儿茶素与表儿茶素稳定性考察-最新资料

12种儿茶素单体以下是12种儿茶素单体：1. 儿茶素（Catechin）：是最常见的儿茶素单体，具有抗氧化和抗炎作用。

2. 表儿茶素（Epicatechin）：与儿茶素结构相似，也具有抗氧化和抗炎作用。

3. 儿茶素-3-加醇（Catechin-3-gallate）：具有抗氧化、抗癌和抗炎作用。

4. 表儿茶素-3-加醇（Epicatechin-3-gallate）：与儿茶素-3-加醇结构相似，也具有类似的作用。

5. 儿茶素-3-儿茶酰基（Catechin-3-O-gallate）：具有抗氧化和抗癌作用。

6. 表儿茶素-3-儿茶酰基（Epicatechin-3-O-gallate）：与儿茶素-3-儿茶酰基结构相似，也具有类似的作用。

7. 儿茶素-3'-咖啡酰基（Catechin-3'-caffeoyl）：具有抗氧化和抗癌作用。

8. 儿茶素-4'-咖啡酰基（Catechin-4'-caffeoyl）：具有抗氧化和抗癌作用。

9. 儿茶素-3',4'-双咖啡酰基（Catechin-3',4'-dicaffeoyl）：具有抗氧化和抗癌作用。

10. 儿茶素-3'-咖啡酰基-4'-咖啡酰基（Catechin-3'-caffeoyl-4'-caffeoyl）：具有抗氧化和抗癌作用。

11. 表儿茶素-3'-咖啡酰基（Epicatechin-3'-caffeoyl）：具有抗氧化和抗癌作用。

12. 表儿茶素-3',4'-双咖啡酰基（Epicatechin-3',4'-dicaffeoyl）：具有抗氧化和抗癌作用。

这些儿茶素单体在茶叶、葡萄酒、巧克力等食物中都可以找到。

它们被广泛研究，已被发现具有多种健康益处，包括抗氧化、抗癌、抗炎和心血管保护等作用。

表儿茶素的色谱条件
儿茶素（catechins）是茶叶中的重要成分，常用的高效液相色谱（HPLC）方法一般用于分析和测定儿茶素的含量。

以下是一种常用的HPLC色谱条件：
1. 色谱柱：常见的色谱柱包括C18柱和C8柱，一般使用5μm或3μm的粒径，柱长一般为150mm。

2. 流动相：常用的流动相是乙腈和水的混合物，可以添加0.1%的磷酸作为缓冲剂。

初始流动相的组成可以设置为85%乙腈和15%水，然后随着时间的推移逐渐增加乙腈的浓度。

3. 流速：常见的流速为1.0 mL/min。

4. 检测波长：儿茶素在紫外区域具有吸收峰，常见的检测波长为280nm。

5. 注射体积：一般情况下，儿茶素的样品注射体积为10μL。

需要注意的是，以上条件仅供参考，具体的色谱条件可能会有一定的差异，取决于仪器设备和具体分析要求。

在实际操作中，可以根据需要进行优化调整。

A NTIMICROBIAL A GENTS AND C HEMOTHERAPY,Feb.2002,p.558–560Vol.46,No.2 0066-4804/02/$04.00ϩ0DOI:10.1128/AAC.46.2.558–560.2002Copyright©2002,American Society for Microbiology.All Rights Reserved.Epigallocatechin Gallate Synergistically Enhances the Activity of Carbapenems against Methicillin-Resistant Staphylococcus aureus Zhi-Qing Hu,1*Wei-Hua Zhao,1Nozomi Asano,1Yoshiyuki Yoda,1Yukihiko Hara,2and Tadakatsu Shimamura1Department of Microbiology and Immunology,Showa University School of Medicine,1and Tokyo Food Techno Co.Ltd.,2Tokyo,JapanReceived13April2001/Returned for modification22August2001/Accepted25October2001Combinations of carbapenems and epigallocatechin gallate(EGCg;a main constituent of tea catechins)showed potent synergy against24clinical isolates of methicillin-resistant Staphylococcus aureus(MRSA).MICsof imipenem in the presence of EGCg at3.125,6.25,12.5,and25␮g/ml,were restored to the susceptiblebreakpoint(<4␮g/ml)for8,38,46,and75%of the MRSA isolates,respectively.Similar results were alsoobserved for combinations of panipenem or meropenem and EGCg.Therefore,the combinations may be worthyof further evaluation in vivo against MRSA infection.Methicillin-resistant Staphylococcus aureus(MRSA)has be-come a major nosocomial pathogen in the past2decades. Therapeutic options for MRSA infection are very limited be-cause most MRSA strains are resistant not only to␤-lactams but also to multiple antimicrobial agents,such as macrolides, aminoglycosides,andfluoroquinolones(8).The emergence of MRSA strains with reduced susceptibility to vancomycin sug-gests that MRSA may eventually become fully resistant to vancomycin(1,2).Therefore,new chemotherapeutic agents and new approaches are urgently needed to combat such mul-tiple-antibiotic-resistant bacteria.Carbapenems are relatively new␤-lactams that have a broad spectrum and strong activity against many pathogens.How-ever,the carbapenems(imipenem[IPM],panipenem[PAPM], and meropenem[MEM])do not show high levels of activity against MRSA.It has been previously demonstrated that epigallocatechin gallate(EGCg;a main constituent of tea catechins)is able to act synergistically with␤-lactams against MRSA(5,12).Two groups using an aqueous extract of tea further confirmed the synergy between tea and␤-lactams(14,15).It was