Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 37
Filter
1.
J Sci Food Agric ; 102(15): 6858-6867, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35654754

ABSTRACT

BACKGROUND: High-quality tea requires leaves of similar size and tenderness. The grade of the fresh leaves determines the quality of the tea. The automated classification of fresh tea leaves improves resource utilization and reduces manual picking costs. The present study proposes a method based on an improved genetic algorithm for identifying fresh tea leaves in high-speed parabolic motion using the phenotypic characteristics of the leaves. During parabolic flight, light is transmitted through the tea leaves, and six types of fresh tea leaves can be quickly identified by a camera. RESULTS: The influence of combinations of morphology, color, and custom corner-point morphological features on the classification results were investigated, and the necessary dimensionality of the model was tested. After feature selection and combination, the classification performance of the Naive Bayes, k-nearest neighbor, and support vector machine algorithms were compared. The recognition time of Naive Bayes was the shortest, whereas the accuracy of support vector machine had the best classification accuracy at approximately 97%. The support vector machine algorithm with only three feature dimensions (equivalent diameter, circularity, and skeleton endpoints) can meet production requirements with an accuracy rate reaching 92.5%. The proposed algorithm was tested by using the Swedish leaf and Flavia data sets, on which it achieved accuracies of 99.57% and 99.44%, respectively, demonstrating the flexibility and efficiency of the recognition scheme detailed in the present study. CONCLUSION: This research provides an efficient tea leaves recognition system that can be applied to production lines to reduce manual picking costs. © 2022 Society of Chemical Industry.


Subject(s)
Algorithms , Support Vector Machine , Bayes Theorem , Plant Leaves , Tea
2.
J Agric Food Chem ; 69(10): 3154-3164, 2021 Mar 17.
Article in English | MEDLINE | ID: mdl-33666433

ABSTRACT

Methyl jasmonate (MeJA), a volatile organic compound, is a principal flowery aromatic compound in tea. During the processing of black tea, MeJA is produced by jasmonic acid carboxyl methyltransferase (JMT) of the jasmonic acid (JA) substrate, forming a specific floral fragrance. CsJMT was cloned from tea leaves; the three-dimensional structure of CsJMT was predicted. Enzyme activity was identified, and protein purification was investigated. Site-directed deletions revealed that N-10, S-22, and Q-25 residues in the beginning amino acids played a key functional role in enzyme activity. The expression patterns of CsJMT in tea organs differed; the highest expression of CsJMT was observed in the fermentation process of black tea. These results aid in further understanding the synthesis of MeJA during black tea processing, which is crucial for improving black tea quality using specific fragrances and could be applied to the aromatic compound regulation and tea breeding improvement in further studies.


Subject(s)
Odorants , Tea , Acetates , Cyclopentanes , Methyltransferases , Oxylipins , Plant Breeding
3.
Chinese Acupuncture & Moxibustion ; (12): 1283-1290, 2021.
Article in Chinese | WPRIM | ID: wpr-921046

ABSTRACT

By searching the randomized controlled trials (RCTs) of acupuncture and moxibustion from CNKI since its inception date to december 31 of 2019, the development status and hot trend of RCTs of acupuncture and moxibustion in China were summarized. The CiteSpace and VOSviewer software were used to perform keyword co-occurrence analysis, clustering analysis, time-zone analysis and citation-burst analysis, and visual map was drawn. As a result, a total of 60 995 articles were included, which were published in 1027 academic journals with 1787 keywords. The publication date was from 1975 to 2019. During the past 45 years, the publications of RCTs on acupuncture and moxibustion had shown an overall growth trend with characteristics of the times. The RCTs of manual acupuncture ranked the top, and its proportion of publications every 5 years was stable in the past 30 years. Since 1994, the hot words such as electroacupuncture, warming needling, auricular point sticking and various acupoint therapies had emerged; meanwhile, the spectrum of diseases had broadened, and an evolutionary trend corresponding to therapies and disease systems had been formed. In recent decade, the RCTs using moxibustion therapy have increased significantly, and the hot words such as "sub-health" "winter diseases being treated in summer" and "acupoint application/ moxibustion during the dog days" had indicated that acupuncture clinical research was further inclined to the field of chronic disease prevention and health services, which was in line with social development and the needs of the times.


