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Basic Information about the Journal
Journal title: Journal of Tea science
Inscription of journal title: ZHU De
Responsible Institution: China Association for Science and Technology
Sponsored by: China Tea Science Society
Tea Research Institute, Chinese Academy of Agricultural Science
Editing and Publishing: Editorial Office, Journal of Tea science
Start time: 1964
No. of issues: Bi-monthly
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    Research Progress on Chemical Composition and Biological Activity of Liupao Tea
    MA Wanjun, MA Shicheng, LIU Chunmei, LONG Zhirong, TANG Baojun, LIN Zhi, LYU Haipeng
    Journal of Tea Science    2020, 40 (3): 289-304.   DOI: 10.13305/j.cnki.jts.2020.03.001
    Abstract403)      PDF(pc) (1369KB)(386)       Save
    Liupao tea is a kind of distinctive dark tea products in Guangxi Zhuang Autonomous Region with a long history of production and marketing. It has unique flavor quality characteristics and health-care effects, which has attracted much attention in recent years. In this paper, the research progress on chemical composition and biological activity of Liupao tea over the last 20 years was reviewed, and the future research interests of Liupao tea were also discussed preliminarily.
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    Analysis of the Tea Projects Supported by National Natural Science Foundation of China from 1999 to 2019
    XIONG Xingping, ZHANG Xinzhong, YANG Zhenwei
    Journal of Tea Science    2020, 40 (3): 305-318.   DOI: 10.13305/j.cnki.jts.2020.03.002
    Abstract332)      PDF(pc) (380KB)(300)       Save
    Based on the tea projects supported by National Natural Science Foundation of China (NSFC) from 1999 to 2019, a statistical analysis was carried out from the aspects of supporting year, category, department, nature of the supporting units, distribution of the supporting regions, project leaders and branches of disciplines. The current situation, characteristics and development trends of basic tea research in China were explored and the existing problems and shortcomings were discussed and analyzed. The purpose of study was to provide reference for the selection of ideas and scientific research development for tea scientists.
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    Analysis of Arbuscular Mycorrhizal Fungal Community Structure in the Rhizosphere of Different Tea Cultivars
    HE Fei, LI Donghua, BU Fan
    Journal of Tea Science    2020, 40 (3): 319-327.   DOI: 10.13305/j.cnki.jts.2020.03.003
    Abstract166)      PDF(pc) (343KB)(93)       Save
    In order to enrich the arbuscular mycorrhizal (AM) fungal germplasm resources of tea plants (Camellia sinensis) in China, the community structure of AM fungi in the rhizosphere soil of different tea cultivars grown in Hanshuiyun tea garden of Ankang City, Shaanxi Province were analyzed. The results show that species richness, species and genera composition of AM fungi in the rhizosphere soil varied with tea cultivars. A total of six AM fungal species were isolated from the rhizosphere soil of Ziyang population. Likewise, five from Shancha 1, four from Longjing Changye, four from Longjing 43, and three species from Fuding Dabai. Soil collected from the rhizosphere of Longjing Changye had the highest spore density (3.57 spores per gram of dry soil), while the lowest spore density (1.10 spores per gram of dry soil) was found in the rhizosphere of Longjing 43. The highest Shannon-Wiener and Pielou evenness indices were found in the rhizosphere of Ziyang population (0.63 and 0.096), whereas the lowest values were observed in the rhizosphere of Longjing Changye (0.18 and 0.027). The maximum mycorrhizal colonization (29.5%) was found in the rhizosphere of Longjing Changye, whereas the minimum value (15.8%) was observed in the rhizosphere of Fuding Dabai. The Sorenson’s similarity coefficient of AM fungal species composition among five tested tea cultivars ranged from 0.111 to 0.750, with the highest between Longjing Changye and Longjing 43, and the lowest between Fuding Dabai and Ziyang population. The results reveal obvious differences in AM fungal community composition among the five tea cultivars. The identified AM fungal resources in rhizosphere soil are of great significance for further screening, researching AM fungi agent, and promoting the development of tea industrialization.