recently demonstrated that the EGCg-induced damage of the bacterial cell wall and interference with its integrity through direct bind-ing with peptidoglycan are responsible for the synergism be-tween EGCg and␤-lactams against MRSA(16).In determining the possible clinical use of EGCg against MRSA infections,the bioavailable concentration of EGCg in vivo is the most crucial factor.In this study,therefore,we examined carbapenems in combination with the lowest possi-ble concentrations of EGCg in vitro.EGCg was extracted from green tea,and the purity of the EGCg was confirmed to be98%by high-performance liquid chromatography analysis.The following antibiotics were used:IPM(Banyu Pharmaceutical Co.,Tokyo,Japan),PAPM (Sankyo Organic Chemicals Co.,Kawasaki,Japan),and MEM (Sumitomo Pharmaceuticals Co.,Osaka,Japan).The twenty-four clinical isolates of MRSA used were from specimens submitted for routine culture at the clinical micro-biology laboratories of Showa University Hospital.All24iso-lates carried the mecA gene,which was confirmed by PCR analysis as described previously(6,16).Mueller-Hinton broth supplemented with25mg of Ca2ϩ/liter,12.5mg of Mg2ϩ/liter, and2%NaCl was used for susceptibility tests and time-kill assays.MICs were determined by the broth microdilution and checkerboard methods(11)with afinal inoculum concentra-tion ofϾ5ϫ105CFU/ml.After stationary incubation of the isolates at35°C for24h,the lowest concentration of the two-fold-serial-diluted antibiotic(s)and/or EGCg at which no visi-ble growth occurred was defined as the antibiotic’s or EGCg’s MIC.The bacteria were also cultured in3ml of Mueller-Hinton broth,and their growth was detected with a spectro-photometer(optical density at600nm)at24h.Synergy was measured by a fractional inhibitory concentration(FIC)index. The FIC of the combination was calculated by dividing the MIC of the antibiotic-EGCg combination by the MIC of the antibiotic or of EGCg alone,and the FIC index was obtained by adding the FIC of the antibiotic and that of EGCg.The FIC index results were interpreted as follows:Յ0.5,synergy;Ͼ0.5 to1,additive effect;andϾ1to2,no effect.In the killing curves, synergy was defined as present when the decrease in CFU per milliliter between results of treatment with the combination and those of its most active constituent after24h wasՆ2-log10 and when the number of surviving organisms after treatment with the combination of␤-lactams and EGCg at their sub-MICs wasՆ2-log10CFU/ml below the starting concentration of inoculum.The data from time-kill assays are presented as the meansϮstandard deviations(see Fig.1).The MIC of EGCg alone for the MRSA isolates was100␮g/ml.Synergy was observed when␤-lactams were combined with EGCg at a concentration of less than one-fourth the MIC of EGCg alone.Among the tested␤-lactams,which included penicillins(benzylpenicillin,ampicillin,oxacillin,and methicil-lin),cephems(cephalexin,cefmetazole,and cefotaxime),and carbapenems(IPM,PAPM,and MEM),the combinations be-*Corresponding author.Mailing address:Department of Microbi-ology and Immunology,Showa University School of Medicine,1-5-8 Hatanodai,Shinagawa-ku,Tokyo142-8555,Japan.Phone:81-3-3784-8131.Fax:81-3-3784-3069.E-mail:zqhu@med.showa-u.ac.jp.558tween carbapenems and EGCg showed the most potent syn-ergy.The effects of combination of carbapenems and EGCg are summarized in Table1.The synergistic or additive effects were observed to occur against100%of the MRSA strains