德松.2006.杉树木质纤维素对酯型儿茶素类选择性吸附的研究[J].32(6)：665-670.
梁慧玲.2006.茶叶功能成分制备和分离新工艺研究[D].浙江大学博士学位论文.
林峰,黄荣华,陈贤峰.一种从茶叶中同时提取茶多酚、茶多糖、咖啡因的新方法：CN101508690[P].
林智,杨勇,谭俊峰,尹军峰,成浩,杨贤强.2004.茶氨酸提取纯化工艺研究[J].天然产物研究与开发,16(5)：442-447.
林种玉,傅锦坤,杨茹,古萍英.1999.聚酰胺/硅胶吸附剂吸附分离茶多酚的红外光谱[J].厦门大学学报(自然科学版),38(5)：716-719.
刘传富,孙润仓,叶君.2005.纤维素类吸附剂的研究进展[J].中国造纸学报,20(2)：207-210.
刘菊湘,刘国栋,阎虎生,程晓辉,何炳林,姜根华,杨国英.2000.用离子交换树脂脱除氨基酸与盐混合液中的盐[J].离子交换与吸附,16(6)：521-527.
刘菊湘,刘国栋,阎虎生,程晓辉,何炳林,姜根华,杨国英.2001.用低交换容量聚苯乙烯型强酸性阳离子交换树脂柱色谱分离中性氨基酸[J].高等学校化学学报,22(12)：2100-2103.
卢卫国,孙立伟,王淑豪,刘萍,孙君社.2009.离子交换法分离提取谷氨酸转化液中的丫-氨基丁酸[J].精细化工,26(8)：776-780.
吕毅,郭雯飞,倪捷儿,杨贤强.2003.茶氨酸的生理作用及合成[J].茶叶科学,23(1)：1-5.
马卫东,顾国维,YUQiming, KAEWSARNPairat.2001.海洋巨藻(Durvilaea potatorum)生物吸附剂对Hg2+的吸附动力学研究[J].应用与环境生物学报,7(4)：344-347.
满瑞林,贾海亭,蒋崇文,倪网东.2005.水在超临界CO_2脱除绿茶中咖啡因的作用研究[J].化学工程师,(2)：9-12.
毛清黎,施兆鹏,李玲,刘仲华,朱旗.2007.茶叶儿茶素保健及药理功能研究新进展[J].食品科学,28(8)：584-589.
牛桂玲,孙乃有,邵小模.1999.超临界流体萃取法从吸附有咖啡因的活性炭中提取咖啡因[J].化学试剂,21(4)：237-244.
欧阳振,邱杨,吴嘉妮,余瑶章,龚莉红,李海航.2009.几种天然材料对茶多酚和咖啡因的吸附与分离特性[J].科技导报,27(8).
彭亚勤,钟宏,王帅,王爱萍,张骞.2008.聚苯乙烯型离子交换树脂的研究进展[J].广州化学,33(3)：67-71.
戚向阳,谢笔钧,胡慰望.1994.高纯度表没食子儿茶素没食子酸酯(EGCG)的分离与制备[J].11(4)：40-46.
三达膜科技(厦门)有限公司.高纯茶多酚和咖啡因的生产方法：CN1651424[P].
上海交通大学.用超临界二氧化碳脱除茶多酚中咖啡因的方法：CN1613855[P].
石亚亚,贾尚智,闵彩云.2010.茶氨酸保健功能研究进展[J].氨基酸和生物资源,32(1)：52-56.
史作清,施荣富.2008.吸附分离树脂在医药工业中的应用[M].化学工业出版社.
孙培宾,刘平飞,尹进华,陈学玺.2011.咖啡因的精制方法研究进展[J].精细石油化工进展,12(4)：53-56.
孙庆磊.2010.茶用植物成分提取和品质鉴定[D].浙江大学博士学位论文.
唐课文,周春山,钟世安,朱介丁.2003.聚酰胺树脂对茶多酚和咖啡因吸附选择性研究[J].光谱学与光谱分析,23(1)：143-145.
唐仕荣,宋慧,姜小忠,蒋永红,王建.2006.低咖啡因茶氨酸产品的精制工艺研究[J].食品科技,(11)：119-122.
宛晓春.2006.茶叶生物化学[M].中国农业出版社.
汪承源.从茶叶中提取天然咖啡因的方法：CN1120043[P].
汪东风,谢晓凤,严俊,王泽农.1998.茶多糖等有效成分综合提取研究[J].中草药,29(11)：739-740.
汪小钢,萧伟祥.1998.超临界CO2提取茶叶中咖啡碱[J].茶叶科学,18(1)：65-69.
王诚刚.2009.咖啡因分子印迹物的制备及其性能研究[J].广州化工,37(8)：138-139.
王黎明,夏文水.2005.蒽酮-硫酸法测定茶多糖含量的研究[J].食品科学,26(7)：185-188.
王穆君,孙越,周玮,费正皓,张全兴,任怀兴.2004.大孔树脂对水溶液中邻苯二甲酸的吸附行为及其热力学研究[J].离子交换与吸附,20(6)：533-540.
王平,陈成飞,戴春伟,苏为科.2010.HPD-600大孔吸附树脂分离茶多酚的研究[J].中成药,32(4)：683-686.
王庆利,张力军,吴明春,凌娜佳.2008.茶氨酸对脑缺血损伤大鼠自由基代谢的影响[J].实用医学杂志,24(11)：1898-1900.
王瑞芳,陈发河,吴光斌,翁凌,张凌晶,田标.2009.茶多酚树脂吸附层析法脱咖啡因的性能研究[J].食品科学,30(20)：122-125.
王瑞芳,蓝伟光,张世文,仇农学.2005.茶叶中有效成分的开发利用进展[J].亚热带农业研究,1(3)：64-69.
王三永,李晓光,李春荣,李韶雄.2001.L-茶氨酸的合成研究[J].精细化工,18(4)：223-224.
王翔,李萍艳,万再聪,刘维班.2009.绿茶中提取咖啡因的方法研究[J].安徽农业科学,37(8)：3598-3599.
