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1.
J Agric Food Chem ; 67(38): 10685-10693, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31479251

RESUMO

Theanine is the most abundant non-protein amino acid in Camellia sinensis, but it is not known how a tea plant accumulates such high levels of theanine. The endophyte isolated from in vitro grown plantlets of C. sinensis cultivars was identified as Luteibacter spp., showing strong biocatalytic activity for converting both glutamine and ethylamine to theanine. Theanine was secreted outside of the bacteria. The endophyte isolated from in vitro plantlets of Camellia oleifera cultivar was identified as Bacillus safensis and did not convert glutamine and ethylamine to theanine. Enzymatic assays in vitro indicated that γ-glutamyltranspeptidases rCsEGGTs from the endophyte Luteibacter strains converted glutamine and ethylamine to theanine at higher rates than rCsGGTs from C. sinensis. This is the first report on theanine biosynthesis by an endophyte from C. sinensis, which provides a new pathway to explore the mechanism of theanine biosynthesis in C. sinensis and the interactions between an endophyte and tea plants.


Assuntos
Bactérias/metabolismo , Camellia sinensis/microbiologia , Endófitos/metabolismo , Glutamatos/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Camellia sinensis/química , Camellia sinensis/classificação , Endófitos/classificação , Endófitos/genética , Endófitos/isolamento & purificação , Etilaminas/metabolismo , Glutamina/metabolismo , Folhas de Planta/química , Folhas de Planta/microbiologia
2.
J Agric Food Chem ; 67(38): 10624-10636, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31483633

RESUMO

The freshness and color quality of postharvest tea leaves can be markedly prolonged and retained by proper preservation measures. Here, we investigated the dynamic changes of chlorophyll and its derivatives in postharvest tea leaves under different low-temperature treatments using natural withering as a control. Chlorophyll decomposition was found closely related with chlorophyllide, pheophorbide, and pheophytin. Low-temperature withering could slow chlorophyll degradation in postharvest tea leaves via significant inhibition on the enzyme activity and gene expression of Mg-dechelatase, chlorophyllase, and pheophorbide a oxygenase. At the initial stage of withering, a significant increase was observed in the chlorophyll content, expression of chlorophyll-synthesis-related enzymes (such as glutamyl-tRNA synthetase, etc.), and chlorophyll synthase activity in newly picked tea leaves. Moreover, an obvious decrease was found in the content of l-glutamate as the foremost precursor substance of chlorophyll synthesis. Hence, our findings revealed that the chlorophyll synthesis reaction was induced by the light-dehydration-stress in the initial withering of tea leaves. This study provides a theoretical basis for exploring preservation technology in actual green tea production.


Assuntos
Camellia sinensis/genética , Camellia sinensis/metabolismo , Clorofila/metabolismo , Manipulação de Alimentos/métodos , Regulação da Expressão Gênica de Plantas , Camellia sinensis/química , Camellia sinensis/crescimento & desenvolvimento , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Clorofila/química , Cor , Enzimas/genética , Enzimas/metabolismo , Oxigenases/genética , Oxigenases/metabolismo , Folhas de Planta/química , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Temperatura Ambiente
3.
Chem Pharm Bull (Tokyo) ; 67(9): 935-939, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31474732

RESUMO

Chafuroside A and chafuroside B are flavone C-glycosides isolated from oolong tea leaves. They have a number of beneficial pharmacological activities related to antiinflammation at various concentrations. However, no crystallographic study of chafurosides has yet been reported. In the present study, the crystal structures of chafuroside A and chafuroside B were investigated using single-crystal X-ray diffraction. The asymmetric unit of the chafuroside A crystal consists of one chafuroside A and two water molecules, and that of chafuroside B contains one chafuroside B and one water molecule. The flavone moiety of chafuroside A is curved, i.e., the angle between the best-fit planes of the chromene and phenyl rings is 18.9°, whereas the chafuroside B flavone moiety is relatively flat. A comparison of the curvatures of the flavone moieties of various C-glycosides showed that the curvature of chafuroside A is significantly larger than those of the others. This structural feature might contribute to the differences between the strengths of the pharmacological activities of chafurosides A and B.