tested in a dose-dependent manner.The MIC at which50%of the iso-lates treated with IPM were inhibited decreased from128␮g/ml to64,32,8,8,and0.25␮g/ml when in combination with 1.56,3.125,6.25,12.5,and25␮g of EGCg/ml,respectively. Furthermore,the MICs of IPM in the presence of EGCg at 3.125,6.25,12.5,and25␮g/ml were restored to the suscepti-bility breakpoint(Յ4␮g/ml)for8,38,46,and75%of MRSA isolates,respectively.Figure1A shows the results for the IPM-EGCg combination against strain F-74,which has a high level of resistance to carbapenems(MIC,128␮g/ml).The growth of F-74was in-hibited by EGCg even at the low concentration of1.56␮g/ml. Figure1B,shows the results of time-kill assays of strain F-74. The combination of32␮g of IPM/ml and25␮g of EGCg/ml (concentrations that are one-fourth their MICs)showed syn-ergistic bactericidal activity,resulting after24h in aϾ2-log10 decrease in CFU per milliliter from that resulting from treat-ment with IPM or EGCg alone and from the starting inoculum. PAPM-EGCg and MEM-EGCg combinations also showed similar results(data not shown).Tea,one of the most popular beverages in the world,is consumed every day by billions of people.Capsules of tea catechins and EGCg are becoming available for research and preclinical trials.The safe consumption of tea for thousands of years indicates the low toxicity of tea and EGCg.However,it is hard to predict synergistic effects in vivo on the basis of the presented in vitro evidence alone because it is difficult to es-timate the in vivo concentration of EGCg,especially the bio-available concentration of free(active)EGCg,after tea has been drunk or EGCg capsules have been ingested. Recently,researchers began to pay attention to the effects of the pharmacokinetics of EGCg and tea catechins on their absorption,distribution,and elimination in animals and hu-mans(3,4,7,9,10,13,17).Usually the EGCg concentration in tea is2to3mg/ml.EGCg is absorbed through the digestive tract and distributed to many organs in both animals and hu-mans.EGCg at5.6␮g/ml in rat blood plasma was detected after the administration of EGCg at500mg/kg of body weight (9).Total catechins,including epicatechin,epicatechin gallate, and EGCg,were detected in rat blood plasma at15to112␮g/ml at2h after oral administration of catechins at5,000 mg/kg(17).EGCg was detected at2␮g/ml in human blood plasma90min after525mg of EGCg in capsule form had been ingested(10).Therefore,the combination of carbapenemsTABLE1.Effects of carbapenems in combination with EGCg against24MRSA isolatesCombinationMIC50(␮g/ml)a ofcombination%of MRSA isolatesshowing indicated effect:Synergistic Additive None MIC ofՅ4␮g/ml bEGCg1.56␮g/mlIPM64046540 PAPM32433634 MEM64042580EGCg3.125␮g/mlIPM324241178 PAPM162963821 MEM32386204EGCg6.25␮g/mlIPM88317038 PAPM87517846 MEM88317025EGCg12.5␮g/mlIPM88812046 PAPM2839867 MEM88812042EGCg25␮g/mlIPM0.25928075 PAPM0.58812075 MEM28317071a MICs at which50%of the isolates treated with carbapenem alone are inhibited:IPM,128␮g/ml;PAPM32␮g/ml;MEM,64␮g/ml.b MIC susceptibility breakpoint isՅ4␮g/ml for IPM and MEM,as determined by NCCLS,but is not available for PAPM atpresent.FIG.1.Synergistic anti-MRSA effects of combinations of IPM andEGCg.(A)Growth inhibition curves.E,IPM alone;F,IPM plusEGCg at1.56␮g/ml;Œ,IPM plus EGCg at3.12␮g/ml; ,IPM plusEGCg at6.25␮g/ml;},IPM plus EGCg at12.5␮g/ml;s,IPM plusEGCg at25␮g/ml;OD,optical density.