陈勤操^1,2, 戴伟东^,1, 蔺志远^1,2, 解东超^1,2, 吕美玲³, 林智^,11 中国农业科学院茶叶研究所/农业部茶树生物学与资源利用重点实验室,杭州 310008
2 中国农业科学院研究生院,北京 100081
3 安捷伦科技（中国）有限公司,北京 100102

Effects of Shading on Main Quality Components in Tea (Camellia Sinensis (L) O. Kuntze) Leaves Based on Metabolomics Analysis

CHEN QinCao^1,2, DAI WeiDong^,1, LIN ZhiYuan^1,2, XIE DongChao^1,2, Lü MeiLing³, LIN Zhi^,1 1 Tea Research Institute, Chinese Academy of Agricultural Sciences/Key Laboratory of Tea Biology and Resource Utilization of Ministry of Agriculture, Hangzhou 310008
2 Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081
3 Agilent Technologies (China) Co., Ltd., Beijing 100102

通讯作者: 林智，E-mail：linzhi@caas.cn 戴伟东，E-mail：daiweidong@tricaas.com

责任编辑: 赵伶俐
收稿日期:2018-11-12接受日期:2019-01-10网络出版日期:2019-03-16

基金资助:

国家现代农业产业技术体系建设专项资金.CARS-19 国家自然科学基金青年基金.31500561

Received:2018-11-12Accepted:2019-01-10Online:2019-03-16
作者简介 About authors
陈勤操,E-mail： cqc459145372@tricaas.com。








摘要
【目的】 茶叶生产上常采用遮阴处理来提高其品质,然而,黑暗遮阴对茶叶品质的影响尚未清楚。本文重点研究黑暗遮阴对茶叶中主要品质成分的影响,以期更加详细了解遮阴与茶叶品质的关系。【方法】利用遮阳网对茶树进行中度（65.0%）、黑暗（99.7%）两个遮阴处理,不遮阴作为对照;采用紫外分光光度法检测总多酚、总氨基酸、总黄酮的含量,同时采用超高效液相色谱-四级杆-飞行时间质谱（UHPLC-Q-TOF/MS）对茶叶中的主要品质成分进行详细调查。【结果】 与对照相比,中度遮阴显著降低了茶叶的总氨基酸、总黄酮含量（P<0.05）,轻微降低了总多酚含量,增加了酚氨比;黑暗遮阴显著降低了总氨基酸和总黄酮含量,显著增加了总多酚含量和酚氨比（P<0.05）。主成分分析（PCA）表明,两个遮阴处理明显改变了茶树叶片的代谢组。进一步鉴定得到了87个化合物,包括2个生物碱、18个氨基酸、12个儿茶素类、8个儿茶素二聚体类、19个黄酮（醇）糖苷、5个香气糖苷、6个核苷（酸）、9个酚酸、8个其他化合物;与对照相比,82个化合物在遮阴处理后出现显著差异（P<0.05）。遮阴后,生物碱含量显著增加;氨基酸呈现多样性变化,半数以上氨基酸含量显著下降;部分儿茶素类及二聚儿茶素类物质的含量在中度遮阴后显著降低,然而大部分儿茶素类和儿茶二聚体素类物质的含量却在黑暗遮阴后显著上升;绝大部分黄酮（醇）糖苷的含量在遮阴后出现显著下降,且遮阴程度越高,下降越多;大部分香气糖苷含量在遮阴后显著上升;大部分核苷（酸）含量在遮阴后显著降低;多数酚酸的含量在遮阴后显著上升。【结论】黑暗遮阴后,生物碱、儿茶素类及儿茶素二聚体类等物质含量显著上升,氨基酸含量显著下降,酚氨比显著上升,预示黑暗遮阴处理可能不利于提高茶叶的品质。
关键词： 茶叶;遮阴;代谢组学;液质联用;次生代谢

Abstract
【Objective】Shading treatment is widely used to improve the quality of teas in tea yielding. However, the effects of dark shading on the quality of teas remain unclear. This study focused on the effects of dark shading on the main quality components in teas to understand the relationship between shading and tea quality in detail.【Method】Moderate (65.0%) and dark (99.7%) shading treatments were applied to tea plants by using black shading net, with non-shading as control. Ultraviolet spectrophotometry was employed to determine the contents of total polyphenols, total amino acids and total flavonoids, and ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) was employed to investigate the quality components in tea leaves.【Result】Compared with the control group, moderate shading treatment significantly reduced the contents of total amino acids and total flavonoids (P<0.05), and slightly reduced the content of total polyphenols, and therefore increased the ratio of polyphenols to amino acids. Dark shading treatment significantly reduced the contents of total amino acids and total flavonoids, while significantly increased the contents of total polyphenols and the ratio of phenol to ammonia (P<0.05). Principal component analysis showed that the two shading treatments significantly changed the metabolite pattern in tea leaves. A total of 87 compounds were identified, including 2 alkaloids, 18 amino acids, 12 catechins, 8 dimeric catechins, 19 flavone glycosides and flavonol glycosides, 5 glycosidically bound volatiles (GBVs), 6 nucleosides and nucleotides, 9 phenolic acids, and 8 other compounds. The contents of 82 compounds in two shading groups showed significant differences comparing with the control (P<0.05). After shading, the contents of alkaloids significantly increased; amino acids showed various change trends, with the contents of more than half of amino acids significantly decreased. The contents of several catechins and dimeric catechins significantly decreased in moderate shading group, while the contents of most catechins and their dimers significantly increased in dark shading group. The content of most flavone glycosides and flavonol glycosides showed decreased trend along with the increase of shading degree. The contents of most GBVs significantly increased. The contents of most of nucleosides and nucleotides significantly decreased; the content of most phenolic acids significantly increased.【Conclusion】After dark shading treatment, the contents of alkaloids, catechins and dimeric catechins significantly increased, while the contents of amino acids significantly decreased, and therefore the ratio of phenol to ammonia significantly increased, which indicated that dark shading might not contribute to improve the tea quality.
Keywords：tea;shading;metabolomics;LC-MS;secondary metabolism


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本文引用格式
陈勤操, 戴伟东, 蔺志远, 解东超, 吕美玲, 林智. 代谢组学解析遮阴对茶叶主要品质成分的影响[J]. 中国农业科学, 2019, 52(6): 1066-1077 doi:10.3864/j.issn.0578-1752.2019.06.010
CHEN QinCao, DAI WeiDong, LIN ZhiYuan, XIE DongChao, Lü MeiLing, LIN Zhi. Effects of Shading on Main Quality Components in Tea (Camellia Sinensis (L) O. Kuntze) Leaves Based on Metabolomics Analysis[J]. Scientia Acricultura Sinica, 2019, 52(6): 1066-1077 doi:10.3864/j.issn.0578-1752.2019.06.010

0 引言

【研究意义】茶因其迷人的风味及出色的保健功效而日益受到人们喜爱。滋味作为影响茶叶感官品质的一个重要因素,很大程度上决定了消费者对茶叶的选择。茶叶的滋味主要由茶多酚、咖啡碱、氨基酸、黄酮（醇）及其糖苷、可溶性糖等呈味成分决定^[1],而这些呈味成分的合成与积累又显著受茶园环境条件和管理措施的影响。高温和强光照被认为是造成茶叶苦涩味较重的重要因子^[2,3],因此,生产上常利用遮阴处理来改善茶园环境,提高茶叶品质。详细研究遮阴与茶叶代谢和品质成分的关系,可以更好地在生产实践中利用遮阴来改善茶叶品质。【前人研究进展】目前已有诸多遮阴改变茶园环境、茶叶代谢与品质成分的报道。研究表明,遮阴可以降低树冠面温度、光强,提高空气相对湿度^[4];降低地面和土壤温度,提高土壤水分含量^[5];显著降低树冠层的日极端最高温度、温度日较差和相对湿度日较差^[3]。遮阴后的茶叶,普遍出现总多酚含量降低,氨基酸含量升高,酚氨比下降^[2-3,6];儿茶素品质指数增加^[2,4];咖啡碱含量升高^[7,8,9];黄酮（醇）及其糖苷含量下降^[10,11];叶绿素含量增加^[7,12];粗纤维含量降低^[3,13];可溶性糖含量增加^[13];氮磷钾等养分含量增加^[4]。此外,遮阴对茶叶的香气成分也有明显的影响^[14,15,16]。目前,代谢组学已广泛应用于植物生理代谢、食品加工等领域。本课题组前期已建立了良好的茶叶代谢组学研究平台,并已广泛应用于茶叶滋味成分鉴定^[17]、茶叶生理代谢^[18]、茶叶加工^[19,20]等方面的研究中。【本研究切入点】目前的研究主要聚焦在30%—95%的遮阴水平对茶叶代谢与品质成分的影响,对于黑暗遮阴对茶叶代谢与品质成分的影响则尚无详细的研究报道。此外,受检测技术的限制,以上研究主要集中在常规成分（如儿茶素类、咖啡因、氨基酸、没食子酸等）上,导致许多对滋味有重要作用的化合物被遗漏,如儿茶素聚合物、核苷（酸）等^[17]。代谢组学方法以生物体内代谢组为研究对象,具有高效、全面及准确的特点。【拟解决的关键问题】本研究对茶树进行中度遮阴（65.0%）和黑暗遮阴（99.7%）处理,同时采用UHPLC-Q-TOF/MS对遮阴后茶叶中主要品质成分进行分析,以期更加详细地了解遮阴与茶叶品质的关系。

1 材料与方法

1.1 仪器与试剂

代谢组学分析：超高效液相色谱（Infinity 1290,Agilent Tech,美国）串联四级杆飞行时间质谱（Q-TOF 6540,Agilent Tech,美国）;儿茶素、没食子酸与咖啡碱检测：超高效液相色谱系统（Acquity H-Class,Waters,美国）;紫外分光光度计为UV-3600（Shimadzu,日本）,光量子仪为LI-190SA（Lincoln,美国）。

LC-MS级甲醇购于美国Merck公司;福林酚购于麦克林公司;没食子酸一水结合物购自阿拉丁公司;分析纯茚三酮购于Kermel公司;AlCl₃购自上海美兴化工股份有限公司;芦丁购自百灵威公司;儿茶素与咖啡碱标准品购自Sigma-Aldrich公司;甲酸（>99.0%）购于日本TIC公司;试验用水为Milli-Q超纯水。

1.2 样品处理

遮阴处理：试验茶园（北纬30°10′52″,东经120°5′26″）,品种为‘龙井43’,遮阴时期为2018年5月19—28日,共10天,主要为阴雨、多云天气。遮阴处理如图1-A所示,采用黑色遮阳网,设遮光率为65.0%（中度遮阴组,M组）和99.7%（黑暗遮阴组,D组）两组处理,不遮阴作为对照（CK组）。遮阴结束后,采摘一芽二叶,放入液氮中冷冻,然后-50℃冻干36 h,磨碎后放入-20℃冰箱中保存备用。

图1

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图1茶叶遮阴处理(A)及其外观表型变化(B—D)

Fig. 1Shading treatment (A) and appearance changes of tea leaves (B-D)



茶汤提取：考虑到主要是考察遮阴对茶叶品质成分（即茶叶中可用水冲泡出的成分为主）的影响,同时为防止多酚类物质在高温提取过程中被大量氧化,所以茶汤制备参照YANG等^[17]方法并进行稍许改动：准确称取0.1 g茶样放入EP管中,加入15 mL超纯水,放入100℃水中浸提10 min,8 000 r/min离心10 min,取上清液用于后续分析。进超高效液相色谱系统分析前,上清液用0.22 μm滤膜过滤。

1.3 检测方法

1.3.1 茶多酚、氨基酸、总黄酮测定 总多酚含量测定参照国标《GB/T 8313—2013》进行：先将上述茶汤稀释20倍,然后于10 mL刻度试管内加入1.0 mL稀释后的茶汤和5.0 mL 10%的福林酚溶液,摇匀后反应5 min,然后加入4.0 mL 7.5%的NaCO₃溶液,加水定容至10 mL,摇匀后放置60 min。最后用10 mm比色皿在765 nm波长下测定吸光度。

