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1.
Food Res Int ; 188: 114525, 2024 Jul.
Article En | MEDLINE | ID: mdl-38823888

As a kind of green tea with unique multiple baking processes, the flavor code of Lu'an Guapian (LAGP) has recently been revealed. To improve and stabilize the quality of LAGP, further insight into the dynamic changes in odorants during the whole processing is required. In this study, 50 odorants were identified in processing tea leaves, 14 of which were selected for absolute quantification to profile the effect of processes. The results showed that spreading is crucial for key aroma generation and accumulation, while these odorants undergo significant changes at the deep baking stage. By adjusting the conditions of the spreading and deep baking, it was found that low-temperature (4 °C) spreading for 6 h and low-temperature with long-time baking (final leaf temperature: 102 °C, 45 min) could improve the overall aroma quality. These results provide a new direction for enhancing the quality of LAGP green tea.


Odorants , Tea , Volatile Organic Compounds , Odorants/analysis , Tea/chemistry , Volatile Organic Compounds/analysis , Plant Leaves/chemistry , Food Handling/methods , Cooking/methods , Camellia sinensis/chemistry , Gas Chromatography-Mass Spectrometry , Hot Temperature
2.
J Agric Food Chem ; 72(21): 11837-11853, 2024 May 29.
Article En | MEDLINE | ID: mdl-38743877

Diabetes mellitus (DM) is a chronic endocrine disorder that poses a long-term risk to human health accompanied by serious complications. Common antidiabetic drugs are usually accompanied by side effects such as hepatotoxicity and nephrotoxicity. There is an urgent need for natural dietary alternatives for diabetic treatment. Tea (Camellia sinensis) consumption has been widely investigated to lower the risk of diabetes and its complications through restoring glucose metabolism homeostasis, safeguarding pancreatic ß-cells, ameliorating insulin resistance, ameliorating oxidative stresses, inhibiting inflammatory response, and regulating intestinal microbiota. It is indispensable to develop effective strategies to improve the absorption of tea active compounds and exert combinational effects with other natural compounds to broaden its hypoglycemic potential. The advances in clinical trials and population-based investigations are also discussed. This review primarily delves into the antidiabetic potential and underlying mechanisms of tea active compounds, providing a theoretical basis for the practical application of tea and its active compounds against diabetes.


Camellia sinensis , Hypoglycemic Agents , Plant Extracts , Tea , Humans , Hypoglycemic Agents/chemistry , Hypoglycemic Agents/pharmacology , Tea/chemistry , Camellia sinensis/chemistry , Animals , Plant Extracts/chemistry , Plant Extracts/pharmacology , Diabetes Mellitus/drug therapy , Diabetes Mellitus/metabolism , Insulin Resistance , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/metabolism
3.
J Sep Sci ; 47(9-10): e2400142, 2024 May.
Article En | MEDLINE | ID: mdl-38726732

Catechins, renowned for their antioxidant properties and health benefits, are commonly present in beverages, particularly tea and wine. An efficient and cost-effective salting-out assisted liquid-liquid extraction (SALLE) method has been developed and validated for the simultaneous determination of six catechins and caffeine in tea and wine samples using high-performance liquid chromatography-ultraviolet (HPLC-UV). This method demonstrates outstanding performance: linearity (1-120 µg/mL, r2 > 0.999), accuracy (96.5%-103.4% recovery), and precision (≤14.7% relative standard deviation), meeting validation requirements set by the US Food and Drug Administration. The reduced sample size (0.1 g) minimizes matrix interferences and costs without compromising sensitivity. All analytes were detected in Camellia sinensis teas, with green tea displaying the highest total catechin content (47.5-100.1 mg/mL), followed by white and black teas. Analysis of wine samples reveals the presence of catechin in all red and white wines, and epigallocatechin gallate in all red wine samples, highlighting the impact of winemaking processes on catechin content. The SALLE-HPLC-UV approach represents a green alternative by eliminating organic waste, surpassing conventional dilution methods in specificity and sensitivity for catechin determination. AGREEprep assessment emphasizes the strengths of the SALLE procedure, including material reusability, throughput efficiency, minimal sample requirements, low energy consumption, and the absence of organic waste generation.