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    Cloning and Expression Analysis of CssHSP18.1 Gene in Camellia Sinensis
    JIANG Junmei, FANG Yuanpeng, NING Na, CHEN Meiqing, YANG Zaifu, WANG Yong, LI Xiangyang, XIE Xin
    Journal of Tea Science    2020, 40 (3): 328-340.   DOI: 10.13305/j.cnki.jts.2020.03.004
    Abstract164)      PDF(pc) (1059KB)(59)       Save
    The sHSPs gene family encodes a class of small molecular heat shock proteins, which are widely distributed in plants, functioned as molecular chaperones, and play an important role in plant resistance to stresses. In this study, the open reading frame (ORF) of CssHSP18.1 gene cDNA was obtained by gene cloning, which is 480 bp in length and encodes 159 amino acids. Bioinformatics analysis showed that CssHSP18.1 protein contained a typical HSP20 domain. Its molecular weight and isoelectric point are about 18.25 kDa and 5.68 respectively. Phylogenetic tree analysis showed that CssHSP18.1 has the closest relationship with quercus and apple. It was predicted that CssHSP18.1 protein was does not have signal peptide and transmembrane structure. RT-qPCR analysis showed that the expression of CssHSP18.1 under D-Mannitol treatment was lower than that in the control group. GABA could enhance the expression of CssHSP18.1 with its peak at 1 h after GABA treatment. The expression of CssHSP18.1 was upregulated upon IAA and PEG 6000 treatments, and reached the peaks at 0.5 h. Thus, GABA、IAA、PEG 6000 could induce the expression of CssHSP18.1. To obtain CssHSP18.1 soluble protein, a recombinant plasmid pET-28a-CssHSP18.1 was constructed and expressed in prokaryotic system. The expression strains, induction temperatures and induction concentrations of IPTG (isopropyl- -D-thiopyranogalactoside) were optimized. The results showed that the best expression strain of CssHSP18.1 protein was BL21 (DE3), and the best induction temperature and IPTG concentration were 30℃ and 1.2 mmol·L-1 respectively. Finally, western blot was used to verify the expression of CssHSP18.1 protein. This study provided a basis for further study on the biological function of CssHSP18.1 gene.
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    Genetic and Phylogenetic Analysis for Resources of Camellia Sinensis from Kaihua County in Zhejiang Province
    YU Shuping, XU Liyi, WU Rongmei, WANG Liyuan, WU Liyun, WEI Kang, CHENG Hao, WANG Yongqi
    Journal of Tea Science    2020, 40 (3): 341-351.   DOI: 10.13305/j.cnki.jts.2020.03.005
    Abstract123)      PDF(pc) (1454KB)(84)       Save
    In this study, various tea resources from Kaihua County were collected to evaluate genetic diversity and phylogenetic relationships among individuals by SSR markers. Meanwhile, suitable core marker combinations were screened to construct fingerprint map. The results show that: (1) 14 SSR markers were polymorphic in the samples. The number of alleles per SSR locus was from 3 to 6 with the mean value of 4.14, and the average number of effective alleles was 3.08. (2) each germplasm resource could be identified by using 14 SSR markers. And based on the analysis of complex loci, the value of PE-1 and PE-3 were over 0.99 and PE-2 over 0.95, respectively, when 10 core SSR loci, as a simplified combination, were successfully screened to distinguish 36 germplasm resources. (3) 36 samples were divided into three groups based on UPGMA phylogenetic tree, and it was preliminarily speculated that five combinations might have parent-child relationship in the sample group through phylogenetic analysis. Present study indicated that tea germplasms in Kaihua County displayed highly diverse genetic backgrounds and might provide useful plant resources for breeding of new cultivars.
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    Analysis of Fat Content and Fatty Acid Composition and Absolute Content in the Tea Seeds from Southern Henan Tea Germplasms
    CHANG Yali, HUANG Xiaobing, JIANG Shuangfeng, HUANG Shuangjie, SUN Mufang, LIU Wei, GUO Guiyi
    Journal of Tea Science    2020, 40 (3): 352-362.   DOI: 10.13305/j.cnki.jts.2020.03.006
    Abstract134)      PDF(pc) (404KB)(69)       Save
    The kernel percentage, fat content and fatty acid composition and absolute content of the seed kernel of 42 tea germplasm materials from Southern Henan were analyzed in this paper. The results show that the kernel percentage ranged from 33.53% to 71.60%, the fatty content was determined with Soxhlet extraction, varied from 17.77% to 38.39%, totally, 21 fatty acids were identified by GC-MS, and the range of main fatty acid contents, including palmitic acid, stearic acid, cis-oleic acid, linoleic acid and α-linolenic acid, were 2.64%-5.70%, 0.21%-1.11%,7.33%-17.29%, 0.09%-8.44% and 0.01%-0.15%, respectively. Correlation analysis shows that cis-oleic acid was significantly negatively correlated with tridecanoic acid, myristic acid and cis-eicosadienoic acid, linoleic acid was significantly negatively correlated with trans-oleic acid and cis-docosahexaenoic acid. The content ratio of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids of seed kernel of Shuixian 7202 was 3.08∶12.16∶1, and others’ were around 1∶2.69∶1.37. According to higer kernel percentage and fat content of seed kernel, a total of eight tea cultivars including Zhonghuang 1, Nongkangzao, Yingshuang, Echa 11, Longjing 43, Zhongxuan 8, Laoshan 3 and Huangjinye were initially screened as candidate cultivars for constructing tea garderns harvesting leaf and seed.