Subject(s)
Acupuncture , Acupuncture Points , Acupuncture Therapy , Moxibustion , Randomized Controlled Trials as Topic
4.
Wei Sheng Yan Jiu ; 49(5): 795-801, 2020 Sep.
Article in Chinese | MEDLINE | ID: mdl-33070827

ABSTRACT

OBJECTIVE: To study effect of nano-selenium and nano-cerium(nano cerium oxide) on the spermatogenic ability of mice irradiated by 1800 MHz microwave radiation(MR). METHODS: Forty-two ICR mice were randomly divided into groups: blank control group, solvent control group, microwave radiation model group, low, medium and high dose groups of nano-selenium+nano-cerium. In joint effects groups of nano-selenium and nano-cerium, the nano-selenium solution(60, 120 and 240 µg/kg) and the nano-cerium oxide solution(15, 30, 60 µg/kg) were administered to the stomach at 7:30 in the morning and 18:30 in the evening, respectively. The blank control group was orally administered with an equal volume of distilled water, and the solvent control group and the MR group were orally administered with an equal volume of carboxymethylcellulose sodium solution. During the second week of gastric administration, the mice were exposed to microwave radiation(1800 MHz) for 2 h every day(specific absorption ratio: 0. 2986 W/kg). After MR treatment, the daily sperm production of testis, sperm motility and sperm deformity rate in epididymis were measured, and the testicular marker enzymes [G6 PDH(6-phosphatedehydrogenase), ACP(acid phosphatase), LDH(lactate dehydrogenase)], antioxidant indexes [CAT(catalase), MDA(malondialdehyde) and T-AOC(total antioxidant capacity)] in testicular tissue were analyzed. RESULTS: Compared with the solvent control group, MR led to the decrease of sperm motility and the increase of sperm deformity rate, decreased the enzymes activities of G6 PDH, ACP and CAT, increased LDH activity and MDA content, and decreased the T-AOC level in testicular tissue, and the differences were statistically significant(P<0. 05). Compared with the MR group, the joint action of nano-selenium and nano-cerium with medium dose increased the daily sperm production of testis((18. 98±1. 27) ×10~6/g) vs. (15. 53±1. 24) ×10~6/g), decreased the sperm deformity rate(11. 74%±0. 91% vs. 16. 84%±2. 05%), and the joint action of nano-selenium and nano-cerium with medium and high dose increased the sperm motility in epididymis(61. 98%±6. 33%, 54. 17±4. 38 vs. 45. 16%±5. 01%), and the differences were statistically significant(P<0. 05). Compared with the MR group, the joint action of nano-selenium and nano-cerium with low and medium dose increased the activity of ACP(11. 07±0. 98, 14. 85±1. 39 vs. 8. 72±0. 91 nmol/(min·mg prot), P<0. 05). The joint action of nano-selenium and nano-cerium with medium and high dose increased the activity of G6 PDH(24. 12±2. 06, 21. 36±3. 65 vs. 15. 11±1. 73 nmol/(min·mg prot), P<0. 05) and decreased the activity of LDH(15. 52±1. 17, 13. 51±1. 68 vs. 22. 46±2. 01 nmol/(min·mg prot), P<0. 05). The joint action of nano-selenium and nano-cerium with medium dose increased the activity of CAT(17. 92±2. 03 vs. 11. 69±0. 87 nmol/(min·mg prot), P<0. 05) and decreased the content of MDA(5. 17 ±0. 62 vs. 9. 03 ±0. 63 nmol/mg prot, P<0. 05). The joint action of nano-selenium and nano-cerium with low, medium and high dose increased the level of T-AOC(22. 06±1. 54, 29. 36±2. 39, 21. 01±2. 47 vs. 12. 88±1. 82 U/mg prot, P<0. 05). CONCLUSION: The joint addition of nano-selenium and nano-cerium can improve the reproductive function of male mice exposed to MR, and can effectively alleviate the changes of mouse testicular marker enzyme activity and the decline of antioxidant capacity caused by MR.


Subject(s)
Selenium , Animals , Antioxidants , Humans , Male , Mice , Mice, Inbred ICR , Microwaves , Sperm Motility
5.
Spectrochim Acta A Mol Biomol Spectrosc ; 237: 118403, 2020 Aug 15.
Article in English | MEDLINE | ID: mdl-32361319

ABSTRACT

Near-infrared (NIR) spectroscopy is an effective tool for analyzing components relevant to tea quality, especially catechins and caffeine. In this study, we predicted catechins and caffeine content in green and black tea, the main consumed tea types worldwide, by using a micro-NIR spectrometer connected to a smartphone. Local models were established separately for green and black tea samples, and these samples were combined to create global models. Different spectral preprocessing methods were combined with linear partial-least squares regression and nonlinear support vector machine regression (SVR) to obtain accurate models. Standard normal variate (SNV)-based SNV-SVR models exhibited accurate predictive performance for both catechins and caffeine. For the prediction of quality components of tea, the global models obtained results comparable to those of the local models. The optimal global models for catechins and caffeine were SNV-SVR and particle swarm optimization (PSO)-simplified SNV-PSO-SVR, which achieved the best predictive performance with correlation coefficients in prediction (Rp) of 0.98 and 0.93, root mean square errors in prediction of 9.83 and 2.71, and residual predictive deviations of 4.44 and 2.60, respectively. Therefore, the proposed low-price, compact, and portable micro-NIR spectrometer connected to smartphones is an effective tool for analyzing tea quality.