Caffeine , Catechin , Liquid-Liquid Extraction , Tea , Wine , Chromatography, High Pressure Liquid/methods , Wine/analysis , Caffeine/analysis , Catechin/analysis , Tea/chemistry , Liquid-Liquid Extraction/methods , Spectrophotometry, Ultraviolet , Ultraviolet Rays
4.
Front Immunol ; 15: 1362404, 2024.
Article En | MEDLINE | ID: mdl-38745671

Introduction: The anti-inflammatory effect of green tea extract (GTE) has been confirmed in asthmatic mice, however, the pharmacological mechanism is not fully elucidated. Methods: To investigate the therapeutic efficacy of GTE in asthma and identify specific pathways, murine model of allergic asthma was established by ovalbumin (OVA) sensitization and the challenge for 4 weeks, with oral treatment using GTE and dexamethasone (DEX). Inflammatory cell counts, cytokines, OVA-specific IgE, airway hyperreactivity, and antioxidant markers in the lung were evaluated. Also, pulmonary histopathological analysis and western blotting were performed. In vitro, we established the model by stimulating the human airway epithelial cell line NCI-H292 using lipopolysaccharide, and treating with GTE and mitogen-activated protein kinases (MAPKs) inhibitors. Results: The GTE100 and GTE400 groups showed a decrease in airway hyperresponsiveness and the number of inflammatory cells in the bronchoalveolar lavage fluid (BALF) compared to the OVA group. GTE treatment also reduced interleukin (IL)-13, IL-5, and IL-4 levels in the BALF, and OVA-specific immunoglobulin E levels in the serum compared to those in the OVA group. GTE treatment decreased OVA-induced mucus secretion and airway inflammation. In addition, GTE suppressed the oxidative stress, and phosphorylation of MAPKs, which generally occurs after exposure to OVA. GTE administration also reduced matrix metalloproteinase-9 activity and protein levels. Conclusion: GTE effectively inhibited asthmatic respiratory inflammation and mucus hyperproduction induced by OVA inhalation. These results suggest that GTE has the potential to be used for the treatment of asthma.


Asthma , Epithelial Cells , Matrix Metalloproteinase 9 , Oxidative Stress , Plant Extracts , Asthma/drug therapy , Asthma/immunology , Asthma/metabolism , Animals , Oxidative Stress/drug effects , Mice , Humans , Plant Extracts/pharmacology , Matrix Metalloproteinase 9/metabolism , Epithelial Cells/metabolism , Epithelial Cells/drug effects , Disease Models, Animal , Tea/chemistry , Female , Signal Transduction/drug effects , Mice, Inbred BALB C , Mitogen-Activated Protein Kinases/metabolism , Respiratory Mucosa/metabolism , Respiratory Mucosa/drug effects , Respiratory Mucosa/immunology , Respiratory Mucosa/pathology , Cytokines/metabolism , Ovalbumin/immunology , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use
5.
Nutrients ; 16(10)2024 May 11.
Article En | MEDLINE | ID: mdl-38794687

It has been strongly suggested that selenium deficiency and T-2 toxin contamination have a strong relationship with the occurrence and development of Kashin-Beck disease (KBD). In order to provide information for understanding the high prevalence of KBD in Tibet, this study collected the responses to a cubital venous blood and dietary questionnaire of 125 subjects including 75 KBD patients and 50 healthy controls in a KBD-prevalent county (Luolong County) in Tibet, China. A total of 10 household local families were randomly selected in this area, and local diet samples of brick tea, Zanba powder, milk residue, and hulless Barley were collected from these residents. Selenium content in blood was detected by inductively coupled plasma mass spectrometry (ICP-MS). The T-2 toxin contamination level in food sample was assayed using an ELISA kit. The selenium levels of patients and controls were 42.0 ± 19.8 and 56.06 ± 22.4 µg/L, respectively. The serum selenium level in controls was higher than that in patients, but there was no significant difference, and the serum selenium level both in patients and controls in Tibet was lower than the normal range. The results of the dietary survey showed that the number of respondents who consumed butter tea was large; 46.67% of patients indicated that they drank buttered tea every day, which was significantly higher than in controls. The contents of T-2 toxin in Zanba powder, milk residue, hulless barley and drinking water samples were below the detection limit (0.05 µg/kg); this result was labeled Tr. Unexpectedly, the contents of T-2 toxin in brick tea were higher, with average levels of 424 ± 56 µg/kg in Detong village and 396 ± 24 µg/kg in Langcuo village. For the first time, we report the presence of an extremely high concentration of T-2 toxin in brick tea of Tibet.