(B)Time-kill curves.E,noaddition;‚,IPM at32␮g/ml alone;ƒ,EGCg at25␮g/ml alone;F,IPM at4␮g/ml plus EGCg at3.125␮g/ml(1/32of their MICs);Œ,IPMat8␮g/ml plus EGCg at6.25␮g/ml(1/16of their MICs); ,IPM at16␮g/ml plus EGCg at12.5␮g/ml(1/8of their MICs);s,IPM at32␮g/ml plus EGCg at25␮g/ml(1/4of their MICs).V OL.46,2002NOTES559and EGCg against MRSA may be worthy of further evaluation in vivo.REFERENCES1.Centers for Disease Control and Prevention.1997.Update:Staphylococcusaureus with reduced susceptibility to vancomycin—United States,1997.Morb.Mortal.Wkly.Rep.46:813–815.2.Centers for Disease Control and Prevention.1997.Update:Staphylococcusaureus with reduced susceptibility to vancomycin—Japan,1996.Morb.Mor-tal.Wkly.Rep.46:624–635.3.Chen,L.,M.J.Lee,H.Li,and C.S.Yang.1997.Absorption,distribution,elimination of tea polyphenols in rats.Drug Metab.Dispos.25:1045–1050.4.Hamilton-Miller,J.M.T.1995.Antimicrobial properties of tea(Camelliasinensis L.).Antimicrob.Agents Chemother.39:2375–2377.5.Hu,Z.-Q.,W.-H.Zhao,Y.Hara,and T.Shimamura.2001.Epigallocatechingallate synergy with ampicillin-sulbactam against28clinical isolates of me-thicillin-resistant Staphylococcus aureus.J.Antimicrob.Chemother.48:361–364.6.Kohner,P.,J.Uhl,C.Kolbert,D.Persing,and F.Cockerill III.1999.Comparison of susceptibility testing methods with mecA gene analysis for determining oxacillin(methicillin)resistance in clinical isolates of Staphylo-coccus aureus and coagulase-negative Staphylococcus spp.J.Clin.Microbiol.37:2952–2961.7.Lee,M.J.,Z.Y.Wang,H.Li,L.Chen,Y.Sun,S.Gobbo,D.A.Balentine,andC.S.Yang.1995.Analysis of plasma and urinary tea polyphenols in humansubjects.Cancer Epidemiol.Biomark.Prev.4:393–399.8.Maple,P.A.C.,J.M.T.Hamilton-Miller,and W.Brumfitt.1989.World-wide antibiotic resistance in methicillin-resistant Staphylococcus n-cet i:537–540.9.Nakagawa,K.,and T.Miyazawa.1997.Absorption and distribution of teacatechin,(Ϫ)-epigallocatechin-3-gallate in rats.J.Nutr.Sci.Vitaminol.(To-kyo)43:679–684.10.Nakagawa,K.,S.Okuda,and T.Miyazawa.1997.Dose-dependent incorpo-ration of tea catechins,(Ϫ)-epigallocatechin-3-gallate and(Ϫ)-epigallocat-echin,into human plasma.Biosci.Biotechnol.Biochem.61:1981–1985. 11.Norden,C.W.,H.Wentzel,and parison of techniquesfor measurement of in vitro antibiotic synergism.J.Infect.Dis.140:629–633.12.Takahashi,A.,Z.Cai,M.Toda,Y.Hara,and T.Shimamura.1995.Appear-ance of antibacterial activity of oxacillin against methicillin resistant Staph-ylococcus aureus(MRSA)in the presence of catechin.J.Jpn.Assoc.Infect.Dis.69:1126–1134.(In Japanese.)13.Unno,T.,K.Kondo,H.Itakura,and T.Takeo.1996.Analysis of(Ϫ)-epigallocatechin gallate in human serum obtained after ingesting green tea.Biosci.Biotechnol.Biochem.60:2066–2068.14.Yam,T.S.,J.M.T.Hamilton-Miller,and S.Shah.1998.The effect of acomponent of tea(Camellia sinensis)on methicillin resistance,PBP2Јsyn-thesis,and␤-lactamase production in Staphylococcus aureus.J.Antimicrob.Chemother.42:211–216.15.Yamazaki,K.1996.Enhancing effect of Japanese green tea extract on thegrowth-inhibitory activity of antibiotics against clinically isolated MRSA strains.Jpn.J.Chemother.44:477–482.(In Japanese.)16.Zhao,W.-H.,Z.-Q.Hu,S.Okubo,Y.Hara,and T.Shimamura.2001.Mech-anism of synergy between epigallocatechin gallate and␤-lactams against methicillin-resistant Staphylococcus aureus.Antimicrob.Agents Chemother.45:1737–1742.17.Zhu,M.,Y.Chen,and R.C.Li.2000.Oral absorption and bioavailability oftea catechins.Planta Med.66:444–447.560NOTES A NTIMICROB.A GENTS C HEMOTHER.。