总氨基酸含量测定参照国标《GB/T 8314—2013》进行：吸取1 mL茶汤注入25 mL比色管中,加入0.5 mL pH 8.0磷酸盐缓冲液和0.5 mL 2%的茚三酮溶液,然后在沸水中加热15 min,待冷却到室温后定容至25 mL,放置10 min后用5 mm比色皿于570 nm波长下检测吸光度。

总黄酮含量测定采用三氯化铝法：吸取1 mL茶汤注入25 mL比色管中,加入1 mL 10% AlCl₃溶液,4 mL pH 5.5的乙酸钠溶液,定容至25 mL,反应30 min,然后于415 nm波长下用10 mm比色皿测定吸光度。

1.3.2 儿茶素类、没食子酸、咖啡碱测定 参照YANG等^[17]的方法进行：色谱柱为BEH C18 column（100 mm×2.1 mm,1.7 μm,Waters,Manchester,UK）,柱温为35℃。流动相：A相为0.1%的甲酸溶液,B相为纯甲醇。洗脱程序为：0 min,3% B相;3 min,8% B相;7.5 min,20% B相;11 min,20% B相;13 min,60% B相;14.5 min,60% B相;15 min,3% B相;19 min,3% B相。

流速为0.35 mL?min^-1,进样量为5 μL。

1.3.3 代谢组学分析 采用UHPLC-Q-TOF/MS进行测定,色谱柱为Zorbax Eclipse Plus C18柱（150 mm×3.0 mm,1.8 μm,安捷伦公司,美国）。主要参数如下：色谱条件流动相A相为0.1%甲酸-水,B相为甲醇;进样量为3 μL;流速为0.4 mL?min^-1;柱温为40℃;流动相线性梯度洗脱为：0 min,10% B相;4 min,15% B相;7 min,25% B相;9 min,32% B相;16 min,40% B相;22 min,55% B相;28 min,95% B相;30 min,95% B相;柱后平衡时间为5 min。质谱采用电喷雾离子化（ESI）模式,扫描方式为正离子模式;毛细管电压为3 500 V;干燥气温度和流速分别为300℃和8 L/min;雾化气压强为35 psi;鞘气温度和流速分别为300℃和11 L?min^-1;质谱扫描范围,质荷比（m/z）为100—1 000。

1.4 数据处理

UHPLC-Q-TOF/MS分析获得的原始图谱分别采用DA Reprocessor software（Agilent Tech.,Santa Clara,CA）和Mass Profiler Professional 13.0软件（Agilent Tech.,Santa Clara,美国）进行峰匹配和积分。主成分分析（PCA）使用Simca-P 11.5软件。Tukey s-b（K）检验使用PASWstat software（版本18.0,美国）软件。

2 结果

2.1 遮阴对茶叶外观表型及含水率的影响

遮阴后（图1-A）,茶叶的外观表型变化如图1-B—D所示。与对照相比,黑暗遮阴处理的茶叶颜色明显更深更绿,这是因为适当遮阴可以增加茶叶的叶绿素含量^[7,12],以让茶叶在弱光照条件下捕获更多的光子,增强光合作用。然而,与中度遮阴处理的茶叶颜色变深变绿不同,黑暗遮阴处理的茶叶颜色明显变浅,这与CHEN等^[21]的结果相一致。由此可知,适当遮阴可以增加茶叶叶绿素含量,但黑暗遮阴反而会导致叶绿素被分解。另外,遮阴后,茶叶的含水率出现显著增加（表1）,这应该为遮阴后茶园的温度降低,空气湿度增加,茶叶嫩度增加所致。

Table 1
表1
表1遮阴对茶叶中主要生化成分及含水率的影响
Table 1The effects of shading on main biochemical compositions and moisture content of tea leaves

	对照CK	中度遮阴（M）Moderate shading	黑暗遮阴（D）Dark shading
总多酚 Total polyphenols (%)	9.99±0.4a	9.77±0.71a	12.75±0.57b
总氨基酸 Total amino acids (%)	4.63±0.14a	4.20±0.05b	4.33±0.06b
总黄酮 Total flavonoids (%)	3.28±0.17a	2.17±0.06b	1.46±0.14c
酚氨比Ratio of polyphenols to amino acids	2.16±0.05a	2.33±0.17a	2.95±0.17b
没食子酸Gallic acid (mg?g-1)	3.78±0.22a	4.51±0.29b	4.63±0.11b
表没食子儿茶素 EGC (mg?g-1)	14.93±0.37a	13.49±0.08b	10.56±0.34c
儿茶素 C (mg?g-1)	4.19±0.13a	3.99±0.03b	8.24±0.08c
表没食子儿茶素没食子酸酯EGCG (mg?g-1)	29.12±3.86a	28.35±2.7a	53.38±6.08b
表儿茶素EC (mg?g-1)	6.42±0.05a	5.58±0.07b	5.64±0.12b
表儿茶素没食子酸酯ECG (mg?g-1)	2.19±0.63a	1.79±0.37a	5.69±1.12b
咖啡碱Caffeine (mg?g-1)	26.93±0.87a	28.88±0.08b	39.4±0.19c
含水率Moisture content (%)	78.67±0.13a	80.15±0.28b	80.85±0.25c

The data are mean value±sd (n=3); different letters mean there is significant difference between two groups (P<0.05, Tukey s-b (K) test)
数据代表平均值±标准差（n=3）;不同字母表示差异显著（P<0.05,Tukey s-b(K) test）

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2.2 遮阴对茶叶多酚、氨基酸、黄酮总含量的影响

一般而言,遮阴后茶叶的多酚含量会降低,氨基酸含量会上升,从而促使酚氨比下降,提升茶叶的品质^[2-4,9,11]。然而,本研究的结果却不尽一样。如表1所示,总多酚含量在中度遮阴处理后没有显著变化,然而在黑暗遮阴处理后则出现显著增加。与对照相比,总氨基酸含量在中度遮阴和高度遮阴后均显著下降,其中黑暗遮阴处理的含量稍高于中度遮阴处理;不管是中度遮阴还是黑暗遮阴处理,总黄酮含量与对照相比均显著下降;酚氨比作为评价茶叶品质的重要指标之一,其在黑暗遮阴处理后显著上升,预示高度遮阴可能不利于提高茶叶的品质。

2.3 遮阴对茶叶代谢物的影响

为了更加详细地了解遮阴对茶叶代谢与品质成分的影响,对3组处理茶叶的代谢物进行了UHPLC-Q- TOF/MS分析。经过峰提取和匹配后,共得到3 236个化合物特征离子,其中2 044个在QC样品中RSD<30%的特征离子用于下一步分析。PCA分析显示3组样品之间被明显的区分开来,表明遮阴后茶叶的代谢物发生了明显的变化（图2）。

图2

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图23组样品的主成分分析得分图（R²X=0.757, Q²=0.687）

Fig. 2PCA score plot of 3 sets of samples (R²X=0.757, Q²=0.687)



结合笔者课题组前期在代谢组学分析和化合物鉴定方面的工作^{[17,18,19,20]},本次总鉴定出87个化合物,包括2个生物碱、18个氨基酸、12个儿茶素类物质、8个儿茶素二聚体类物质、19个黄酮（醇）糖苷、5个香气糖苷、6个核苷（酸）、9个酚酸、8个其他化合物,其中82个化合物在遮阴后出现显著差异（P<0.05）（表2）。此外,由于EGCG、咖啡碱在本次LC-MS分析时因含量过高而发生信号过载,以及没食子酸在这次正离子模式下难以被检测,本研究进一步对儿茶素类物质、咖啡碱、没食子酸进行了绝对定量,结果如表1所示。

Table 2
表2
表2茶叶中鉴定到的化合物及其相对含量（峰面积,counts）
Table 2Identified compounds and their relative contents in tea leaves (peak area, counts)