Subject(s)
Caffeine/analysis , Catechin/analysis , Food Analysis/instrumentation , Spectroscopy, Near-Infrared/instrumentation , Tea/chemistry , Algorithms , Caffeine/chemistry , Calibration , Camellia sinensis/chemistry , Catechin/chemistry , Cheminformatics/methods , Food Analysis/methods , Food Quality , Linear Models , Models, Chemical , Nonlinear Dynamics , Smartphone , Spectroscopy, Near-Infrared/methods , Support Vector Machine
6.
J Sci Food Agric ; 100(10): 3803-3811, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32201954

ABSTRACT

BACKGROUND: The quality of fresh tea leaves after harvest determines, to some extent, the quality and price of commercial tea. A fast and accurate method to evaluate the quality of fresh tea leaves is required. RESULTS: In this study, the potential of hyperspectral imaging in the range of 328-1115 nm for the rapid prediction of moisture, total nitrogen, crude fiber contents, and quality index value was investigated. Ninety samples of eight tea-leaf varieties and two picking standards were tested. Quantitative partial least squares regression (PLSR) models were established using a full spectrum, whereas multiple linear regression (MLR) models were developed using characteristic wavelengths selected by a successive projections algorithm (SPA) and competitive adaptive reweighted sampling. The results showed that the optimal SPA-MLR models for moisture, total nitrogen, crude fiber contents, and quality index value yielded optimal performance with coefficients of determination for prediction (R2 p) of 0.9357, 0.8543, 0.8188, 0.9168; root mean square error of 0.3437, 0.1097, 0.3795, 1.0358; and residual prediction deviation of 4.00, 2.56, 2.31, and 3.51, respectively. CONCLUSION: The results suggested that the hyperspectral imaging technique coupled with chemometrics was a promising tool for the rapid and nondestructive measurement of tea-leaf quality, and had the potential to develop multispectral imaging systems for future online detection of tea-leaf quality. © 2020 Society of Chemical Industry.


Subject(s)
Camellia sinensis/chemistry , Hyperspectral Imaging/methods , Plant Leaves/chemistry , Camellia sinensis/classification , Nitrogen/analysis , Plant Leaves/classification , Quality Control
7.
J Chem Neuroanat ; 105: 101751, 2020 04.
Article in English | MEDLINE | ID: mdl-32027950

ABSTRACT

Schisandrin A and B (Sch A and B) are the main effective components of Schisandra chinensis (S. chinensis), which is traditionally used to enhance mental and intellectual functions in eastern Asia. Previously, we reported Sch A and B remarkably affect adult neurogenesis in the subventricular zone of mouse lateral ventricle. Since the neurogenesis in the hippocampal dentate gyrus (DG) is more important to learning, memory and cognition, here we further examined their effects on the adult DG neurogenesis. Phosphohistone H3 (PHH3) immunostaining showed that Sch B significantly enhanced the cell proliferation in the DG. Glial fibrillary acidic protein (GFAP, mostly labels astrocytes and some stem cells) staining was used to further identify the proliferating cell type. Dramatically, increases of GFAP+ cells in both Sch A and B treated groups were observed. What's more, the total numbers of the mature neurons labeled by neuron-specific nuclear protein (NeuN) were also increased in both Sch A and B treated groups compared with the controls. Together, Sch A and B enhance the adult DG neurogenesis by increasing astrocytes/stem cells and improving the survival and maturation of DG neurons. Our study shed a new light on the neuropharmacological functions of the herbal medicine S. chinensis.


Subject(s)
Cyclooctanes/pharmacology , Dentate Gyrus/drug effects , Lignans/pharmacology , Neurogenesis/drug effects , Neurons/drug effects , Polycyclic Compounds/pharmacology , Animals , Cell Proliferation/drug effects , Hippocampus/drug effects , Male , Mice
8.
Article in Chinese | WPRIM | ID: wpr-824966