Assuntos
Flavonas/química , Glicosídeos/química , Compostos Heterocíclicos de 4 ou mais Anéis/química , Chá/química , Camellia sinensis/química , Camellia sinensis/metabolismo , Cristalografia por Raios X , Conformação Molecular , Folhas de Planta/química , Folhas de Planta/metabolismo
4.
Anticancer Res ; 39(8): 4101-4110, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31366494

RESUMO

BACKGROUND/AIM: Despite improvements in cancer therapy, life expectancy after tumor recurrence remains low. Relapsed cancer is characterized by drug resistance, often mediated through overexpression of multidrug resistance (MDR) genes. Camellia sinensis non fermentatum extract is known for its anticancer properties in several cancer cell lines and might improve cancer therapy outcome after tumor recurrence. MATERIALS AND METHODS: Embryonal rhabdomyosarcoma cell lines, alveolar rhabdomyosarcoma cell lines and primary rhabdomyosarcoma MAST139 cells were used to test NPE® effects on cell viability in combination with chemotherapeutic agents. Cell viability was measured by the WST-1 assay and CV staining. Gene expression levels of chemotherapy-induced efflux pumps and their activity was assessed upon NPE® treatment by measuring doxorubicin retention through evaluation of the autofluorescence signal. RESULTS: Administration of increasing doxorubicin concentrations triggered immediate adaptation to the drug, which was surprisingly overcome by the addition of NPE®. Investigating the mechanism of immediate adaptation, MDR1 gene overexpression was observed upon doxorubicin treatment. Although NPE® did not alter pump gene expression, it was able to reduce pump activity, thus allowing the chemotherapeutic agent to stay inside the cells to exert its full anticancer activity. CONCLUSION: NPE® might improve chemotherapeutic treatment by re-sensitizing relapsed tumors to anticancer drugs. Fighting MDR represents the key to overcome tumor relapse and improve the overall survival of cancer patients.


Assuntos
Antineoplásicos/farmacologia , Camellia sinensis/química , Recidiva Local de Neoplasia/tratamento farmacológico , Rabdomiossarcoma Alveolar/tratamento farmacológico , Antineoplásicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/farmacologia , Resistência a Múltiplos Medicamentos/genética , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Rabdomiossarcoma Alveolar/patologia
5.
J Agric Food Chem ; 67(35): 9967-9978, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31403784

RESUMO

Following the recent completion of the draft genome sequence of the tea plant, high-throughput decoding of gene function, especially for those involved in complex secondary metabolic pathways, has become a major challenge. Here, we profiled the metabolome and transcriptome of 11 tea cultivars, and then illustrated a weighted gene coexpression network analysis (WGCNA)-based system biological strategy to interpret metabolomic flux, predict gene functions, and mine key regulators involved in the flavonoid biosynthesis pathway. We constructed a multilayered regulatory network, which integrated the gene coexpression relationship with the microRNA target and promoter cis-regulatory element information. This allowed us to reveal new uncharacterized TFs (e.g., MADSs, WRKYs, and SBPs) and microRNAs (including 17 conserved and 15 novel microRNAs) that are potentially implicated in different steps of the catechin biosynthesis. Furthermore, we applied metabolic-signature-based association method to capture additional key regulators involved in catechin pathway. This provides important clues for the functional characterization of five SCPL1A acyltransferase family members, which might be implicated in the production balance of anthocyanins, galloylated catechins, and proanthocyanins. Application of an "omics"-based system biology strategy should facilitate germplasm utilization and provide valuable resources for tea quality improvement.


