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Research Progress of Tea Quality Evaluation Technology LIU Qi, OUYANG Jian, LIU Changwei, CHEN Hongyu, LI Juan, XIONG Ligui, LIU Zhonghua, HUANG Jian'an Journal of Tea Science    2022, 42 (3): 316-330.   DOI: 10.13305/j.cnki.jts.20220416.001 Abstract （937）      PDF（pc） （812KB）（962）       Knowledge map    Save The quality of tea is the embodiment of the shape and inner quality of tea, and evaluating the quality of tea quickly and accurately is essential for tea trade and processing. Sensory evaluation, composition analysis and detection, and emerging technologies are the main tea quality evaluation techniques at present. This article summarized the research progress of three major evaluation technologies in recent years, and focused on the development trend of emerging technologies. Sensory evaluation is greatly influenced by subjective factors, but combined with quantitative description and analysis can reduce the influence of subjectivity. Component analysis detection has high threshold, difficult operation, time-consuming and labor-consuming, and the results obtained are relatively accurate. Emerging technologies are simple, fast, and non-destructive, but at present they cannot achieve satisfactory accuracy. In the tea product diversification today, only multi-dimensional comprehensive utilization of multiple methods can quickly and efficiently detect the quality of tea, and provide assistance for the healthy and efficient development of the tea industry. Reference | Related Articles | Metrics

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Research Advances of Fluoride Accumulation Mechanisms in Tea Plants (Camellia sinensis) XING Anqi, WU Zichen, XU Xiaohan, SUN Yi, WANG Genmei, WANG Yuhua Journal of Tea Science    2022, 42 (3): 301-315.   DOI: 10.13305/j.cnki.jts.20220416.003 Abstract （900）      PDF（pc） （876KB）（481）       Knowledge map    Save Camellia sinensis (L.) O. Kuntze is a hyper fluoride (F) accumulation plant, whose F content in tea leaves is much higher than other plants, without any toxic symptoms. However, F is not an essential element for tea plant growth, and under high F stress, F affects the normal growth of plants by destroying the cell structure and inhibiting enzyme activities. In order to provide a theoretical basis for the future study of F accumulation in tea plants, the research progresses in the absorption, enrichment and accumulation/detoxification mechanisms of F in tea plants were reviewed. Reference | Related Articles | Metrics

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Analysis on the Competitiveness and Complementarity of Tea Trade between China and RCEP Members LI Zheng, LIU Ding, HUO Zenghui, CHEN Fuqiao Journal of Tea Science    2022, 42 (5): 740-752.   DOI: 10.13305/j.cnki.jts.2022.05.010 Abstract （783）      PDF（pc） （532KB）（280）       Knowledge map    Save The signing of RCEP had facilitated intra-regional trade liberalization. It is of great practical significance to investigate the impact of RCEP on China's tea import and export trade. Based on the tea trade data of China and other RCEP members from 2011 to 2020, combining the analysis of the current situation of intra-regional import and export trade, this study calculated several indicators such as revealed comparative advantage index (RCA), export similarity index (ESI), trade complementarity index (TCI), trade intensity index (TI) and intra-industry trade index (GL) to measure the competitiveness and complementarity of bilateral tea trade. The results indicate that the tea export competitions between China, Vietnam and Indonesia were more prominent. China's tea export had long-term comparative advantages, and the comparative advantages of green tea export were obvious, while the comparative advantages of China's export of large packaged black tea lag behind Indonesia and Vietnam. China's tea export was highly similar to Japan, Thailand, Singapore and South Korea, and had strong competitiveness in export structure. In addition, the tea trade between China and New Zealand, Brunei, Australia was highly complementary. China's tea trade with Indonesia, New Zealand and Vietnam was mainly intra-industry trade in some years, while with Australia and Myanmar was mainly inter-industry trade. Finally, under the framework of RCEP agreement, strategies including expanding potential markets, dealing with technical barriers to trade and optimizing export structure were proposed. Reference | Related Articles | Metrics