王元凤,金征宇.2004.茶多糖脱色的研究[J].食品与发酵工业,30(12)：60-65.
王志祥,张志炳,何志敏,余国琮.2001.制备型高效液相色谱分离过程的放大研究(I)填料尺寸[J].化工时刊,(1)：28-31.
武彩莲,郭长江.2005.离子交换法与氨基酸的分离纯化[J].氨基酸和生物资源,27(4)：50-53.
西北大学.一种从茶叶中提取茶多酚副产咖啡碱和茶多糖的方法：CN1699586[P].
肖伟涛,朱小兰,陈波,姚守拙.2004.制备高效液相色谱分离纯化茶氨酸对照品[J].中草药,35(2)：34-36.
萧力争,肖文军,龚志华,王伟,刘仲华.2006.膜技术富集儿茶素渣中茶氨酸效应研究[J].茶叶科学,26(1)：37-41.
徐怀德.2006.天然产物提取工艺学[M].中国轻工业出版社.
徐向群,陈瑞锋,王华夫.1995.吸附茶多酚树脂的筛选[J].茶叶科学,15(2)：137-140.
许勇泉,尹军峰,袁海波,陈建新,汪芳.2008.茶叶脱咖啡因技术研究进展[J].茶叶科学,28(1)：1-8.
杨盛美,唐一春,汪云刚,张俊.2010.茶树组织培养研究进展及其应用[J].中国农学通报,26(4)：25-29.
杨晓丽,陆建良,董占波.2008.分子印迹技术在茶叶功能成份分离与分析中的应用[J].茶叶,34(1)：15-18.
杨晓丽.2008.儿茶素类专用吸附剂的合成及性能研究[D].浙江大学硕士学位论文.
叶俭慧,金晶,梁慧玲,梁月荣.2008.茶梗木质纤维素对儿茶素类吸附动力学研究[J].茶叶科学,28(5)：313-318.
叶俭慧,梁月荣.2006.大孔吸附树脂分离茶多酚的研究[J].茶叶,32(3)：128-132.
叶俭慧.2011.茶叶提取物脱除咖啡因和儿茶素类制备[D].浙江大学博士学位论文.
袁地顺,倪元栋,邝平喜.2003.茶细胞培养法生产茶氨酸的技术研究——茶愈伤组织的诱导体系建立[J].福建茶叶,(3)：27-28.
袁弟顺,林丽明,孙威江,林金科.2004.不同品种茶树愈伤组织的培养与茶氨酸的积累[J].福建农业大学学报,33(2)：178-181.
袁华,高小红,闫志国,喻宗沅,吴元欣.2006.离子交换法从茶叶中提取茶氨酸[J].精细石油化工进展,7(3)：42-44.
袁华,高小红,闫志国,喻宗沅,吴元欣.2007.沉淀法从茶叶中提取茶氨酸[J].生物学通报,42(5)：46-48.
袁黎明.2005.制备色谱技术及应用[M].化学工业出版社.
岳婕.2010.高茶氨酸茶树品种筛选及栽培技术研究[D].湖南农业大学硕士学位论文.
张朝晖,胡宇芳,张华斌,李辉,姚守拙.2009.咖啡因印迹复合膜的制备及性能研究[J].化学学报,(18)：2121-2126.
张健,荣绍丰,龚钢明,邱子春.2008.不同茶叶中茶氨酸含量的测定比较[J].食品科学,29(4)：335-337.
张凌云.2003.不同茶树品种绿茶饮料适制性研究[D].浙江大学博士学位论文.
张守政.从茶叶中提取茶多酚、茶氨酸、茶多糖、茶色素的方法：CN1837201[P].
张伟.2007.聚酰胺树脂分离纯化复方山楂提取物的工艺研究[D].天津大学硕士学位论文.
张卫红,张效林,王同宝.2005.茶叶活性成分的复合酶解提取[J].西北大学学报(自然科学网络版),3(7)：1-6.
张燕辉,吴明春,王庆利.2010.茶氨酸对大鼠局灶性脑缺血性损伤后炎性细胞因子表达的影响[J].中国临床神经外科杂志,15(9)：544-546.
赵和涛.1990.红茶绿茶加工中氨基酸变化及与品质关系[J].氨基酸杂志,(3)：47-49.
浙江大学.从提取过茶多酚的下脚料中提取茶多糖的方法：CN1431226[P].
浙江大学.梁月荣,陆建良.用茶树生叶制取低咖啡因速溶茶粉和天然咖啡因粗品的方法：CN1911061[P].
中国农业科学院茶叶研究所.从茶叶中综合提取茶多糖、茶多酚、茶氨酸、咖啡碱的方法：CN1557841[P].
钟俊辉,陶文沂.1997.茶愈伤组织培养及其茶氨酸的累积[J].无锡轻工大学学报,16(3)：3-9.
钟世安,贺国文,雷启福,黄可龙.2007.儿茶素活性成分分子印迹聚合物的固相萃取研究[J].分析试验室,26(10)：1-4.
重庆华康生物化工厂.从茶叶中提取天然咖啡因的生产工艺：CN1067895[P].
周海滨,宋新生.2003.超临界CO2脱除茶叶咖啡碱的工艺优化研究[J].食品科学,24(5)：88-91.
周媛媛,孟子晖,董美伶.2009.分子印迹技术在天然产物有效成分分离纯化中的应用[J].色谱,27(3)：359-363.
Agency Response Letter GRAS Notice No. GRN 000209, FDA.2012. (2009-05-20). http://www.fda.gov/Food/FoodIngredientsPackaging/GenerallyRecognizedasSafeGRAS/GRASLi stings/ucm 153810.htm.
Aksu Z.2001. Biosorption of reactive dyes by dried activated sludge:equilibrium and kinetic modelling[J]. Biochemical Engineering Journal,7(1):79-84.
Al-Hazzani A A, Alshatwi A A.2011. Catechin hydrate inhibits proliferation and mediates apoptosis of SiHa human cervical cancer cells[J]. Food and Chemical Toxicology,49(12):3281-3286.