Assuntos
Camellia sinensis/metabolismo , Flavonoides/química , Redes Reguladoras de Genes , Camellia sinensis/química , Camellia sinensis/classificação , Camellia sinensis/genética , Flavonoides/metabolismo , Regulação da Expressão Gênica de Plantas , Metabolômica , Folhas de Planta/química , Folhas de Planta/classificação , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transcriptoma
6.
J Agric Food Chem ; 67(36): 10165-10173, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31398024

RESUMO

Chin-brick tea polysaccharide conjugates (TPC-C) were prepared to study their emulsion capabilities. Interfacial tension and the effects of some factors, such as storage time, metal ion concentrations (Na+, Ca2+), pH (2.0-8.0), and heat treatment (70-100 °C) on the emulsions stabilized by TPC-C were studied. The interfacial tension of TPC-C (10.88 mN/m) was lower than that of gum arabic (15.18 mN/m) at a concentration of 0.08%. As the TPC-C concentration increased from 0.1 to 3.0 wt %, the mean particle diameter (MPD) (d32) of emulsions stabilized by TPC-C decreased from 1.88 to 0.16 µm. Furthermore, at a concentration of 0.5 wt % or higher, the MPD (d32) of emulsions stabilized by TPC-C at 25 and 60 °C for 10 days was between 0.20 and 0.50 µm. In the tested pH conditions from 2.0 to 8.0, the MPD (d32) of emulsions stabilized by 2.0 wt % TPC-C was less than 0.20 µm. At Na+ concentration conditions between 0.10 and 0.50 mol/L, the MPD (d32) of emulsions was between 0.19 and 0.20 µm, and the zeta potential values varied from -34.10 to -32.60 mV. However, with an increasing Ca2+ concentration from 0.01 to 0.05 mol/L, the MPD (d32) of emulsions was between 0.20 and 21.65 µm, and the zeta potential raised sharply from -34.10 to -28.46 mV. The emulsions stabilized by TPC-C have a decent storage stability after a high-temperature heat treatment. Overall, tea polysaccharide conjugates strongly stabilized the emulsions, which support their new application as natural emulsifiers.


Assuntos
Camellia sinensis/química , Emulsificantes/química , Extratos Vegetais/química , Polissacarídeos/química , Emulsões/química , Concentração de Íons de Hidrogênio , Tamanho da Partícula
7.
J Agric Food Chem ; 67(36): 10235-10244, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31436988

RESUMO

Tea provides a rich taste and has healthy properties due to its variety of bioactive compounds, such as theanine, catechins, and caffeine. Theanine is the most abundant free amino acid (40%-70%) in tea leaves. Key genes related to theanine biosynthesis have been studied, but relatively little is known about the regulatory mechanisms of theanine accumulation in tea leaves. Herein, we analyzed theanine content in tea (Camellia sinensis) and oil tea (Camellia oleifera) and found it to be higher in the roots than in other tissues in both species. The theanine content was significantly higher in tea than oil tea. To explore the regulatory mechanisms of theanine accumulation, we identified genes involved in theanine biosynthesis by RNA-Seq analysis and compared theanine-related modules. Moreover, we cloned theanine synthase (TS) promoters from tea and oil tea plants and found that a difference in TS expression and cis-acting elements may explain the difference in theanine accumulation between the two species. These data provide an important resource for regulatory mechanisms of theanine accumulation in tea plants.


Assuntos
Camellia sinensis/genética , Camellia/genética , Glutamatos/biossíntese , Proteínas de Plantas/genética , Transcriptoma , Camellia/química , Camellia/metabolismo , Camellia sinensis/química , Camellia sinensis/metabolismo , Glutamatos/análise , Folhas de Planta/química , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/química , Raízes de Plantas/genética , Raízes de Plantas/metabolismo
8.
J Agric Food Chem ; 67(28): 7855-7868, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31274310

RESUMO

Bee pollen (BP) collected from different floras possesses various potential bioactivities, but the mechanism-related research on anti-inflammatory effects is limited. Here, three types of BP originating from Camellia sinensis L. (BP-Cs), Nelumbo nucifera Gaertn. (BP-Nn), and Brassica campestris L. (BP-Bc) were assessed using molecular and metabolomics methods to determine their anti-inflammatory effects. The differences in polyphenolic abundance of three types of BP extracts were determined by HPLC-DAD/Q-TOF-MS. In vitro anti-inflammatory effects of three BP extracts were evaluated in a lipopolysaccharide (LPS)-induced RAW 264.7 cells model. BP-Cs extract with the most abundant polyphenols was found to be the most effective in reducing inflammation by downregulating inflammatory-related genes expression and blocking the activation of MAPK and NF-κB signaling pathways. Polyphenol-rich BP-Cs was further evaluated for their in vivo anti-inflammatory effect in a LPS-induced acute lung injury mouse model. An UPLC-Q-TOF/MS-based metabolomics approach was applied to analyze metabolite changes in mouse serum. Weshowed that the pretreated BP-Cs extract alleviated inflammation and regulated glycerophospholipid metabolism significantly. Our findings provide a foundation for developing and justifying BP as a potential anti-inflammatory ingredient in functional foods or nutraceutical formulations.