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Identification and Transcriptional Regulation of CLH Gene Family and Expression Analysis in Albino Tea Plants (Camellia sinensis) WANG Tao, WANG Yiqing, QI Siyu, ZHOU Zhe, CHEN Zhidan, SUN Weijiang Journal of Tea Science    2022, 42 (3): 331-346.   DOI: 10.13305/j.cnki.jts.2022.03.003 Abstract （635）      PDF（pc） （1540KB）（263）       Knowledge map    Save Chlorophyllase (CLH) is the key enzyme in the degradation of chlorophyll, stripping its phytol to form dephytolithochlorophyll a. The full-length cDNA sequences of three CsCLHs genes were obtained from the second leaves of albino tea cultivar ‘Baijiguan', and bioinformatics analysis was performed. The results show that the three CsCLH genes could be divided into two subfamilies. The full length of CsCLHs was 894-975 bp, encoding 297-324 amino acids. The protein molecular weights were 31.99-34.91 kDa. The isoelectric points were 4.89-7.61, and the instability coefficients were 38.94-48.24. CsCLH1.1 and CsCLH1.2 were unstable proteins, while CsCLH2 was a stable protein. The subcellular localization prediction results of Cell Ploc show that three CsCLH proteins were located in chloroplast, while the results of Wolf Psort show that CsCLH1.1 and CsCLH1.2 were located in cytoplasm and CsCLH2 was located in chloroplast. The qRT-PCR results on the ‘Baijiguan' leaves indicated that expressions of CsCLHs were inhibited by shading treatment and light induced CsCLHs' expressions. Expression pattern analysis of CsCLHs shows that CsCLH1s were highly expressed in the albino cultivars. In addition, it was identified that CsCDF5 could bind to the CsCLH1.1 and CsCLH2 promoters according to the yeast one hybrid system. In conclusion, CsCLHs in albino tea leaves might be involved in chlorophyll degradation and play an important role in the process of albino leaf, which provided a reference for further investigation in the function of the CLH gene family and the albinism of leaves in tea plants. Reference | Related Articles | Metrics

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Nomenclature, Typification, and Natural Distribution of Camellia sinensis var. assamica (Theaceae) ZHAO Dongwei Journal of Tea Science    2022, 42 (4): 491-499.   DOI: 10.13305/j.cnki.jts.2022.04.007 Abstract （606）      PDF（pc） （547KB）（293）       Knowledge map    Save Camellia sinensis var. assamica (Theaceae) is a globally cultivated plant for beverages. The efforts to clarify its nomenclature and type are reviewed here. Griffith proposed Camellia sect. Thea (L.) Griff. as a name at new rank rather than a new taxon in 1854 based on Art. 41.4 of the Shenzhen Code. Camellia sealyana T.L. Ming is excluded from sect. Thea because of its abaxially punctate leaves and free styles. Masters did not validly publish Thea assamica in 1844, but this Latin name was validated in 1847 by Hooker. Steenis first proposed the new combination, Camellia sinensis (L.) Kuntze var. assamica (Hook.) Steenis, in 1949, and this is the accurate scientific name for Assam tea. The specimen, W. Griffith s.n. (K000939670) at herbarium K, was designated as the neotype of T. assamica in 2021. Seven known heterotypic synonyms of C. sinensis var. assamica and their protologues and types were summarized here. Although Darlington and Ammal proposed the new combination, C. assamica, in 1945, Assam tea is, however, widely accepted as a variety of C. sinensis based on morphological, geological, and phylogenetic analyses. If the specific rank was applied, the earlier heterotypic name of Assam tea, C. theifera published in 1838, would gain priority over C. assamica. Then the widely used epithet “assamica” might be conserved under Art. 14 of the Shenzhen Code. The natural distribution of Assam tea was summarized based on the comprehensive examination of specimens collected from China, India, Laos, Myanmar, Thailand, and Vietnam. The status of natural populations of Assam tea in each country was discussed with the different applications of utilization and conservation. Reference | Related Articles | Metrics