ABSTRACT

Objective: To observe the effects of laurocapram and borneol as transdermal penetration enhancers applied to herbal cake-partitioned moxibustion on liver lipids, hormone-sensitive lipase (HSL) and hydroxymethylglutaryl CoA (HMG-CoA) reductase in hyperlipidemia rabbits.Methods: Forty New-Zealand rabbits were randomly divided into 5 groups using the random number table method, with 8 rats in each group. Rabbits in the blank group were fed routinely with a normal diet; rabbits in the other groups were fed with high-fat diet for 12 weeks to establish the hyperlipidemia model. Rabbits in the blank and the model groups were not given any intervention. After the model was prepared successfully, rabbits in the non-transdermal penetration enhancer group received herbal cake-partitioned moxibustion without transdermal penetration enhancers; rabbits in the laurocapram group and the borneol group received herbal cake-partitioned moxibustion with laurocapram or borneol respectively. After 4 weeks of treatment, the serum was isolated and enzyme-linked immunosorbent assay (ELISA) was applied for the detection of HSL and HMG-CoA reductase. The liver tissues were isolated, and total cholesterol (TC) and triglycerides (TG) were measured by enzymatic methods. One-step method was applied for high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) detection, and transmission turbidimetry was for apolipoprotein A1 (Apo-A1) and apolipoprotein B (Apo-B) detection. Results: The serum concentrations of the drugs in the laurocapram and the borneol groups were significantly higher than those in the non-transdermal penetration enhancer group (both P<0.05); all drug penetrations in the borneol group were significantly higher than those in the laurocapram group (both P<0.05), except for tanshinone ⅡA. Compared with the non-transdermal penetration enhancer group, the HSL was significantly increased while the HMG-CoA reductase was significantly decreased in the laurocapram and the borneol groups (both P<0.05); between groups, the HSL in the borneol group was significantly higher than that in the laurocapram group (P<0.05). Compared with the blank group, the levels of LDL-C, TG, TC and Apo-B in rabbit liver were significantly increased in the model group (P<0.05); compared with the model group, the levels of LDL-C, TG, TC and Apo-B in the non-transdermal penetration enhancer, the laurocapram, and the borneol groups were significantly decreased (all P<0.05); between groups, the TG and TC in the laurocapram group and the LDL-C, TG, TC and Apo-B in the borneol group were significantly lower than those in the non-transdermal penetration enhancer group (all P<0.05), and the TG, LDL-C and Apo-B in the borneol group were significantly lower than those in the laurocapram group (all P<0.05). Compared with the blank group, the HDL-C and Apo-A1 were significantly decreased in the model group (both P<0.05), while compared with the model group, the HDL-C and Apo-A1 were significantly increased in the non-transdermal penetration enhancer, the laurocapram, and the borneol groups (all P<0.05). Between groups, the Apo-A1 in the laurocapram group, the HDL-C and Apo-A1 in the borneol group were significantly higher than those in the non-transdermal penetration enhancer group (all P<0.05).Conclusion: The application of laurocapram and borneol, as transdermal penetration enhancers, in herbal cake-partitioned moxibustion can promote the penetration of the drugs in the herbal cake, increase the levels of HDL-C and Apo-A1, improve the metabolism of HSL and HMG-CoA reductase, and also simultaneously reduce the levels of TC, TG, LDL-C and Apo-B in the liver. The transdermal penetration enhancement effect of borneol is slightly better than or equivalent to that of laurocapram.

9.
J Sci Food Agric ; 100(1): 161-167, 2020 Jan 15.
Article in English | MEDLINE | ID: mdl-31471904

ABSTRACT

BACKGROUND: Rapid and accurate diagnosis of nitrogen (N) status in field crops is of great significance for site-specific N fertilizer management. This study aimed to evaluate the potential of hyperspectral imaging coupled with chemometrics for the qualitative and quantitative diagnosis of N status in tea plants under field conditions. RESULTS: Hyperspectral data from mature leaves of tea plants with different N application rates were preprocessed by standard normal variate (SNV). Partial least squares discriminative analysis (PLS-DA) and least squares-support vector machines (LS-SVM) were used for the classification of different N status. Furthermore, partial least squares regression (PLSR) was used for the prediction of N content. The results showed that the LS-SVM model yielded better performance with correct classification rates of 82% and 92% in prediction sets for the diagnosis of different N application rates and N status, respectively. The PLSR model for leaf N content (LNC) showed excellent performance, with correlation coefficients of 0.924, root mean square error of 0.209, and residual predictive deviation of 2.686 in the prediction set. In addition, the important wavebands of the PLSR model were interpreted based on regression coefficients. CONCLUSION: Overall, our results suggest that the hyperspectral imaging technique can be an effective and accurate tool for qualitative and quantitative diagnosis of N status in tea plants. © 2019 Society of Chemical Industry.