广东化工2019年第13期·54·第46卷总第399期茶多酚EGCG的不稳定性初探张营，刘丹，杨娜，程康(上海相宜本草化妆品股份有限公司，上海200071)Preliminary Study on the Instability of Tea Polyphenol EGCGZhang Ying,Liu Dan,Yang Na,Cheng Kang(Shanghai Inoherb Cosmetics Co.,Ltd.,Shanghai200071,China)Abstract:In order to investigate the unstable properties of polyphenol EGCG(epigallocatechin gallate),three different temperature conditions,43℃,25℃, 4℃,four kinds of solvent,butanediol,glycerol,propylene glycol,PEG400were tested,respectively.The effect of temperature and solvent factors on the instability of EGCG was investigated over a period of20days.The results show that different kinds of solvents,different percentages of the solvents,and different temperature conditions all will have a certain impact on the degradation of EGCG.Among these solvents,60%butanediol has the best stability to EGCG.At high temperature of 43℃,20days,EGCG degraded by26.5%.The butanediol was used as a solvent,the high proportion of butanediol and low temperature conditions in the system have a certain effect on the degradation of EGCG;Polyphenol EGCG exhibits poor stability to the temperature and solvent selected for the test.Therefore,the raw material containing the tea polyphenol EGCG component may have the risk of degradation by added to the aqueous alcohol-containing system directly.Independent packaging,ready-to-use,and nano-packages should be a more rational formulation for this type of raw materials.Keywords:tea polyphenol EGCG；instability；formulation application茶在日常养生保健方面扮演着重要角色。