编号 NO.	化合物 Compound	对照 CK	中度遮阴（M） Moderate shading	黑暗遮阴（D） Dark shading
	生物碱 Alkaloids
1	可可碱 Theobromine*	21601922±564017a	23610245±1235150b	31765707±910344c
2	咖啡碱 Caffeine*	81927164±669239a	84157969±833682b	92249135±626755c
	氨基酸 Amino acids
3	赖氨酸 Lysine*	415102±33333a	304636±13196b	287939±21857b
4	组氨酸 Histidine*	106521±2331a	114046±1501b	115505±4088b
5	精氨酸 Arginine*	1080777±17439a	411284±30083b	310232±11544c
6	谷氨酰胺 Glutamine*	11504894±248750a	9510890±228064b	8544787±165748c
7	天冬酰胺 Asparagine*	269010±4047a	330815±12527b	386838±12683c
8	天冬氨酸 Aspartic acid*	2471046±65470a	3061948±147858b	3511442±163262c
9	苏氨酸 Threonine*	508856±15011a	541787±29692a	658518±34367b
10	谷氨酸 Glutamic acid*	12341565±309155a	13270317±611986b	13439150±632674b
11	脯氨酸 Proline*	2645963±379642a	2440953±213986ab	2108482±62378b
12	哌啶酸 Pipecolic acid	3248531±142042a	2935336±171353b	1764292±38796c
13	缬氨酸 Valine*	2339386±101496a	2238141±130139a	1919611±60701b
14	焦谷氨酸 Pyroglutamic acid	1062221±57097a	811492±72660b	771975±48705b
15	茶氨酸 Theanine*	68360338±585955a	66479617±411838b	68385572±731671a
16	络氨酸 Tyrosine*	1786868±93078a	1549169±153847b	1106611±81550c
17	亮氨酸 Leucine*	1443868±81819a	1408718±79026a	1573454±70977b
18	异亮氨酸 Isoleucine*	3262703±121220a	3024099±132531ab	2798292±251013b
19	苯丙氨酸 Phenylalanine*	4853644±269826a	4666955±267358a	2267113±388453b
20	色氨酸 Tryptophan*	5472135±160789a	5984855±345522b	11062018±429397c
	儿茶素类物质 Catechins
21	没食子儿茶素 GC*	10739724±248150a	7266229±1746807b	6619543±177288b
22	表没食子儿茶素 EGC*	39500597±1284644a	37443505±1664176b	34546359±1417812c
23	儿茶素 C*	8415688±210799a	7060237±384357b	8382320±246267a
24	表没食子儿茶素没食子酸酯 EGCG*	29958037±706088a	30326483±808249a	34639578±1220789b
25	表没食子儿茶素-3,5-二没食子酸酯 EGC 3,5-digallate	273480±42970a	283272±48547a	1053013±139393b
26	没食子儿茶素没食子酸酯 GCG	972901±112326a	1030902±94020a	1425857±71356b
27	表儿茶素 EC*	19771924±1020879a	18019916±667293b	19623903±522374a
28	表没食子儿茶素-3- (3-O-甲基)没食子酸酯 EGCG3''Me*	120447±4955a	140818±4851b	199237±10846c
29	表儿茶素没食子酸酯 ECG*	18779724±793807a	17384430±501165a	24909140±1543699b
30	表阿夫儿茶精 Epiafzelechin*	734021±40623a	779426±44759a	632343±30136b
31	表没食子儿茶素-3-O (4-O-甲基)没食子酸酯 EGCG4''Me	172678±3694a	186962±6304b	117215±7432c
32	表阿夫儿茶精-3-没食子酸酯 Epiafzelechin 3-gallate	361261±14773a	417017±48019a	872386±74888b
	儿茶素二聚体类物质 Dimeric catechins
33	原花青素B3 Procyanidin B3	1456926±144947a	1318465±164090a	1777328±154439b
34	原花青素B5 Procyanidin B5	676231±36224a	607400±27511a	865820±81000b
35	原花青素B1 Procyanidin B1	12734590±529138a	11845963±653962a	14682473±1649024b
36	原花青素B2 Procyanidin B2*	3648511±97335a	3372480±218490b	4396056±133796c
37	原花青素C1 Procyanidin C1	442411±27557a	407848±31717a	576841±29677b
38	聚酯型儿茶素B Theasinensin B	2686283±501963a	2475063±384834a	2088193±324752a
39	聚酯型儿茶素A Theasinensin A	1078878±239782a	1060887±272465a	1853021±224828b
40	表儿茶素-4α-8-表儿茶素没食子酸酯 EC-(4alpha->8)-ECG	3126006±328977a	3187820±548213a	3992103±491254b
	黄酮（醇）糖苷 Flavone glycosides and flavonol glycosides
41	芹菜素 6,8-C-二葡萄糖苷 Apigenin 6,8-C-diglucoside*	1613798±56930a	1630940±131948a	777980±59120b
42	芹菜素 6-C-葡糖-8-C-阿拉伯糖苷 Apigenin 6-C-glucosyl-8-C-arabinoside	1660183±106041a	1503259±97807b	810637±78142c
43	芹菜素 6-C-阿拉伯糖-8-C-葡萄糖苷 Apigenin 6-C-arabinoside-8-C-glucoside	1496711±129603a	1518132±151862a	788376±65889b
44	槲皮素三葡萄糖苷1 Quercetin triglucoside1	1612840±57495a	1363996±78280b	580505±25067c
45	槲皮素二葡萄糖苷 Quercetin diglucoside	67381±3565a	55609±3754b	107029±9284c
46	槲皮素三葡萄糖苷2 Quercetin triglucoside2	1084804±46160a	1141132±51278a	638989±30546b
47	杨梅酮 3-葡萄糖苷 Myricetin 3-glucoside	18182085±616935a	12072654±310669b	3589507±251769c
48	牡荆素 Vitexin (Apigenin 8-C-glucoside)*	765594±51330a	782206±55471a	271503±22369b
49	异牡荆素 Isovitexin (Apigenin 6-C-glucoside)*	1181313±24234a	979750±147049b	233632±18079c
50	槲皮素 3-半乳糖苷Quercetin 3-O-galactoside*	1099792±11518a	506247±12394b	143146±3610c
51	槲皮素 3-葡萄糖酰芸香糖苷 Quercetin 3-O-glucosylrutinoside	14979656±3750206a	8112166±2330341b	3161317±67104c
52	芦丁 Rutin (Quercetin 3-rutinoside)*	2164395±550873a	1090625±197167b	198801±14635c
53	异槲皮苷 Isoquercitrin (Quercetin 3-glucoside)*	17026726±301235a	7759338±124311b	1851133±23502c
54	山奈酚 3-半乳糖酰芸香糖苷 Kaempferol 3-galactosylrutinoside	7541465±350174a	7835962±171382a	4825756±137690b
55	山奈酚 3-葡糖酰芸香糖苷 Kaempferol 3-glucosylrutinoside	7016794±174776a	5664808±182475b	1898898±51123c
56	山奈酚 3-半乳糖苷 Kaempferol 3-O-galactoside*	23176288±330927a	20712077±535708b	7805419±171856c
57	山奈酚 3-芸香糖苷 Kaempferol 3-O-rutinoside*	2816105±37743a	1598996±83538b	483109±13085c
58	山奈酚 3-葡萄糖苷 Kaempferol 3-O-glucoside*	5081721±116589a	3529878±58811b	936048±18986c
59	山奈酚 3-阿拉伯糖苷 Kaempferol 3-O-arabinoside*	1525796±41047a	1362198±34642b	469329±16088c
	香气糖苷 Glycosidically bound volatiles
60	苯甲基樱草糖苷 Benzyl primeveroside	355943±33789a	418331±21363b	457889±16047c
61	苯乙基樱草糖苷 Phenylethyl primeveroside	303228±36908a	670857±67252b	2026015±184020c
62	顺-3-己烯基樱草糖苷 cis-3-Hexenyl b-primeveroside	115287±8765a	129325±6209b	219121±11667c
63	芳樟醇氧化物樱草糖苷 Linalool oxide primeveroside	2152086±267169a	2604541±163205b	972995±35694c
64	芳樟基樱草糖苷 Linalyl primeveroside	142195±5721a	232484±9465b	256285±15269c
	核苷（酸） Nucleosides and nucleotides
65	腺嘌呤核苷二磷酸 ADP	289424±11725a	241159±17959b	233107±15448b
66	腺嘌呤核苷酸 AMP	2320655±155694a	2183139±147428a	1661637±77320b
67	(S)-5'-脱氧-5' -（甲基亚磺酰基）腺苷 (S)-5'-Deoxy-5'-(methylsulfinyl)adenosine	3129086±882862a	2919162±1223813a	1980296±688545a
68	腺苷 Adenosine*	11518652±412666a	10370580±354834b	8366365±330059c
69	鸟苷 Guanosine*	2390845±190284a	2035461±70401b	1463535±89231c
70	5'-甲硫腺苷 5'-Methylthioadenosine	3089992±571947a	3567162±597102a	3150748±579503a
	酚酸 Phenolic acids
71	茶没食子素 Theogallin*	25899247±573438a	31559584±533807b	50027889±838726c
72	木麻黄素 Strictinin*	1774131±71441a	1958248±182106a	3045129±305136b
73	4-香豆酰奎宁酸 4-Coumaroylquinic acid	1490324±342313a	1610962±50961a	1667523±402289a
74	绿原酸 Chlorogenic acid*	951977±26554a	1163181±36488b	1210987±22284c
75	二没食子葡萄糖苷 Digalloylglucose	54447±5062a	65531±4727b	136856±7065c
76	3-O-p-香豆酰奎宁 3-O-p-Coumaroylquinic acid	5148816±226499a	5686498±191820a	4357076±794521b
77	鲁米诺酸 Lucuminic acid	393779±42713a	428757±27110a	180194±17712b
78	咖啡酰莽草酸 Caffeoylshikimic acid	124053±3716a	71765±2542b	0±0c
79	2''-O-反式香豆酰紫云英苷2''-O-trans-p-Coumaroylastragalin	315833±14488a	427880±10136ab	481791±180927b
	其他 Others
80	胆碱磷酸 Phosphocholine	996444±32181a	1102106±31318b	2057178±51259c
81	甘油磷酸胆碱 Glycerophosphocholine	3593165±298005a	1005165±240471b	689645±68058c
82	N-乳酰乙醇胺 N-Lactoyl ethanolamine	1479644±40550a	1231846±44941b	956384±48087c
83	茶氨酸葡萄糖苷 Theanine glucoside	1570632±195849a	1325741±40281b	1732060±143831a
84	1-乙基-5-羟基-2-吡咯烷酮1-Ethyl-5-hydroxy-2-pyrrolidinone*	2415457±132124a	2761946±73300b	2371416±94210a
85	泛酸 Pantothenic acid	307404±16208a	262262±7379b	236161±10922c
86	二氢猕猴桃内脂 Dihydroactinidiolide	199672±27481a	226319±14022b	135856±6966c
87	N, N'-二环己基脲 N,N'-Dicyclohexylurea	3100145±55344a	3096187±43286a	3041915±59904a

* means the compound was verified by standard; the data are mean value±sd (n=3). Different letters mean there is significant difference between two groups (P<0.05, Tukey s-b (K) test)
*代表该物质采用标准品验证;数据代表平均值±标准差（n=3）;不同字母表示差异显著（P<0.05,Tukey s-b(K) test）

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2.3.1 遮阴对氨基酸（amino acids）的影响 氨基酸被认为是茶汤鲜爽味的重要贡献者,但有报道显示只有茶氨酸、谷氨酸、天冬氨酸、天冬酰胺才呈鲜味,其他氨基酸则呈苦味或甜味^[22]。如表2所示,所有鉴定到的氨基酸均表现为极显著差异,但是变化趋势不尽相同。其中组氨酸、天冬酰胺、天冬氨酸、苏氨酸、谷氨酸、色氨酸的含量随遮阴出现显著上升;赖氨酸、精氨酸、谷氨酰胺、脯氨酸、哌啶酸、缬氨酸、焦谷氨酸、络氨酸、异亮氨酸、苯丙氨酸的含量随遮阴出现显著下降;茶氨酸和亮氨酸的含量在中度遮阴处理后下降,在黑暗遮阴处理后上升。

2.3.2 遮阴对儿茶素类（catechins）及儿茶素二聚体类（dimeric catechins）物质的影响 儿茶素类物质被认为是茶叶中最重要的类黄酮物质,含量上以表儿茶素为主。其在一系列酶的作用下,可以聚合生成原花青素、聚酯型儿茶素等儿茶素二聚体类物质。如表1和表2所示,与对照相比,中度遮阴处理后,非酯型儿茶素（没食子儿茶素、表没食子儿茶素、儿茶素、表儿茶素）和甲基化儿茶素（表没食子儿茶素-3- (3-O-甲基)没食子酸酯、表没食子儿茶素-3- (4-O-甲基)没食子酸酯）的含量出现显著下降,其他儿茶素没有出现显著差异;黑暗遮阴处理后,大部分儿茶素类物质（表没食子儿茶素没食子酸酯、表没食子儿茶素-3,5-二没食子酸酯、没食子儿茶素没食子酸酯、表没食子儿茶素-3-(3-O-甲基)没食子酸酯、表儿茶素没食子酸酯、表阿夫儿茶精-3-没食子酸酯）含量都出现显著上升,没食子儿茶素、表没食子儿茶素、表阿夫儿茶精、表没食子儿茶素-3-(4-O-甲基)没食子酸酯的含量出现显著降低,儿茶素和表儿茶素的含量没有显著变化,但相对中度遮阴处理显著上升。对儿茶素二聚体类物质来说,中度遮阴处理后,只有原花青素B2出现显著降低,其他没有显著变化;黑暗遮阴处理后,除聚酯型儿茶素B外,所有儿茶素二聚体类物质都出现显著上升。大部分儿茶素类物质及其二聚体含量的上升,解释了为什么黑暗遮阴处理后茶叶多酚总量会上升。儿茶素类,尤其酯型儿茶素被认为是茶叶中最重要的苦涩味物质;此外,新近研究表明原花青素、聚酯型儿茶素类物质与白茶的苦涩味呈正相关^[17]。因此,儿茶素类、原花青素类、聚酯型儿茶素类物质含量的上升可能会增强黑暗遮阴处理组茶叶的苦涩味,导致茶叶品质下降。

2.3.3 遮阴对黄酮（醇）糖苷（flavone glycosides and flavonol glycosides）的影响 如表2所示,本次研究中主要检测到由芹菜素、槲皮素、山奈酚、杨梅酮生成的黄酮（醇）糖苷。中度遮阴处理后,大部分黄酮（醇）糖苷含量都出现了显著下降;黑暗遮阴处理后,几乎所有黄酮（醇）糖苷在中度遮阴处理组基础上,其含量出现进一步降低,但槲皮素二葡萄糖苷的含量显著上升,这与WANG等^[10]的研究结果一致。黄酮（醇）糖苷一般认为是绿茶的重要呈色物质,有研究显示黄酮（醇）糖苷具有涩味,是红茶、绿茶的主要涩味成分^[22,23],可以增强茶汤的苦涩口感^[24],其含量的下降或许可以在一定程度上降低茶汤的苦涩味。

2.3.4 遮阴对香气糖苷（glycosidically bound volatiles）的影响 茶叶中挥发性成分除以游离的形式存在外,某些醇类香气,如顺-3-己烯醇、苯甲/乙醇、芳樟醇等也可以和樱草糖、葡萄糖等结合生成香气糖苷,作为香气前体物质而存在于茶叶中^[25]。中度遮阴处理后,5个香气糖苷的含量都出现了显著上升;黑暗遮阴处理后,除芳樟醇氧化物樱草糖苷的含量显著降低外,其他4个香气糖苷的含量在中度遮阴处理的基础上进一步显著上升（表2）。近期研究表明,香气糖苷对红茶、白茶的香气形成具有重要贡献^[26,27]。因此,香气糖苷含量的上升,可能有利于在茶叶加工过程中,水解释放更多的香气,改善茶叶的香气品质。因此,遮阴处理改善茶叶的香气品质除了增加香气总量和丰富香气种类外^[14,15,16],还可能通过提高茶叶中香气前体物质含量来实现。

2.3.5 遮阴对酚酸（phenolic acids）的影响 有研究指出酚酸对茶叶的涩味和鲜味有重要影响,如KANEKO等^{[28, 29]}的研究表明茶没食子素本身呈涩味,但是在滋味重组试验中,茶没食子素能极显著的增强日本抹茶的鲜味。如表1和表2所示,中度遮阴处理后,没食子酸、茶没食子素、绿原酸、二没食子酰葡萄糖苷的含量显著上升,咖啡酰莽草酸的含量显著降低,其他没有显著变化;黑暗遮阴处理后,没食子酸、茶没食子素等大部分酚酸的含量显著上升,而咖啡酰莽草酸、鲁米诺酸、3-O-p-香豆酰奎宁酸的含量显著降低。酚酸与儿茶素类、黄酮（醇）糖苷等同属于类黄酮代谢途径,它们不同的变化趋势预示遮阴对类黄酮代谢途径的下游分支起着差异性调控。