Assuntos
Lesão Pulmonar Aguda/tratamento farmacológico , Anti-Inflamatórios/administração & dosagem , Extratos Vegetais/administração & dosagem , Pólen/química , Lesão Pulmonar Aguda/genética , Lesão Pulmonar Aguda/imunologia , Animais , Anti-Inflamatórios/química , Abelhas , Brassica/química , Camellia sinensis/química , Cromatografia Líquida de Alta Pressão , Humanos , Lipopolissacarídeos/efeitos adversos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos ICR , Quinases de Proteína Quinase Ativadas por Mitógeno/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/imunologia , NF-kappa B/genética , NF-kappa B/imunologia , Nelumbo/química , Extratos Vegetais/química , Polifenóis/administração & dosagem , Polifenóis/química , Células RAW 264.7
9.
J Agric Food Chem ; 67(28): 7869-7879, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31287296

RESUMO

Carnitine, a dietary quaternary amine mainly from red meat, is metabolized to trimethylamine (TMA) by gut microbiota and subsequently oxidized to trimethylamine-N-oxide (TMAO) by host hepatic enzymes, flavin monooxygenases (FMOs). The objective of this study aims to investigate the effects of flavonoids from oolong tea and citrus peels on reducing TMAO formation and protecting vascular inflammation in carnitine-feeding mice. The results showed that mice treated with 1.3% carnitine in drinking water significantly (p < 0.05) increased the plasma levels of TMAO compared to control group, whereas the plasma TMAO was remarkedly reduced by flavonoids used. Meanwhile, these dietary phenolic compounds significantly (p < 0.05) decreased hepatic FMO3 mRNA levels compared to carnitine only group. Additionally, oolong tea extract decreased mRNA levels of vascular inflammatory markers such as tissue necrosis factor-alpha (TNF-α), vascular cell adhesion molecule-1 (VCAM-1) and E-selectin. Polymethoxyflavones significantly lowered the expression of VCAM-1 and showed a decreasing trend in TNF-α and E-selectin mRNA expression compared to the carnitine group. Genus-level analysis of the gut microbiota in the cecum showed that these dietary phenolic compounds induced an increase in the relative abundances of Bacteroides. Oolong tea extract-treated group up-regulated Lactobacillus genus, compared to the carnitine only group. Administration of polymethoxyflavones increased Akkermansia in mice.


Assuntos
Aterosclerose/tratamento farmacológico , Aterosclerose/metabolismo , Camellia sinensis/química , Carnitina/metabolismo , Citrus/química , Flavonas/administração & dosagem , Extratos Vegetais/administração & dosagem , Animais , Aterosclerose/genética , Aterosclerose/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Biotransformação/efeitos dos fármacos , Feminino , Flavonas/análise , Microbioma Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/microbiologia , Humanos , Metilaminas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Extratos Vegetais/análise , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Molécula 1 de Adesão de Célula Vascular/genética , Molécula 1 de Adesão de Célula Vascular/metabolismo
10.
J Agric Food Chem ; 67(32): 8847-8854, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31328515

RESUMO

Microbiome has been revealed as a key element involved in maintaining the circadian rhythms. Oolong tea polyphenols (OTP) has been shown to have potential prebiotic activity. Therefore, this study focused on the regulation mechanisms of OTP on host circadian rhythms. After 8 weeks of OTP administration, a large expansion in the relative abundance of Bacteroidetes with a decrease in Firmicutes was observed, which reflected the positive modulatory effect of OTP on gut flora. In addition, Kyoto Encyclopedia of Genes and Genomes pathways of ATP-binding cassette transporters, two-component system, and the biosynthesis of amino acids enriched the most differentially expressed genes after OTP treatment. Of the differentially expressed proteins identified, most were related to metabolism, genetic information processing, and environmental information processing. It underscores the ability of OTP to regulate circadian rhythm by enhancing beneficial intestinal microbiota and affecting metabolic pathways, contributing to the improvement of host microecology.