Subject(s)
Camellia sinensis/chemistry , Nitrogen/analysis , Spectrum Analysis/methods , Camellia sinensis/metabolism , Fertilizers/analysis , Least-Squares Analysis , Nitrogen/metabolism , Plant Leaves/chemistry , Plant Leaves/metabolism , Support Vector Machine
10.
Org Lett ; 21(13): 5147-5151, 2019 07 05.
Article in English | MEDLINE | ID: mdl-31247775

ABSTRACT

Racemic trimethylallantoin monomer (1), mesomeric and racemic trimethylallantoin dimers (2 and 3), were isolated from tea. Two pairs of optically pure enantiomers (1a, 1b and 3a, 3b) were separated by chiral column from the two racemes (1 and 3). Their structures were elucidated by a combination of extensive spectroscopic techniques, single-crystal X-ray diffraction, and experimental and calculated electronic circular dichroism. A novel caffeine catabolic pathway was proposed based on the caffeine stable isotopic tracer experiments.


Subject(s)
Caffeine/chemistry , Caffeine/metabolism , Dimerization , Tea/metabolism , Methylation , Models, Molecular , Molecular Conformation , Stereoisomerism
11.
Plant Biotechnol J ; 17(10): 1938-1953, 2019 10.
Article in English | MEDLINE | ID: mdl-30913342

ABSTRACT

Tea is the world's widely consumed nonalcohol beverage with essential economic and health benefits. Confronted with the increasing large-scale omics-data set particularly the genome sequence released in tea plant, the construction of a comprehensive knowledgebase is urgently needed to facilitate the utilization of these data sets towards molecular breeding. We hereby present the first integrative and specially designed web-accessible database, Tea Plant Information Archive (TPIA; http://tpia.teaplant.org). The current release of TPIA employs the comprehensively annotated tea plant genome as framework and incorporates with abundant well-organized transcriptomes, gene expressions (across species, tissues and stresses), orthologs and characteristic metabolites determining tea quality. It also hosts massive transcription factors, polymorphic simple sequence repeats, single nucleotide polymorphisms, correlations, manually curated functional genes and globally collected germplasm information. A variety of versatile analytic tools (e.g. JBrowse, blast, enrichment analysis, etc.) are established helping users to perform further comparative, evolutionary and functional analysis. We show a case application of TPIA that provides novel and interesting insights into the phytochemical content variation of section Thea of genus Camellia under a well-resolved phylogenetic framework. The constructed knowledgebase of tea plant will serve as a central gateway for global tea community to better understand the tea plant biology that largely benefits the whole tea industry.


Subject(s)
Camellia sinensis/genetics , Computational Biology , Genome, Plant , Genomics , Phylogeny , Tea
12.
J Agric Food Chem ; 67(12): 3400-3411, 2019 Mar 27.
Article in English | MEDLINE | ID: mdl-30830771

ABSTRACT

Caffeine is a crucial secondary metabolic product in tea plants. Although the presence of caffeine in tea plants has been identified, the molecular mechanisms regulating relevant caffeine metabolism remain unclear. For the elucidation of the caffeine biosynthesis and catabolism in Camellia plants, fresh, germinated leaves from four Camellia plants with low (2), normal (1), and high (1) caffeine concentrations, namely, low-caffeine tea 1 (LCT1, Camellia crassicolumna), low-caffeine tea 2 (LCT2, C. crassicolumna), Shuchazao (SCZ, C. sinensis), and Yunkang 43 (YK43, C. sinensis) were used in this research. Transcriptome and purine alkaloids analyses of these Camellia leaves were performed using RNA-Seq and liquid chromatography-mass spectrometry (LC-MS). Moreover, 15N-caffeine tracing was performed to determine the metabolic fate of caffeine in leaves of these plants. Caffeine content was correlated with related gene expression levels, and a quantitative real-time (qRT) PCR analysis of specific genes showed a consistent tendency with the obtained transcriptomic analysis. On the basis of the results of stable isotope-labeled tracer experiments, we discovered a degradation pathway of caffeine to theobromine. These findings could assist researchers in understanding the caffeine-related mechanisms in Camellia plants containing low, normal, and high caffeine content and be applied to caffeine regulation and breeding improvement in future research.