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    Identification and Expression Analysis of Terpene Synthesis Related Genes during the Withering of White Tea
    CHEN Xuejin, WANG Pengjie, LIN Xinying, GU Mengya, ZHENG Yucheng, ZHENG Zhilin, YE Naixing
    Journal of Tea Science    2020, 40 (3): 363-374.   DOI: 10.13305/j.cnki.jts.2020.03.007
    Abstract171)      PDF(pc) (1459KB)(215)       Save
    Terpenes are the important secondary metabolites in plants and play an important role in the composition of the volatile aroma of tea plants. In this study, 141 tea plant terpenoid synthesis-related genes were identified from the tea plant genome database. Their expression specificities in different tissues were analyzed. Sixteen terpene synthetic genes which were highly expressed in the apical buds and young leaves of tea plants were screened. The results of bioinformatics methods show that the phylogenetic relationship divides the genes related to terpene synthesis of tea plant, Arabidopsis and grape into four subfamilies. The terpenoid synthesis related genes contain 5 to 14 exons and a large number of cis-related elements closely related to light response, plant growth and development, hormone and stress response according to the upstream promoter region analysis. Fluorescence quantitative detection showed that the expressions of CsMVK, CsDXS and CsGGPS were significantly up-regulated during the withering process of white tea. The expressions of CsDXR, CsMCT, CsCMK, CsMCS, CsHDS, CsGPPS and CsGGPPS showed the highest expressions at 4 h and 24 h after withering. The results of this study provided a theoretical basis for further exploring the functions of terpenoid synthesis related genes in tea.
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    Parameter Optimization and Experimental Study of Tea Twisting Machine Based on EDEM
    LI Bing, LI Weining, BAI Xuanbing, HUANG Jianhong
    Journal of Tea Science    2020, 40 (3): 375-385.   DOI: 10.13305/j.cnki.jts.2020.03.008
    Abstract115)      PDF(pc) (3748KB)(130)       Save
    To solve the problems caused by unstable quality in the process of tea twisting, the 6CR-40 tea twisting machine was taken as the research object in this study. The three-dimensional modeling of tea twisting machine was established based on Solidworks. The numerical simulation of the twisting process of tea twisting machine was carried out by the discrete element simulation software EDEM. The influences of various experimental factors on the performance indexes of tea twisting machine were obtained. The quadratic orthogonal rotation test was carried out and the Design-Expert was used to optimize the solution and obtain the best combination of structural parameters of twisting quality. The results showed that: when the twisting barrel rotational speed, the prismatic height, twisting plate inclination angles, forming rate of tea and breaking rate of tea were 42 r·min-1, 10 mm, 3.8°, 88.55% and 1.83% respectively, the tea twisting machine had a good quality of twisting. The results of verification test and simulation optimization were basically consistent.