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Clinical Trial on the Effect of Drinking Jinhua Xiangyuan Tea for 3 Months on the Improvement of Glucose and Lipid Metabolism in A Small Sample Hyperlipidemia Population SUN Ying, CHEN Xin, YANG Hua, YING Jian, SHAO Danqing, LÜ Xiaohua, XIAO Jie, CHEN Zhixiong, LI Song, QIN Junjie, ZHENG Bin, GAO Jianshe Journal of Tea Science    2022, 42 (4): 561-576.   DOI: 10.13305/j.cnki.jts.2022.04.010 Abstract （584）      PDF（pc） （1135KB）（277）       Knowledge map    Save This study is aimed at investigating the clinical effect of drinking Jinhua Xiangyuan tea for 3 months on the glucose and lipid metabolism in a small sample patients with hyperlipidemia (with/without non-alcoholic fatty liver). Jinhua Xiangyuan tea was produced by the new process using Eurotium cristatum. In this study, before-and-after control design was used. The body composition (body weight, BMI, waist hip ratio, percentage of body fat, visceral fat grade), blood biochemical indicators (fasting blood glucose, uric acid, blood lipid), fatty liver, and gut microbiota were examined before and after the test. After drinking Jinhua Xiangyuan tea for 3 months, the body weight, BMI, percentage of body fat, visceral fat grade, serum total cholesterol, low-density lipoprotein cholesterol, and fasting blood glucose of 38 volunteers were significantly reduced (P<0.05). Fatty liver was less severe. Gut microbiota’s diversity and richness were increased. The relative abundance of Phascolarctobacterium, Ruminococcus, Haemophilus and Veillonella were increased, and Dialister and Butyricimonas were decreased. Jinhua Xiangyuan tea could increase the relative abundance of short-chain fatty acid-producing bacteria, increasing short-chain fatty acids, and improving insulin resistance, then improving glucose and lipid metabolism. The results of this study still need to be further confirmed by more rigorous long-term experimental observation. Reference | Related Articles | Metrics

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Comparison on Chemical Components of Yunnan and Fuding White Tea Based on Metabolomics Approach GAO Jianjian, CHEN Dan, PENG Jiakun, WU Wenliang, CAI Liangsui, CAI Yawei, TIAN Jun, WAN Yunlong, SUN Weijiang, HUANG Yan, WANG Zhe, LIN Zhi, DAI Weidong Journal of Tea Science    2022, 42 (5): 623-637.   DOI: 10.13305/j.cnki.jts.20220601.001 Abstract （577）      PDF（pc） （1197KB）（349）       Knowledge map    Save In order to investigate the differences in chemical compositions between Yunnan white tea and Fuding white tea, 9 Yunnan white tea samples and 6 Fuding white tea samples were studied by ultrahigh performance liquid chromatography-quadrupole orbitrap mass spectrometer (UHPLC-Q-Exactive/MS) combined with sensory evaluation to analyze the non-volatile chemical components of white tea in two places. A total of 109 compounds were structurally identified in this study, including catechins, dimeric catechins, flavonoid glycosides (flavone/flavonol-O-glycosides and flavone/flavonol-C-glycosides), N-ethyl-2-pyrrolidinone-substituted flavan-3-ols (EPSFs), amino acids, phenolic acids, organic acids, alkaloids, lipids, et al. The partial least squares discriminant analysis and heatmap analysis show that there were distinct differences in the chemical components between Yunnan white tea and Fuding white tea. A total of 46 compounds showed significant differences between groups (P<0.05). The contents of epicatechins, dimericcatechins, flavonoid glycosides (kaempferol-3-galactoside, quercetin-3-glucoside, etc.), phenolic acids, organic acids, and lipids were relatively high in Yunnan white tea; while the contents of nonepicatechins, flavonoid glycosides (quercetin-3-galactoside, myricetin-3-galactoside, etc.), amino acids and alkaloids were relatively higher in Fuding white tea, which was speculated to be related with tea cultivars and drying processes. This study provided a theoretical basis for the understanding and recognition of the difference in the chemical substance and flavor quality of different white tea between two places, as well as the identification of white tea origins. Reference | Related Articles | Metrics