Subject(s)
Caffeine/metabolism , Camellia sinensis/metabolism , Gene Expression Regulation, Plant , Plant Proteins/genetics , Caffeine/analysis , Camellia sinensis/chemistry , Camellia sinensis/genetics , Catechin/metabolism , Gene Expression Profiling , Plant Proteins/metabolism , Theobromine/metabolism
13.
Planta ; 249(2): 363-376, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30209617

ABSTRACT

MAIN CONCLUSION: A normal tea plant with one albino branch was discovered. RNA sequencing, albinism phenotype and ultrastructural observations provided a valuable understanding of the albino mechanism in tea plants. Tea plants with a specific color (white or yellow) have been studied extensively. A normal tea plant (Camellia sinensis cv. quntizhong) with one albino branch was discovered in a local tea plantation in Huangshan, Anhui, China. The pure albino leaves on this special branch had accumulated a fairly high content of amino acids, especially theanine (45.31 mg/g DW), and had a low concentration of polyphenols and an extremely low chlorophyll (Chl) content compared with control leaves. Ultrastructural observation of an albino leaf revealed no chloroplasts, whereas it was viable in the control leaf. RNA sequencing and differentially expressed gene (DEG) analysis were performed on the albino leaves and on control leaves from a normal green branch. The related genes involved in theanine and polyphenol biosynthesis were also investigated in this study. DEG expression patterns in Chl biosynthesis or degradation, carotenoid biosynthesis or degradation, chloroplast development, and biosynthesis were influenced in the albino leaves. Chloroplast deletion in albino leaves had probably destroyed the balance of carbon and nitrogen metabolism, leading to a high accumulation of free amino acids and a low concentration of polyphenols in the albino leaves. The obtained results can provide insight into the mechanism underlying this special albino branch phenotype, and are a valuable contribution toward understanding the albino mechanism in tea plants.


Subject(s)
Amino Acids/metabolism , Camellia sinensis/metabolism , Chlorophyll/metabolism , Gene Expression Regulation, Plant , Polyphenols/metabolism
14.
J Sci Food Agric ; 99(5): 2596-2601, 2019 Mar 30.
Article in English | MEDLINE | ID: mdl-30411367

ABSTRACT

BACKGROUND: Confirmation of food labeling that claims production in a small geographic region is critical to traceability, quality control and brand protection. In the current study, isotope ratio mass spectrometry (IRMS) was used to generate profiles of δ13 C and δ15 N to determine if the stable isotope signatures of Keemun black tea differ within the three counties that claim production. Other factors (cultivar type, leaf maturity and manufacturing process) were considered for their potential effects. RESULTS: Both cultivar type and leaf maturity have remarkable impact on the δ15 N values of tea leaves, and that the cultivar influenced the δ13 C values. Keemun black tea from Qimen county could be easily discriminated from samples from Dongzhi and Guichi counties based on δ15 N signatures. The k-NN model was cross-validated with an accuracy of 91.6%. Environmental factors and/or genotype seem to be the major reasons for δ15 N differences in Keemun black tea from the selected regions. CONCLUSION: This article provides a potential effective method to delineate the geographic point-of-origin of Keemun black tea based on δ15 N signatures. © 2018 Society of Chemical Industry.


Subject(s)
Camellia sinensis/chemistry , Mass Spectrometry/methods , Nitrogen Isotopes/analysis , Tea/chemistry , Carbon Isotopes/analysis , Discriminant Analysis
15.
Article in Chinese | WPRIM | ID: wpr-824932

ABSTRACT

Objective:To observe the lipid-lowering effect of different transdermal absorption enhancers applied to the herbal cake-partitioned moxibustion in hyperlipidemia model rabbits, and to explore the possible mechanism. Methods:Forty New-Zealand rabbits were randomly divided into 5 groups using the random number table method, with 8 rats in each group. Rabbits in the blank group were fed routinely with normal diet; rabbits in the other groups were fed with high-fat diet for 12 weeks to establish the hyperlipidemia model. Rabbits in the blank and the model groups were not treated. After the model was prepared, rabbits in the non-transdermal absorption enhancer group received herbal cake-partitioned moxibustion without transdermal absorption enhancer; rabbits in the laurocapram group and the borneol group received herbal cake-partitioned moxibustion with laurocapram or borneol respectively. After 4 weeks of treatment, serum was collected for enzyme-linked immunosorbent assay (ELISA), and the liver tissues were isolated for immunohistochemistry, quantitative polymerase chain reaction (qPCR) and Western-blotting (WB) detection. Results: Serum ELISA results showed that leptin was significantly decreased in the model group compared with the blank group (P<0.05); compared with the model group, leptin was significantly increased in the non-transdermal absorption enhancer, the laurocapram and the borneol groups (all P<0.05); compared with the non-transdermal absorption enhancer group, leptin was significantly increased in the laurocapram group and the borneol group (both P<0.05); there was no significant difference in leptin between the laurocapram and the borneol groups (P>0.05). The qPCR results of rabbit liver tissues showed that the mRNA expressions of leptin, Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) in the model group were significantly lower than those in the blank group (all P<0.05); compared with the model group, the mRNA expressions of leptin, leptin receptor (LR), JAK2 and STAT3 in the non-transdermal absorption enhancer, the laurocapram and the borneol groups were significantly increased (all P<0.05); compared with the non-transdermal absorption enhancer group, the mRNA expressions of leptin, LR, JAK2 and STAT3 in the laurocapram and the borneol groups were significantly increased (all P<0.05); compared with the laurocapram group, the mRNA expressions of leptin, LR, JAK2 and STAT3 in the borneol group were significantly increased (P<0.05). The trend of immunohistochemistry and WB detection results was basically consistent with the qPCR assay results. The immunohistochemistry and WB detection results of phosphorylated JAK2 (phospho-JAK2) and phosphorylated STAT3 (phospho-STAT3) were basically consistent with those of JAK2 and STAT3. Conclusion: The molecular expression of Leptin/JAK2/STAT3 pathway in the hyperlipidemia model rabbits was decreased. The molecular expression of Leptin/JAK2/STAT3 pathway was significantly increased after the herbal cake-partitioned moxibustion. The application of laurocapram and borneol, as transdermal absorption enhancers, in the herbal cake-partitioned moxibustion could more obviously up-regulate the factors of the Leptin/JAK2/STAT3 lipid-regulating pathway than the herbal cake-partitioned moxibustion alone.