Kashin-Beck Disease , Selenium , T-2 Toxin , Humans , Tibet/epidemiology , Kashin-Beck Disease/epidemiology , Kashin-Beck Disease/blood , T-2 Toxin/blood , T-2 Toxin/analogs & derivatives , T-2 Toxin/analysis , Female , Male , Selenium/blood , Adult , Middle Aged , Prevalence , Beverages , Food Contamination/analysis , Tea/chemistry , Diet/statistics & numerical data , Case-Control Studies , Diet Surveys
6.
J Sep Sci ; 47(9-10): e2300628, 2024 May.
Article En | MEDLINE | ID: mdl-38801755

The contents of organic acids (OAs) in tea beverage and their relationship with taste intensity have not been fully understood. In this work, a rapid (10 min for a single run) and sensitive (limits of quantification: 0.0044-0.4486 µg/mL) method was developed and validated for the simultaneous determination of 17 OAs in four types of tea, based on liquid chromatography-tandem mass spectrometry with multiple reaction monitoring mode. The contents of 17 OAs in 96 tea samples were measured at levels between 0.01 and 11.80 g/kg (dried weight). Quinic acid, citric acid, and malic acid were determined as the major OAs in green, black, and raw pu-erh teas, while oxalic acid and tartaric acid exhibited the highest contents in ripe pu-erh tea. Taking the OAs composition as input features, a partial least squares regression model was proposed to predict the sourness intensity of tea beverages. The model achieved a root-mean-square error of 0.58 and a coefficient of determination of 0.84 for the testing set. The proposed model provides a theoretical way to evaluate the sensory quality of tea infusion based on its chemical composition.


Tandem Mass Spectrometry , Tea , Tea/chemistry , Tandem Mass Spectrometry/methods , Chemometrics , Chromatography, Liquid/methods , Taste , Chromatography, High Pressure Liquid/methods
7.
J Chromatogr A ; 1726: 464961, 2024 Jul 05.
Article En | MEDLINE | ID: mdl-38723491

The improvement of the stability and adsorption properties of materials on targets in sample pre-treatment has long been an objective. Extensive efforts have been made to achieve this goal. In this work, metal-organic framework Ni-MOF precursors were first synthesized by solvothermal method using polyvinylpyrrolidone (PVP) as an ideal templating agent, stabiliser and nanoparticle dispersant. After carbonization and acid washing, the nanoporous carbon microspheres material (Ni@C-acid) was obtained. Compared with the material without acid treatment (Ni@C), the specific surface area, pore volume, adsorption performance of Ni@C-acid were increased. Thanks to its excellent characteristics (high stability, abundant benzene rings), Ni@C-acid was used as fiber coatings in headspace solid-phase microextraction (HS-SPME) technology for extraction and preconcentration of polycyclic aromatic hydrocarbons (PAHs) prior to gas chromatography-flame ionization detector (GC-FID) analysis. The experimental parameters of extraction temperature, extraction time, agitation speed, desorption temperature, desorption time and sodium chloride (NaCl) concentration were studied. Under optimal experimental conditions, the wide linear range (0.01-30 ng mL-1), the good correlation coefficient (0.9916-0.9984), the low detection limit (0.003-0.011 ng mL-1), and the high enrichment factor (5273-13793) were obtained. The established method was successfully used for the detection of trace PAHs in actual tea infusions samples and satisfied recoveries ranging from 80.94-118.62 % were achieved. The present work provides a simple method for the preparation of highly stable and adsorbable porous carbon microsphere materials with potential applications in the extraction of environmental pollutants.


Carbon , Limit of Detection , Metal-Organic Frameworks , Microspheres , Polycyclic Aromatic Hydrocarbons , Solid Phase Microextraction , Tea , Solid Phase Microextraction/methods , Polycyclic Aromatic Hydrocarbons/isolation & purification , Polycyclic Aromatic Hydrocarbons/analysis , Tea/chemistry , Carbon/chemistry , Metal-Organic Frameworks/chemistry , Porosity , Adsorption , Nickel/chemistry , Nickel/isolation & purification , Chromatography, Gas/methods , Reproducibility of Results
8.
Food Chem ; 451: 139478, 2024 Sep 01.
Article En | MEDLINE | ID: mdl-38692242