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Research Progress on the Bitterness of Green Tea MA Yuanyuan, CAO Qingqing, GAO Yizhou, LIU Yuyi, DENG Sihan, YIN Junfeng, XU Yongquan Journal of Tea Science    2023, 43 (1): 1-16.   DOI: 10.13305/j.cnki.jts.2023.01.001 Abstract （514）      PDF（pc） （602KB）（790）       Knowledge map    Save Tea, as a hobby drink, the flavor is its first quality attribute. The presentation of its taste is the comprehensive perception effect of the human taste organs on the flavor components in tea infusion, which is generally manifested as bitter, astringent, fresh, sweet and other sensory experiences. Among them, bitterness is the most easily perceived taste attribute, and as a crucial factor affecting the flavor quality of tea. Meanwhile, due to the bitter taste, summer and autumn tea resources are faced with the dilemma of large abandonment, resulting in a great waste of resources. Based on this, this paper reviewed the physiological basis of bitter perception and the evaluation methods of bitter taste perception. Taking green tea infusion as the main carrier, the bitter taste components of tea were systematically integrated, and the interaction effect between other taste monomers and bitter compounds, as well as the regulatory mechanism of post-treatment on the bitter taste of tea infusion were discussed. It was expected to enrich the theoretical basis of taste chemistry and clarify the flavor characteristics of bitter compounds of tea, the taste mechanism and the interaction effect between taste substances, and provide theoretical reference for promoting the high-value utilization and taste regulation of summer and autumn tea. Reference | Related Articles | Metrics

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Research Progress of Tea Plant (Camellia sinensis) Growth under Light Regulation GAI Shujie, WANG Yixiong, LI Lan, LIU Shuoqian, LI Yinhua, CHENG Xiao, XIA Mao, LIU Zhonghua, ZHOU Zhi Journal of Tea Science    2022, 42 (6): 753-767.   DOI: 10.13305/j.cnki.jts.2022.06.005 Abstract （480）      PDF（pc） （882KB）（473）       Knowledge map    Save The growth and development of tea plants are affected by external environmental factors, and light is one of the most important factors, which can affect the growth and secondary metabolites of tea plants alone or in coordination with other environmental factors such as temperature, etc. This paper introduced the research progress of light regulation of tea plant growth and metabolic at domestic and abroad in recent years. The main points of discussion were the effects of different spectral bands, photon flux and photoperiod on tea plant growth, types and contents of metabolites. It’s mainly for clarifying the light regulated metabolic process of tea plant growth, analyzing the light regulated mechanism, and providing theoretical support for the development of light regulated metabolic technology that can be used in production practice. Reference | Related Articles | Metrics

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The Control Efficiency of Afidopyropen to Tea Green Leafhoppers and Evaluation of Residue in Tea GUO Mingming, LI Zhaoqun, LIU Yan, RAO Fuqiang, YU Jiawei, WU Luchao, ZHOU Li, CHEN Zongmao Journal of Tea Science    2022, 42 (3): 358-366.   DOI: 10.13305/j.cnki.jts.20220506.002 Abstract （476）      PDF（pc） （505KB）（184）       Knowledge map    Save Afidopyropen is a novel biogenic insecticide derived from the natural fermentation product. This study aimed to evaluate the feasibility of afidopyropen for tea green leafhoppers (Empoasca onukii Matsuda) control and tea safety after the application of afidopyropen in tea garden. The dosage field trials and demonstration trials were conducted to evaluate the control efficiency of afidopyropen to tea green leafhoppers and the terminal residues in tea. The results of the dosage field trials in 2 locations show that 50 g·L-1 afidopyropen dispersible concentrate was more effective against the green leafhoppers than chlorfenapyr which was commonly used pesticide for the green leafhoppers control. At the dosages of 15.00 g·hm-2 and 22.50 g·hm-2, control efficiencies were 88.6%-93.4% on the 1st day after treatment and 75.5%-85.5% on the 14th day, demonstrating a quick control effect and good persistence. At the dosage of 18.75 g·hm-2 in 7 locations, the control efficiencies were 88.9%-100.0% on the 3rd day after treatment, and 60.2%-100.0% on the 14th day, which were better than the local commonly used pesticides. The terminal residues of afidopyropen in green tea ranged from 0.17-0.64 mg·kg-1 on the 7th day after the application, the leaching rate of afidopyropen from dry tea to tea brew ranged from 17.1%-19.1% during the brewing process, and the risk quotient values were far less than 1, indicating a very low health risk caused by the afidopyropen intake through drinking tea. In conclusion, afidopyropen is suitable for resistance management and comprehensive management of tea green leafhoppers with the advantages of low dosage, high-efficiency and low-healthy risk for tea consumer. Reference | Related Articles | Metrics