2018年9月 第39卷第18期食品研究与&发Food Research And Development标准与检测D01：10.3969/j.issn.l005-6521.2018.18.030RP -HPLC 法测定猕猴桃根中儿茶素和表儿茶素含量(1.安顺职业技术学院应用医药系，贵州安顺561100:2.深圳市泰康制药有限公司，广东深圳518110)摘要：建立用反相高效液相色谱法（reversed-phase high performance liquid chromatography ，RP-HPLC )测定1猴桃根 中儿茶素和表儿茶素含量的方法，并分析不同采挖季节猕猴桃根中儿茶素和表儿茶素含量的变化。

采用AgilentTC - C 18(250 mmx 4.6mm ，5 !m )色谱柱，以乙腈-1L 乙酸水溶液为流动相，以1.0mL /min 的流速梯度洗脱，检测波长 280nm ，柱温30"，进样量10!L 。

结果显示，儿茶素和表儿茶素的浓度线性范围分别为LOpg /mL -D +j p g /mL^N 0.999 9)和 1.0 !g /mL #201.0 !g /mL (r "=0.999 9)，儿茶素平均加样回收率为 99.16 %，相对标准偏差（relative standard deviation ，RSD )为0.66%(n =9)，表儿茶素平均加样回收率为100.99%，RSD 为0.74%(n =9)。

本法适用于猕猴桃根中儿茶素和表儿茶素的精确定量，检测结果表明，初春采收的猕猴桃根中的儿茶素和表儿茶素含量明显高于秋冬。

关键词：含量;猕猴桃根;儿茶素;表儿茶素;反相高效液相色谱法Content Determination of Catechin and L-Epicatechin in Actinidia chinensis Planch by RP-HPLCW A N G M i n1，MA Y u-m e i 2, Z H O U X i a o -song 1(1. Applied Medical D e p a r t m e n t ，Vocational a n d Technical College of A n s h u n ，A n s h u n 561100，G u i z h o u ，C h i n a ; 2. Taikang Pharmaceutical C o .，L TD .，of S h e n z h e n City ，S h e nzhen 518110，G u a n g d o n g ，C h i n a )Abstract ： A reversed-phase high performance liquid chromatography m e t h o d w a s developed for simultaneousdetermination of catschin a n d L-epicatechin inActinidiachinensisPlanch .T h e catechin a n d L-epicatechin inActinidiachinensisPlanch of different harvesting season were analyzed . T h e separation w a s performed o n anAgilent T C-C 18 (250 m m x 4.6 mm)5 !m *c o l u m n with a gradient elution system with flow rate of 1.0 m L /m i n .T h e mobile phase consisted of acetonitrile a n d 1.0 % acetic acid solution .The detection U V wavelength w a s at280 n m.T h e c o l u m n temperature w a s 30 ".T h e injection vo l u m e w a s 10 !L.The results s h o w e d that the linearranges of catechin a n d L-epicatechin were 1.0 !g /m L-198.6 !g /m L (r 2=0.999 9*a n d 1.0 !g /m L -201.0 !g /m L(r 2=0.999 9*,respectively . T h e average recovery of the catechin w a s 99.16 % ,relative standard deviation wa s 0.66 %(n =9),a n d the average recovery of the L-epicatechin w a s 100.99 %, relative standard deviation w a s 0.74 %(n =9).The m e t h o d is suitable for the determination of catechin a n d L-epicatechin in Actinidia chinensisPlanch .T h e results indicated that the content of catechin a n d L-epicatechin in ActinidiachinensisPlanchcollected in early spring were significantly higher than those in a u t u m n a n d winter .Key words ： content ; Actinidia chinensis Planch - catechin ; L-epicatechin ; reversed-phase high performanceliquid chromatography引文格式：王敏，马玉梅，周晓松.RP -HPLC 法测定猕猴桃根中儿茶素和表儿茶素含量[J ].食品研究与开发，2018,39(18): 168-172 WANG Min ， MA Yumei，ZHOU Xiaosong . Content Determination of Catechin and L-Epicatechin in Actinidia chinensis Planch by RP -HPLC [J ]. Food Research and Development ，2018,39( 18) : 168-172王敏马玉梅2#周晓松1基金项目：安顺市科技计划项目(安市科[2016&3号）作者简介:王敏(1978—)，女(汉)，副教授，硕士，主要从事药食两用植物的研究和中医药学的研究。