2.3.6 遮阴对生物碱（alkaloids）和核苷（酸）（nucleosides and nucleotides）的影响 生物碱（咖啡碱、可可碱）是茶叶苦味的重要贡献者,其含量随着遮阴程度的增强而上升（表1和表2）。最近有报道认为核苷（酸）对茶叶滋味有一定的影响^[17],并具有诸多保健功效^[30],但遮阴显著降低了腺嘌呤核苷二磷酸、腺嘌呤核苷磷酸、腺苷、鸟苷在鲜叶中的含量（表2）,与YANG等^[14]的研究结果相一致。核苷（酸）类物质是能量供应、RNA合成的重要前体,其含量的降低,或许是因为遮阴后光合作用减弱,导致整体代谢减弱所致。

此外,胆碱磷酸、1-乙基-5-羟基-2-吡咯烷酮的含量在中度遮阴后出现显著上升,而甘油磷酸胆碱、N-乳酰乙醇胺、茶氨酸糖苷、泛酸的含量在遮阴后出现显著下降,二氢猕猴桃内酯的含量在中度遮阴处理后显著上升,而在黑暗遮阴处理后则显著下降（表2）。

3 讨论

3.1 叶绿体与游离氨基酸含量存在着紧密的联系

研究发现中度遮阴处理可以加深茶叶的颜色,让茶叶更绿,而黑暗遮阴处理则会导致茶叶绿色变浅,这与前人的研究结果一致^[7,21]。一般来说,遮阴后茶叶的氨基酸含量会上升,但本研究中,中度遮阴处理反而降低了总氨基酸含量,黑暗遮阴处理使总氨基酸含量有所回升。氨基酸含量的上升有氨基酸生物合成加强和蛋白质水解增加两条途径。CHEN等^[21]研究发现,遮阴（黑暗）处理后,游离氨基酸含量上升并非是由于氨基酸合成的增强,而是由于叶绿体蛋白的水解。在特异性茶树品种‘安吉白茶’叶片白化时期,叶绿素含量降低,氨基酸含量上升,返绿后则出现相反变化^[31];进一步研究显示,在白化时期,与光合磷酸化及叶绿体发育相关基因的表达发生显著下调,而返绿后相关基因的表达又显著上调^[32]。此外,‘黄金芽’茶树在遮阴后,叶片变绿,叶绿素含量上升,氨基酸含量降低,自然生长时则表现出相反的趋势^[33,34]。这些研究表明,叶绿体蛋白与游离氨基酸含量存在着此消彼长的关系。本研究中,中度遮阴处理后氨基酸含量的降低,很可能是因为其被利用合成了叶绿体蛋白,以结合更多的叶绿素,让茶叶在低光照条件下提高光合效率;而黑暗遮阴处理后,茶树叶片接收到的光强度剧烈降低,导致茶树生物体所需的叶绿素量随之下降,从而导致叶绿体中蛋白质降解,促使游离氨基酸含量相较于中度遮阴处理有所回升。

3.2 遮阴对茶叶碳氮代谢具有双向性

本研究中,遮阴并没有提高总氨基酸的含量,黑暗遮阴处理后总多酚含量反而出现了显著上升。一般来说,遮阴会降低总多酚的含量,提升总氨基酸的含量。然而,也有少量研究与此相反。有研究显示遮阴覆盖会导致春茶的总多酚、粗纤维等的含量上升,总氨基酸含量的下降,而夏秋茶则表现出相反的结果^[35]。在春茶采摘末期（4月26日至5月24日）,40%遮光率+2.5 m遮荫高度处理使茶叶总多酚含量和酚氨比上升,总氨基酸含量降低,导致茶汤浓厚、苦涩味加重^[36]。在春季进行遮阴处理,会增强碳代谢的强度,相对削弱氮代谢的强度^[37],这可能是因为春季温度不高、光照不强,遮阴导致光合作用强度不够所致。本次研究中,总多酚含量的显著上升,很大程度是由表没食子儿茶素没食子酸酯（EGCG）、表儿茶素没食子酸酯（ECG）含量的上升导致（表1）,LEE等^[7]和李明等^[38]也发现遮阴导致表没食子儿茶素没食子酸酯（EGCG）、表儿茶素没食子酸酯（ECG）含量的显著增加。这些结果说明,遮阴对茶叶的碳氮代谢调控具有双向性。光照与温度有利于茶叶多酚的积累,而不利于氨基酸的积累。在夏秋季节,适当的遮阴会逆转高温、强光的作用,从而促使碳代谢向氮代谢转变,降低酚氨比。本遮阴试验中,因为遮阴时段为春季末期,且主要为阴雨、多云天气,光照不强,温度也不是很高,所以遮阴后,特别是黑暗遮阴后,会导致光照严重不足,从而相对加强茶树的碳代谢,降低氮代谢,导致多酚含量显著升高,氨基酸含量显著降低。遮阴后,多酚含量上升,氨基酸含量下降的具体机制仍有待解析。

3.3 基于LC-MS的代谢组学方法具有强大的优势

在本研究中,采用基于LC-MS的代谢组学方法除了检测到儿茶素类、氨基酸、生物碱等常规成分外,还鉴定到了一些常规分析方法难以检测到的物质,如氨基酸中的哌啶酸、焦谷氨酸;核苷（酸）;儿茶素二聚体类;香气糖苷等物质。这些物质均对茶叶品质具有重要影响,如有报道显示焦谷氨酸对茶汤的鲜味具有重要作用^[11]。因此,采用代谢组学技术研究遮阴对茶叶代谢的影响,可以更加全面地了解茶树对光照调控的代谢应答和代谢产物的变化规律,以及遮阴对茶叶品质的影响。

4 结论

本文研究了遮阴对茶叶代谢及主要品质成分的影响,发现中度、黑暗遮阴降低了总氨基酸、黄酮含量,而黑暗遮阴增加了总多酚含量及酚氨比。此外,采用UHPLC-Q-TOF/MS详细研究了遮阴对茶叶代谢的作用,总计鉴定得到了87个化合物,主要为氨基酸、儿茶素类及其二聚物、黄酮（醇）糖苷、香气糖苷、酚酸等,其中82个化合物在遮阴后出现显著性变化。遮阴对茶树叶片的代谢调控是一个复杂的过程,对碳氮代谢具有双向性,适当的遮阴可以提高茶叶品质,但黑暗遮阴则可能不利于提高茶叶的品质。

参考文献 View Option 原文顺序
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被引期刊影响因子

[1] HARBOWY M E, BALENTINE D A, DAVIES A P, CAI Y . Tea chemistry
Critical Reviews in Plant Sciences, 1997,16(5):415-480.
DOI:10.1080/07352689709701956URL [本文引用: 1]

[2] 孙京京, 朱小元, 罗贤静丽, 邓骋, 宁井铭 . 不同遮荫处理对绿茶品质的影响
安徽农业大学学报, 2015,42(3):387-390.
DOI:10.13610/j.cnki.1672-352x.20150424.018URL [本文引用: 4]
苦涩味重是影响夏、秋绿茶品质 的重要因素。通过对不同季节的茶园进行不同程度的遮荫处理,对茶叶中与茶汤苦涩味相关的主要化学成分进行分析。结果表明,遮荫处理能使茶叶中氨基酸含量增 加;茶多酚含量、酚氨比比值降低,优化了氨基酸和儿茶素组分,同时叶绿素含量也增加,从而提高了绿茶的品质。遮荫处理对于夏茶的影响较大,秋茶次之,春茶 的影响较小,且双层黑色遮荫网的效果优于单层黑色遮荫网的效果。
SUN J J, ZHU X Y , LUO X J L, DENG C, NING J M . Effects of different degrees of shading on green tea quality
Journal of Anhui Agricultural University, 2015,42(3):387-390. (in Chinese)
DOI:10.13610/j.cnki.1672-352x.20150424.018URL [本文引用: 4]
苦涩味重是影响夏、秋绿茶品质 的重要因素。通过对不同季节的茶园进行不同程度的遮荫处理,对茶叶中与茶汤苦涩味相关的主要化学成分进行分析。结果表明,遮荫处理能使茶叶中氨基酸含量增 加;茶多酚含量、酚氨比比值降低,优化了氨基酸和儿茶素组分,同时叶绿素含量也增加,从而提高了绿茶的品质。遮荫处理对于夏茶的影响较大,秋茶次之,春茶 的影响较小,且双层黑色遮荫网的效果优于单层黑色遮荫网的效果。

[3] 张文锦, 梁月荣, 张方舟, 陈常颂, 张应根, 陈荣冰, 翁伯奇 . 覆盖遮荫对乌龙茶产量、品质的影响
茶叶科学, 2004,24(4):276-282.
DOI:10.3969/j.issn.1000-369X.2004.04.010URL [本文引用: 4]
夏暑季乌龙茶园覆盖遮荫的生态生理生化效应及其对茶树生长、产量和品质的影响结果表明:遮荫后,1)树冠层的白昼平均温度、日极端最高温度、温度日较差和相对湿度日较差显著下降,白昼平均相对湿度和日极端最低相对湿度显著增加。2)夏、暑梢1芽3叶含水率分别增加了4.57%~6.47%和2.24%~2.78%。3)夏、暑梢叶绿素总量及其a、b含量分别提高了41.70%~48.92%和52.38%~91.06%、38.96%~47.25%和 50.94%~72.52%、43.83%~54.58%和67.98%~155.81%;叶绿素a、b比值下降了0.1042~0.1868和1.10~3.54。4)叶片及其表
ZHANG W J, LIANG Y R, ZHANG F Z, CHEN C S, ZHANG Y G, CHEN R B, WENG B Q . Effects on the yield and quality of oolong tea by covering with shading net
Journal of Tea Science, 2004,24(4):276-282. (in Chinese)
DOI:10.3969/j.issn.1000-369X.2004.04.010URL [本文引用: 4]
夏暑季乌龙茶园覆盖遮荫的生态生理生化效应及其对茶树生长、产量和品质的影响结果表明:遮荫后,1)树冠层的白昼平均温度、日极端最高温度、温度日较差和相对湿度日较差显著下降,白昼平均相对湿度和日极端最低相对湿度显著增加。2)夏、暑梢1芽3叶含水率分别增加了4.57%~6.47%和2.24%~2.78%。3)夏、暑梢叶绿素总量及其a、b含量分别提高了41.70%~48.92%和52.38%~91.06%、38.96%~47.25%和 50.94%~72.52%、43.83%~54.58%和67.98%~155.81%;叶绿素a、b比值下降了0.1042~0.1868和1.10~3.54。4)叶片及其表

[4] 石元值, 肖强, 吕闰强, 韩国方 . 不同遮荫材料对茶树叶产量与品质的影响//第十五届中国科协年会, 2013.
[本文引用: 4]

SHI Y Z, XIAO Q, Lü R Q, HAN G F . The effects of the shading mate rials on the tea yield and tea qualities//The 15th Annual Meeting of China Association for Science and Technology
, 2013. (in Chinese)
[本文引用: 4]

[5] 肖润林, 王久荣, 汤宇, 刘永胜, 彭晚霞, 宋同清 . 高温干旱季节遮阳网覆盖对茶园温湿度和茶树生理的影响
生态学杂志, 2005,24(3):251-255.
URL [本文引用: 1]
研究了高温干旱季节采用遮阳网覆盖红壤丘陵茶园的生态作用和对茶树生理的影响.与露地对照茶园相比,遮阳网覆盖处理茶园在高温干旱季节,各个观测时段的气温、树冠温度、叶面温度、地面温度和土壤温度均明显降低,茶园土壤水分含量、空气湿度和茶叶含水量明显提高,茶叶新梢的叶绿素、咖啡碱和氨基酸含量大幅度提高,茶多酚含量降低11.6%.连续高温干旱27～29 d后遮阳网覆盖下茶树的叶片气孔导度、蒸腾速率和净光合速率均明显高于露地对照茶园.
XIAO R L, WANG J R, TANG Y, LIU Y S, PENG W X, SONG T Q . Effects of covering with outer shading screens during hot-dry season in tea plantation
Chinese Journal of Ecology, 2005,24(3):251-255. (in Chinese)
URL [本文引用: 1]
研究了高温干旱季节采用遮阳网覆盖红壤丘陵茶园的生态作用和对茶树生理的影响.与露地对照茶园相比,遮阳网覆盖处理茶园在高温干旱季节,各个观测时段的气温、树冠温度、叶面温度、地面温度和土壤温度均明显降低,茶园土壤水分含量、空气湿度和茶叶含水量明显提高,茶叶新梢的叶绿素、咖啡碱和氨基酸含量大幅度提高,茶多酚含量降低11.6%.连续高温干旱27～29 d后遮阳网覆盖下茶树的叶片气孔导度、蒸腾速率和净光合速率均明显高于露地对照茶园.