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Tea Buds Detection Model Using Improved YOLOv4-tiny FANG Mengrui, LÜ Jun, RUAN Jianyun, BIAN Lei, WU Chuanyu, YAO Qing Journal of Tea Science    2022, 42 (4): 549-560.   DOI: 10.13305/j.cnki.jts.2022.04.009 Abstract （466）      PDF（pc） （1758KB）（229）       Knowledge map    Save Precise detection of tea buds is a prerequisite for intelligent mechanical picking of tea. Aiming at the problems of poor salience and high missed detection rate of small-scale buds caused by different sizes of tea leaves and the cover of other tea leaves, this paper proposed a kind of tea buds detection model based on improved YOLOv4-tiny. In this model, a 52×52 shallow feature layer was added in the neck network to promote the attention of YOLOv4-tiny network to small target buds. A convolutional block attention module (CBAM) was introduced to suppress the background noise and improve the salience of buds, and a bidirectional feature pyramid network (BiFPN) was used to integrate characteristic information of different scales, so as to propose the YOLOv4-tiny-Tea, a high performance light weight tea buds detection model. The results of model training and performance testing on the same training set and test set show that for the YOLOv4-tiny-Tea model, the detection precision and recall rate were 97.77% and 95.23% respectively, which were 5.58% and 23.14% higher than those before modification. An ablation experiment verified the effectiveness of the modified network structure in detecting different scales of buds, and a comparison of YOLOv4-tiny-Tea model with three YOLO algorithms found that the F1 value of YOLOv4-tiny-Tea model was 12.11%, 11.66% and 6.76% higher than F1 values of YOLOv3, YOLOv4 and YOLOv5l models respectively. The number of parameters in YOLOv4-tiny-Tea model was merely 13.57%, 13.06% and 35.05% of the three network models. The experimental results demonstrate that the method proposed in this paper effectively improved the detection precision of buds under different scales, greatly reduced the missed detection rate of buds for small size or under shading, and significantly bettered the detection precision based on a lightweight computation overhead. Therefore, the method can meet the needs of agricultural robots for real-time detection and embedded development, thus providing a reference for intelligent tea buds picking. Reference | Related Articles | Metrics

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Effects of Light Waves on the Aroma Substances of Fresh Tea Leaves in Summer and Autumn During Spreading and the Quality of Final Green Tea LIU Jianjun, ZHANG Jinyu, PENG Ye, LIU Xiaobo, YANG Yun, HUANG Tao, WEN Beibei, LI Meifeng Journal of Tea Science    2022, 42 (4): 500-514.   DOI: 10.13305/j.cnki.jts.20220520.001 Abstract （454）      PDF（pc） （1983KB）（225）       Knowledge map    Save The rough aroma is an important factor affecting the quality of summer and autumn green tea. In order to improve the quality of summer and autumn green tea, this experiment took Fuding Dabai tea as the research object, and irradiated fresh leaves in vitro with red light, yellow light, blue light and purple light, and the nature light was used as the control. Headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to qualitatively and quantitatively detect the volatile components of the fresh leaves. Supplemented by Hierarchical Cluster Analysis (HCA), Principal Component Analysis (PCA) and Partial least squares discriminant analysis (PLS-DA), the optimal light wave and key substances that promote the formation of tea's floral and fruity aroma were identified. The results show that different light qualities had significant effects on the types and contents of aroma substances. A total of 36 aroma substances were identified from 5 samples, of which alcohols and terpenes were the most numerous, and the average content of esters was the highest, followed by alcohols. Red light was the best light to promote the accumulation of tea aroma components. 3-Carene, β-Myrcene and phenylethyl alcohol were the key substances for improving the aroma in tea leaves. All light treatments could promote the free amino acids and caffeine in fresh leaves, and reduce the ratio of phenol to ammonia. After light treatment, the fresh and floral flavor of green tea was more obvious, and the taste was fresh. The comprehensive score of the tea samples treated with red light was the best. The research has shown that red light irradiation of fresh tea leaves in summer and autumn could increase the types and contents of tea aroma substances, significantly improve the key substances in the formation of flower and fruit aroma, and increase the freshness of tea soup. Reference | Related Articles | Metrics