Assuntos
Camellia sinensis/química , Transtornos Cronobiológicos/tratamento farmacológico , Microbioma Gastrointestinal/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Polifenóis/administração & dosagem , Animais , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Transtornos Cronobiológicos/microbiologia , Transtornos Cronobiológicos/fisiopatologia , Modelos Animais de Doenças , Feminino , Humanos , Intestinos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Chá/química
11.
J Agric Food Chem ; 67(32): 9079-9087, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31353905

RESUMO

Organic anion transporting polypeptides (OATPs) 1B1 and 1B3 are two highly homologous transporters expressed in the human liver. However, epigallocatechin gallate (EGCG), which is the most predominant catechin in green tea, has opposite effects on the function of OATP1B1 and OATP1B3. In the present study, the critical structural domains and amino acid residues for the activation of OATP1B3 by EGCG have been determined by characterizing the function of a series of OATP1B3-derived chimeric transporters, site-directed mutagenesis, and kinetic studies. Our results showed that G45 and F555 in transmembrane domains 1 and 10 are the most important amino acid residues for OATP1B3 activation. Kinetic studies showed that the activation of OATP1B3 by EGCG at a low substrate concentration was due to its increased substrate binding affinity. However, EGCG caused increased Km and decreased Vmax for 1B3-G45A and 1B3-F555H. The flexibility at position 45 and aromaticity at position 555 might be important for OATP1B3 activation. While 1B3-G45A and 1B3-F555H could not be activated by EGCG, their transport activity for EGCG was comparable to that of wild-type OATP1B3. In conclusion, the present study elucidated the molecular mechanism for OATP1B3 activation by EGCG.


Assuntos
Catequina/análogos & derivados , Extratos Vegetais/metabolismo , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/química , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/metabolismo , Motivos de Aminoácidos , Camellia sinensis/química , Catequina/química , Catequina/metabolismo , Células HEK293 , Humanos , Cinética , Fígado/metabolismo , Transportador 1 de Ânion Orgânico Específico do Fígado/química , Transportador 1 de Ânion Orgânico Específico do Fígado/genética , Transportador 1 de Ânion Orgânico Específico do Fígado/metabolismo , Modelos Moleculares , Extratos Vegetais/química , Domínios Proteicos , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto/genética
12.
Food Chem ; 298: 125046, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260981

RESUMO

We established a novel Dianhong black tea grades discriminant analytic technique based on a fluorescence image along with carbon quantum dots (CDs) as fluorescent probes. Different grades of Dianhong black tea contain different various amounts of tea polyphenols. Tea polyphenols can quench the fluorescent intensity of CDs, resulting in different fluorescent peaks; Dianhong black tea grades can then be discriminated through the use of principal component analysis and Bayesian analysis. Compared with the additional data processing required in other methods, the advantage of our method is that the fluorescence curve can be used directly, and it achieves satisfactory results. We firstly used CDs combined with chemometrics to identify eight grades of Dianhong black tea, and we also provide a new method that improves the identification rate using nanotechnology to avoid performing complex data processing.