紫外可见光谱法研究EGCG的稳定性作者：李邦玉吴媛吴虹燕刘臣来源：《江苏农业科学》2015年第07期摘要：考察绿茶中表没食子儿茶素没食子酸酯在多种体系中的稳定性。

通过柱色谱分离纯化绿茶中的表没食子儿茶素没食子酸酯（EGCG）产品；采用紫外可见分光光度法定性研究温度、时间、酸碱、紫外光、溶剂等对EGCG稳定性影响，以及EGCG分别与H2O2、DPPH·的反应。

研究结果，温度、时间、酸碱、紫外光等都不同程度影响EGCG稳定性，紫外可见光谱跟踪到了H2O2、DPPH·与EGCG的反应。

关键词：表没食子儿茶素没食子酸酯（EGCG）；稳定性；紫外可见分光光度法中图分类号：TS201.2 文献标志码： A 文章编号：1002-1302（2015）07-0294-03表没食子儿茶素没食子酸酯（EGCG）是绿茶所含儿茶素中含量最多的功能成分。

因为含有多个酚羟基，EGCG具有很强的抗氧化活性，医药工业上应用于抗菌、抗癌、抗衰老等治疗，能够改善癌细胞对化疗的敏感性并减轻对心脏的毒性[1-3]。

在食品工业中EGCG应用于抗氧化、保鲜、祛臭等产品，日化工业中作特殊功能添加剂等[4]。

但是在含茶叶的食品、药品和饮料的加工和储藏过程中，EGCG易受到温度、金属离子、酶和pH值等因素的影响，极易发生化学变化，从而改变了其原先的结构和生物活性[5-7]。

因此考察EGCG的稳定性很有必要。

本试验采用紫外可见分光光度法，定性研究不同环境条件下EGCG的稳定性。

1 材料与方法1.1 材料与仪器EGCG对照品（南京广润生物制品，98%），DPPH·（Sigma 公司生产）、无水乙醇、30%过氧化氢、盐酸、氢氧化钠、己烷、乙酸乙酯、四氯化碳、三氯甲烷、甲醇，以上药品皆为国产分析纯试剂。

绿茶为苏州东山碧螺春茶厂提供。

紫外可见分光光度计：型号UV-1801；十万分之一天平：CPA 225D；电热恒温水浴锅；三用紫外分析仪：WFH-203，上海精科实业有限公司；P230 型高效液相色谱仪：配有P230+紫外检测器；P230/P230p高压恒泵；EC2000 色谱工作站：大连依利特分析仪器有限公司生产；RUC-5200型超声波清洗机：上海睿祺公司生产。

影响荔枝果皮褐变底物(-)-表儿茶素稳定性的因素孙健;蒋跃明;彭宏祥;李月标;段学武;杨宝;尤艳丽;宋丽丽;程桂平【期刊名称】《果树学报》【年(卷),期】2010()1【摘要】分析光照、温度、pH值、气体成分、氧化还原物质和金属离子等因素对荔枝果皮酶促褐变底物(-)-表儿茶素稳定性的影响。

结果表明,(-)-表儿茶素在光照、高温和碱性条件下不稳定,容易变褐;O2处理提高了褐变底物与PPO的反应能力,而CO2处理明显起减缓作用;氧化剂H2O2加速了该酶促反应,但还原剂Vc及Na2S2O5阻止底物酶促褐变;K+、Na+、Ca2+和Zn2+对(-)-表儿茶素溶液的稳定性无显著影响,而在Fe3+、Fe2+、Cu2+、Pb2+存在下(-)-表儿茶素不稳定。