Astill C, Birch M R, Dacombe C, Humphrey P G, Martin P T.2001. Factors affecting the caffeine and polyphenol contents of black and green tea infusions[J]. Journal of Agricultural and Food Chemistry,49(11):5340-5347.
Bailey D T, Yuhasz R L, Zheng B L. Method for isolation of caffeine-free catechins from green tea.
Barrera-Garcia V D, Gougeon R D, Karbowiak T, Voilley A, Chassagne D.2008. Role of wood macromolecules on selective sorption of phenolic compounds by wood[J]. Journal of Agricultural and Food Chemistry,56(18):8498-8506.
Baudouin S X.2010. Process for purifying theanine[P]. EP Patent 2,144,868.
Baxter N J, Lilley T H, Haslam E, Williamson M P.1997. Multiple interactions between polyphenols and a salivary proline-rich protein repeat result in complexation and precipitation[J]. Biochemistry,36(18):5566-5577.
Belza A, Toubro S, Astrup A.2009. The effect of caffeine, green tea and tyrosine on thermogenesis and energy intake[J]. European Journal of Clinical Nutrition,63(1):57-64.
Benjamin M M, Leckie J O.1981. Multiple-Site Adsorption of Cd, Cu, Zn, and Pb on Amorphous Iron Oxyhydroxide[J]. Journal of Colloid and Interface Science,79(1):209-221.
Bettuzzi S, Rizzi F, Belloni L.2007. Clinical relevance of the inhibitory effect of green tea catechins (GtCs) on prostate cancer progression in combination with molecular profiling of catechin-resistant tumors:an integrated view[J]. Polish Journal of Veterinary Sciences, 10(1):57-60.
Bolton S, Null G.1981. Caffeine:Psychological effects, use and abuse[J]. Orthomolecular Psychiatry, 10(3):202-211.
Caffeine-From Wikipedia, the free encyclopedia, Wikipedia.2012. (2012-02-20). http://en.wikipedia.org/wiki/Caffeine.
Caturla N, Vera-Samper E, Villalain J, Mateo C R, Micol V.2003. The relationship between the antioxidant and the antibacterial properties of galloylated catechins and the structure of phospholipid model membranes[J]. Free Radical Biology and Medicine,34(6):648-662.
Chacko S M, Thambi P T, Kuttan R, Nishigaki I.2010. Beneficial effects of green tea:a literature review[J]. Chinese Medicine,5:13.
Chao Y C, Chiang B H.1999. Cream formation in a semifermented tea[J]. Journal of the Science of Food and Agriculture,79(13):1767-1774.
Charlton A J, Baxter N J, Khan M L, Moir A J, Haslam E, Davies A P, Williamson M P.2002. Polyphenol/peptide binding and precipitation[J]. Journal of Agricultural and Food Chemistry, 50(6):1593-1601.
Chen C H, Ho M L, Chang J K, Hung S H, Wang G J.2005. Green tea catechin enhances osteogenesis in a bone marrow mesenchymal stem cell line[J]. Osteoporosis International,16(12):2039-2045.
Chen Z Y, Zhu Q Y, Wong Y F, Zhang Z, Chung H Y.1998. Stabilizing effect of ascorbic acid on green tea catechins[J]. Journal of Agricultural and Food Chemistry,46(7):2512-2516.
Cohen S, Booth G J.1975. Gastric acid secretion and lower-esophageal-sphincter pressure in response to coffee and caffeine[J]. The New England Journal of Medicine,293(18):897-899.
Cooper R, Morre D J, Morre D M.2005. Medicinal benefits of green tea:Part I. Review of noncancer health benefits[J]. Journal of Alternative and Complementary Medicine,11(3):521-528.
Curatolo P W, Robertson D.1983. The health consequences of caffeine[J]. Annals of Internal Medicine,98(5 Pt 1):641-653.
Dabrowski A, Podkoscielny P, Hubicki Z, Barczak M.2005. Adsorption of phenolic compounds by activated carbon--a critical review[J]. Chemosphere,58(8):1049-1070.
Dash S S, Gummadi S N.2006. Catabolic pathways and biotechnological applications of microbial caffeine degradation[J]. Biotechnology Letters,28(24):1993-2002.
De Araujo I E, Kringelbach M L, Rolls E T, Hobden P.2003. Representation of umami taste in the human brain[J]. Journal of Neurophysiology,90(1):313-319.
Demeule M, Michaud-Levesque J, Annabi B, Gingras D, Boivin D, Jodoin J, Lamy S, Bertrand Y, Beliveau R.2002. Green tea catechins as novel antitumor and antiangiogenic compounds [J]. Current Medicinal Chemistry-Anti-Cancer Agents,2(4):441-463.
Deng W W, Ogita S, Ashihara H.2008. Biosynthesis of theanine ([gamma]-ethylamino-l-glutamic acid) in seedlings of Camellia sinensis[J]. Phytochemistry Letters,1(2):115-119.
Deng W W, Ogita S, Ashihara H.2010. Distribution and biosynthesis of theanine in Theaceae plants[J]. Plant Physiology and Biochemistry,48(1):70-72.
Desai M J, Gill M S, Hsu W H, Armstrong D W.2005. Pharmacokinetics of theanine enantiomers in rats[J]. Chirality,17(3):154-162.
Di X, Yan J, Zhao Y, Zhang J, Shi Z, Chang Y, Zhao B.2010. L-theanine protects the APP (Swedish mutation) transgenic SH-SY5Y cell against glutamate-induced excitotoxicity via inhibition of the NMDA receptor pathway[J]. Neuroscience,168(3):778-786.
Dielectric Constant Values, ClipperControls.2012. (2012-01-15). http://www.clippercontrols.com/pages/Dielectric-Constant-Values.html.
Ekanayake A, Bunger J R, Mohlenkamp Jr M J.1999. Green tea extract subjected to cation exchange treatment and nanofiltration to improve clarity and color[P]. Patent US5879733.
Ekanayake A, Li J J.2007. Process for enriching extracts of natural theanine[P].Patent US20050084544.
Ekborg-Ott K H, Taylor A, Armstrong D W.1997. Varietal differences in the total and enantiomeric composition of theanine in tea[J]. Journal of Agricultural and Food Chemistry,45(2):353-363.