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Analysis of the Saponin Contents and Composition in Tea Seeds of Different Germplasms CHEN Yuhong, GAO Ying, HAN Zhen, YIN Junfeng Journal of Tea Science    2022, 42 (5): 705-716.   DOI: 10.13305/j.cnki.jts.2022.05.005 Abstract （444）      PDF（pc） （1571KB）（200）       Knowledge map    Save Tea saponins are abundant in the seeds of Camellia sinensis with specific biological activities. Their contents and composition in tea seeds of different germplasms remain unclear. In this study, seeds from 21 tea germplasms were collected from the same region of Zhejiang and used as experimental materials to determine the basic characteristics, saponin contents and composition. Correlation analysis between germplasm and saponin composition was also performed. The results show that the seed weight, shell kernel ratio and saponin content of different tea seeds were significantly different (P<0.05). The saponin content detected by UV spectral method and HPLC ranged from 30.82% to 48.16% and 16.93% to 31.82%, respectively. ‘Huangguanyin' had the highest saponin content in tea seeds. Totally 68 tea seed saponin monomers were detected simultaneously using ultrahigh performance liquid chromatography-quadrupole orbitrap mass spectrometer（UHPLC-Q-Exactive/MS）. Theasaponin E1 had the highest relative intensity. Orthogonal partial least squares discriminant analysis (OPLS-DA) shows that the 21 tea seed germplasms can be distinguished into 2 groups according to tree type with 21 different Camelliasaponin B1/B2, Theasaponin A5/A6, Camelliasaponin C1/C2 and Assamsaponin G were the most significant characteristic substances of semi-tree form and arbor form resources. The results of the study laid the foundation for the selection and value-added utilization of tea seed saponins. Reference | Related Articles | Metrics

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Characterization of the Key Aroma in Corn-scented Congou Black Tea Manufactured from Camellia nanchuanica by Sensory Omics Techniques OUYANG Ke, ZHANG Cheng, LIAO Xueli, KUN Jirui, TONG Huarong Journal of Tea Science    2022, 42 (3): 397-408.   DOI: 10.13305/j.cnki.jts.20220506.003 Abstract （438）      PDF（pc） （1290KB）（237）       Knowledge map    Save Camellia nanchuanica is endemic to Nanchuan district, Chongqing and has a high development value. In this study, the characteristic aroma of corn-scented Congou black tea from Camellia nanchuanica was analyzed by headspace-solid phase microextraction, gas chromatography-mass spectrometry (HS-SPME-GC/MS), gas chromatography-olfactometry (GC-O), odor activity value (OAV) and aroma character impact value (ACI). The results show that 22 key aroma compounds with OAVs≥1 were identified in the corn-scented black tea. Dimethyl sulfide had the highest OAV (1 187.32), and its ACI was 51.56%. A total of 26 odor-active compounds were perceived by GC-O. Dimethyl sulfide had a higher olfactory intensity, which had a “corn-like” odor. The results obtained by the OAV approaches and by GC-O method for key aroma identification were in good agreement. The importance of dimethyl sulfide in corn-scented black tea was verified by aroma recombination and omission test. Focusing on the analysis of the active aromas of corn-scented black tea would provide a theoretical basis for the quality control of this prized tea. Reference | Related Articles | Metrics

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Recent Advances in Catechin Biomedical Nanomaterials YU Rongxin, ZHENG Qinqin, CHEN Hongping, ZHANG Jinsong, ZHANG Xiangchun Journal of Tea Science    2022, 42 (4): 447-462.   DOI: 10.13305/j.cnki.jts.2022.04.004 Abstract （431）      PDF（pc） （2659KB）（528）       Knowledge map    Save Catechins are a kind of bioactive substances rich in tea, which have the functions of anti-oxidation, anti-tumor, anti-virus, anti-inflammatory and immune regulation. However, due to the high activity of phenolic hydroxyl groups, catechins are easy to lose in vitro and in vivo activities, resulting in lower bioavailability. The recent development of nanobiotechnologies is expected to solve the problem of low bioavailability of catechins through ligand design, accurate synthesis and intelligent regulation, which can expand its application in the field of life and health. In this review, a summary on the progress of catechin biomedical nanomaterials in recent years, including the anti-tumor, antibacterial, anti-inflammatory, drug delivery and anti-virus activities, was firstly made. Later, the construction and biological mechanism of catechin biomedical nanomaterials were discussed in detail. Finally, future perspectives on the design and application of novel catechin nanomaterials were provided. Reference | Related Articles | Metrics