[6] 肖润林, 王久荣, 单武雄, 黎星辉, 宋同清, 汤宇 . 不同遮荫水平对茶树光合环境及茶叶品质的影响
中国生态农业学报, 2007,15(6):6-11.
URLMagsci [本文引用: 1]
试验研究了夏秋季80%、61%、37%遮光率遮阳网覆盖处理对茶园生态环境、茶树光合作用特性和茶叶内含成分的影响。结果表明：与露地对照茶园相比，3种遮光率遮荫处理茶园夏秋季气温、叶面温度、地面温度和土壤温度均明显降低；茶园土壤水分含量、茶园空气湿度明显提高。遮荫改善了茶园生态环境，且遮光率越高，效果越明显。与对照茶园比较，80%、61%、37%遮光率遮阳网覆盖处理日平均净光合速率增加了365%、283%和68%；茶叶新梢的叶绿素a含量增加了57.5%、29.3%和15.9%，叶绿素总量增加了52.2%、29.2%和14.3%；茶叶氨基酸含量增加了68.6%、33.5%和2.16%；茶叶茶多酚含量降低了15.3%、12.5%和5.4%。80%遮光率处理1芽2叶新梢制作的茶叶酚氨比达到名优绿茶标准，61%遮光率和37%遮光率处理的茶叶酚氨比也均达到高档绿茶标准，茶叶品质明显优于对照茶园。
XIAO R L, WANG J R, DAN W X, LI X H, SONG T Q, TANG Y . Tea plantation environment and quality under different degrees of shading
Chinese Journal of Eco-Agriculture, 2007,15(6):6-11. (in Chinese)
URLMagsci [本文引用: 1]
试验研究了夏秋季80%、61%、37%遮光率遮阳网覆盖处理对茶园生态环境、茶树光合作用特性和茶叶内含成分的影响。结果表明：与露地对照茶园相比，3种遮光率遮荫处理茶园夏秋季气温、叶面温度、地面温度和土壤温度均明显降低；茶园土壤水分含量、茶园空气湿度明显提高。遮荫改善了茶园生态环境，且遮光率越高，效果越明显。与对照茶园比较，80%、61%、37%遮光率遮阳网覆盖处理日平均净光合速率增加了365%、283%和68%；茶叶新梢的叶绿素a含量增加了57.5%、29.3%和15.9%，叶绿素总量增加了52.2%、29.2%和14.3%；茶叶氨基酸含量增加了68.6%、33.5%和2.16%；茶叶茶多酚含量降低了15.3%、12.5%和5.4%。80%遮光率处理1芽2叶新梢制作的茶叶酚氨比达到名优绿茶标准，61%遮光率和37%遮光率处理的茶叶酚氨比也均达到高档绿茶标准，茶叶品质明显优于对照茶园。

[7] LEE L S, CHOI J H, SON N, KIM S H, PARK J D, JANG D J, JEONG Y, KIM H J . Metabolomic analysis of the effect of shade treatment on the nutritional and sensory qualities of green tea
Journal of Agricultural & Food Chemistry, 2013,61(2):332-338.
DOI:10.1021/jf304161yURLPMID:23256790 [本文引用: 5]
We analyzed metabolites from a 50% aqueous methanol extract of green teas treated with different shade periods (0, 15, 18, and 20 days) to investigate the effect of low light on their nutritional and sensory qualities. The shaded groups could be clearly distinguished from the control (0 day), and the 20 day group was separated from the 15 and 18 day groups. The shade treatment increased quercetin-galactosylrutinoside, kaempferol-glucosylrutinoside, epicatechin gallate, epigallocatechin gallate, tryptophan, phenylalanine, theanine, glutamine, glutamate, and caffeine levels but decreased quercetin-glucosylrutinoside, kaempferol-glucoside, gallocatechin, and epigallocatechin levels. Further studies on the nutritional benefits of these metabolites are needed. However, this result, along with the sensory evaluation and color measurement data, suggests that shade treatment improves the nutritional and sensory quality of green tea. Thus, we proposed a metabolomic pathway related to the effect of low light, which could elucidate the relationship between low light and tea quality.

[8] ZHANG Q F, SHI Y Z, MA L F, YI X Y, RUAN J Y . Metabolomic analysis using ultra-performance liquid chromatography-quadrupole- time of flight mass spectrometry (UPLC-Q-TOF MS) uncovers the effects of light intensity and temperature under shading treatments on the metabolites in tea
PLoS One, 2014,9(11):1-10.
DOI:10.1371/journal.pone.0112572URLPMID:4229221 [本文引用: 1]
To investigate the effect of light intensity and temperature on the biosynthesis and accumulation of quality-related metabolites, field grown tea plants were shaded by Black Net and Nano-insulating Film (with additional 209“400°C cooling effect) with un-shaded plants as a control. Young shoots were subjected to UPLC-Q-TOF MS followed by multivariate statistical analysis. Most flavonoid metabolites (mainly flavan-3-ols, flavonols and their glycosides) decreased significantly in the shading treatments, while the contents of chlorophyll, 0205-carotene, neoxanthin and free amino acids, caffeine, benzoic acid derivatives and phenylpropanoids increased. Comparison between two shading treatments indicated that the lower temperature under Nano shading decreased flavonols and their glycosides but increased accumulation of flavan-3-ols and proanthocyanidins. The comparison also showed a greater effect of temperature on galloylation of catechins than light intensity. Taken together, there might be competition for substrates between the up- and down-stream branches of the phenylpropanoid/flavonoid pathway, which was influenced by light intensity and temperature.

[9] 刘建军, 袁丁, 司辉清, 庞晓莉, 唐晓波, 杨洁 . 遮荫对不同季节茶树新梢的内含成分影响研究
西南农业学报, 2013,26(1):115-118.
DOI:10.3969/j.issn.1001-4829.2013.01.024URL [本文引用: 2]
对福鼎大白茶园进行不同遮荫方式处理,并用冷冻干燥对鲜叶固样, 分析其主要的化学成分.结果表明:遮荫能使夏秋茶的多酚类、粗纤维含量减少,酚氨比下降；氨基酸、咖啡碱、叶绿素含量增加.不同季节遮荫效果不一样,春季 遮荫效果不明显,夏季效果最好,秋季次之；不同遮荫方式的遮荫效果也不一样,以黑色双层遮阳网遮荫效果最好.
LIU J J, YUAN D, SI H Q, PANG X L, TANG X B, YANG J . Effects of shading on ingredients of tea shoots in different seasons
Journal of Southwest Agriculture, 2013,26(1):115-118. (in Chinese)
DOI:10.3969/j.issn.1001-4829.2013.01.024URL [本文引用: 2]
对福鼎大白茶园进行不同遮荫方式处理,并用冷冻干燥对鲜叶固样, 分析其主要的化学成分.结果表明:遮荫能使夏秋茶的多酚类、粗纤维含量减少,酚氨比下降；氨基酸、咖啡碱、叶绿素含量增加.不同季节遮荫效果不一样,春季 遮荫效果不明显,夏季效果最好,秋季次之；不同遮荫方式的遮荫效果也不一样,以黑色双层遮阳网遮荫效果最好.

[10] WANG Y S, GAO L P, SHAN Y, LIU Y J, TIAN Y W, XIA T . Influence of shade on flavonoid biosynthesis in tea (Camellia sinensis(L.) O. Kuntze)
Scientia Horticulturae, 2012,141(3):7-16.
DOI:10.1016/j.scienta.2012.04.013URL [本文引用: 2]
Tea (Camellia sinensis (L.) O. Kuntze) is a commercially important crop valued for its secondary metabolites. Different cultivation methods affect tea quality by altering the biosynthesis of flavonoids. Shade can effectively improve the quality of tea beverages by causing reduction of the concentration of flavonoids, the main compounds that contribute to astringency, in the leaves. The aim of this study was to analyze the influence of shade on flavonoid biosynthesis in relation to expression of the flavonoid pathway genes in tea leaves. Our data revealed that shade had notable effects on both flavonoid (including catechins, O-glycosylated flavonols and proanthocyanins (PAs)) and lignin biosynthesis, but had no significant effect on anthocyanin accumulation. Among all the detected compounds, the concentration of PAs and O-glycosylated flavonols in shaded leaves changed more than other compounds, decreasing 53.37% and 43.26%, respectively, compared to the sunlight-exposed leaves. Expression of phenylalanine ammonialyase (PAL), flavanone 3-hydroxylase (F3H), flavonoid 3′-hydroxylase (F3′H), dihydroflavonol reductase (DFR) and anthocyanidin reductase1 (ANR1) was notably correlated with the concentration of PAs in leaves, and expression of chalcone synthase (CHS) and flavonoid 3′,5′-hydroxylase (F3′5′H) was remarkably correlated with the concentration of O-glycosylated flavonols. It is suggested that polymerization of catechins and glycosylation of flavonols might be key pathways of flavonoid metabolism in tea leaves affected by shade treatment. Regarding phenolic acids, a marked increase in concentration in shaded leaves and negative correlation with lignin accumulation suggests that phenolic acids might compete for the same substrate with lignins and flavonoids in tea leaves under different illumination conditions. Further investigations are required to understand the relationship between phenolic acids and other flavonoid compounds in tea plants.

[11] KU K M, CHOI J N, KIM J, KIM J K, YOO L G, LEE S J, HONG Y S, LEE C H . Metabolomics analysis reveals the compositional differences of shade grown tea (Camellia sinensis L.)
Journal of Agricultural & Food Chemistry, 2010,58(1):418-426.
DOI:10.1021/jf902929hURLPMID:19994861 [本文引用: 3]
The different cultivation methods affect tea quality by altering the basic metabolite profiles. In this study, the metabolome changes were investigated in green tea and shade cultured green tea (tencha) by liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) coupled with a multivariate data set. The principal component analysis (PCA) and orthogonal projection to latent structures discriminate analysis (OPLS-DA) of green tea clearly showed higher levels of galloylquinic acid, epigallocatechin, epicatechin, succinic acid, and fructose, together with lower levels of gallocatechin, strictinin, apigenin glucosyl arabinoside, quercetin p-coumaroylglucosyl-rhamnosylgalactoside, kaempferol p-coumaroylglucosylrhamnosylgalactoside, malic acid, and pyroglutamic acid than tencha. The effects of some seasonal variations were also observed in the primary metabolite concentrations such as amino acids and organic acids. In addition, green tea showed stronger antioxidant activity than tencha in both April and July. The antioxidant activity of green tea samples were significantly correlated with their total phenol and total flavonoid contents. This present study delineates the possibility to get high umami and less astringent green teas in shade culture. It highlights the metabolomic approaches to find out the effect of cultivation methods on chemical composition in plants and the relationship with antioxidant activity.