Assuntos
Camellia sinensis/química , Corantes Fluorescentes/química , Teorema de Bayes , Camellia sinensis/metabolismo , Análise Discriminante , Polifenóis/análise , Análise de Componente Principal , Pontos Quânticos/química , Espectrometria de Fluorescência
13.
J Sci Food Agric ; 99(14): 6509-6514, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31321773

RESUMO

BACKGROUND: Rare earth elements (REEs) have been used for the identification of the geographical origins of an increasing number of foods. This study analyzed the effects of geographical origin, harvest season, variety, and their interactions on REEs in tea leaves to investigate whether REEs were suitable for geographical identification of tea leaves. Tea leaves of different varieties and the corresponding soils were collected in different seasons from different areas of China. The concentrations of 14 REEs in tea leaves and soils were determined, and then analyzed with one-way analysis of variance (ANOVA), multi-way ANOVA, correlation analysis, and linear discriminant analysis. RESULTS: All factors significantly affected the contents of REEs in tea leaves. The concentrations of REEs in tea leaves were related to those in provenance soils. However, the concentrations of most REEs in tea leaves were primarily affected by the harvest season. CONCLUSION: Seasonal variations should be considered when REE fingerprinting is applied for the identification of tea for authentication purposes. © 2019 Society of Chemical Industry.


Assuntos
Camellia sinensis/química , Metais Terras Raras/análise , Folhas de Planta/química , Camellia sinensis/classificação , China , Análise Discriminante , Geografia , Folhas de Planta/classificação , Estações do Ano
14.
J Sci Food Agric ; 99(13): 5834-5841, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31206711

RESUMO

BACKGROUND: Many studies have described cocoa polyphenols as being bioactive compounds with a potential positive effect on human health. Although dark chocolate is a most powerful source of antioxidants, their content is lower in milk chocolate; conversely, in white chocolate the fat-free cocoa solids are omitted. The aim of this study was to increase polyphenol content and antioxidant capacity of white chocolate by adding encapsulated green tea extract (GTE) in amounts of 60, 80 and 100 g kg-1 . RESULTS: GTE influenced the particle size parameters, increasing the volume weighted mean from 15.43 µm in white chocolate to 19.34 µm in chocolate with 100 g kg-1 GTE. At the same time, the viscosity of enriched chocolate also increased owing to the addition of new solid particles. The surface color of enriched chocolates changed in accordance with the amount of encapsulate, where all enriched chocolates had a slightly lighter color after 12 months of storage. Total polyphenol content (mg gallic acid equivalents (GAE) kg-1 ) increased from 0.41 in white chocolate to 2.73 in chocolate enriched with maximal GTE. This amount of GTE increased antioxidant capacity (mmol Trolox equivalents kg-1 ) from 1.22 in white chocolate to 16.12. After 12 months of storage, degradation of polyphenols was found to be a maximum of 37.27%, while antioxidant capacity decreased up to 44.14%. CONCLUSION: In addition to the impact on chocolate viscosity, GTE added value through the polyphenol content and sensorial profile of the new product with an unusual green tea flavor and a shelf life of at least 12 months. © 2019 Society of Chemical Industry.


Assuntos
Cacau/química , Camellia sinensis/química , Chocolate/análise , Aditivos Alimentares/análise , Extratos Vegetais/análise , Antioxidantes/análise , Manipulação de Alimentos , Humanos , Polifenóis/análise , Paladar , Viscosidade
15.
J Agric Food Chem ; 67(26): 7538-7546, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31180663

RESUMO

Thiamethoxam (TMX) has already been proven to have a physiological effect in plant tissue or cell expect for the insecticidal activity. In our previous study, TMX was verified to be metabolized by tea cells in either a suspension culture or tea plant into several metabolites. Here, tea cell suspension cultures were treated for 45 days to investigate the metabolite effects in both the tea cells and the culture supernatants by nontargeted metabolomics. Using multivariate analysis (PCA and OPLS-DA), all treatment and control groups could be clearly separated. Inside the cells, 113 metabolites were found to be up-regulated while 122 were down-regulated, when compared with untreated cells. In the culture supernatant, there were 128 up-regulated and 35 down-regulated metabolites, compared to untreated cultures. KEGG searches revealed that the alanine, aspartate, and glutamate metabolic pathways were strongly affected by TMX metabolism within the tea cell. Molecular docking models showed that (i) 4-aminobutyrate aminotransferase may be related to the formation of 2-chloro-thiazole-5-carboxylic acid and (ii) 3'(2'),5'-bisphosphate nucleotidase may be able to interact with TMX. This study can help us to understand the interaction mechanism of pesticides with plant cells.