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Functional Identification of CsbHLH024 and CsbHLH133 Transcription Factors in Tea Plants LIU Renjian, WANG Yuyuan, LIU Shaoqun, SHU Canwei, SUN Binmei, ZHENG Peng Journal of Tea Science    2022, 42 (3): 347-357.   DOI: 10.13305/j.cnki.jts.2022.03.001 Abstract （393）      PDF（pc） （1629KB）（202）       Knowledge map    Save Tea plant leaf trichomes contain various secondary metabolites and play an important role in the tea appearance quality as well as the response of tea plants to biotic and abiotic stresses. In this study, the function of leaf trichome-related genes CsbHLH024 and CsbHLH133 were analyzed using Bimolecular Fluorescent Complimentary (BiFC), GUS staining and overexpression experiments. The results show that CsbHLH024/CsbHLH133 and CsTTG1 could interact in plants, and their promoters could drive downstream gene expression in leaf tissues. They were further transformed into wild Arabidopsis thaliana (Col) and corresponding homozygous mutants, respectively to get overexpression lines. Both genes could affect the leaf trichome formation in Arabidopsis thaliana, restore the phenotype of the mutants, and induce the expression levels of trichome-related genes. This study provided a theoretical basis for further research on the molecular regulation mechanism of trichome formation in tea leaves. Reference | Related Articles | Metrics

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Research Progress on Colored Substances in Tea LONG Piaopiao, SU Shengxiao, ZHANG Liang Journal of Tea Science    2023, 43 (5): 593-606.   DOI: 10.13305/j.cnki.jts.2023.05.010 Abstract （386）      PDF（pc） （733KB）（378）       Knowledge map    Save The color of tea leaves and infusions is an important attribute to tea flavor and quality. Colored substances contain chromophore and auxochrome groups, which contribute to producing different shades of green, yellow, and red hue in tea infusion. As the concentrations of colored substances increase, the tea infusions’ color will increase accordingly, presenting different colors such as yellowish-green, reddish-yellow and reddish-brown. Furthermore, fermentation (enzymatic oxidation) and drying stages during processing, as well as temperature, pH, and concentration in sensory evaluation, affect the color and brightness of tea infusions. This review revealed the color formation mechanisms by summarizing the chemical structures, color characteristics, coloration mechanisms and other factors of color substances in tea. It also provided a theoretical evidence for the quality improvement of tea flavor and the innovation of processing technology. Reference | Related Articles | Metrics

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Genetic and Phylogenetic Analysis for Germplasm Resources of Camellia sinensis from Wuzhou City WANG Liubin, HUANG Liyun, TENG Cuiqin, WU Liyun, CHENG Hao, YU Cuiping, WANG Liyuan Journal of Tea Science    2022, 42 (5): 601-609.   DOI: 10.13305/j.cnki.jts.2022.05.004 Abstract （382）      PDF（pc） （701KB）（228）       Knowledge map    Save Based on the SSR markers, the genetic diversity and genetic relationship of the germplasm resources of tea plants from Liubao town and Nandu town were fully analyzed in this study. The core molecular markers for the efficient identification of these germplasm resources were successfully screened. The main results show that: (1) 98 alleles were amplified from 17 pairs of SSR primers, and each pair of SSR primers amplified 3-8 alleles, with an average of 5.764 7 alleles per locus. (2) Totally 8 core markers were selected from 17 SSR markers to distinguish each germplasm resource. (3) The average number of alleles (4.647 1), genotypes per marker (7.000 0), genetic diversity (0.675 4), and the polymorphic information content (0.628 3) of native tea trees in Liubao town were higher than wild tea trees in Nandu, and close to the cultivated population. (4) Cluster analysis shows that the majority germplasm resources from Liubao town were clustered together except for several tea plants grouped with large-leaf tea cultivars from Yunnan province and a few resources were grouped into the same cluster with tea cultivars from Zhejiang and Guizhou provinces. The wild tea germplasm resources from Nandu town were grouped into the same cluster with two germplasm materials from Liubao town. In conclusion, it was showed that there are rich tea germplasm resources with high genetic diversity in Wuzhou city. This study might lay a solid foundation for the further studies to develop and utilize these tea resources. Reference | Related Articles | Metrics