The market share of Sichuan pepper oleoresin (SPO) in the flavor industry is increasing steadily; however, its high volatility, low water solubility, and poor stability continue to pose significant challenges to application. The microencapsulation prepared by emulsion embedding and spray drying is considered as an effective technique to solve the above problems. Sodium octenyl succinate starch (OSA starch) and tea polyphenols (TPs) were used to develop OSA-TPs complex as encapsulants for SPO to prepare orally soluble microcapsules. And the optimum doping of TPs was determined. SPO microcapsules have good properties with high encapsulation efficiency up to 88.13 ± 1.48% and high payload up to 41.58 ± 1.86% with low water content and high heat resistance. The binding mechanism of OSA starch with TPs and its regulation mechanism and effect on SPOs were further analyzed and clarified. The binding mechanism between OSA starch and TPs was clarified in further analyses. The OSA-TPs complexes enhanced the rehydration, release in food matrix and storage stability of SPO, and exhibited good sensory immediacy. Flavor-improved mooncakes were successfully developed, achieving the combination of mooncake flavor and SPO flavor. This study provided a valuable way to prepare flavoring microcapsules suitable for the catering industry, opened up the combined application of SPO and bakery ingredients, and was of great practical value and significance for improving the processing quality of flavor foods, driving the development of the SPO industry, and enhancing the national dietary experience.


Drug Compounding , Flavoring Agents , Plant Extracts , Polyphenols , Starch , Taste , Polyphenols/chemistry , Starch/chemistry , Flavoring Agents/chemistry , Plant Extracts/chemistry , Humans , Tea/chemistry , Capsicum/chemistry , Solubility , Capsules/chemistry , Camellia sinensis/chemistry
9.
Food Res Int ; 187: 114316, 2024 Jul.
Article En | MEDLINE | ID: mdl-38763629

This study investigates the dynamic changes in the aroma profile of Tuo tea during long-term storage, a process not well understood yet critical to the formation of aged tea's unique characteristics. Aroma profiling of Tuo tea samples stored for 2 to 25 years was conducted using sensory evaluation and the HS-SPME/GC × GC-QTOFMS technique, revealing a progressive transition from fresh, fruity, and floral scents to more stale, woody, and herbal notes. Among 275 identified volatiles, 55 were correlated with storage duration (|r| > 0.8, p < 0.05), and 49 differential compounds (VIP > 1, FC > 1.2, FC < 0.833, p < 0.05) were identified across three storage stages (2-4, 5-10, and 13-25 years). Furthermore, theaspirane, eucalyptol, o-xylene, and 1-ethylidene-1H-indene were selected as potential markers of Tuo tea aging, incorporating the implementation of a Random Forest (RF) model. Additionally, our model exhibited high accuracy in predicting the age of Tuo tea within a prediction error range of -2.51 to 2.84 years. This research contributes to a comprehensive understanding of the impact of storage time on tea aroma and aids in the precise identification of tea age.


Food Storage , Gas Chromatography-Mass Spectrometry , Odorants , Tea , Volatile Organic Compounds , Odorants/analysis , Tea/chemistry , Volatile Organic Compounds/analysis , Food Storage/methods , Time Factors , Humans , Camellia sinensis/chemistry , Solid Phase Microextraction
10.
Food Res Int ; 187: 114330, 2024 Jul.
Article En | MEDLINE | ID: mdl-38763633

Processing technology plays a crucial role in the formation of tea aroma. The dynamic variations in volatile metabolites across different processing stages of fresh scent green tea (FSGT) were meticulously tracked utilizing advanced analytical techniques such as GC-E-Nose, GC-MS, and GC × GC-TOFMS. A total of 244 volatile metabolites were identified by GC-MS and GC × GC-TOFMS, among which 37 volatile compounds were concurrently detected by both methods. Spreading and fixation stages were deemed as pivotal processes for shaping the volatile profiles in FSGT. Notably, linalool, heptanal, 2-pentylfuran, nonanal, ß-myrcene, hexanal, 2-heptanone, pentanal, 1-octen-3-ol, and 1-octanol were highlighted as primary contributors to the aroma profiles of FSGT by combining odor activity value assessment. Furthermore, lipid degradation and glycoside hydrolysis were the main pathways for aroma formation of FSGT. The results not only elucidate the intricate variations in volatile metabolites but also offer valuable insights into enhancing the processing techniques for improved aroma quality of green tea.