Assuntos
Camellia sinensis/química , Camellia sinensis/metabolismo , Inseticidas/metabolismo , Tiametoxam/metabolismo , Células Cultivadas , Inseticidas/química , Redes e Vias Metabólicas , Metabolômica , Simulação de Acoplamento Molecular , Tiametoxam/química
16.
J Agric Food Chem ; 67(26): 7325-7335, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31184120

RESUMO

Tea polyphenols (TP) possess the ability to regulate dyslipidemia and gut microbiota dysbiosis. However, the underlying mechanism is still elusive. The present study explored the intervention of TP on high fat diet induced metabolic disorders, gut microbiota dysbiosis in mice, and the underlying intestinal mechanism. As a result, TP significantly ameliorated hyperlipidemia, improved the expression levels of hepatic lipid metabolism genes, and modulated gut microbiota. The underlying mechanism was supposed to rely on the maintaining of intestinal redox state by TP. Intestinal redox related indicators were significantly correlated with the distribution of gut microbiota. An unidentified genus of Lachnospiraceae, Bacteroides, Alistipes, and Faecalibaculum were identified as the biomarkers for intestinal redox state. Importantly, different dosages of TP modulated intestinal redox state and gut microbiota in varied patterns, and an overdose intake attenuated the beneficial effects on gut health. Our findings offered novel insights into the mechanism of TP on intestinal homeostasis.


Assuntos
Camellia sinensis/química , Microbioma Gastrointestinal/efeitos dos fármacos , Hiperlipidemias/tratamento farmacológico , Intestinos/microbiologia , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Polifenóis/administração & dosagem , Animais , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Dieta Hiperlipídica/efeitos adversos , Feminino , Humanos , Hiperlipidemias/genética , Hiperlipidemias/metabolismo , Hiperlipidemias/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Chá
17.
J Agric Food Chem ; 67(26): 7547-7560, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31192593

RESUMO

In this study, isobaric tags for relative and absolute quantitation (iTRAQ) technology were used to investigate three samples from postharvest tea leaves that were treated at room temperature (25 °C, control group), high temperature (38 °C), and low temperature (4 °C) for 4 h. In heat and cold treatments, a total of 635 and 566 differentially expressed proteins (DEPs) were determined, respectively. DEPs were annotated to GO and KEGG databases, which revealed that DEPs involved in various aspects of biological process. Three catechins-related DEPs, CsCHI, CsF3H, and CsANR, were identified. Both catechins contents and the expression profiles of catechins biosynthesis-related genes changed significantly under different temperature treatments. The correlations between catechins contents, gene expression profiles, and DEPs were analyzed. This study provides potential new insights into the molecular basis for tea production of postharvest leaves and catechins content changes at diverse temperature conditions and will guide the improvement of tea-processing technology.


Assuntos
Camellia sinensis/crescimento & desenvolvimento , Catequina/biossíntese , Folhas de Planta/química , Proteínas de Plantas/genética , Camellia sinensis/química , Camellia sinensis/metabolismo , Catequina/análise , Regulação da Expressão Gênica de Plantas , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Proteômica , Temperatura Ambiente , Transcriptoma
18.
Food Chem ; 296: 40-46, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31202304

RESUMO

Gallotannin 1,2,6-tri-O-galloyl-ß-d-glucopyranose (1,2,6-TGGP) plays multiple roles against multidrug-resistant bacteria and other diseases. Nevertheless, its availability in tea (Camellia sinensis) has rarely been reported. Herein, the identification and verification of 1,2,6-TGGP from Camellia sinensis using ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-qTOF MS/MS), electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) were reported. The isolated 1,2,6-TGGP was used for the chemotaxonomy analysis of 17 tea cultivars. The contents of 1,2,6-TGGP ranged from 1.96 to 43.20 mg g-1, with a mean of 13.75 mg g-1. Relatively high 1,2,6-TGGP contents (>30 mg g-1) in two tea cultivars indicate that the beneficial effects of 1,2,6-TGGP can be obtained by consuming these teas. The chemotaxonomy analysis showed a biosynthetic relation between 1,2,6-TGGP and gallic acid. Further analysis showed that the 1,2,6-TGGP contents significantly decreased with the plucking times irrespective of the cultivars. Moreover, a positive and significant correlation was also observed between 1,2,6-TGGP and gallic acid. The identification of tea cultivars that are rich in 1,2,6-TGGP was first reported and the obtained results should boost their potential use in food and medicine.