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    A Preliminary Study on the Degradation Pathway of Caffeine in Tea Microbial Solid-state Fermentation
    ZHENG Chengqin, MA Cunqiang, ZHANG Zhengyan, LI Xiaohong, WU Tingting, ZHOU Binxing
    Journal of Tea Science    2020, 40 (3): 386-396.   DOI: 10.13305/j.cnki.jts.2020.03.009
    Abstract141)      PDF(pc) (1079KB)(94)       Save
    In order to explore caffeine degradation products and pathways under the action of microorganisms, the dominant strains including Aspergillus sydowii NRRL250, Aspergillus pallidofulvus NRRL4789, Aspergillus sesamicola CBS137324 and Penicillium mangini CBS253.31 were screened and identified during pu-erh tea fermentation. Strains were inoculated into sun-dried green tea leaves for solid-state fermentation. High performance liquid chromatography (HPLC) was used to determine caffeine, theobromine and theophylline contents to explore the effect of microorganisms on caffeine metabolism. UHPLC-QTOF-MS was used for the metabonomic analysis of Aspergillus sydowii inoculated fermentation with sterilization treatment group (ST group) and raw material group (RM group). The results show that the dominant strains such as A. pallidofulvus NRRL4789, A. sesamicola CBS137324 and Penicillium mangini CBS253.31 had no significant effects on the metabolism of caffeine and other purine alkaloids. However, caffeine content was decreased significantly (P<0.05) with a great reduction about 83.89% during the inoculated fermentation of Aspergillus sydowii. Additionally, theophylline content was increased significantly (P<0.05) and arrived to (25.03±1.17) mg·g-1 at the end of fermentation. While theobromine content remained stable. Therefore, Aspergillus sydowii has a profound effect on caffeine degradation metabolism. Nine metabolites related to caffeine degradation were detected by UHPLC-QTOF-MS during the inoculated fermentation, Among them, theophylline, 3-methylxanthine, 1,7-dimethylxanthine and 7-methylxanthine contents were significantly increased (P<0.05) under the action of Aspergillus sydowii which were related to N-demethylation pathway of caffeine and its related metabolites. 1,7-dimethyluric acid and 1-methyluric acid were related to the oxidation pathway of caffeine-related metabolites. It can be seen that Aspergillus sydowii is the dominant strain that can degrade caffeine and has the potential ability to convert caffeine into theophylline. Under the action of spergillus sydowii, both N-demethylation and oxidation were found in caffeine degradation metabolism, and the former was the dominant.
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    Determination of Pesticide Residue in Fresh Tea Leaves and Dry Tea by Solid Extraction and Dispersive Solid Extraction Cleanup Coupled with Tandem Mass Spectrum
    YANG Jie, ZHOU Li, YU Huan, SUN Hezhi, WANG Xinru, ZHANG Xinzhong, YANG Mei, CHEN Zongmao, LUO Fengjian
    Journal of Tea Science    2020, 40 (3): 397-406.   DOI: 10.13305/j.cnki.jts.2020.03.010
    Abstract97)      PDF(pc) (426KB)(154)       Save
    A method for the determination of 9 pesticide residues in fresh and dry tea was established. Residual pesticides in samples were extracted by acetonitrile, purified by Florisil/GCB solid phase extraction column, followed by absorbent of PSA and GCB as dispersed solid phase, and determined by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and gas chromatography-mass spectrometry (GC-MS). In the spiked range of 0.005-1.000 mg·kg-1, the average recoveries of target pesticides in fresh leaves and dried tea were 70.3%-103.9%, and the relative standard deviations (RSD) were less than 20%. In the range of 0.005-2.000 mg·kg-1, the linear relationship of target pesticides in fresh leaves and dry tea matrix was good, with r>0.995 4. The limit of quantity (LOQ) was 0.005 mg·kg-1. The test results of actual samples showed that the method was highly sensitive and reproducible, and can meet the requirements of multi-residue detection.
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    The Intergative Effects of Epigallocatechin-3-gallate and Vitamin C on Serum Uric Acid Levels in Hyperuricemic Mice
    XU Yan, CAI Xiaqiang, XIE Qianjin, TAI Lingling, LIU Zenghui
    Journal of Tea Science    2020, 40 (3): 407-414.   DOI: 10.13305/j.cnki.jts.2020.03.011
    Abstract150)      PDF(pc) (1457KB)(78)       Save
    KM male mice were used as subjects of the study. Yeast extracts (7.5 g·kg-1) and potassium oxonate (250 mg·kg-1) were administered to establish the hyperuricemic mice model. The study aimed to investigate the integrative effect of EGCG and vitamin C (Vc) on serum uric acid levels of hyperuricemic mice. Mice were randomly divided into 6 groups (n=6): blank group, model group, allopurinol group, EGCG group, EGCG + Vc group and Vc group. The biochemical indexes of mice were measured after 7 d of continuous administration. The results show that the serum uric acid (UA), serum urea nitrogen (BUN) and creatinine (Cr) of EGCG + Vc group were significantly lower than those of the model group (P<0.001). The combination of EGCG and Vc could remarkably inhibited the activities of adenosine deaminase (ADA) and xanthine oxidase (XOD) in the liver (P<0.05 or P<0.01) and significantly down-regulated the expression of glucose transporter 9 (GLUT9) in the kidney (P<0.001). The results of kidney slices indicated that EGCG + Vc could obviously improve the damages to the kidney in hyperuricemic mice. In addition, the integrative effect of EGCG + Vc on hyperuricemic mice was better than that of EGCG.