Food Handling , Gas Chromatography-Mass Spectrometry , Odorants , Tea , Volatile Organic Compounds , Volatile Organic Compounds/analysis , Volatile Organic Compounds/metabolism , Gas Chromatography-Mass Spectrometry/methods , Odorants/analysis , Tea/chemistry , Food Handling/methods , Electronic Nose , Aldehydes/analysis , Aldehydes/metabolism , Acyclic Monoterpenes/metabolism , Acyclic Monoterpenes/analysis , Camellia sinensis/chemistry , Camellia sinensis/metabolism , Ketones/analysis , Ketones/metabolism , Octanols
11.
Food Res Int ; 187: 114359, 2024 Jul.
Article En | MEDLINE | ID: mdl-38763643

Chinese Xiaokeng green tea (XKGT) possesses elegant and fascinating aroma characteristics, but its key odorants are still unknown. In this study, 124 volatile compounds in the XKGT infusion were identified by headspace-solid phase microextraction (HS-SPME), stir bar sorptive extraction (SBSE), and solvent extraction-solid phase extraction (SE-SPE) combined with gas chromatography-mass spectrometry (GC-MS). Comparing these three pretreatments, we found HS-SPME was more efficient for headspace compounds while SE-SPE was more efficient for volatiles with higher boiling points. Furthermore, SBSE showed more sensitive to capture ketones then was effective to the application of pretreatment of aroma analysis in green tea. The aroma intensities (AIs) were further identified by gas chromatography-olfactometry (GC-O). According to the AI and relative odor activity value (rOAV), 27 compounds were identified as aroma-active compounds. Quantitative descriptive analysis (QDA) showed that the characteristic aroma attributes of XKGT were chestnut-like, corn-like, fresh, and so on. The results of network analysis showed that (E, Z)-2,6-nonadienal, nonanal, octanal and nerolidol were responsible for the fresh aroma. Similarly, dimethyl sulfide, (E, E)-2,4-heptadienal, (E)-2-octenal and ß-cyclocitral contributed to the corn-like aroma. Furthermore, indole was responsible for the chestnut-like and soybean-like aroma. This study contributes to a better understanding of the molecular mechanism of the aroma characteristics of XKGT.


Gas Chromatography-Mass Spectrometry , Odorants , Olfactometry , Solid Phase Microextraction , Tea , Volatile Organic Compounds , Odorants/analysis , Tea/chemistry , Volatile Organic Compounds/analysis , Solid Phase Microextraction/methods , Humans , Camellia sinensis/chemistry , Solid Phase Extraction/methods
12.
Food Res Int ; 187: 114392, 2024 Jul.
Article En | MEDLINE | ID: mdl-38763654

Variations in cultivars and cultivation altitudes have significant impacts on tea flavour compounds however lack of comprehensive understanding. This study provided insights into differential accumulation of crucial flavour compounds in response to cultivars, cultivation altitudes, and processing. Twelve flavonoids (262.4 âˆ¼ 275.4 mg•g-1) and 20 amino acids (AAs) (56.5 âˆ¼ 64.8 mg•g-1) were comparative analyzed in 'Longjing 43' and 'Qunti' fresh leaves harvested at low (80 m, LA) and high (500 m, HA) altitudes. Additionally, an in-depth correlation unravelling of 31 alkaloids, 25 fatty acids, 31 saccharides, 8 organic acids, and 7 vitamins and flavonoids/AAs during green tea (GT) and black tea (BT) processing was performed. Enhenced flavonoid accumulation alongside higher AAs and saccharides in HA GT promoted a sweet/mellow flavour. Abundant flavonoids, AAs, and saccharides derivates in LA BT gave rise to a sweet aftertaste. The study presents an integrated illustration of major flavour compounds' differential accumulation patterns and their interrelations, providing new insights into the influence of cultivation conditions on tea flavour.


Altitude , Camellia sinensis , Flavonoids , Plant Leaves , Tea , Plant Leaves/chemistry , Plant Leaves/metabolism , Flavonoids/analysis , Tea/chemistry , Camellia sinensis/chemistry , Camellia sinensis/growth & development , Camellia sinensis/metabolism , Taste , Amino Acids/analysis , Amino Acids/metabolism , Food Handling/methods , Flavoring Agents/analysis , Alkaloids/analysis , Alkaloids/metabolism
13.
J Sep Sci ; 47(11): e2300730, 2024 Jun.
Article En | MEDLINE | ID: mdl-38819790