16.
J Agric Food Chem ; 66(32): 8566-8573, 2018 Aug 15.
Article in English | MEDLINE | ID: mdl-30021435

ABSTRACT

The tea tree is a perennial woody plant, and pruning is one of the most crucial cultivation measurements for tea plantation management. To date, the relationship between long-term pruning and metabolic flux enhancement in tea trees has not been studied. In this research, 11-year-old pruned tea trees from four different cultivars were randomly selected for transcriptome analysis and characteristic secondary metabolite analysis together with controls. The findings revealed that epigallocatechin gallate (EGCG) accumulation in pruned tea trees was significantly higher than that in unpruned tea trees. SCPL1A expression (encoding a class of serine carboxypeptidase), which has been reported to have a catalytic ability during EGCG biosynthesis, together with LAR, encoding leucoanthocyanidin reductase, was upregulated in the pruned tea trees. Moreover, metabolic flux enhancement and transcriptome analysis revealed low EGCG accumulation in the leaves of unpruned tea trees. Because of the bitter and astringent taste of EGCG, these results provide a certain understanding to the lower bitterness and astringency in teas from "ancient tea trees", growing in the wild with no trimming, than teas produced from pruned plantation trees.


Subject(s)
Camellia sinensis/genetics , Camellia sinensis/metabolism , Catechin/analogs & derivatives , Crop Production/methods , Plant Proteins/genetics , Camellia sinensis/growth & development , Catechin/analysis , Catechin/biosynthesis , Gene Expression Profiling , Humans , Plant Proteins/metabolism , Taste , Tea/chemistry , Trees/genetics , Trees/metabolism
17.
J Agric Food Chem ; 65(50): 11036-11045, 2017 Dec 20.
Article in English | MEDLINE | ID: mdl-29160698

ABSTRACT

Methyl salicylate (MeSA) is one of the volatile organic compounds (VOCs) that releases floral scent and plays an important role in the sweet flowery aroma of tea. During the withering process for white tea producing, MeSA was generated by salicylic acid carboxyl methyltransferase (SAMT) with salicylic acid (SA), and the specific floral scent was formed. In this study, we first cloned a CsSAMT from tea leaves (GenBank accession no. MG459470) and used Escherichia coli and Saccharomyces cerevisiae to express the recombinant CsSAMT. The enzyme activity in prokaryotic and eukaryotic expression systems was identified, and the protein purification, substrate specificity, pH, and temperature optima were investigated. It was shown that CsSAMT located in the chloroplast, and the gene expression profiles were quite different in tea organs. The obtained results might give a new understanding for tea aroma formation, optimization, and regulation and have great significance for improving the specific quality of white tea.


Subject(s)
Camellia sinensis/enzymology , Methyltransferases/metabolism , Plant Leaves/enzymology , Plant Proteins/metabolism , Salicylates/analysis , Camellia sinensis/chemistry , Camellia sinensis/genetics , Enzyme Stability , Food Handling , Hydrogen-Ion Concentration , Methyltransferases/chemistry , Methyltransferases/genetics , Plant Leaves/chemistry , Plant Leaves/genetics , Plant Proteins/chemistry , Plant Proteins/genetics , Salicylates/metabolism , Temperature , Volatile Organic Compounds/analysis , Volatile Organic Compounds/metabolism
18.
PLoS One ; 11(3): e0151424, 2016.
Article in English | MEDLINE | ID: mdl-26962860