Eteng M U, Eyong E U, Akpanyung E O, Agiang M A, Aremu C Y.1997. Recent advances in caffeine and theobromine toxicities:a review[J]. Plant Foods for Human Nutrition,51(3):231-243.
Evans S M, Griffiths R R.1992. Caffeine tolerance and choice in humans[J]. Psychopharmacology (Berl),108(1-2):51-59.
Fenster L, Eskenazi B, Windham G C, Swan S H.1991. Caffeine consumption during pregnancy and spontaneous abortion[J]. Epidemiology,2(3):168-174.
Fernandes O, Sabharwal M, Smiley T, Pastuszak A, Koren G, Einarson T.1998. Moderate to heavy caffeine consumption during pregnancy and relationship to spontaneous abortion and abnormal fetal growth:a meta-analysis[J]. Reproductive Toxicology,12(4):435-444.
Ford R P, Schluter P J, Mitchell E A, Taylor B J, Scragg R, Stewart A W.1998. Heavy caffeine intake in pregnancy and sudden infant death syndrome. [J]. Archives of Disease in Childhood, 78(1):9-13.
Friedman M, Mackey B E, Kim H J, Lee I S, Lee K R, Lee S U, Kozukue E, Kozukue N.2007. Structure-activity relationships of tea compounds against human cancer cells[J]. Journal of Agricultural and Food Chemistry,55(2):243-253.
Furuya T, Orihara Y, Tsuda Y.1990. Caffeine and theanine from cultured cells of Camellia sinensis[J]. Phytochemistry,29(8):2539-2543.
Gaffney S H, Martin R, Lilley T H, Haslam E, Magnolato D.1986. The association of polyphenols with caffeine and α-and β-cyclodextrin in aqueous media[J]. Journal of the Chemical Society, Chemical Communications,(2):107-109.
Gailliot F P.1998. Initial extraction and product capture[M]Natural Products Isolation. ed. by Humana Press Inc:Totawa, New Jersey:53-89.
Gilliland K, Bullock W.1983. Caffeine:a potential drug of abuse[J]. Advances in Alcohol and Substance Abuse,3(1-2):53-73.
Glade M J.2010. Caffeine—Notjust a stimulant[J]. Nutrition,26(10):932-938.
Gokulakrishnan A, Ali A R.2010. Cigarette smoke-induced biochemical perturbations in human erythrocytes and attenuation by epigallocatechin-3-gallate--tea catechin[J]. Pharmacological Reports,62(5):891-899.
Gomez-Ramirez M, Higgins B A, Rycroft J A, Owen G N, Mahoney J, Shpaner M, Foxe J J.2007. The deployment of intersensory selective attention:a high-density electrical mapping study of the effects of theanine[J]. Clinical Neuropharmacology,30(1):25-38.
Hall K R, Eagleton L C, Acrivos A, Vermeulen T.1966. Pore-and solid-diffusion kinetics in fixed-bed adsorption under constant-pattern conditions[J]. Industrial and Engineering Chemistry Fundamentals,5(2):212-223.
Haskell C F, Kennedy D O, Milne A L, Wesnes K A, Scholey A B.2008. The effects of L-theanine, caffeine and their combination on cognition and mood[J]. Biological Psychology,77(2):113-122.
Hay P, Leigh D, Liardon R.2002. Caffeine imprint polymer[P]. EP Patent 0,776,607.
He Y S, Dufour J, Meurens M.2003. Synthesis and Characterization of Highly Pure Theanine[J]. Journal of Tea Science,(2):99-104.
Heaney R P.2002. Effects of caffeine on bone and the calcium economy[J]. Food and Chemical Toxicology,40(9):1263-1270.
Henning S M, Fajardo-Lira C, Lee H W, Youssefian A A, Go V L, Heber D.2003. Catechin content of 18 teas and a green tea extract supplement correlates with the antioxidant capacity[J]. Nutrition and Cancer-an International Journal,45(2):226-235.
Hering-Hanit R, Gadoth N.2003. Caffeine-induced headache in children and adolescents[J]. Cephalalgia,23(5):332-335.
Hinman D C, Saleeb F Z.1984. Decaffeination with treated activated carbon[P].Patent US4481223.
Hirasawa M, Takada K, Makimura M, Otake S.2002. Improvement of periodontal status by green tea catechin using a local delivery system:a clinical pilot study[J]. Journal of Periodontal Research, 37(6):433-438.
Ho Y S, McKay G.1998. Kinetic models for the sorption of dye from aqueous solution by wood C-8624-2009[J]. Process Safety and Environmental Protection,76(B2):183-191.
Ho Y S, McKay G.1999. Pseudo-second order model for sorption processes[J]. Process Biochemistry, 34(5):451-465.
Ho Y S, Ofomaja A E.2006. Pseudo-second-order model for lead ion sorption from aqueous solutions onto palm kernel fiber[J]. Journal of Hazardous Materials,129(1-3):137-142.
Hostettmann K, Marston A, Hostettmann M.1998. Preparative chromatography techniques: applications in natural product isolation[M]. Springer Verlag.
Huang K J, Wu J J, Chiu Y H, Lai C Y, Chang C M.2007. Designed polar cosolvent-modified supercritical CO2 removing caffeine from and retaining catechins in green tea powder using response surface methodology [J]. Journal of Agricultural and Food Chemistry,55(22):9014-9020.
Huo C, Wan S B, Lam W H, Li L, Wang Z, Landis-Piwowar K R, Chen D, Dou Q P, Chan T H.2008. The challenge of developing green tea polyphenols as therapeutic agents[J]. Inflammopharmacology,16(5):248-252.
James J E.2004. Critical review of dietary caffeine and blood pressure:a relationship that should be taken more seriously[J]. Psychosomatic Medicine,66(1):63-71.
Jang A, Seo Y, Bishop P L.2005. The removal of heavy metals in urban runoff by sorption on mulch[J]. Environmental Pollution,133(1):117-127.
Jaycock M J, Parfitt G D.1981. Chemistry of interfaces[M]. Ellis Horwood.