[12] 杨剑超, 姜学玲, 王德涛, 贺晶, 张晓伟, 孙晓, 王冰 . 遮荫处理对胶东丘陵地区设施夏茶品质的影响
现代农业科技, 2018(6):23-34.
URL [本文引用: 2]
苦涩味是影响胶东丘陵地区夏、秋绿茶品质的主要因素。通过对6—7月的设施茶园进行遮荫处理,对遮荫后茶园的光照和土壤环境变化进行检测、对茶叶与茶汤中苦涩味相关的主要化学成分进行分析,并制作茶样进行感官评测。结果表明,遮荫处理能有效降低茶园光照强度,提高土壤含水量,降低土壤温度,使夏季茶树也能在适宜的环境下生长;遮荫使茶叶中茶多酚含量降低,优化了氨基酸和茶多酚组分;同时叶绿素、含水量和水浸出物也增加;感官上,遮荫有效地降低了胶东丘陵地区夏茶的苦涩味,汤色更明亮,香气更持久,从而提高了胶东丘陵地区夏茶的品质。
YANG J C, JIANG X L, WANG D T, HE J, ZHANG X W, SUN X, WANG B . Effect of shading treatment on summer green tea quality in Jiaodong hilly area
.Science of Modern Agricultures, 2018(6):23-34. (in Chinese)
URL [本文引用: 2]
苦涩味是影响胶东丘陵地区夏、秋绿茶品质的主要因素。通过对6—7月的设施茶园进行遮荫处理,对遮荫后茶园的光照和土壤环境变化进行检测、对茶叶与茶汤中苦涩味相关的主要化学成分进行分析,并制作茶样进行感官评测。结果表明,遮荫处理能有效降低茶园光照强度,提高土壤含水量,降低土壤温度,使夏季茶树也能在适宜的环境下生长;遮荫使茶叶中茶多酚含量降低,优化了氨基酸和茶多酚组分;同时叶绿素、含水量和水浸出物也增加;感官上,遮荫有效地降低了胶东丘陵地区夏茶的苦涩味,汤色更明亮,香气更持久,从而提高了胶东丘陵地区夏茶的品质。

[13] 单武雄, 肖润林, 王久荣, 陈佩, 付晓青 . 遮光对丘陵茶园白露毛尖茶产量和品质的影响
农业现代化研究, 2010,31(3):368-372.
DOI:10.3969/j.issn.1000-0275.2010.03.026URL [本文引用: 2]
通过80%、60%和40%3个不同遮光率处理和露地对照试验,比较了遮光处理对秋季名优绿茶产量和品质的影响。试验表明,和露地对照处理比较:3个遮光处理茶园的田间气温和地表温度显著降低,空气湿度明显增加,有害高温和低湿出现的频率降低;1芽1叶长度、芽密度、百芽重和鲜叶产量下降,但差异不显著;鲜叶中叶绿素含量显著增加;白露毛尖茶中粗纤维含量显著降低,苦涩味组分茶多酚等含量降低,氨基酸含量显著增加,可溶性糖含量和水浸出物总量增加,酚氨比值下降,白露毛尖茶色泽、滋味和香气等感官品质明显改善。结果表明遮光处理显著改善白露毛尖茶品质,提升秋季名优绿茶档次,效果以80%遮光率最好,60%遮光率次之。
DAN W X, XIAO R L, WANG J R, CHEN P, FU X Q . Effects of shading on yield and quality of Bailu Maojian famous tea
Research of Agricultural Modernzation, 2010,31(3):368-372. (in Chinese)
DOI:10.3969/j.issn.1000-0275.2010.03.026URL [本文引用: 2]
通过80%、60%和40%3个不同遮光率处理和露地对照试验,比较了遮光处理对秋季名优绿茶产量和品质的影响。试验表明,和露地对照处理比较:3个遮光处理茶园的田间气温和地表温度显著降低,空气湿度明显增加,有害高温和低湿出现的频率降低;1芽1叶长度、芽密度、百芽重和鲜叶产量下降,但差异不显著;鲜叶中叶绿素含量显著增加;白露毛尖茶中粗纤维含量显著降低,苦涩味组分茶多酚等含量降低,氨基酸含量显著增加,可溶性糖含量和水浸出物总量增加,酚氨比值下降,白露毛尖茶色泽、滋味和香气等感官品质明显改善。结果表明遮光处理显著改善白露毛尖茶品质,提升秋季名优绿茶档次,效果以80%遮光率最好,60%遮光率次之。

[14] YANG Z Y, KOBAYASHI E, KATSUNO T, ASANUMA T, FUJIMORI T, ISHIKAWA T, TOMOMURA M, MOCHIZUKI K, WATASE T, NAKAMURA YWATANABE N . Characterisation of volatile and non-volatile metabolites in etiolated leaves of tea ( Camellia sinensis) plants in the dark
Food Chemistry, 2012,135(4):2268-2276.
DOI:10.1016/j.foodchem.2012.07.066URLPMID:22980801 [本文引用: 3]
Aroma is an essential factor affecting the quality of tea (Camellia sinensis) products. While changes of volatile compounds during tea manufacturing have been intensively studied, the effect of environmental factors on volatile contents of fresh tea leaves has received less attention. We found that C. sinensis var. Yabukita kept in darkness by shading treatment for 3weeks developed etiolated leaves with significantly increased levels of volatiles, especially volatile phenylpropanoids/benzenoids (VPBs). Upstream metabolites of VPBs, in particular shikimic acid, prephenic acid, and phenylpyruvic acid, showed lower levels in dark treated than in control leaves, whereas the contents of most amino acids including l-phenylalanine, a key precursor of VPBs, were significantly enhanced. In addition, analysis by ultra performance liquid chromatography-time of flight mass spectrometry, capillary electrophoresis–time of flight mass spectrometry, high performance liquid chromatography, and gas chromatography–mass spectrometry indicated that volatile and non-volatile metabolite profiles differed significantly between dark treated and untreated leaves.

[15] TONTUL I, TORUN M, DINCER C, SAHIN-NADEEM H, TOPUZ A, TURNA T, OZDEMIR F . Comparative study on volatile compounds in Turkish green tea powder: Impact of tea clone, shading level and shooting period
Food Research International, 2013,53(2):744-750.
DOI:10.1016/j.foodres.2012.12.026URL [本文引用: 2]
The objective of this study was to determine volatile compounds in green tea powders produced from a clone of two different teas (Camellia sinensis (L.) O. Kuntze) grown under different shade levels and harvested in two consecutive shooting periods. Both hydrodistillation and solid phase microextraction (SPME) methods were comparatively performed to identify maximum number and amount of volatile compounds. SPME method enables the identification of the greatest number of volatile compounds which principally comprise limonene, alpha-terpineol and heptanal. A few specific volatile compounds were identified for differentiation of green tea samples depending on the treatments, such as, heptanal in 1st shooting period, ethyl benzene, xylene and benzenacetal for 2nd shooting period, and phytol and tridecane for shading treatments. The treatments were significantly clustered either as tea clones or shooting period by the volatile compounds i.e. linalool, alpha-terpineol, 3-methylbutanal, 2-methylbutanal and p-cresol, 2,6-di-tert-buthyl determined in hydrodistillation method and tridecane, heptanal, linalool, nonanal, hexanal, alpha-terpineol, 1-pentanol, pentanal, dimethylsulfide, 2,2,4-trimethylhexane, limonene and 1-hexanol in SPME method as shown by principal component analysis (PCA). (C) 2012 Elsevier Ltd. All rights reserved.

[16] 张文锦, 梁月荣, 张应根, 陈常颂, 张方舟 . 遮荫对夏暑乌龙茶主要内含化学成分及品质的影响
福建农业学报, 2006,21(4):360-365.
DOI:10.3969/j.issn.1008-0384.2006.04.015URL [本文引用: 2]
探讨了黄旦、铁观音和本山茶园 覆盖遮荫对茶叶品质的影响。结果表明:遮荫可以显著提高夏、暑乌龙茶的品质,明显降低酚/氨比值,优化儿茶素组分和香气组分。遮荫度为30%、45%和 60%3种处理的夏、暑乌龙茶品质得分均极显著高于不遮荫对照处理,而遮荫处理间的差异不显著;与对照相比,遮荫后夏茶乌龙茶鲜叶的茶多酚总量、儿茶素和 EGC的含量分别下降了2.59%~12.40%、2.14%~13.63%、11.17%~29.47%,暑茶乌龙茶鲜叶茶多酚总量、儿茶素和EGC含 量分别下降了8.68%~11.05%、3.09%~10.61%、12.76%~24.23%;儿茶素品质指数分别提高了54.13~84.87和 167~682;夏茶氨基酸含量提高了13.52%~60.00%,其中茶氨酸、苏氨酸和天门冬氨酸的总量增加了7.57%~19.12%;夏、暑乌龙茶 的香气种类和香精油总量分别增加了25~40种和21.20%~38.85%,香气组分明显得以优化。
ZHANG W J, LIANG Y R, ZHANG Y G, CHEN C S, ZHANG F Z . Effects on quality and chemical components of oolong tea by shading in summer
Fujian Journal of Agricultural Sciences, 2006,21(4):360-365. (in Chinese)
DOI:10.3969/j.issn.1008-0384.2006.04.015URL [本文引用: 2]
探讨了黄旦、铁观音和本山茶园 覆盖遮荫对茶叶品质的影响。结果表明:遮荫可以显著提高夏、暑乌龙茶的品质,明显降低酚/氨比值,优化儿茶素组分和香气组分。遮荫度为30%、45%和 60%3种处理的夏、暑乌龙茶品质得分均极显著高于不遮荫对照处理,而遮荫处理间的差异不显著;与对照相比,遮荫后夏茶乌龙茶鲜叶的茶多酚总量、儿茶素和 EGC的含量分别下降了2.59%~12.40%、2.14%~13.63%、11.17%~29.47%,暑茶乌龙茶鲜叶茶多酚总量、儿茶素和EGC含 量分别下降了8.68%~11.05%、3.09%~10.61%、12.76%~24.23%;儿茶素品质指数分别提高了54.13~84.87和 167~682;夏茶氨基酸含量提高了13.52%~60.00%,其中茶氨酸、苏氨酸和天门冬氨酸的总量增加了7.57%~19.12%;夏、暑乌龙茶 的香气种类和香精油总量分别增加了25~40种和21.20%~38.85%,香气组分明显得以优化。

[17] YANG C, HU Z Y, LU M L, LI P L, TAN J F, CHEN M, LV H P, ZHU Y, ZHANG Y, GUO L, PENG Q H, DAI W D, LIN Z . Application of metabolomics profiling in the analysis of metabolites and taste quality in different subtypes of white tea
Food Research International, 2018,106:909-919.
DOI:10.1016/j.foodres.2018.01.069URLPMID:29580004 [本文引用: 7]
Three subtypes of white tea, Silver Needle (SN), White Peony (WP), and Shou Mei (SM), differ in their taste, aroma, bioactivity, and commercial value. Here, a metabolomics investigation on the chemical compositions combining taste equivalent-quantification and dose-over-threshold (DoT) determination on the taste qualities were applied to comprehensively characterize the white tea subtypes for the first time. Significant differences in the contents of catechins, dimeric catechins, amino acids, phenolic acids, flavonol/flavone glycosides, and aroma precursors were observed among these 3 white teas. Metabolite content comparison and partial least-squares (PLS) analysis suggest that theanine, aspartic acid, asparagine, and AMP were positively correlated with the umami taste in white tea, and flavan-3-ols, theasinensins, procyanidin B3, and theobromine had positive correlations with higher bitterness and astringency tastes. In addition, puckering astringent (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG) and theogallin, bitter-tasting caffeine, and the mouth-drying/velvety-like astringent -aminobutyric acid (GABA) were identified as key taste compounds of white tea infusion by absolute quantification and DoT factor calculations. This work provided systematic and comprehensive knowledge on the chemical components, taste qualities, and sensory active metabolites for the subtypes of white tea.

[18] DAI W D, QI D D, YANG T, LV H P, GUO L, ZHANG Y, ZHU Y, PENG Q H, XIE D C, TAN J F, LIN Z . Nontargeted analysis using ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry uncovers the effects of harvest season on the metabolites and taste quality of tea ( Camellia sinensis L.)
Journal of Agricultural & Food Chemistry, 2015,63(44):9869-9878.
[本文引用: 2]

[19] DAI W D, XIE D C, LU M L, LI P L, LV H P, YANG C, PENG Q H, ZHU Y, GUO L, ZHANG Y, TAN J F, LIN Z . Characterization of white tea metabolome: Comparison against green and black tea by a nontargeted metabolomics approach
Food Research International, 2017,96:40-45.
DOI:10.1016/j.foodres.2017.03.028URLPMID:28528106 [本文引用: 2]
Abstract White tea is considered the least processed form of tea and is reported to have a series of potent bioactivities, such as antioxidant, anti-inflammatory, anti-mutagenic, and anti-cancer activities. However, the chemical composition of white tea and the dynamic changes of the metabolites during the manufacturing process are far from clear. In this study, we applied a nontargeted metabolomics approach based on ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS) to comprehensively profile the characteristic metabolites of white tea. There were significant differences in the content of amino acids, catechins, dimeric catechins, flavonol and flavone glycosides, and aroma precursors in white tea compared with green and black teas that were manufactured from the same fresh tea leaves. Furthermore, the dynamic changes of the metabolites in the tea samples with various withering durations of 0, 4, 8, 12, 16, 20, 24, 28, and 36 h were also profiled. This study offers a comprehensive characterization of the metabolites and their changes in white tea. Copyright 2017. Published by Elsevier Ltd.