ABSTRACT

Tea is one of the most popular beverages across the world and is made exclusively from cultivars of Camellia sinensis. Many wild relatives of the genus Camellia that are closely related to C. sinensis are native to Southwest China. In this study, we first identified the distinct genetic divergence between C. sinensis and its wild relatives and provided a glimpse into the artificial selection of tea plants at a genome-wide level by analyzing 15,444 genomic SNPs that were identified from 18 cultivated and wild tea accessions using a high-throughput genome-wide restriction site-associated DNA sequencing (RAD-Seq) approach. Six distinct clusters were detected by phylogeny inferrence and principal component and genetic structural analyses, and these clusters corresponded to six Camellia species/varieties. Genetic divergence apparently indicated that C. taliensis var. bangwei is a semi-wild or transient landrace occupying a phylogenetic position between those wild and cultivated tea plants. Cultivated accessions exhibited greater heterozygosity than wild accessions, with the exception of C. taliensis var. bangwei. Thirteen genes with non-synonymous SNPs exhibited strong selective signals that were suggestive of putative artificial selective footprints for tea plants during domestication. The genome-wide SNPs provide a fundamental data resource for assessing genetic relationships, characterizing complex traits, comparing heterozygosity and analyzing putatitve artificial selection in tea plants.


Subject(s)
Camellia sinensis/genetics , Genes, Plant , Genome-Wide Association Study , High-Throughput Nucleotide Sequencing , Polymorphism, Single Nucleotide
19.
Int J Mol Sci ; 17(1)2016 Jan 05.
Article in English | MEDLINE | ID: mdl-26742036

ABSTRACT

Tea plant is known to be a hyper-accumulator of fluoride (F). Over-intake of F has been shown to have adverse effects on human health, e.g., dental fluorosis. Thus, understanding the mechanisms fluoride accumulation and developing potential approaches to decrease F uptake in tea plants might be beneficial for human health. In the present study, we found that pretreatment with the anion channel inhibitor NPPB reduced F accumulation in tea plants. Simultaneously, we observed that NPPB triggered Ca(2+) efflux from mature zone of tea root and significantly increased relative CaM in tea roots. Besides, pretreatment with the Ca(2+) chelator (EGTA) and CaM antagonists (CPZ and TFP) suppressed NPPB-elevated cytosolic Ca(2+) fluorescence intensity and CaM concentration in tea roots, respectively. Interestingly, NPPB-inhibited F accumulation was found to be significantly alleviated in tea plants pretreated with either Ca(2+) chelator (EGTA) or CaM antagonists (CPZ and TFP). In addition, NPPB significantly depolarized membrane potential transiently and we argue that the net Ca(2+) and H⁺ efflux across the plasma membrane contributed to the restoration of membrane potential. Overall, our results suggest that regulation of Ca(2+)-CaM and plasma membrane potential depolarization are involved in NPPB-inhibited F accumulation in tea plants.


Subject(s)
Calcium/metabolism , Calmodulin/metabolism , Camellia sinensis/drug effects , Fluorides/metabolism , Ion Pumps/antagonists & inhibitors , Nitrobenzoates/pharmacology , Plant Proteins/metabolism , Camellia sinensis/cytology , Camellia sinensis/metabolism , Membrane Potentials/drug effects , Plant Roots/cytology , Plant Roots/drug effects , Plant Roots/metabolism
20.
Food Chem ; 197(Pt A): 161-7, 2016 Apr 15.
Article in English | MEDLINE | ID: mdl-26616936

ABSTRACT

Green tea, oolong tea and black tea were separately introduced to brew three kinds of tea beers. A model was designed to investigate the tea beer flavour character. Comparison of the volatiles between the sample of tea beer plus water mixture (TBW) and the sample of combination of tea infusion and normal beer (CTB) was accomplished by triangular sensory test and HS-SPME GC-MS analysis. The PCA of GC-MS data not only showed a significant difference between volatile features of each TBW and CTB group, but also suggested some key compounds to distinguish TBW from CTB. The results of GC-MS showed that the relative concentrations of many typical tea volatiles were significantly changed after the brewing process. More interestingly, the behaviour of yeast fermentation was influenced by tea components. A potential interaction between tea components and lager yeast could be suggested.


Subject(s)
Beer/analysis , Camellia sinensis/chemistry , Flavoring Agents/analysis , Saccharomyces cerevisiae/growth & development , Tea/chemistry , Volatile Organic Compounds/analysis , Beer/microbiology , Fermentation , Gas Chromatography-Mass Spectrometry/methods , Solid Phase Microextraction/methods , Taste
SELECTION OF CITATIONS
SEARCH DETAIL