为进一步明确襄阳绿茶品质特征,在感官审评基础上,选取具有代表性香气的17种绿茶样品,采用高效液相色谱法、气质色谱联用法及多元分析法,系统测定分析其滋味成分、香气成分的组成和含量.结果表明:不同香型襄阳绿茶中水浸出物、茶多酚、非酯型儿茶素含量和儿茶素总量是有显著差异的(P ＜0.05),氨基酸、咖啡碱、没食子酸和酯型儿茶素的含量无显著差异,同时水浸出物、茶多酚和表没食子儿茶素没食子酸酯含量,栗香型＞嫩香型＞清香型,而氨基酸含量,栗香型＜嫩香型＜清香型;不同香型绿茶的香气成分,共检测出65种香气物质成分,包括醛类9种,酮类5种,醇类13种,烯类11种,芳香烃7种,酯类16种和其他类4种,其中醇类物质含量最高,酯类化合物含量其次,含量较高的成分有芳樟醇、己酸顺式-3-己烯酯和香叶醇;进一步进行差异分析,发现顺-氧化芳樟醇、反-丁酸-3-己烯酯、顺-3-己烯异戊酸酯可作为嫩香型的特征挥发性性组分,6-十一酮、反-香叶基丙酮、δ-杜松烯可作为清香型的特征挥发性性组分,苯乙醇、桉树醇、α-法尼烯可作为栗香型的特征挥发性性组分.

运用定量描述分析法、顶空固相微萃取法、气相色谱-质谱-嗅闻(gas chromatography-mass spectrometry-olfactory,GC-MS-O)联用仪,并结合多元统计方法分析橘红茶及其原料的主要香气轮廓及挥发性风味成分.结果 表明,橘红茶的主体香气是果香和甜香.GC-MS共鉴定出92种挥发性物质,其中醛类23种,醇类23种,烯类20种,酮类9种,酯类9种和其他类8种,烯类和醇类是主导香气化合物.综合GC-O及气味活度值分析,柠檬烯、β-紫罗酮、芳樟醇、癸醛、β-大马烯酮、(E,E)-2,4-癸二烯醛和辛醛可能是橘红茶中重要的致香物质.相关性分析结果表明,月桂烯、苯乙醛、芳樟醇等11个挥发性成分对果香、花香、甜香、青香和木香风味属性的表征有较大的贡献.通过正交偏最小二乘判别分析得出了橘红茶与其原料间的标志差异性挥发性成分.本实验可为研究橘红茶及其他柑橘代用茶的香气质量提供参考依据.

Tea plant ( Camellia sinensis ) is a well-known Al-accumulating plant, showing a high level of aluminum (Al) tolerance. However, the molecular mechanisms of Al tolerance and accumulation are poorly understood. We carried out transcriptome analysis of tea plant leaves in response to three different Al levels (0, 1, 4 mM, for 7 days). In total, 794, 829 and 585 differentially expressed genes (DEGs) were obtained in 4 mM Al vs. 1 mM Al, 0 Al vs. 1 mM Al, and 4 mM Al vs. 0 Al comparisons, respectively. Analysis of genes related to polysaccharide and cell wall metabolism, detoxification of reactive oxygen species (ROS), cellular transport, and signal transduction were involved in the Al stress response. Furthermore, the transcription factors such as zinc finger, myeloblastosis (MYB), and WRKY played a critical role in transcriptional regulation of genes associated with Al resistance in tea plant. In addition, the genes involved in phenolics biosynthesis and decomposition were overwhelmingly upregulated in the leaves treated with either 0 Al and 4 mM Al stress, indicating they may play an important role in Al tolerance. These results will further help us to understand mechanisms of Al stress and tolerance in tea plants regulated at the transcriptional level.

为探究不同冲泡条件对橘红茶抗氧化特性的影响,该文研究在冲泡时间、冲泡次数、冲泡温度等冲泡条件下,橘红茶茶汤多酚类物质含量、氨基酸含量、总抗氧化能力、DPPH自由基清除率以及羟自由基清除能力的变化规律.结果表明,宜红茶中多酚类物质显著高于橘壳,而氨基酸、可溶性糖、表没食子儿茶素含量及DPPH自由基清除效率显著低于橘壳(p<0.05);橘红茶总抗氧化能力和羟自由基清除能力显著高于橘壳和宜红茶(p<0.05);冲泡次数对橘红茶茶汤抗氧化活性和化学成分的浸出影响最大,其次是冲泡温度,冲泡时间的影响最小.因此,饮用较高抗氧化活性橘红茶的冲泡条件为:冲泡温度85℃～95℃,冲泡时间5 min～10 min,冲泡次数为1次～2次.