[20] TAN J F, DAI W D, LU M L, LV H P, GUO L, ZHANG Y, ZHU Y, PENG Q H, LIN Z . Study of the dynamic changes in the non-volatile chemical constituents of black tea during fermentation processing by a non-targeted metabolomics approach
Food Research International, 2016,79:106-113.
DOI:10.1016/j.foodres.2015.11.018URL [本文引用: 2]
61A LC–MS based metabolomics approach was used to study the tea fermentation process.61Obvious stepwise alterations of the tea metabolome were observed.61Dynamic changes of 61 identified metabolites were profiled.61Changes of metabolites along the phenylpropanoid/flavonoid pathway were mapped.61A novel derivative of theanine was discovered and identified as theanine glucoside.

[21] CHEN Y Y, FU X N, MEI X, ZHOU Y, CHENG S H, ZENG L T, DONG F, YANG Z Y . Proteolysis of chloroplast proteins is responsible for accumulation of free amino acids in dark-treated tea ( Camellia sinensis) leaves
Journal of Proteomics, 2017,157:10-17.
DOI:10.1016/j.jprot.2017.01.017URLPMID:28163235 [本文引用: 3]
61Dark increased content of amino acids and reduced content of soluble proteins in tea leaves.61Amino acid accumulation in dark-treated leaves was not due to activation of amino acid biosyntheses.61Proteolysis of chloroplast protein contributed to amino acid accumulation in dark-treated leaves.61Two chloroplasts proteases were upregulated in dark-treated tea leaves.

[22] 张英娜 . 绿茶茶汤主要儿茶素呈味特性研究
[D]. 北京: 中国农业科学院, 2016.
[本文引用: 2]

ZHANG Y N . Study on the taste characteristics of the main catechins in green tea infusion
[D]. Beijing: Chinese Academy of Agricultural Science, 2016. ( in Chinese)
[本文引用: 2]

[23] SCHARBERT S, HOLZMANN N, HOFMANN T . Identification of the astringent taste compounds in black tea infusions by combining instrumental analysis and human bioresponse
Journal of Agricultural & Food Chemistry, 2004,52(11):3498-3508.
DOI:10.1021/jf049802uPMID:15161222 [本文引用: 1]
Application of taste dilution analyses on freshly prepared black tea infusions revealed neither the high molecular weight thearubigen-like polyphenols nor the catechins and theaflavins,but a series of 14 flavon-3-ol glycosides as the main contributors to the astringent taste perceived upon black tea consumption.Among these glycosides,the apigenin-8-C-[alpha-L-rhamnopyranosyl-(1->2)-O-beta-D-glu-copyranoside] was identified for the first time in tea infusions.Depending on the structure,the flavon-3-ol glycosides were found to induce a velvety and mouth-coating sensation at very low threshold concentrations,which were far below those of catechins or theaflavins;for example,the threshold of 0.001mumol/L found for quercetin-3-O-[alpha-L-rhamnopyranosyl-(1->6)-O-beta-D-glucopyranoside] is 190,000,or 16,000 times below the threshold determined for epigallocatechin gallate or theaflavin,respectively.Moreover,structure/activity considerations revealed that,besides the type of flavon-3-ol aglycon,the type and the sequence of the individual monosaccharides in the glycosidic chain are key drivers for astringency perception of flavon-3-ol glycosides.

[24] SCHARBERT S, HOFMANN T . Molecular definition of black tea taste by means of quantitative studies, taste reconstitution, and omission experiments
Journal of Agricultural & Food Chemistry, 2005,53(13):5377-5384.
DOI:10.1021/jf050294dURLPMID:15969522 [本文引用: 1]
Recently, bioresponse-guided fractionation of black tea infusions indicated that neither the high molecular weight thearubigens nor the theaflavins, but a series of 14 flavon-3-ol glycopyranosides besides some catechins, might be important contributors to black tea taste. To further bridge the gap between pure structural chemistry and human taste perception, in the present investigation 51 putative taste compounds have been quantified in a black tea infusion, and their close-over-threshold (Dot) factors have been calculated on the basis of a dose/threshold relationship. To confirm these quantitative results, an aqueous taste model was prepared by blending aqueous solutions of 15 amino acids, 14 flavonol-glycosides, 8 flavan-3-ols, 5 theaflavins, 5 organic acids, 3 sugars, and caffeine in their "natural" concentrations. Sensory analyses revealed that the taste profile of this artificial cocktail did not differ significantly from the taste profile of the authentic tea infusion. To further narrow the number of key taste compounds, finally, taste omission experiments have been performed, on the basis of which a reduced recombinate was prepared containing the bitter-tasting caffeine, nine velvety astringent flavonol-3-glycosides, and the puckering astringent catechin as well as the astringent and bitter epigallocatechin-3-gallate. The taste profile of this reduced recombinate differed not significantly from that of the complete taste recombinate, thus confirming these 12 compounds as the key taste compounds of the tea infusion. Additional sensory studies demonstrated for the first time that the flavanol-3-glycosides not only impart a velvety astringent taste sensation to the oral cavity but also contribute to the bitter taste of tea infusions by amplifying the bitterness of caffeine.

[25] HO C T, ZHENG X, LI S M . Tea aroma formation
Food Science & Human Wellness, 2015,4(1):9-27.
[本文引用: 1]

[26] CHEN Q C, ZHU Y, DAI W D, LV H P, MU B, LI P L, TAN J F, NI D J, LIN Z . Aroma formation and dynamic changes during white tea processing
Food Chemistry, 2019,274:915-924.
DOI:10.1016/j.foodchem.2018.09.072URL [本文引用: 1]

[27] GUI J D, FU X M, ZHOU Y, KATSUNO T, MEI X, DENG R F, XU X L, ZHANG L Y, DONG F, WATANABE N, YANG Z Y . Does enzymatic hydrolysis of glycosidically bound volatile compounds really contribute to the formation of volatile compounds during the oolong tea manufacturing process?
Journal of Agricultural & Food Chemistry, 2015,63(31):6905-6914.
DOI:10.1021/acs.jafc.5b02741URLPMID:26212085 [本文引用: 1]
It was generally thought that aroma of oolong tea resulted from hydrolysis of glycosidically bound volatiles (GBVs). In this study, most GBVs showed no reduction during the oolong tea manufacturing process. β-Glycosidases either at protein or gene level were not activated during the manufacturing process. Subcellular localization of β-primeverosidase provided evidence that β-primeverosidase was located in the leaf cell wall. The cell wall remained intact during the enzyme-active manufacturing process. After the leaf cell disruption, GBV content was reduced. These findings reveal that, during the enzyme-active process of oolong tea, nondisruption of the leaf cell walls resulted in impossibility of interaction of GBVs and β-glycosidases. Indole, jasmine lactone, and trans-nerolidol were characteristic volatiles produced from the manufacturing process. Interestingly, the contents of the three volatiles was reduced after the leaf cell disruption, suggesting that mechanical damage with the cell disruption, which is similar to black tea manufacturing, did not induce accumulation of the three volatiles. In addition, 11 volatiles with flavor dilution factor ≥4(4) were identified as relatively potent odorants in the oolong tea. These results suggest that enzymatic hydrolysis of GBVs was not involved in the formation of volatiles of oolong tea, and some characteristic volatiles with potent odorants were produced from the manufacturing process.

[28] KANEKO S, KUMAZAWA K, MASUDA H, HENZE A, HOFMANN T . Molecular and sensory studies on the umami taste of Japanese green tea
Journal of Agricultural & Food Chemistry, 2006,54(7):2688-2694.
DOI:10.1021/jf0525232URLPMID:16569062 [本文引用: 1]
Aimed at defining the key drivers for the quality-determining umami taste of a high-grade powdered green tea, called mat-cha, a bioactivity-guided fractionation using solvent extraction, solvent precipitation, preparative chromatographic separations, and human psychophysical experiments was applied on freshly prepared mat-cha. Liquid chromatography-tandem mass spectrometry and one-/two-dimensional nuclear magnetic resonance studies on isolated fractions led to the identification of L-theanine, succinic acid, 3,4,5-trihydroxybenzoic acid (gallic acid), and (1R,2R,3R,5S)-5-carboxy-2,3,5-trihydroxycyclohexyl-3,4,5-trihydroxybenzoate (theogallin) as umami-enhancing compounds in the green tea beverage, and it can be shown by sensory studies that these compounds are able to raise the umami intensity of sodium L-glutamate proportionally.

[29] KANEKO S, KUMAZAWA K, MASUDA H, HENZE A, HOFMANN T . Sensory and structural characterisation of an umami enhancing compound in green tea (mat-cha)
Developments in Food Science, 2006,43(43):181-184.
DOI:10.1016/S0167-4501(06)80043-9URL [本文引用: 1]

[30] ZHAO F, QIU X H, YE N X, QIAN J, WANG D H, ZHOU P, CHEN M J . Hydrophilic interaction liquid chromatography coupled with quadrupole-orbitrap ultra high resolution mass spectrometry to quantitate nucleobases, nucleosides, and nucleotides during white tea withering process
Food Chemistry, 2018,266:343-349.
DOI:10.1016/j.foodchem.2018.06.030URL [本文引用: 1]
Nucleotides, nucleosides, and nucleobases are important bioactive compounds. Recent studies suggested that they possess taste activity. However, it remains unknown about their presence in white tea and how they change during white tea manufacture. Here, we first established method based on hydrophilic interaction liquid chromatography coupled with quadrupole-orbitrap ultra high resolution mass spectrometry (HILIC-Quadrupole-Orbitrap-UHRMS) platform, then applied it to study the dynamic changes of nucleotides, nucleosides, and nucleobases during white tea withering process. Five compounds, including adenosine 5'-monophosphate monohydrate (AMP), guanosine 5'-monophosphate disodium salt hydrate (GMP), adenosine, cytidine, thymine and uracil, were detected from withering samples. They showed a general decline trend during white tea withering process, however, considerable amount of them was retained after withering for 48 hours except adenosine which was below detection limit after withering for 21 hours. This study provided a complete picture about nucleotides, nucleosides and nucleobases changes during white tea withering process.

[31] LI C F, YAO M Z, MA C L, MA J Q, JIN J Q, CHEN L . Differential metabolic profiles during the albescent stages of ‘Anji Baicha’ ( Camellia sinensis)
PLoS One, 2015,10:1-18.
[本文引用: 1]

[32] MA C L, CHEN L, WANG X C, JIN J Q, MA J Q, YAO M Z, WANG Z L . Differential expression analysis of different albescent stages of 'Anji Baicha' ( Camellia sinensis(L.) O. Kuntze) using cDNA microarray
Scientia Horticulturae, 2012,148:246-254.
DOI:10.1016/j.scienta.2012.09.033URL [本文引用: 1]
Tea cultivar ‘Anji Baicha’ is a special green-revertible albino mutant and is widely cultivated in China for producing high price, high quality green tea with jade color, high aroma and nice taste. However, the molecular mechanism of the albino mutation is still unclear until now. The first tea plant cDNA microarray with 4866 clones was developed to analyze gene expression profiling of different albescent stages. A total of 671 differentially expressed genes at different albescent stages were found via the microarray analysis, which could be grouped into five clusters. The corresponding genes were involved in energy metabolism, carbon fixation, cell expansion, secondary metabolism, plant growth and defence, and other physiological processes including protein, nucleotide synthesis, etc. Particularly, some differentially expressed genes encoding important catalyzing enzymes or regulatory proteins which took part in chlorophyll biosynthesis or chloroplast development were identified. Some candidate genes possibly related to the albino process were further analyzed by using real-time PCR. The present study gave some useful clues for genes worthy of further understanding the albino phenotype of ‘Anji Baicha’ and also provided a model for utilization of the microarray technology in the tea plant.