Assuntos
Camellia sinensis/química , Taninos Hidrolisáveis/análise , Camellia sinensis/genética , Camellia sinensis/metabolismo , Cromatografia Líquida de Alta Pressão , Análise por Conglomerados , Variação Genética , Taninos Hidrolisáveis/química , Taninos Hidrolisáveis/metabolismo , Espectroscopia de Ressonância Magnética , Extratos Vegetais/química , Espectrometria de Massas em Tandem
19.
Food Chem ; 296: 69-77, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31202308

RESUMO

Volatile compounds and non-phenolic metabolites (amino acids, organic acids, and sugars) of aqueous green tea extracts obtained by ultrasonic extraction (UE), agitation extraction (AE), hot water extraction (HWE), and conventional extraction (CE) were determined using SPME-GC-MS and HPLC, respectively. Significantly higher (P < 0.05) yields of volatiles and non-phenolic metabolites were obtained via UE and AE than via HWE and CE. UE, AE, HWE, and CE released 212, 201, 103, and 65 volatiles, respectively. Sum total of amino acid and organic acid in extracts was 54.57, 54.35, 27.11, and 12.67 (mg/100 g), and 5.96, 6.19, 3.81, and 1.68 (mg/100 g) for UE, AE, HWE, and CE, respectively. Volatiles except nitrogen-containing compounds had higher positive correlations with l-theanine, sucrose, malic acid, and catechins yields. Findings of the current study suggest that an efficient extraction technique may significantly increase volatile and non-phenolic metabolite yields in aqueous green tea extract.


Assuntos
Aminoácidos/análise , Camellia sinensis/metabolismo , Açúcares/análise , Compostos Orgânicos Voláteis/análise , Aminoácidos/isolamento & purificação , Aminoácidos/metabolismo , Camellia sinensis/química , Cromatografia Líquida de Alta Pressão , Análise Discriminante , Análise dos Mínimos Quadrados , Malatos/análise , Malatos/isolamento & purificação , Extratos Vegetais/química , Análise de Componente Principal , Microextração em Fase Sólida , Sonicação , Açúcares/isolamento & purificação , Açúcares/metabolismo
20.
Food Chem ; 295: 423-431, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174778

RESUMO

Effects of natural phenolics on the shelf life of dried scallop adductor muscle predicted by accelerated shelf life testing (ALST) combined with Arrhenius model were investigated. This allows the food industries to reliably and rapidly determine the shelf life of dried shellfish species treated with antioxidants. The shelf life of dried scallop adductor muscle treated with antioxidants of bamboo leaves (AOB) and tea polyphenols (TP) was more than 1.70-fold that of dried control scallop adductor muscle. Thus, the highly nutritional value of dried scallop adductor muscle, based on its lipid constituents, is maintained during storage. OXITEST method further confirmed the improvement of lipid stability of antioxidant treated dried scallop adductor muscle by protecting polyunsaturated fatty acids, especially eicosapentaenoic and docosahexaenoic acids, against autoxidation. Moreover, the natural phenolics employed effectively limited lipid oxidation by breaking the autoxidative chain reaction and/or inhibiting free radical formation in dried scallop adductor muscle during storage.


Assuntos
Armazenamento de Alimentos , Lipídeos/química , Pectinidae/química , Polifenóis/química , Frutos do Mar , Animais , Antioxidantes/química , Camellia sinensis/química , Ácidos Graxos Insaturados/análise , Ácidos Graxos Insaturados/química , Liofilização , Músculo Esquelético/química , Valor Nutritivo , Oxirredução , Folhas de Planta/química , Carbamilação de Proteínas , Sasa/química
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