A fast and effective analytical method with biomass solid-phase microextraction sorbent combined with a high-performance liquid chromatography-ultraviolet detector was proposed for the determination of benzoylurea (BU) insecticides in tea products. The novel sorbent was prepared by activating and then carbonizing water hyacinth with a fast growth rate and low application value as raw material and showed a high specific surface area and multiple interactions with analytes, such as electrostatic action, hydrogen bonding, and π-π conjugation. After optimizing the three most important extraction parameters (pH [X1], sample loading rate [X2], and solution volume [X3]) by Box-Behnken design, the as-established analytical method showed good extraction performance: excellent recovery (80.13%-106.66%) and wide linear range (1-400 µg/L) with a determination coefficient of 0.9992-0.9999, a low limit of detection of 0.02-0.1 µg/L and the satisfactory practical application results in tea products. All these indicate that the water hyacinth-derived material has the potential as a solid-phase extraction sorbent for the detection and removal of BU insecticides from tea products, and at the same time, it can also achieve the effect of rational use of biological resources, maintaining ecological balance, turning waste into treasure, and achieving industrial production.


Biomass , Eichhornia , Insecticides , Tea , Insecticides/analysis , Insecticides/chemistry , Insecticides/isolation & purification , Eichhornia/chemistry , Tea/chemistry , Adsorption , Chromatography, High Pressure Liquid , Solid Phase Microextraction , Phenylurea Compounds/analysis , Phenylurea Compounds/chemistry , Phenylurea Compounds/isolation & purification
14.
Sci Rep ; 14(1): 10424, 2024 05 07.
Article En | MEDLINE | ID: mdl-38710752

The storage process has a significant impact on tea quality. Few is known about effect of storage on quality of oolong tea. This study aimed to assess the effect of different storage times on the key chemical components of oolong tea by measuring changes in catechin, free amino acid, and alkaloid content. Variation in the main substances was determined by principal component analysis and heat map analysis. The results revealed notable effects of the storage process on the levels of theanine, epigallocatechin gallate (EGCG), and glutamine. These findings suggest that these compounds could serve as indicators for monitoring changes in oolong tea quality during storage. Additionally, the study observed an increase in the antibacterial ability of tea over time. Correlation analysis indicated that the antibacterial ability against Micrococcus tetragenus and Escherichia coli was influenced by metabolites such as aspartic acid, threonine, serine, gamma-aminobutyric acid, ornithine, alanine, arginine, and EGCG. Overall, this study presents an approach for identifying key metabolites to monitor tea quality effectively with relatively limited data.


Alkaloids , Amino Acids , Anti-Bacterial Agents , Catechin , Tea , Catechin/analogs & derivatives , Catechin/pharmacology , Catechin/chemistry , Catechin/analysis , Tea/chemistry , Amino Acids/analysis , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Alkaloids/pharmacology , Alkaloids/analysis , Alkaloids/chemistry , Food Storage/methods , Escherichia coli/drug effects , Camellia sinensis/chemistry
15.
Anal Chim Acta ; 1307: 342624, 2024 Jun 08.
Article En | MEDLINE | ID: mdl-38719414

BACKGROUND: Pesticides are used in agricultural production for prevent and control crop diseases and pests, but it is easy to cause excessive pesticides residues in agricultural products, polluting the environment and endangering human health. Due to their unmatched and sustainable capabilities, nanoextraction procedures are becoming every day more important in Analytical Chemistry. In particular, nanoconfined liquid phase extraction has shown extraction capabilities toward polar, medium polar, and/or nonpolar substances, which can be easily modulated depending on the nanoconfined solvent used. Furthermore, this "green" technique showed excellent characteristics in terms of recoveries, extraction time (≤1 min), reliability, and versatility. (97) RESULTS: In this work, the advantages of this technique have been coupled with those of filtration membrane extraction, making use of carbon nanofibers (CnFs) growth on carbon microspheres (CµS). This substrate has been deposited on a filter, which combined with gas chromatographic mass spectrometry (GC-MS) analysis successfully employed for the nanoextraction of 30 pesticides (18 organochlorine and 12 pyrethroids) in tea samples. Under the optimized extraction conditions, the linear range with standard solutions was from 1 to 1000 ng mL-1 (R2 ≥ 0.99), the limit of detections in tea samples were in the range 0.56-17.98 µg kg-1. The accuracy of the developed method was evaluated by measuring the extraction recovery of the spiked tea samples, and recoveries between 74.41 % and 115.46 %. (119) SIGNIFICANCE: Considering the versatility of nanoconfined liquid phase extraction and the functionality of the filtration membrane extraction procedure, this new extraction method can be considered a powerful candidate for automatized high-throughput analyses of real samples. (34).