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    Study on Pattern Evolution and Spatial Agglomeration of Tea Production: A Case Study of Guangdong Province
    HUANG Xiujie, YAO Fei, MA Li, CHU Xialing
    Journal of Tea Science    2020, 40 (3): 415-429.   DOI: 10.13305/j.cnki.jts.2020.03.012
    Abstract138)      PDF(pc) (3066KB)(56)       Save
    Analyzing the evolution characteristics and agglomeration effect of tea production pattern is of great significance to the planning and layout of tea industry in Guangdong Province. In this study, the spatial gravity center model was introduced. The pattern evolution process and characteristics, and the spatial agglomeration effect of tea production in Guangdong Province were analyzed by using GIS technology and spatial autocorrelation analysis method. Results show that: (1) The planting area and yield of tea in Guangdong Province increased steadily from 1992 to 2017, and the growth rate was more obvious after 2008. (2) There were significant spatial differences in tea production in Guangdong. The northern and eastern Guangdong accounted for more than 85% of the planting area, and more than 83% of yield in Guangdong. The reduction in western Guangdong and the Pearl River Delta was obvious. (3) The center of gravity of tea production in Guangdong Province tended to move eastward and northward. The eastward shift of gravity center of tea planting area and yield reflected that the tea production has been gradually concentrated in east and north of Guangdong. (4) The spatial polarization and spillover of tea production in Guangdong Province were significant. The tea production agglomeration areas in Raoping, Chaoan, Dapu, Fengshun, Wuhua, Xingning, Yingde and Dongyuan were formed, which constituted the ‘hot spots’ of tea production in Guangdong Province, and they had stimulating effects on surrounding counties and cities. (5) Geographical environment and other natural factors were the basis for the expansion of area, the incentive and support of government policy was an important driving force for the formation of tea industry, the huge market consumption power was the direct factor of the rapid development of tea industry, the application and popularization of new cultivars and technologies were the important reasons for the expansion of tea planting area. The results indicate that the spatial agglomeration effect of tea production in Guangdong Province needs to be further strengthened. Next, it is necessary to promote the clustering development of tea production according to regional natural resources, geographical conditions and planting traditions, so as to enhance the market competitiveness of tea in Guangdong Province.
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    Research Progress of Tea Aroma Based on CiteSpace Visual Analysis
    YIN Xia, HUANG Jian'an, HUANG Jing, BAO Xiaocun, ZHOU Lingyun, LI Wei, LIU Hongyan, ZHANG Shuguang, LIU Zhonghua
    Journal of Tea Science    2020, 40 (2): 143-156.   DOI: 10.13305/j.cnki.jts.2020.02.001
    Abstract324)      PDF(pc) (1249KB)(223)       Save
    In this paper, the literatures collected by WOS (Web of science) and CNKI from 1979-2019 were taken as the research object. CiteSpace's bibliometric method was used to analyze the aroma quality of tea from the aspects of age, author, institution, country, research hotspot, evolution trend, etc. The results show that the literatures of tea aroma research had a significant growth trend since 2006. Currently, a stable core group of authors had been formed but there were little cooperation among these groups. China had the largest research influence in this field, followed by Japan and the United States. The hot research areas mainly focused on the following topics: the mechanism of aroma formation, the extraction and detection methods of aroma substances, and the key aroma compounds. According to the time zone map, the research progress and development stage of tea aroma at present were pointed out.