Jun X, Shuo Z, Bingbing L, Rui Z, Ye L, Deji S, Guofeng Z.2010. Separation of major catechins from green tea by ultrahigh pressure extraction[J]. International Journal of Pharmaceutics, 386(1-2):229-231.
Juneja L R, Chu D C, Okubo T, Nagato Y, Yokogoshi H.1999. L-theanine--a unique amino acid of green tea and its relaxation effect in humans [J]. Trends in Food Science & Technology, 10(6-7):199-204.
Kakuda T.2011. Neuroprotective effects of theanine and its preventive effects on cognitive dysfunction[J]. Pharmacological Research,64(2):162-168.
Kato M, Mizuno K, Crozier A, Fujimura T, Ashihara H.2000. Caffeine synthase gene from tea leaves[J]. Nature,406(6799):956-957.
Kawagishi H, Sugiyama K.1992. Facile and large-scale synthesis of L-theanine[J]. Bioscience, Biotechnology, and Biochemistry,56(4):689.
Khan N, Mukhtar H.2007. Tea polyphenols for health promotion[J]. Life Sciences,81 (7):519-533.
Kim Y Y, Up N S, Kim M H, Kim H S, Kang H, Kim H O, Park Y M.2011. Effects of topical application of EGCG on testosterone-induced hair loss in a mouse model[J]. Experimental Dermatology,20(12):1015-1017.
Kimura K, Ozeki M, Juneja L R, Ohira H.2007. L-Theanine reduces psychological and physiological stress responses[J]. Biological Psychology,74(1):39-45.
Kimura M, Umegaki K, Kasuya Y, Sugisawa A, Higuchi M.2002. The relation between single/double or repeated tea catechin ingestions and plasma antioxidant activity in humans[J]. European Journal of Clinical Nutrition,56(12):1186-1193.
Kobayashi K, Nagato Y, Aoi N, Juneja L R, Kim M, Yamamoto T, Sugimoto S.1998. Effects of L-theanine on the release of alpha-brain waves in human volunteers[J]. Nippon Nogeikagaku Kaishi,72(2):153-157.
Kurihara S, Shibahara S, Arisaka H, Akiyama Y.2007. Enhancement of antigen-specific immunoglobulin G production in mice by co-administration of L-cystine and L-theanine[J]. Journal of Veterinary Medical Science,69(12):1263-1270.
Kuzuhara T, Suganuma M, Fujiki H.2008. Green tea catechin as a chemical chaperone in cancer prevention[J]. Cancer Letters,261(1):12-20.
Kwon O S, Han J H, Yoo H G, Chung J H, Cho K H, Eun H C, Kim K H.2007. Human hair growth enhancement in vitro by green tea epigallocatechin-3-gallate (EGCG)[J]. Phytomedicine, 14(7-8):551-555.
Laborde B, Moine-Ledoux V, Richard T, Saucier C, Dubourdieu D, Monti J P.2006. PVPP-polyphenol complexes:a molecular approach[J]. Journal of Agricultural and Food Chemistry, 54(12):4383-4389.
Lachova M, Lehotay J, Karasova G, Skacani I, Armstrong D W.2007. Isolation of 1-Theanine from Plant Material using a Molecularly Imprinted Polymer[J]. Journal of Liquid Chromatography & Related Technologies,30(14):2045-2058.
Langmuir I.1918. The adsorption of gases on plane surfaces of glass, mica and platinum.[J]. Journal of the American Chemical Society,40(9):1361-1403.
Lee S, Park M K, Kim K H, Kim Y S.2007. Effect of supercritical carbon dioxide decaffeination on volatile components of green teas[J]. Journal of Food Science,72(7):S497-S502.
Leone A M.2001. Method for decaffeinating an aqueous solution using molecularly imprinted polymers[P]. Patent US6322834.
Leone A M.2002. Method and product for decaffeinating an aqueous solution using molecularly imprinted polymers[P]. Patent US20020031580.
Li G, Ye Y, Kang J, Yao X, Zhang Y, Jiang W, Gao M, Dai Y, Xin Y, Wang Q, Yin Z, Luo L.2012. 1-Theanine prevents alcoholic liver injury through enhancing the antioxidant capability of hepatocytes[J]. Food and Chemical Toxicology,50(2):363-372.
Li P, Wang Y, Ma R, Zhang X.2005. Separation of tea polyphenol from Green Tea Leaves by a combined CATUFM-adsorption resin process[J]. Journal of Food Engineering,58(43):8851-8856.
Liang H, Liang Y, Dong J, Lu J, Xu H, Wang H.2007. Decaffeination of fresh green tea leaf(Camellia sinensis) by hot water treatment[J]. Food Chemistry,101(4):1451-1456.
Liang Y, Xu Y.2001. Effect of pH on cream particle formation and solids extraction yield of black tea[J]. Food Chemistry,74(2):155-160.
Lichtenstein N.1942. Preparation of γ-alkylamides of glutamic acid[J]. Journal of the American Chemical Society,64(5):1021-1022.
Lill G, Voit S, Schror K, Weber A A.2003. Complex effects of different green tea catechins on human platelets[J]. Febs Letters,546(2-3):265-270.
Lin S D, Liu E H, Mau J L.2008. Effect of different brewing methods on antioxidant properties of steaming green tea[J]. LWT-Food Science and Technology,41(9):1616-1623.
Liu J, Wang M, Peng S, Zhang G.2011. Effect of green tea catechins on the postprandial glycemic response to starches differing in amylose content[J]. Journal of Agricultural and Food Chemistry, 59(9):4582-4588.
Liu Q, Duan H, Luan J, Yagasaki K, Zhang G.2009. Effects of theanine on growth of human lung cancer and leukemia cells as well as migration and invasion of human lung cancer cells[J]. Cytotechnology,59(3):211-217.
Lloyd T, Rollings N, Eggli D F, Kieselhorst K, Chinchilli V M.1997. Dietary caffeine intake and bone status of postmenopausal women[J]. American Journal of Clinical Nutrition,65(6):1826-1830.