Filtration , Hydrocarbons, Chlorinated , Liquid-Liquid Extraction , Pesticides , Pyrethrins , Tea , Tea/chemistry , Pyrethrins/analysis , Pyrethrins/isolation & purification , Hydrocarbons, Chlorinated/analysis , Hydrocarbons, Chlorinated/isolation & purification , Liquid-Liquid Extraction/methods , Filtration/methods , Pesticides/analysis , Pesticides/isolation & purification , Gas Chromatography-Mass Spectrometry/methods , Membranes, Artificial
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 316: 124349, 2024 Aug 05.
Article En | MEDLINE | ID: mdl-38692107

Fluorine (F) is a pivotal element in the formation of human dental and skeletal tissues, and the consumption of water and tea constitutes a significant source of fluoride intake. However, prolonged ingestion of water and tea with excessive fluoride content can lead to fluorosis, which poses a serious health hazard. In this manuscript, a novel turn-on fluorescent probe DCF synthesized by bis-coumarin and tert-butyldiphenylsilane (TBDPS) was introduced for detecting F- in potable water and tea infusions. By leveraging the unique chemical affinity between fluoride and silicon, F- triggers the silicon-oxygen bond cleavage in DCF, culminating in a conspicuous emission of yellow fluorescence. Validated through a succession of optical tests, this probe exhibits remarkable advantages in terms of superior selectivity, a low detection limit, a large Stokes shift, and robust interference resistance when detecting inorganic fluoride. Moreover, it can serve as portable test strips for on-site real-time identification and quantitative analysis of F-. Furthermore, the application of DCF for in-situ monitoring and imaging of F- in zebrafish and soybean root tissues proved its significant value for F- detection in both animal and plant systems. This probe potentially functions as an efficient instrument for delving into the toxic mechanisms of fluoride in physiological processes.


Coumarins , Fluorescent Dyes , Tea , Zebrafish , Fluorescent Dyes/chemistry , Animals , Coumarins/chemistry , Tea/chemistry , Drinking Water/analysis , Spectrometry, Fluorescence/methods , Fluorine/analysis , Fluorine/chemistry , Fluorides/analysis , Glycine max/chemistry , Limit of Detection , Optical Imaging/methods
17.
Food Res Int ; 186: 114379, 2024 Jun.
Article En | MEDLINE | ID: mdl-38729702

The relationship between the chemical composition and quality of Lushan Yunwu tea (LYT) from different geographical origins is not clear. Sensory evaluation, metabolomics analyses combined with chemometrics were conducted on LYT from 8 different geographical origins, and altitude was identified as the main factor responsible for the differences among LYT. A total of 32 non-volatile and 27 volatile compounds were identified as marker metabolites to distinguish the origins of high altitudes from those of low altitudes. LYT samples from higher altitude areas contained more free amino acids, sugars, and organic acids, and less catechins, which may contribute to the reduction of bitterness and astringency and the enhancement of umami. The contents of geranylacetone, ethyl hexanoate, ethyl caprylate, 3-carene, d-cadinene, linalool, nerol, and nerolidol in high altitude areas were higher than those in low altitude areas, indicating that LYT from high altitude had strong floral and fruity aroma. The altitudes were positively correlated with pH value, total flavonoids, soluble protein, total free amino acids, and the antioxidant capacities of the LYT. This study provided a theoretical basis for the study of the effect of altitude on tea quality.


Altitude , Metabolomics , Tea , Volatile Organic Compounds , Tea/chemistry , Volatile Organic Compounds/analysis , Humans , Odorants/analysis , Taste , Antioxidants/analysis , Camellia sinensis/chemistry , Amino Acids/analysis , Flavonoids/analysis , Male , China , Female
18.
Food Res Int ; 186: 114401, 2024 Jun.
Article En | MEDLINE | ID: mdl-38729704

Fuzhuan brick tea (FBT) fungal fermentation is a key factor in achieving its unique dark color, aroma, and taste. Therefore, it is essential to develop a rapid and reliable method that could assess its quality during FBT fermentation process. This study focused on using electronic nose (e-nose) and spectroscopy combination with sensory evaluations and physicochemical measurements for building machine learning (ML) models of FBT. The results showed that the fused data achieved 100 % accuracy in classifying the FBT fermentation process. The SPA-MLR method was the best prediction model for FBT quality (R2 = 0.95, RMSEP = 0.07, RPD = 4.23), and the fermentation process was visualized. Where, it was effectively detecting the degree of fermentation relationship with the quality characteristics. In conclusion, the current study's novelty comes from the established real-time method that could sensitively detect the unique post-fermentation quality components based on the integration of spectral, and e-nose and ML approaches.