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    The Inhibitory Role and Mechanism of White Tea Extracts on Pulmonary Fibrosis Induced by Nano-sized SiO2 in Rats
    PARK Soomi, KIM Eunhye, CHEN Xinghua, WANG Qianchao, HE Puming, TU Youying
    Journal of Tea Science    2020, 40 (2): 157-164.   DOI: 10.13305/j.cnki.jts.2020.02.002
    Abstract111)      PDF(pc) (5033KB)(104)       Save
    Fifty-four Wistar rats were randomly divided into six groups: control group, model group, white silver needle extract group, high and low dose white peony extracts and EGCG group, with 9 rats in each group. The other five groups except the control group were treated with nano-sized SiO2 dust (80 mg·mL-1) by non-exposed endotracheal intubation. After two weeks of intragastric administration, the contents of hydroxyproline(HYP), nitric oxide (NO), superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px) and the morphological changes of lung tissues were detected. The results show that compared with the model group, the pathological changes of each white tea extract treatment group and EGCG group were alleviated in varying degrees, and the effect of white silver needle extract group was the best. The content of NO and inflammatory factor IL-6 in lung of rats treated with white tea extract and EGCG were significantly lower than those of model group (P<0.05), GSH-Px activity was higher than that of model group (P<0.05). High-dose white peony extract group had the best effect on reducing NO content and increasing GSH-Px activity. This study shows that white tea extract had a significant effect on oxidative stress injury of lung fibrosis induced by nano-sized SiO2 in rats. The slow and repairing effects are mainly related to the antioxidant effect and the inhibition of inflammatory reaction.
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    Effects of ‘Eurotium cristatum Loose Tea’ and ‘Eurotium cristatum Powder’ on the Expressions of JAK2/STAT3 Inflammation and Phosphorylated Proteins in Lung Tissue of Passive Smoking Mice
    ZENG Hongzhe, HUANG Xiangxiang, YU Lijun, ZHOU Yufei, XU Shuai, QU Furong
    Journal of Tea Science    2020, 40 (2): 165-172.   DOI: 10.13305/j.cnki.jts.2020.02.003
    Abstract170)      PDF(pc) (1655KB)(138)       Save
    In order to investigate the prevention and recovery mechanism of ‘Eurotium cristatum Loose Tea’ and its ‘Eurotium cristatum powder’ on mouse lung tissues which were injured by passive smoking, passive cigarette smoking environment (CSE) model on SPF C57BL/6 female mice were established. Mice were fed by 600 mg∙kg-1 Eurotium cristatum tea extract (ECTE) and Eurotium cristatum powder extract (ECPE). Comparing with the CSE model mice, the morphology integrity of lung tissue in passive smoking mice feeding with ECPE and ECTE were significantly protected by observing the pathological slice of lung tissue. The up-regulation levels of IL-6, IL-8, IL-1β, IFN-γ and TNF-α in the serum of mice were inhibited by ELISA analysis. Western blot results show that the expression levels of p-JAK2, p-STAT3, p-JAK2/JAK2, p-STAT3/STAT3 in lung tissues of passive smoking mice fed with ECPE and ECTE were inhibited. These results reveal the prominent protective roles of ECPE and ECTE in the lung injury of passive smoking mice. As a whole, ECPE feeding groups were superior to ECTE feeding groups, while prevention groups were better than treatment groups.
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    Study on Soil Selenium Content and Its Influencing Factors in Typical Tea Garden of Fujian Province
    YU Wenquan, WANG Feng, CHEN Yuzhen, SHANG Riyang, YOU Zhiming, ZANG Chunrong, CHEN Changsong
    Journal of Tea Science    2020, 40 (2): 173-185.   DOI: 10.13305/j.cnki.jts.2020.02.004
    Abstract177)      PDF(pc) (350KB)(116)       Save
    A total of 60 samples of surface soils (0-20 cm) were collected from main tea producing areas of Fujian province to assess the total and available soil selenium. Their relations with soil physical and chemical properties were also discussed. The results show that content of total selenium in the surface soils ranged from 0.22 mg·kg-1 to 2.20 mg·kg-1 with an average of 0.73 mg·kg-1, and 86.67% of the soils belonged to Se-rich soils. The ranges of available selenium in soil were from 5.21 to 448.86 μg·kg-1, with a mean of 62.98 μg·kg-1. The available rate of selenium ranged from 1.10% to 31.64%, with a mean of 8.76%. The total and available selenium contents in soils from glutenite and tuff were higher, and those in soils from purple sandstone and river alluvium were lower. For different soil types, alpine meadow soil showed the highest total and available selenium content, while moisture sand yand paddy soils were relatively lower. The total and available selenium contents in mature and old tea gardens were the highest, and the young tea garden was the lowest. The total and available selenium contents in the middle-high elevation tea garden were the highest, and the low elevation tea garden was the lowest. Selenium content in tea garden soil was significantly positively correlated with soil organic matter and total nitrogen contents. Whereas the soil pH also significantly affect the selenium content in red soil and young tea garden. And, the soil available phosphate was also a significant effect on selenium content in mature and middle-high elevation tea garden. In general, the Se-enriched soils in the tea gardens provided a source guarantee for the development of Se-enriched tea. However, the effectiveness of soil selenium was not high and should be adjusted in tea garden via different cultivation measures (additional application of organic fertilizers, ameliorant and calcium magnesium phosphate fertilizers) to increase availability selenium content.