湖北是"茶圣"陆羽故里,产茶历史悠久,生态环境优越,文化底蕴深厚.近年来,在湖北省委、省政府和各级政府及农业农村部门的高度重视下,湖北茶产业发展迅猛,茶叶已成为山区农民脱贫攻坚的支柱、绿色、特色和亮点产业.广大茶叶科技工作者克难攻坚、协同创新,为茶产业转型升级提供了强有力的科技支撑.2021年1月22日,湖北省十三届人大常委会第二十次会议表决通过了《湖北省促进茶产业发展条例》,并将于2021年5月1日起施行.

为了解青砖毛茶的健康功能以及对高脂饮食小鼠肠道微生物的影响,对青砖毛茶干预高脂饮食小鼠的主要生理、生化指标进行比较分析,并利用高通量测序技术分析小鼠肠道微生物的结构和组成.结果表明:青砖毛茶能够显著降低高脂饮食诱导的小鼠体重、肠系脂肪、肝脏质量和血清中主要血脂指标的增加;有效缓解高脂饮食小鼠肝脏肿大,降低高脂饮食诱导肝脏中的脂肪空泡的体积和数量增加,以及肝细胞损伤引起血清中谷丙转氨酶和谷草转氨酶的增加.青砖毛茶可以调节高脂饮食诱导的肠道微生物菌群紊乱,并与低脂组有相似的健康肠道菌群组成.共筛选到46个关键差异OTU在高脂饮食后发生显著改变,后又被青砖毛茶调节回来,其中有39个OTU与小鼠中至少1个主要生理、生化指标呈显著正相关或负相关.青砖毛茶可能是通过调节厚壁菌门/拟杆菌门的比值和丹毒丝菌科、红蝽杆菌科、红蝽杆菌科和瘤胃球菌科等菌群的相对丰度来缓解高脂饮食引起的代谢综合症.

Tea polyphenols (TPs) may reach the soil through root secretions and the decomposition of fallen leaves in the tea garden ecosystem and may activate elements existing in the soil through complexation. We designed different epigallocatechin gallate (EGCG) concentration, residence time, and extraction reagent to determine the effect of these treatments on the mobilization of potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), and manganese (Mn). The results showed that the EGCG concentration had a significant impact on the mobilization of these five elements. According to the correlation coefficient of desorptive kinetic equations, K, Ca, Mg, Fe, and Mn desorption onto soil was well described by first-order kinetic equation model (R-2 > 0.98, P < .01). The effect of LMWOAs (low molecular weight organic acids) was greater than that of EGCG on mobilizing amounts of large elements including K, Ca, and Mg. Our study provides a more detailed understanding of the interactions between EGCG and minerals, which may offer prospects for improving plant nutrient acquisition through direct modifications of rhizosphere management.

为优化扁形绿茶自动化生产线做形和炒干工艺,以外观度、色泽度和成形度为评价指标进行单因素试验;在此基础上,以感官评分、容重、茶汤-b/a值、儿茶素品质指数为评价指标进行正交试验,对其工艺参数进行优化,并采用感官评价和理化分析相结合的方式分析扁形绿茶加工过程中品质成分变化.结果表明:做形工序最佳工艺参数为投叶量75 g、时间75 s、温度220℃,炒干工序最佳工艺参数为投叶量60 g、时间160 s、温度160℃.扁形绿茶加工过程中理化成分发生了一系列变化,在制品的含水率、水浸出物、茶多酚和咖啡碱含量呈不断减少趋势;游离氨基酸总量呈先减少后不断增加趋势,在杀青工序含量最低;可溶性糖含量呈先增加后减少趋势,在炒干工序含量最高.相比采用传统工艺加工的扁形绿茶,利用优化工艺加工扁形绿茶的感官评分提高了2.27分,茶叶容重增加10.84％,茶汤色泽有明显改善,儿茶素品质指数上升.