Electronic Nose , Fermentation , Spectroscopy, Near-Infrared , Taste , Tea , Tea/chemistry , Tea/microbiology , Spectroscopy, Near-Infrared/methods , Odorants/analysis , Chemometrics/methods , Humans , Fungi/metabolism , Machine Learning , Volatile Organic Compounds/analysis
19.
J Chromatogr A ; 1727: 465000, 2024 Jul 19.
Article En | MEDLINE | ID: mdl-38763086

Design and preparation of fiber coatings with excellent electrochemical performance and high polarity is significant for efficient extraction of polar targets in electro-enhanced solid-phase microextraction (EE-SPME). In this work, a combination strategy for structure regulation of covalent organic framework (COF) was proposed to fabricate a nitrogen-rich thiocarbamide linked COF coating (Thiocarbamide-TZ-DHTP) via molecular design and post-synthetic thiocarbamide conversion. The prepared COF coating possesses a large number of O, N, and S functional groups, which not only endow the coating with higher polarity but also significantly enhance its electrochemical performance. The COF coating was used for EE-SPME of polar bisphenols (BPs), demonstrating excellent enrichment efficiency and durability. Subsequently, coupled with gas chromatography-tandem mass spectrometry (GC-MS/MS), a sensitive method was developed for determination of trace BPs. The established method possess wide linear ranges (2.0-800.0 ng L-1), good correlation coefficients (0.9985-0.9994) and low detection limits (0.1-2.0 ng L-1). Moreover, the established method had been successfully applied to detection of trace BPs in tea beverage with satisfactory recoveries (81.6 % to 118.6 %). This research provides a feasible pathway for preparing COF coating with excellent electrochemical performance and high polarity for EE-SPME.


Gas Chromatography-Mass Spectrometry , Limit of Detection , Metal-Organic Frameworks , Nitrogen , Phenols , Solid Phase Microextraction , Tandem Mass Spectrometry , Solid Phase Microextraction/methods , Phenols/analysis , Phenols/isolation & purification , Phenols/chemistry , Gas Chromatography-Mass Spectrometry/methods , Metal-Organic Frameworks/chemistry , Tandem Mass Spectrometry/methods , Nitrogen/chemistry , Benzhydryl Compounds/analysis , Benzhydryl Compounds/isolation & purification , Benzhydryl Compounds/chemistry , Electrochemical Techniques/methods , Reproducibility of Results , Tea/chemistry
20.
Int J Biol Macromol ; 269(Pt 2): 132128, 2024 Jun.
Article En | MEDLINE | ID: mdl-38723807

Selenium-rich tea polysaccharides (Se-TPS) were extracted via high hydrostatic pressure technology with a pressure of 400 MPa (200-500 MPa) for 10 min (3-20 min) at a material-to-solvent ratio of 1:40 (1:20-1:50). Subsequently, Se-TPS1-4 were isolated and purified, with Se-TPS3-4 as the main components. A spectral analysis proved that Se, which has antioxidant activity, existed. An in vitro study found that among Se-TPS, Se-TPS3-4 attenuated the release of ß-hexosaminidase, histamine, and interleukin (IL)-4. Furthermore, in vivo experiments revealed that treatment with Se-TPS downregulated IL-4 levels and upregulated TGF-ß and interferon-γ levels to improve imbalanced Th1/Th2 immunity in tropomyosin-sensitized mice. Moreover, Se-TPS promoted Lactobacillus and norank_f_Muribaculaceaek growth and upregulated metabolites such as genipin and coniferyl alcohol. Overall, these results showed the strong anti-allergy potential of Se-TPS by regulating mast cell-mediated allergic inflammatory responses and microbiota regulation, highlighting the potential of Se-TPS as a novel therapeutic agent to regulate allergy-associated metabolic disorders.


Gastrointestinal Microbiome , Hydrostatic Pressure , Polysaccharides , Tea , Animals , Gastrointestinal Microbiome/drug effects , Polysaccharides/pharmacology , Polysaccharides/chemistry , Mice , Tea/chemistry , Mast Cells/metabolism , Mast Cells/drug effects , Mast Cells/immunology , Anti-Allergic Agents/pharmacology , Anti-Allergic Agents/chemistry , Anti-Allergic Agents/isolation & purification , beta-N-Acetylhexosaminidases/metabolism , Cytokines/metabolism , Male , Tropomyosin/metabolism , Tropomyosin/immunology
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