Lowry T H, Richardson S, Mechanism K.1987. Theory in Organic Chemistry[J]. Harper&Row:New York.
Lu J L, Wu M Y, Yang X L, Dong Z B, Ye J H, Borthakur D, Sun Q L, Liang Y R.2010. Decaffeination of tea extracts by using poly (acrylamide-co-ethylene glycol dimethylacrylate) as adsorbent[J]. Journal of Food Engineering,97(4):555-562.
Magalhaes P J, Vieira J S, Goncalves L M, Pacheco J G, Guido L F, Barros A A.2010. Isolation of phenolic compounds from hop extracts using polyvinylpolypyrrolidone:characterization by high-performance liquid chromatography-diode array detection-electrospray tandem mass spectrometry[J]. Journal of Chromatography a,1217(19):3258-3268.
Mandal V, Mohan Y, Hemalatha S.2007. Microwave assisted extraction-an innovative and promising extraction tool for medicinal plant research[J]. Pharmacognosy Reviews,1(1):7-18.
Manikandan R, Beulaja M, Arulvasu C, Sellamuthu S, Dinesh D, Prabhu D, Babu G, Vaseeharan B, Prabhu N M.2012. Synergistic anticancer activity of curcumin and catechin:an in vitro study using human cancer cell lines[J]. Microscopy Research and Technique,75(2):112-116.
Martin R, Lilley T H, Bailey N A, Falshaw C P, Haslam E, Magnolato D, Begley M J.1986. Polyphenol-caffeine complexation[J]. J. Chem. Soc., Chem. Commun.,(2):105-106.
Maruyama N, Suzuki Y, Sakata K, Yagi A, Ina K.1991. NMR spectroscopic and computer graphics studies on the creaming down of tea[C].
Mason R.2001.200 mg of Zen:L-theanine boosts alpha waves, promotes alert relaxation[J]. Alternative and Complementary Therapies,7(2):91-95.
Matsuyama T, Tanaka Y, Kamimaki I, Nagao T, Tokimitsu I.2008. Catechin safely improved higher levels of fatness, blood pressure, and cholesterol in children[J]. Obesity,16(6):1338-1348.
McMillan B, Riggs D R, Jackson B J, Cunningham C, McFadden D W.2007. Dietary influence on pancreatic cancer growth by catechin and inositol hexaphosphate[J]. Journal of Surgical Research, 141(1):115-119,
Mcmurrough I, Madigan D, Smyth M R.1995. Adsorption by Polyvinylpolypyrrolidone of Catechins and Proanthocyanidins from Beer[J]. Journal of Agricultural and Food Chemistry, 43(10):2687-2691.
Melis S, Markos J, Cao G, Morbidelli M.1996. Ion-exchange equilibria of amino acids on a strong acid resin[J]. Industrial & Engineering Chemistry Research,35(6):1912-1920.
Miodownik C, Maayan R, Ratner Y, Lerner V, Pintov L, Mar M, Weizman A, Ritsner M S.2011. Serum levels of brain-derived neurotrophic factor and cortisol to sulfate of dehydroepiandrosterone molar ratio associated with clinical response to 1-theanine as augmentation of antipsychotic therapy in schizophrenia and schizoaffective disorder patients[J]. Clinical Neuropharmacology,34(4):155-160.
Miura Y, Chiba T, Tomita I, Koizumi H, Miura S, Umegaki K, Hara Y, Ikeda M, Tomita T.2001. Tea catechins prevent the development of atherosclerosis in apoprotein E-deficient mice[J]. Journal of Nutrition,131(1):27-32.
Miyagawa K, Hayashi Y, Kurihara S, Maeda A.2008. Co-administration of 1-cystine and 1-theanine enhances efficacy of influenza vaccination in elderly persons:nutritional status-dependent immunogenicity[J]. Geriatrics and Gerontology International,8(4):243-250.
Murase T, Haramizu S, Shimotoyodome A, Tokimitsu I.2006. Reduction of diet-induced obesity by a combination of tea-catechin intake and regular swimming[J]. International Journal of Obesity, 30(3):561-568.
Murray N J, Williamson M P, Lilley T H, Haslam E.1994. Study of the interaction between salivary proline-rich proteins and a polyphenol by 1H-NMR spectroscopy[J]. European Journal of Biochemistry,219(3):923-935.
Nakamura H, Ukai T, Yoshimura A, Kozuka Y, Yoshioka H, Yoshinaga Y, Abe Y, Hara Y.2010. Green tea catechin inhibits lipopolysaccharide-induced bone resorption in vivo[J]. Journal of Periodontal Research,45(1):23-30.
Narukawa M, Morita K, Hayashi Y,2008. L-theanine elicits an umami taste with inosine 5'-monophosphate[J]. Bioscience, Biotechnology, and Biochemistry,72(11):3015-3017.
Nehlig A, Daval J L, Debry G.1992. Caffeine and the central nervous system:mechanisms of action, biochemical, metabolic and psychostimulant effects[J], Brain Research Reviews,17(2):139-170.
Nikken F K.1994. Manufacture of low caffeine tea catechins[P]. JP Patent 06,116,258.
Nkhili E, Tomao V, El Hajji H, El Boustani E S, Chemat F, Dangles O.2009. Microwave-assisted water extraction of green tea polyphenols[J]. Phytochemical Analysis,20(5):408-415.
Nobre A C, Rao A, Owen G N.2008. L-theanine, a natural constituent in tea, and its effect on mental state[J]. Asia Pacific Journal of Clinical Nutrition,17 Suppl 1:167-168.
Nwuha V.2000. Novel studies on membrane extraction of bioactive components of green tea in organic solvents:part I[J]. Journal of Food Engineering,44(4):233-238.
O'Reilly J P.1994. The use and function of PVPP in beer stabilization[J]. Brewers' Guardian, 123(9):32-36.
Orbeta R L, Overpeck M D, Ramcharran D, Kogan M D, Ledsky R.2006. High caffeine intake in adolescents:associations with difficulty sleeping and feeling tired in the morning[J]. Journal of Adolescent Health,38(4):451-453.