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Effects of Air Conditions Preset for Withering on Flavor Quality and Chemical Profiles of White Teas ZHANG Yinggen, XIANG Lihui, CHEN Lin, LIN Qingxia, SONG Zhenshuo, WANG Lili Journal of Tea Science    2022, 42 (4): 525-536.   DOI: 10.13305/j.cnki.jts.2022.04.011 Abstract （377）      PDF（pc） （851KB）（208）       Knowledge map    Save To realize the quality control of white tea based on withering environment, indoor temperature and relative humidity were preset at (30±2)℃ with RH (35±5)% or (20±2)℃ with RH (55±5)% to investigate the effects of four different air conditions on the sensory quality and chemical profiles of 6 tea cultivars (Camellia sinensis), including Fuan-dabaicha, Huangdan, Huangguanyin, etc. According to whether the indoor temperature and relative humidity were mutually switched at the point when the weight loss rate of tea shoots reached 45% during the whole withering procedure, the levels of each withering treatment were named as Low-Low, Low-High, High-Low and High-High, respectively. The results show that the flavor quality of white tea was mainly determined by the physical and chemical characteristics of raw materials (tea cultivars). White teas obtained under Low-Low treatment had a slightly light taste and a little grassy flavor, while the white teas from the same tea cultivars had the similar quality characteristics in appearance and soup color when they were treated with High-High and Low-High, just as High-Low and Low-Low during withering. The ultraviolet and near-infrared spectra of all white tea samples had similar fluctuations, and the near-infrared spectra could provide more abundant chemical information for their pattern recognition. The contents of gallic acid, epicatechin gallate, gallocatechin, caffeine and theobromine in white tea samples were different among tea cultivars, but withering treatment had no significant effect on the contents of detected biochemical components (catechins and purine alkaloids). Moreover, principal component analysis based on ultraviolet spectra, especially near-infrared spectra or biochemical compositions of white tea samples could better discriminate white tea samples into the same groups according to their raw materials (tea cultivars). The effects of different air conditions on the profiles of spectra or biochemical compositions were exclusively drowned by the characteristics of raw materials. However, the influence of withering treatment on the profiles of near-infrared spectra and biochemical compositions of white tea samples manufactured from different raw materials could be effectively revealed by multilevel principal component analysis, and the classification and identification results of all white tea samples were almost consistent with the characteristics of sensory quality. These facts could provide a reference for the technological regulation of white tea flavor quality. Reference | Related Articles | Metrics

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The Antifungal Effect and Mechanism of Berberine on Different Colletotrichum Species Causing Tea Brown Blight Disease ZHANG Zhipeng, CHENG Qinghua, XIE Jingkang, WAN Yuhe, TONG Huarong, CHEN Yingjuan Journal of Tea Science    2022, 42 (3): 367-375.   DOI: 10.13305/j.cnki.jts.2022.03.006 Abstract （365）      PDF（pc） （2110KB）（156）       Knowledge map    Save To explore the application prospects of berberine on the prevention and control of tea diseases, the antifungal activity of berberine against five different Colletotrichum species (C. fioriniae, C. karstii, C. chongqinggense, C. camelliae and C. gloeosporioides) were studied and the differences in antifungal activities were compared. The results show that berberine has the best inhibitory effect on both C. camelliae and C. chongqinggense, reaching 100% at the concentration of 12 mg·mL-1, followed by C. gloeosporioides, C. karstii and C. fioriniae. The EC50 (Concentration for 50% of maximal effect) of the five Colletotrichum species were 2.828, 3.288, 4.164, 4.778 mg·mL-1 and 5.104 mg·mL-1, respectively. The conidial and hyphal morphology of five Colletotrichum species under the treatment of berberine were examined, showing that berberine had a significant impact on the mycelial and conidial growth of five Colletotrichum species. With the increase of berberine concentration, part of hyphae expanded irregularly and the conidia grew abnormally. Results of the biological activity of Colletotrichum species show that the cell structure was damaged, the permeability of cell membrane was increased and the cell oxidative stress response was enhanced. Results of this study firstly confirm the antifungal activity and application prospects of berberine against Colletotrichum species, which provided a new approach and theoretical basis for the prevention and control of tea disease caused by Colletotrichum. Reference | Related Articles | Metrics