为了解保康不同等级绿茶的品质特征及其差异,收集保康绿茶一级茶样4个、二级茶样4个,联合采用感官审评法、高效液相色谱法、气质色谱联用法和主成分分析法系统测定分析了其香气成分、滋味成分的组成和含量.结果显示:一级绿茶的感官总分均高于90分,二级绿茶低于90分,感官品质得分与市场所定等级一致;一级绿茶的水浸出物、茶多酚、氨基酸、咖啡碱、酯型儿茶素和儿茶素总量均值均高于二级绿茶,只有非酯型儿茶素总量略低于二级绿茶;不同等级绿茶中咖啡碱、没食子酸、酯型儿茶素和儿茶素总含量均值有显著差异,水浸出物、茶多酚、氨基酸和非酯型儿茶素含量均值无显著差异;8个茶样共检测到64种香气化合物,包括醇类13种、醛类9种、酮类5种、烯类12种、芳香烃6种、酯类15种和其他类4种,其中醇类物质平均含量最高,酯类其次,含量较高的成分有芳樟醇、香叶醇和己酸顺式-3-己烯酯;进一步主成分分析发现,4个主成分方差累计贡献率达到89.608％,其中第1主成分方差贡献率为45.080％,综合了β-紫罗酮、邻二甲苯、乙苯、苯乙烯、二甲基戊酸甲酯和顺-茉莉酮的贡献,主要反映绿茶中的花果香及特有芳香;一级绿茶醇类和酯类香气化合物的平均含量低于二级绿茶,醛类、酮类、烯类、芳烃类和其他类香气化合物含量均高于二级绿茶.

Changes in key odorants and aroma profiles of Qingzhuan tea (QZT) during its manufacture were determined using headspace solid-phase microextraction gas chromatography-mass spectrometry/olfactometry. An aroma profile was constructed to illustrate sensory changes during manufacture. The characteristic aroma of QZT was aged fragrance, which was mostly developed during pile fermentation and was enhanced during the aging and drying stages. Using volatile compounds found in the raw materials, sun-dried green tea and QZT finished product were compared by orthogonal partial least square-discriminant analysis. Among 108 detected volatiles, 19 were significantly upregulated and 15 were downregulated. (E)-β-Ionone, (E,Z)-2,6-nonadienal, 1-octen-3-one, (E,E)-2,4-heptadienal, (E,E)-2,4-nonadienal, safranal, (E)-2-nonenal, α-ionone, and 1,2,3-trimethoxybenzene were found to be significant contributors to the aged QZT fragrance, reflecting their high odor-activity values and aroma intensities. Finally, the metabolic transformation of key aroma-active compounds was systematically analyzed. This study provided a theoretical basis for improving the processing and quality of QZT.

为探究中国工夫红茶主要品质成分含量特征,建立茶汤滋味品质综合评价方法.对17个国内主产茶区工夫红茶的多酚类、氨基酸、茶色素类、香气组分等品质指标进行测定,运用主成分分析、聚类分析和偏最小二乘-判别分析(partial least squares-discrimination analysis,PLS-DA)对其品质进行综合评价.结果 表明:不同产区工夫红茶的品质成分组成与含量存在明显差异,多酚类及其氧化产物是主要的品质成分,茶黄素和茶红素之和与茶褐素的比值为1.05～1.12,是其滋味鲜醇、汤色红亮的物质基础;英红、海红、信阳红、宜红、越红、黔红和祁红的可溶性糖质量分数均高于4％,是其茶汤甜醇滋味的重要物质基础;黄酮在大叶种红茶(滇红、英红和海红)中的质量分数较高且大于2.7％.醇类和醛类是主要的香气化合物,尤其是呈现甜香、花香的萜烯醇含量较高.利用主成分分析法建立滋味品质评价模型,该预测模型对红茶滋味品质评价结果与感官审评结果较为相似,存在极显著相关(P＜0.01),相关系数为0.735;茶黄素和茶多酚含量是进行工夫红茶品质分析的重要指标.系统聚类分析显示闽红自为一类,滇红、英红和海红等大叶种红茶聚为一类,其他中小叶种红茶聚为一类.PLS-DA可将2类不同品种工夫红茶明显区分,并获得8种差异性指标,尤其是芳樟醇、香叶醇和己醛等,可作为区分大叶种和中小叶种工夫红茶的指标物质.该研究丰富了工夫红茶风味品质的基础理论,同时为红茶品质的科学评价提供新的思路和方法.