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    Acidification Characteristics and Nutrient Contents in Soils of Tea Garden and Adjacent Woodland in Subtropical Region
    LIN Cheng, CHEN Zicong, WU Yiqun, YAN Mingjuan
    Journal of Tea Science    2020, 40 (2): 186-193.   DOI: 10.13305/j.cnki.jts.2020.02.005
    Abstract143)      PDF(pc) (300KB)(79)       Save
    In this study, 38 tea garden and adjacent woodland were chosen in An’xi county to investigate soil pH and nutrient changes. The results show that, soil pH was decreased by 0.031 units per year from 4.81 in woodland to 4.17 in tea garden. Contrast to woodland, the ratio of tea-grown soils with pH 4.0-4.5 and pH<4.0 were increased by 27% and 36.8%, which significantly increased the contents of total exchangeable acid, exchangeable H+ and exchangeable aluminum Al3+. After the conversion of forest land to tea garden, the contents of soil total nitrogen, hydrolysable nitrogen, available phosphorus and available potassium were increased by 0.29 g·kg-1, 33.39 mg·kg-1, 59.06 mg·kg-1 and 29.75 mg·kg-1, respectively. Furthermore, the C/N ratio was significantly decreased by 5.67. With the increase of tea planting years in tea garden, the contents of total nitrogen, hydrolysable nitrogen, available phosphorus were increased significantly. The change of soil pH was significantly and negatively correlated with those of soil hydrolysable nitrogen, available phosphorus and available potassium. The average contents of hydrolysable nitrogen, available phosphorus and available potassium would be increased by 63.92 mg·kg-1, 52.45 mg·kg-1 and 55.84 mg·kg-1 when soil pH was decreased by 1 unit. When the environmental threshold is reached, there is a risk of phosphorus pollution to the environment. The survey results show that the tea garden in Anxi County needs to increase the input of organic fertilizer and carry out targeted formula fertilization to slow down the acidification trend of soil.
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    Study on the Changes of Physical and Chemical Components during the Frying Process of Green Tea by Computer Vision
    WU Xun, LIU Fei, CHEN Zhiwei, WANG Yuwan, CHEN Lin, TU Zheng, ZHOU Xiaofen, YANG Yunfei, YE Yang, TONG Huarong
    Journal of Tea Science    2020, 40 (2): 194-204.   DOI: 10.13305/j.cnki.jts.2020.02.006
    Abstract147)      PDF(pc) (965KB)(139)       Save
    In order to find out the physical and chemical changes during the frying process of green tea, the computer vision technology was applied to real-time monitor the changes of color and shape, and chemical changes were simultaneously measured. The results show that with the increase of frying time, (1) the radius of curvature of unfinished tea gradually decreased, which showed the highest decreasing rate from 10-30 min. R, G, B and average gray value decreased first and then rose. The consistency value was opposite to their trends, with the extreme value in 20 min. H value increased significantly, S value decreased significantly. (2) Epigallocatechin gallate (EGCG), epigallocatechin (EGC), chlorophyll a, chlorophyll b and carotenoids decreased significantly, while gallocatechin gallate (GCG) increased significantly. Experimental results show that the radius of curvature was highly correlated with water content and leaf temperature. H was significantly correlated with chlorophyll a, chlorophyll b. S was significantly correlated with chlorophyll a, carotenoids and epicatechin gallate (ECG). The linear fit of EGCG and H values showed the highest value at 0.922 1. In the future, water content, leaf temperature and H value could be monitored online to predict changes of the radius of curvature and chemical composition during frying.