[33] ZHANG Q F, LIU M Y, RUAN J Y . Integrated transcriptome and metabolic analyses reveals novel insights into free amino acid metabolism in Huangjinya tea cultivar
Frontiers in Plant Science, 2017,8:1-11.
DOI:10.3389/fpls.2017.00291URLPMID:5337497 [本文引用: 1]
The chlorotic tea varietyHuangjinya, a natural mutant, contains enhanced levels of free amino acids in its leaves, which improves the drinking quality of its brewed tea. Consequently, this chlorotic mutant has a higher economic value than the non-chlorotic varieties. However, the molecular mechanisms behind the increased levels of free amino acids in this mutant are mostly unknown, as are the possible effects of this mutation on the overall metabolome and biosynthetic pathways in tea leaves. To gain further insight into the effects of chlorosis on the global metabolome and biosynthetic pathways in this mutant,Huangjinyaplants were grown under normal and reduced sunlight, resulting in chlorotic and non-chlorotic leaves, respectively; their leaves were analyzed using transcriptomics as well as targeted and untargeted metabolomics. Approximately 5,000 genes (8.5% of the total analyzed) and ca. 300 metabolites (14.5% of the total detected) were significantly differentially regulated, thus indicating the occurrence of marked effects of light on the biosynthetic pathways in this mutant plant. Considering primary metabolism, including that of sugars, amino acids, and organic acids, significant changes were observed in the expression of genes involved in both nitrogen (N) and carbon metabolism. The suite of changes not only generated an increase in amino acids, including glutamic acid, glutamine, and theanine, but it also elevated the levels of free ammonium, citrate, and -ketoglutarate, and lowered the levels of mono- and di-saccharides and of caffeine as compared with the non-chlorotic leaves. Taken together, our results suggest that the increased levels of amino acids in the chlorotic vs. non-chlorotic leaves are likely due to increased protein catabolism and/or decreased glycolysis and diminished biosynthesis of nitrogen-containing compounds other than amino acids, including chlorophyll, purines, nucleotides, and alkaloids.

[34] ZHANG Q F, LIU M F, RUAN J Y . Metabolomics analysis reveals the metabolic and functional roles of flavonoids in light-sensitive tea leaves
BMC Plant Biology, 2017,17:1-10.
DOI:10.1186/s12870-016-0951-9URLPMID:5209872 [本文引用: 1]
The low seed vigor and poor field emergence are main factors that restricting the extension of sweet corn in China. Spermidine (Spd) plays an important role in plant growth and development, but little is known about the effect of Spd on sweet corn seed germination. Therefore the effect of exogenous Spd on seed germination and physiological and biochemical changes during seed imbibition of Xiantian No.5 were investigated in this study. Spd soaking treatment not only improved seed germination percentage but also significantly enhanced seed vigor which was indicated by higher germination index, vigor index, shoot heights and dry weights of shoot and root compared with the control; while exogenous CHA, the biosynthesis inhibitor of Spd, significantly inhibited seed germination and declined seed vigor. Spd application significantly increased endogenous Spd, gibberellins and ethylene contents and simultaneously reduced ABA concentration in embryos during seed imbibition. In addition, the effects of exogenous Spd on H2O2and MDA productions were also analyzed. Enhanced H2O2concentration was observed in Spd-treated seed embryo, while no significant difference of MDA level in seed embryo was observed between Spd treatment and control. However, the lower H2O2and significantly higher MDA contents than control were detected in CHA-treated seed embryos. The results suggested that Spd contributing to fast seed germination and high seed vigor of sweet corn might be closely related with the metabolism of hormones including gibberellins, ABA and ethylene, and with the increase of H2O2in the radical produced partly from Spd oxidation. In addition, Spd might play an important role in cell membrane integrity maintaining. The online version of this article (doi:10.1186/s12870-016-0951-9) contains supplementary material, which is available to authorized users.

[35] 大棚课题组. 大棚覆盖技术在茶树上的应用研究初报
蚕桑茶叶通讯, 1998(3):8-10.
URL [本文引用: 1]
塑料薄膜和遮阳网覆盖技术最早用于水稻育秧和反季节蔬菜栽培，而在茶树栽培上的应用及系统研究甚少。茶园应用塑料薄膜大棚和遮阳网的目的在于打破茶树正常的生长规律，促使春茶提早采摘和改善夏秋茶品质，提高经济效益。据此，本课题在茶园冬季覆盖塑料薄膜进行的季节栽培
GROUP G R. Preliminary report on the application of greenhouse covering technology on tea trees
.Sericulture Tea Communication, 1998(3):8-10. (in Chinese)
URL [本文引用: 1]
塑料薄膜和遮阳网覆盖技术最早用于水稻育秧和反季节蔬菜栽培，而在茶树栽培上的应用及系统研究甚少。茶园应用塑料薄膜大棚和遮阳网的目的在于打破茶树正常的生长规律，促使春茶提早采摘和改善夏秋茶品质，提高经济效益。据此，本课题在茶园冬季覆盖塑料薄膜进行的季节栽培

[36] 胡永光, 江丰 , Ashraf MAHMOOD, 刘鹏飞 . 春茶采摘末期遮荫对其生长和品质的影响
农业机械学报, 2018,49(1):283-289.
DOI:10.6041/j.issn.1000-1298.2018.01.035URL [本文引用: 1]
为延长春茶采摘期,提高其产量,进行了遮阳网遮荫栽培试验研究。根据不同遮光率和不同遮荫高度,在茶园中设置4个处理:60%遮光率+2.0 m遮荫高度(T1)、40%遮光率+2.0 m遮荫高度(T2)、40%遮光率+2.5 m遮荫高度(T3)和无遮荫的对照处理(CK);试验全程分为前、中、后期。试验研究以上各处理遮阳网内外温、湿度环境的差异,茶树新稍、叶片生长状况和茶芽叶品质指标。结果表明:遮荫后,茶树冠层处的日最高气温显著降低,遮光率越高降幅越大,最大降幅为3.9℃;08:00—17:00的最低相对湿度均增大,遮光率越高增幅越大,最大增幅为9.01%;新稍长度、粗度均增加,以T1处理的增幅最大,分别为22.3%和13.5%;新稍叶片的叶绿素相对含量和芽叶含水率,随着遮光率增大而增高;与CK处理相比,T1处理的新稍叶片日平均净光合速率变大,而T2和T3显著变小;T3处理增加了茶叶水浸出物、茶多酚和酚氨比,降低了氨基酸含量,导致茶汤浓厚、苦涩味加重;而T1处理在试验前期增加了咖啡碱含量,降低了水浸出物含量和酚氨比。综上所述,在春茶采摘末期采用60%遮光率的遮阳网进行遮荫栽培,对于保持春茶品质、延长采摘期具有重要的生产指导意义。
HU Y G, JIANG F, ASHRAF M, LIU P F . Effects of shading cultivation on growth and quality of spring tea during final harvesting period
Journal of Agricultural Machinery, 2018,49(1):283-289. (in Chinese)
DOI:10.6041/j.issn.1000-1298.2018.01.035URL [本文引用: 1]
为延长春茶采摘期,提高其产量,进行了遮阳网遮荫栽培试验研究。根据不同遮光率和不同遮荫高度,在茶园中设置4个处理:60%遮光率+2.0 m遮荫高度(T1)、40%遮光率+2.0 m遮荫高度(T2)、40%遮光率+2.5 m遮荫高度(T3)和无遮荫的对照处理(CK);试验全程分为前、中、后期。试验研究以上各处理遮阳网内外温、湿度环境的差异,茶树新稍、叶片生长状况和茶芽叶品质指标。结果表明:遮荫后,茶树冠层处的日最高气温显著降低,遮光率越高降幅越大,最大降幅为3.9℃;08:00—17:00的最低相对湿度均增大,遮光率越高增幅越大,最大增幅为9.01%;新稍长度、粗度均增加,以T1处理的增幅最大,分别为22.3%和13.5%;新稍叶片的叶绿素相对含量和芽叶含水率,随着遮光率增大而增高;与CK处理相比,T1处理的新稍叶片日平均净光合速率变大,而T2和T3显著变小;T3处理增加了茶叶水浸出物、茶多酚和酚氨比,降低了氨基酸含量,导致茶汤浓厚、苦涩味加重;而T1处理在试验前期增加了咖啡碱含量,降低了水浸出物含量和酚氨比。综上所述,在春茶采摘末期采用60%遮光率的遮阳网进行遮荫栽培,对于保持春茶品质、延长采摘期具有重要的生产指导意义。

[37] 宛晓春 . 茶叶生物化学. 第三版. 北京: 中国农业出版社, 2003: 165-166.
[本文引用: 1]

WAN X C . Tea Biochemistry. 3th Edition. Beijing: China Agricultural Press, 2003: 165-166. (in Chinese)
[本文引用: 1]

[38] 李明, 张龙杰, 石萌, 林小明, 郑新强, 王开荣, 陆建良, 梁月荣 . 遮光对光照敏感型新梢白化茶春梢化学成分含量的影响
茶叶, 2016,42(3):150-154.
URL [本文引用: 1]
以光照敏感型新梢白化茶树‘黄-2’、‘黄-8’和‘黄-13’为供试材料,在春季一芽一叶期采用30%透光度的黑色遮阳网覆盖遮光处理7天,HLPC法检测一芽二叶新梢咖啡因、儿茶素类、氨基酸类和色素类化合物含量。结果显示,遮光处理对茶叶咖啡因含量无显著影响;遮光对儿茶素类总含量的影响因品种而异,在品系‘黄-2’显著提高,而品系‘黄-8’和‘黄-13’则显著降低;遮光显著提高品系‘黄-13’的氨基酸总含量,降低品系‘黄-8’氨基酸总含量,但对品系‘黄-2’无显著影响;遮光显著提高β-胡萝卜素、叶绿素a、叶绿素b和新黄质的含量,显著降低紫黄质含量。具有热耗散作用的黄体素在光照敏感新梢白化茶品种的含量很低,是其容易受到强光胁迫伤害的原因。在强光照条件下,光照敏感型新梢白化茶叶片呈现黄色,主要是叶绿素含量显著降低,而不是因为胡萝卜素和叶黄素含量提高所致。根据这些研究结果,作者认为:在高温强光季节采取适度遮光,将有助于光照敏感型新梢白化茶提高叶片叶绿素含量,增强光合作用,进而提高茶苗生长势和抗性,有助于提高茶苗移栽成活率。
LI M, ZHANG L J, SHI M, LIN X M, ZHENG X Q, WANG K R, LU J L, LIANG Y R . Effect of light-shading on chemical composition of spring shoots on light-sensitive albino tea plants
Journal of Tea, 2016,42(3):150-154. (in Chinese)
URL [本文引用: 1]
以光照敏感型新梢白化茶树‘黄-2’、‘黄-8’和‘黄-13’为供试材料,在春季一芽一叶期采用30%透光度的黑色遮阳网覆盖遮光处理7天,HLPC法检测一芽二叶新梢咖啡因、儿茶素类、氨基酸类和色素类化合物含量。结果显示,遮光处理对茶叶咖啡因含量无显著影响;遮光对儿茶素类总含量的影响因品种而异,在品系‘黄-2’显著提高,而品系‘黄-8’和‘黄-13’则显著降低;遮光显著提高品系‘黄-13’的氨基酸总含量,降低品系‘黄-8’氨基酸总含量,但对品系‘黄-2’无显著影响;遮光显著提高β-胡萝卜素、叶绿素a、叶绿素b和新黄质的含量,显著降低紫黄质含量。具有热耗散作用的黄体素在光照敏感新梢白化茶品种的含量很低,是其容易受到强光胁迫伤害的原因。在强光照条件下,光照敏感型新梢白化茶叶片呈现黄色,主要是叶绿素含量显著降低,而不是因为胡萝卜素和叶黄素含量提高所致。根据这些研究结果,作者认为:在高温强光季节采取适度遮光,将有助于光照敏感型新梢白化茶提高叶片叶绿素含量,增强光合作用,进而提高茶苗生长势和抗性,有助于提高茶苗移栽成活率。