在生产上可通过合适的处理来减缓荔枝果实褐变发生,以延长货架寿命,进而提高果实商品价值。

【总页数】5页(P45-49)【关键词】荔枝;多酚氧化酶;褐变底物;(-)-表儿茶素;影响因素【作者】孙健;蒋跃明;彭宏祥;李月标;段学武;杨宝;尤艳丽;宋丽丽;程桂平【作者单位】广西农业科学院农产品加工研究所;中国科学院华南植物园;广西农业科学院园艺研究所【正文语种】中文【中图分类】S667.1【相关文献】1.龙眼果实果皮褐变与主要褐变底物及酶活性的关系 [J], 张娥珍;李志春;孙健;游向荣;李昌宝;李丽2.荔枝果皮褐变机理和防褐研究的发展方向 [J], 华进3.贮藏条件对采后龙眼果皮褐变底物性质的影响 [J], 孙健;张娥珍;李昌宝;王振兴;李志春;游向荣;黄冒康;廖芬4.人为调节荔枝果皮有机自由基及其与果皮变褐的可能关系 [J], 林植芳;林桂珠5.荔枝果皮褐变因素以及控制褐变途径的研究进展 [J], 任俊;曹飞;李强因版权原因，仅展示原文概要，查看原文内容请购买。

2018年第09期织保障，这也是“中茶拍”成立多年未能成效的根本原因。

5工业化、标准化与产业整合开拓国内外消费新市场中国是茶叶生产大国，位居全球第一，但在茶叶消费上，人均消费数量并不高，2011年人均消费量世界排名19位；近年来随着居民收入水平的提高和健康消费观念深入人心，我国茶叶消费数量也有较大的增长，据统计，2016年城乡居民年消费茶叶1.3公斤，茶叶消费群体已达4.78亿人。

5.1大众化明星产品的研发与创新改造近几年，以绿茶为主的国内市场，随着新生代人口更迭，茶业消费结构也发生了一些变化，茶按工艺分发酵和不发酵，不发酵的茶叶主要是绿茶，采取茶树新芽，杀青、揉捻、干燥等工艺，因未经发酵，保留了茶叶原汁，清香淡涩后有余甘，口感清淡较单一；发酵茶根据发酵程度不同，又有白、黄、青、红、黑五种，其中红茶和黑茶为全发酵茶，茶叶发酵后，香气馥郁，口感醇厚富层次感，并耐储存，由于发酵茶根据工艺、发酵度、储存时间不同，且采摘生长更长的芽叶，口感可更丰富，更适合大众消费，在采摘、制作、储存方面也更适合工业化生产，因此，欧美国家消费主流一直是红茶，茶叶出口大国除了中国之外均以红茶为主。

浙江作为传统绿茶大省，茶叶品类较为单一，在国内外绿茶需求趋于下降的形势下，在茶产业上不宜固守传统，应将技术创新与市场需求结合，开发、提炼符合大众口味的发酵茶优质产品，举全省之力，地方政府政策支持与茶叶电商结合，以明星产品快速打开市场，再体系化逐步占领细分市场。

目前如西湖工夫红茶，已经将现代技术与传统手工揉捻结合，在历史茶“九曲红梅”原有工艺基础上加以改进，保留了九曲红梅的梅香与优美外形，又规避了九曲红梅的些微酸涩，但在后期推广上尚待发力。

5.2茶叶生产的工业化与自动化改造在我国，喝茶养生健康的观念深入人心，但现代人紧张快速生活节奏很难适应传统的泡茶方式，众多工薪阶层因“没时间喝茶”“泡茶太麻烦”未能进入茶叶消费市场，如何利用现代技术开发工业化、标准化的新型茶产品是传统茶叶走向现代生活的关键。