Qingzhuan tea (QZT) is a dark tea which is widely consumed by Chinese national minority whose staple diets are high fat. It has been previously demonstrated that QZT has anti-inflammatory properties, however its preventive and therapeutic mechanism on metabolic syndromes remains unclear. Particularly, how QZT extract modulates the metabolic syndrome-related gut microbiota composition remains to be elucidated. This study aims to explore the changes in gut microbial communities mediated by a 16-week QZT extract consumption in a diet-induced obese mice model through 16S rRNA sequencing. Our results demonstrate that QZT extract can significantly prevent body weight gain, fat accumulation, and also reduce serum levels of total cholesterol and triglycerides, which is accompanied by a decrease in Firmicutes-to-Bacteroidetes ratio and relative abundance of S24-7 and Ruminococcaceae. Overall, our findings suggest QZT supplementation-induced gut microbial changes so that present benefits on mice with metabolic syndrome in high-fat diet-fed mice.

本文介绍了一种新型解块机,其采用立式转动轴(筒)架构,设置多层打散臂,作业时,茶坯重力自落,多次打散,具有下料快、不易堵塞、解块效率高等特点.经测试,其对不同结块程度的茶坯一轮次作业均可完全打散,且不伤茶条,适用性广.本设备已获得国家发明专利授权,并在全国茶区广泛应用.

BACKGROUND:C. sinensis is an important economic crop with fluoride over-accumulation in its leaves, which poses a serious threat to human health due to its leaf consumption as tea. Recently, our study has indicated that cell wall proteins (CWPs) probably play a vital role in fluoride accumulation/detoxification in C. sinensis. However, there has been a lack in CWP identification and characterization up to now. This study is aimed to characterize cell wall proteome of C. sinensis leaves and to develop more CWPs related to stress response. A strategy of combined cell wall proteomics and N-glycoproteomics was employed to investigate CWPs. CWPs were extracted by sequential salt buffers, while N-glycoproteins were enriched by hydrophilic interaction chromatography method using C. sinensis leaves as a material. Afterwards all the proteins were subjected to UPLC-MS/MS analysis.RESULTS:A total of 501 CWPs and 195 CWPs were identified respectively by cell wall proteomics and N-glycoproteomics profiling with 118 CWPs in common. Notably, N-glycoproteomics is a feasible method for CWP identification, and it can enhance CWP coverage. Among identified CWPs, proteins acting on cell wall polysaccharides constitute the largest functional class, most of which might be involved in cell wall structure remodeling. The second largest functional class mainly encompass various proteases related to CWP turnover and maturation. Oxidoreductases represent the third largest functional class, most of which (especially Class III peroxidases) participate in defense response. As expected, identified CWPs are mainly related to plant cell wall formation and defense response.CONCLUSION:This was the first large-scale investigation of CWPs in C. sinensis through cell wall proteomics and N-glycoproteomics. Our results not only provide a database for further research on CWPs, but also an insight into cell wall formation and defense response in C. sinensis.

Due to the accumulation of experiences on treating disease, tea began to develop to pluralism, and not limited to Camellia sinensis. The leaf buds of Eurya alata Kobuski and Camellia cuspidate were used to make Qianlincha (QLC) and Qiandingcha (QDC), which have special taste, aromas, and health benefits. In our study, the biochemical and volatile components of QLC and QDC were systematically analyzed and compared with a normal green tea (GT, C. sinensis). The biochemical and volatile components in the three tea samples were remarkably different. Compared with those in GT, QLC and QDC exhibited higher content of flavonoids and remarkably lower content of amino acids, catechins, and caffeine. High levels of flavonoids may play a crucial role in taste, liquor color, and health function of QLC and QDC. Low levels of amino acids, catechins, and caffeine may impart mouth-drying or velvety-like astringent taste; umami and refreshing taste of QLC and QDC was not as good as that of GT. High levels of linalool, geraniol, nonanal, dimethyl sulfide, and cis-jasmone may impart a clean and strongly floral or fruity aroma characteristic of QLC. High levels of linalool, 3,7-dimethyl-6-octen-3-ol, (-)-terpinen-4-ol, and terpenes may impart a strongly floral aroma characteristic of QDC.