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    Estimation of Greenhouse Gas Emissions from Fertilization, Production and Transportation of Synthetic Nitrogen for Tea Garden in Typical Region of China
    WANG Feng, CHEN Yuzhen, WU Zhidan, JIANG Fuying, ZHANG Wenjin, WENG Boqi, YOU Zhiming
    Journal of Tea Science    2020, 40 (2): 205-214.   DOI: 10.13305/j.cnki.jts.2020.02.007
    Abstract78)      PDF(pc) (269KB)(61)       Save
    In this research, the amount of greenhouse gas emissions from fertilization, production and transportation of synthetic nitrogen for tea garden in typical region of China was assessed based on the analysis of statistical data using a data mining method. The results show that direct N2O emissions from soil and greenhouse gas emissions (CO2 emission equivalents) from the production of synthetic N fertilizers were the main sources of greenhouse gas emissions from synthetic N fertilization in tea garden. In 14 typical regions, the total greenhouse gas emissions from synthetic N fertilization were 168.1-3 448.0 kt CO2 equivalent per year. And Guizhou, Yunan, Hubei and Sichuan were the top four provinces with high greenhouse gas emissions from synthetic N fertilization. Over 2 000 kt CO2 equivalent per year occurred in each province, which accounted for 59.98% of the total emissions. The greenhouse gas emissions per unit area, per yield and per output value was 3.22-9.76 t CO2 equivalent per hectare, 2.10-12.96 t CO2 equivalent per ton of dry semifinished tea and 0.39-1.90 t CO2 equivalent per 10 000 yuan. In general, the total greenhouse gas emissions, emissions per unit area, per yield and per output value from synthetic N fertilization were mainly concentrated in Guizhou, Yunan, Hubei, Hunan and Sichuan provinces, and the relatively low total emissions and emission intensity were happened in Fujian, Henan provinces and Chongqing city. It was concluded that reducing the synthetic N application rate for tea garden in China to a reasonable level of 300 kg·hm-2 and 450 kg·hm-2 could greatly reduce the emission of greenhouse gases. And the estimated mitigation potential of greenhouse gas emissions for these provinces were 6 170.7, 2 289.4 kt CO2 equivalent per year, and reduce the total greenhouse gas emissions by 34.12% and 12.66%. Notably, Hubei, Sichuan, Guizhou, Hunan and Jiangxi provinces were the leaders of the mitigation potential of greenhouse gas emissions, and these areas should focus on reducing greenhouse gas emissions.
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    Effects of Different Types of Water Quality on the Sensory Properties and Main Chemcial Compositions of Longjing Tea Infusions
    GONG Zhiping, YIN Junfeng, CHEN Gensheng
    Journal of Tea Science    2020, 40 (2): 215-224.   DOI: 10.13305/j.cnki.jts.2020.02.008
    Abstract182)      PDF(pc) (508KB)(126)       Save
    In order to understand the effect of water quality on the flavor of tea infusions, six typical drinking water (including tap water, Wahaha Purified water, Hupao cold spring water, C cell vitality small molecule group water, 5100 Tibet glacier mineral water, Jianlong volcano cold mineral water) were selected as the research objects. The effects of different types of water quality on the flavor quality and chemical composition of tea infusions were studied by sensory evaluation and component analysis. The results show that the purified water and Hupao cold spring water were weakly acidic, and had low Ca2+, Mg2+ and total ion contents, which were more suitable to brew Longjing tea. In terms of the quality of flavor, it could better control the bitterness, astringency and freshness of tea soup, and reflect the richness and purity of the unique aroma of the tea infusions. Through the analysis of flavor substances, with the increase of ion concentration of drinking water, the contents of tea polyphenols, amino acids, EGCG, ester catechins and oxalic acid in the tea infusions were significantly reduced. The contents of caffeine and total sugar were not significantly different. The flavonoid content slightly increased. The mineral water with higher concentrations of Ca2+ and Mg2+ effectively inhibited the release of 17 characteristic aroma components of Longjing tea infusions, such as linalool, Trans-butyrate-3-hexene ester, dodecane, tetradecyl, cis-3-Hexenyl isovalerate, geraniol and β-ionone. This study analyzed the effect of water quality on the composition of tea flavor substances and the volatility of aroma substances, and preliminarily determined that the water quality factor was the main reason for the taste difference of Longjing tea infusions. This research preliminarily illuminated the effect of water quality on the flavor composition and aroma volatilization of tea infusions,and the results provided a theoretical basis for tea flavor chemistry, scientific tea making and water selection for tea beverage manufacturing.
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