Orihara Y, Furuya T.1990. Production of theanine and other γ-glutamyl derivatives by Camellia sinensis cultured cells[J]. Plant Cell Reports,9(2):65-68.
Owen G N, Parnell H, De Bruin E A, Rycroft J A.2008. The combined effects of L-theanine and caffeine on cognitive performance and mood[J]. Nutritional Neuroscience,11(4):193-198.
Packard P T, Recker R R.1996. Caffeine does not affect the rate of gain in spine bone in young women[J]. Osteoporosis International,6(2):149-152.
Park I J, Lee Y K, Hwang J T, Kwon D Y, Ha J, Park O J.2009. Green tea catechin controls apoptosis in colon cancer cells by attenuation of H2O2-stimulated COX-2 expression via the AMPK signaling pathway at low-dose H2O2[J]. Annals of the New York Academy of Sciences, 1171:538-544.
Penders M H G M, Jones D P, Needham D, Pelan E G.1998. Mechanistic study of equilibrium and kinetic behaviour of tea cream formation[J]. Food Hydrocolloids,12(1):9-15.
Perva-Uzunalic A, Skerget M, Knez Z, Weinreich B, Otto F, Gruner S.2006. Extraction of active ingredients from green tea (Camellia sinensis):Extraction efficiency of major catechins and caffeine.[J]. Food Chemistry,96(4):597-605.
Pierpoint W S.2004. The extraction of enzymes from plant tissues rich in phenolic compounds[J]. Methods Mol Biol,244:65-74.
Rapuri P B, Gallagher J C, Kinyamu H K, Ryschon K L.2001. Caffeine intake increases the rate of bone loss in elderly women and interacts with vitamin D receptor genotypes[J]. American Journal of Clinical Nutrition,74(5):694-700.
Ritsner M S, Miodownik C, Ratner Y, Shleifer T, Mar M, Pintov L, Lerner V.2011. L-theanine relieves positive, activation, and anxiety symptoms in patients with schizophrenia and schizoaffective disorder:an 8-week, randomized, double-blind, placebo-controlled,2-center study[J]. Journal of Clinical Psychiatry,72(1):34-42.
Rogers P J, Smith J E, Heatherley S V, Pleydell-Pearce C W.2008. Time for tea:mood, blood pressure and cognitive performance effects of caffeine and theanine administered alone and together[J]. Psychopharmacology (Berl),195(4):569-577.
Romier B, Schneider Y J, Larondelle Y, During A.2009. Dietary polyphenols can modulate the intestinal inflammatory response[J]. Nutrition Reviews,67(7):363-378.
Row K H, Jin Y.2006. Recovery of catechin compounds from Korean tea by solvent extraction[J]. Bioresour Technol,97(5):790-793.
Ruthven D M.1984. Principles of adsorption and adsorption processes[M]. Wiley-Interscience.
Sadzuka Y, Inoue C, Hirooka S, Sugiyama T, Umegaki K, Sonobe T.2005. Effects of theanine on alcohol metabolism and hepatic toxicity[J]. Biological & Pharmaceutical Bulletin, 28(9):1702-1706.
Sakanaka S.2003. A novel convenient process to obtain a raw decaffeinated tea polyphenol fraction using a lignocellulose column[J]. Journal of Agricultural and Food Chemistry,51(10):3140-3143.
Sakato Y.1949. The chemical constituents of tea:Ⅲ. A new amide theanine[J]. Nippon Nogeikagaku Kaishi,23:262-267.
Sari A, Tuzen M.2008. Biosorption of cadmium(Ⅱ) from aqueous solution by red algae (Ceramium virgatum):equilibrium, kinetic and thermodynamic studies[J]. Journal of Hazardous Materials, 157(2-3):448-454.
Sarioglu K.2007. Synthesis of octadecyl acrylate-co-ethylene glycol dimethacrylate resin for removal of dark-colored compound from apple juice and comparison with polyvinylpolypirrolidone (PVPP)[J]. European Food Research and Technology,225(3-4):443-449.
Scaltriti M, Belloni L, Caporali A, Davalli P, Remondini D, Rizzi F, Astancolle S, Corti A, Bettuzzi S. 2006. Molecular classification of green tea catechin-sensitive and green tea catechin-resistant prostate cancer in the TRAMP mice model by quantitative real-time PCR gene profiling[J]. Carcinogenesis,27(5):1047-1053.
Siebert K J, Lynn P Y.1998. Comparison of polyphenol interactions with polyvinylpolypyrrolidone and haze-active protein[J]. Journal of the American Society of Brewing Chemists,56(1):24-31.
Singh T S, Pant K K.2004. Equilibrium, kinetics and thermodynamic studies for adsorption of As (III) on activated alumina[J]. Separation and Purification Technology,36(2):139-147.
Sinija V R, Mishra H N, Bal S.2007. Process technology for production of soluble tea powder[J]. Journal of Food Engineering,82(3):276-283.
Strain E C, Mumford G K, Silverman K, Griffiths R R.1994. Caffeine dependence syndrome. Evidence from case histories and experimental evaluations[J]. Journal of the American Medical Association,272(13):1043-1048.
Swanson B N.1985. Medical use of dimethyl sulfoxide (DMSO)[J]. Reviews in Clinical and Basic Pharmacology,5(1-2):1-33.
Tan X, Zhou D, Zhang Y, Jiang B.2000. Effects of different catechins on cell cycle arrest and induction of apoptosis in LoVo cells[J]. Zhonghua Yu Fang Yi Xue Za Zhi,34(6):333-335.
Tary-Costodes V C, Fauduet H, Porte C, Delacroix A.2003. Removal of Cd(Ⅱ) and Pb(Ⅱ) ions, from aqueous solutions, by adsorption onto sawdust of Pinus sylvestris[J]. Journal of Hazardous Materials,105(1-3):121-142.
Theodoridis G, Manesiotis P.2002. Selective solid-phase extraction sorbent for caffeine made by molecular imprinting[J]. Journal of Chromatography a,948(1-2):163-169.
Tseng R L, Wu F C.2008. Inferring the favorable adsorption level and the concurrent multi-stage process with the Freundlich constant[J]. Journal of Hazardous Materials,155(1-2):277-287.