为了提高湖北绿碎茶产品品质,降低生产成本,以现行绿碎茶加工流程为对照,比较分析不同工艺流程处理所制样品的感官得分、色泽品质、理化成分、香气组分和生产成本,结果表明:轻简化后的工艺流程(处理3)所制的绿碎茶感官得分最高(79.8),高于对照处理1.45分,与对照相比,干茶亮度显著上升(p<0.01),茶汤色相值提高了132％,儿茶素品质指数相对较高(p<0.01),香气组分中的紫罗酮、呋喃、癸醛和反,反-2,4-庚二烯醛等栗香型组分也有所增加,人工成本降低了25％.综上试验结果,轻简化加工流程有效改善了绿碎茶品质,降低了生产成本,可以作为一种提高湖北绿碎茶品质的有效技术手段.

利用正交试验设计优化青砖茶的渥堆发酵工艺,通过感官评价及化学成分分析得到最佳渥堆发酵工艺条件:潮水量30％、渥堆温度55℃、渥堆时间25 d、相对湿度95％.晒青毛茶渥堆后风味成分发生一系列变化,水浸出物、茶多酚、氨基酸、儿茶素总量与茶红素含量减少,而可溶性糖和茶褐素明显增加.醇类和酯类成分大幅减少,其中传统渥堆处理后醇类和酯类成分减幅约50％以上,数控渥堆处理后醇类和酯类成分减幅80％以上,而醛类、酮类、烯类和杂环类物质含量大幅上升,数控渥堆的发酵程度较传统渥堆更深.通过气相色谱-嗅闻仪(GC-O)分析得到12种香气活性物质,其中(E,E)-2,4-庚二烯醛、β-紫罗酮、芳樟醇、(Z)-4-庚烯醛、(E)-2-壬烯醛和香叶醇是青砖茶香气轮廓的主要贡献成分.本结果有助于指导生产实践,同时为青砖茶产品优质香型的精准调控提供理论依据.

Tea (Camellia sinensis [L.] O. Kuntze.) is an important cash crop, which mainly uses tender shoots and young leaves for manufacturing. Due to the marketing characteristic that earlier made tea has higher price, the time of the breaking of winter dormancy buds in spring is extremely important in tea industry. Strigolactones are a group of carotenoids-derived metabolites which regulates bud outgrowth, shoot branching, tiller angle and environmental stress responses. The role of strigolactones in tea plant was briefly summarized in the current review, with an emphasis of the association of strigolactones on bud ecodormancy and shoot branching. The involvement of strigolactones on the biosynthesis of the tea characteristic metabolites flavonoids, caffeine and theanine were also discussed. Moreover, recent advances on the biosynthesis of strigolactones and its regulation by microRNAs and environmental stresses were also presented. This review provides a basis for future investigations underlying the mechanisms of strigolactones on bud winter dormancy and tea secondary metabolism.

Qingzhuan tea (QZT), a post-fermented tea, has been reported to have anti-obesity and anti-hyperglycemic effects, perhaps due to bioactive compounds that inhibit lipase and α-amylase. It is unknown what chemical constituents’ changes and what bioactive compounds occur during the manufacture of QZT. The aim of this study was to determine the secondary metabolites changes that occur during post-fermentation and how these changes affect the ability of QZT to inhibit the activities of lipase and α-amylase. During the processing steps, metabolites levels and their inhibitory effects on lipase and α-amylase were assessed. Changes in content and activities suggested that the first turn over or the second turn over was critical for the formation and conversion of bioactive compounds responsible for the anti-obesity and hypoglycemic effects. The relationship between constituents and activities was further evaluated by correlation analysis, which showed that amino acids and flavonoids might be responsible for the anti-obesity and anti-hyperglycemic effects of QZT. This study clarified that compounds were altered during pile fermentation of QZT and tentatively identified the bioactive compounds formed during QZT manufacture.

鲜叶采摘是茶叶生产过程中占用劳动力最多的环节.当前,我国名优茶的生产发展因劳动力短缺和成本上升而受到制约,名优茶实施机采成为必然趋势.培育适宜机采的良好树冠对鲜叶质量的提升可起到事半功倍的作用.本文综述了茶树树冠形成规律、机采茶园树冠特征及品种筛选、树型修剪、采摘制度与施肥水平等机采树冠培育制度等方面的研究进展,并对机采树冠培育发展趋势进行了展望.