Unno K, Fujitani K, Takamori N, Takabayashi F, Maeda K, Miyazaki H, Tanida N, Iguchi K, Shimoi K, Hoshino M.2011. Theanine intake improves the shortened lifespan, cognitive dysfunction and behavioural depression that are induced by chronic psychosocial stress in mice[J]. Free Radical Research,45(8):966-974.
Vuong Q V, Bowyer M C, Roach P D.2011. L-Theanine:properties, synthesis and isolation from tea[J]. Journal of the Science of Food and Agriculture,91(11):1931-1939.
Wakabayashi C, Numakawa T, Ninomiya M, Chiba S, Kunugi H.2011. Behavioral and molecular evidence for psychotropic effects in L-theanine[J].Psychopharmacology (Berl), 219(4):1099-1109.
Wan X, Zhang Z, Li D, Ho C T, Lin J K, Shahidi F.2009. Chemistry and biological peroperties of theanine[M]Tea and Tea Products, ed. by HoCT L A S. CRC Press:Boca Raton:255-274.
Wang L, Weller C L.2006. Recent advances in extraction of nutraceuticals from plants[J]. Trends in Food Science & Technology,17(6):300-312.
Wang X, Qin Y.2005. Equilibrium sorption isotherms for of Cu2+ on rice bran[J]. Process Biochemistry,40(2):677-680.
Wolfram S.2007. Effects of green tea and EGCG on cardiovascular and metabolic health[J].Journal of the American College of Nutrition,26(4):373S-388S.
Wu F, Sun H, Kluz T, Clancy H A, Kiok K, Costa M.2011. Epigallocatechin-3-gallate (EGCG) protects against chromate-induced toxicity in vitro[J]. Toxicology and Applied Pharmacology, 258(2):166-175.
Wu L Y, Zheng X Q, Lu J L, Liang Y R.2009. Protective effect of green tea polyphenols against ultraviolet B-induced damage to HaCaT cells[J]. Human Cell,22(1):18-24.
Xerri L, Mathoulin M P, Birg F, Bouabdallah R, Stoppa A M, Hassoun J.1994. Heterogeneity of rearranged T-cell receptor V-alpha and V-beta transcripts in tumor-infiltrating lymphocytes from Hodgkin's disease and non-Hodgkin's lymphoma[J]. American Journal of Clinical Pathology, 101(1):76-80.
Xia T, Shi S, Wan X.2006. Impact of ultrasonic-assisted extraction on the chemical and sensory quality of tea infusion[J]. Journal of Food Engineering,74(4):557-560.
Yamaguchi S.1979. The umami taste[J]. Food Taste Chemistry,115:33-51.
Yamano H, Miyagawa K.1997. Buffer capacity curves of green tea extracts using a personal computer with numerically treated online software[J]. Food Science and Technology International, 3(1):69-73.
Ye J H, Dong J J, Lu J L, Zheng X Q, Jin J, Chen H, Liang Y R.2010. Effect of graft copolymerization of fir sawdust lignocellulose with N-vinylpyrrolidone on adsorption capacity to tea catechins[J]. Carbohydrate Polymers,81(2):441-447.
Ye J H, Jin J, Liang H L, Lu J L, Du YY, Zheng X Q, Liang Y R.2009. Using tea stalk lignocellulose as an adsorbent for separating decaffeinated tea catechins[J]. Bioresource Technology, 100(2):622-628.
Ye J H, Liang Y R, Jin J, Liang H L, Du YY, Lu J L, Ye Q, Lin C.2007. Preparation of partially decaffeinated instant green tea[J]. Journal of Agricultural and Food Chemistry,55(9):3498-3502.
Ye J H, Wang L X, Chen H, Dong J J, Lu J L, Zheng X Q, Wu M Y, Liang Y R.2011. Preparation of tea catechins using polyamide[J]. Journal of Bioscience and Bioengineering,111(2):232-236.
Yokogoshi H, Kato Y, Sagesaka Y M, Takihara-Matsuura T, Kakuda T, Takeuchi N.1995. Reduction effect of theanine on blood pressure and brain 5-hydroxyindoles in spontaneously hypertensive rats[J]. Bioscience, Biotechnology, and Biochemistry,59(4):615-618.
Yokogoshi H, Mochizuki M, Saitoh K.1998. Theanine-induced reduction of brain serotonin concentration in rats[J]. Bioscience, Biotechnology, and Biochemistry,62(4):816-817.
Yoshida Y, Kiso M, Goto T.1999. Efficiency of the extraction of catechins from green tea[J]. Food Chemistry,67(4):429-433.
Zhang F, Zheng Q Z, Jiao Q C, Liu J Z, Zhao G H.2010. Enzymatic synthesis of theanine from glutamic acid gamma-methyl ester and ethylamine by immobilized Escherichia coli cells with gamma-glutamyltranspeptidase activity[J]. Amino Acids,39(5):1177-1182.
Zhang G, Miura Y, Yagasaki K.2002. Effects of dietary powdered green tea and theanine on tumor growth and endogenous hyperlipidemia in hepatoma-bearing rats[J]. Bioscience, Biotechnology, and Biochemistry,66(4):711-716.
Zhang Y, Chen B, Huang Z, Shi Z.2004. Preparative isolation and purification of L-theanine by HPLC.[J]. Journal of Liquid Chromatography & Related Technologies,27(5):875.
Zhao B L, Li X J, He R G, Cheng S J, Xin W J.1989. Scavenging effect of extracts of green tea and natural antioxidants on active oxygen radicals[J]. Cell Biophysics,14(2):175-185.
Zhao R, Yan Y, Li M, Yan H.2008. Selective adsorption of tea polyphenols from aqueous solution of the mixture with caffeine on macroporous crosslinked poly (N-vinyl-2-pyrrolidinone)[J]. Reactive and Functional Polymers,68(3):768-774.
Zhu Q Y, Zhang A, Tsang D, Huang Y, Chen Z Y.1997. Stability of green tea catechins[J]. Journal of Agricultural and Food Chemistry,45(12):4624-4628.