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Green tea is a worldwide appreciated food product with Chinese production estimated to reach over 3m tons in 2027 and with many valuable health effects. The development of analytical methods to discriminate among green tea samples is induced by economic benefits and to avoid deliberate origin mislabeling and adulteration. In this study, we present a paper-based colorimetric sensor array comprised of six ordinary reagents tailored for the discrimination of green tea extracts of different brands according to differences in the composition of flavonoids. The colorimetric array was rationally designed based on indicators that differentially react with a variety of flavonoids via specific functional groups. 4 μL of each reagent was impregnated onto the paper surface followed by the addition of the green tea extract. After 1 minute, digital images were acquired using a smartphone and the color changes were employed to build differential maps with a unique fingerprint for each green tea sample. Moreover, principal component analysis (PCA) and hierarchical component analysis (HCA) were employed to successfully discriminate among the samples, enabling the origin and adulteration identification of the samples. Therefore, this study provides a simple, effective, low-cost, and portable method for quick discrimination and quality control of green tea samples.

Improving the shelf lives of fruits is challenging. The biodegradable polysaccharide pullulan exhibits excellent film-forming ability, gas barrier performance, and natural decomposability, making it an optimal material for fruit preservation. To overcome problems of high cost and film porosity of existing packaging technologies, we aimed to develop pullulan-based packaging paper to enhance the shelf lives of fruits. A thin paper coating comprising a mixture of 15 wt.% pullulan solution at various standard viscosities (75.6, 77.8, and 108.5 mPa·s) with tea polyphenols (15:2) and/or vitamin C (150:1) improved the oxygen transmission rate (120–160 cm3 m−2·24 h·0.1 MPa), water vapor transmission rate (<5.44 g·mm−1 m−2·h·kPa), maximum free radical clearance rate (>87%), and antibacterial properties of base packaging paper. Grapes wrapped with these pullulan-based papers exhibited less weight loss (>4.41%) and improved hardness (>16.4%) after 10 days of storage compared to those of control grapes (wrapped in untreated/base paper). Grapes wrapped with pullulan-based paper had >12.6 wt.% total soluble solids, >1.5 mg/g soluble protein, >0.44 wt.% titratable acidity, and ≥4.5 mg 100 g−1 ascorbic acid. Thus, pullulan-based paper may prolong the shelf life of grapes with operational convenience, offering immense value for fruit preservation. [ABSTRACT FROM AUTHOR]

Tea is a vital agricultural product in Taiwan. Due to global warming, the increasing extreme weather events have disrupted tea garden conditions and caused economic losses in agriculture. To address these challenges, a comprehensive tea garden risk assessment model, a Bayesian network (BN), was developed by considering various factors, including meteorological data, disaster events, tea garden environment (location, altitude, tea tree age, and soil characteristics), farming practices, and farmer interviews, and constructed risk assessment indicators for tea gardens based on the climate change risk analysis concept from the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5). The results demonstrated an accuracy of over 92% in both validating and testing the model for tea tree damage and yield reduction. Sensitivity analysis revealed that tea tree damage and yield reduction were mutually influential, with weather, fertilization, and irrigation also impacting tea garden risk. Risk analysis under climate change scenarios from various global climate models (GCMs) indicated that droughts may pose the highest risk with up to 41% and 40% of serious tea tree growth damage and tea yield reduction, respectively, followed by cold events that most tea gardens may have less than 20% chances of serious impacts on tea tree growth and tea yield reduction. The impacts of heavy rains get the least concern because all five tea gardens may not be affected in terms of tea tree growth and tea yield with large chances of 67 to 85%. Comparing farming methods, natural farming showed lower disaster risk than conventional and organic approaches. The tea plantation risk assessment model can serve as a valuable resource for analyzing and offering recommendations for tea garden disaster management and is used to assess the impact of meteorological disasters on tea plantations in the future., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Phthalic acid ester (PAE) contamination in popular drink bubble tea has been hardly studied in the world. In this work, a liquid-liquid extraction following solid phase extraction (LLE-SPE)-UPLC-MS/MS method was first established for trace determination of ten PAEs in bubble tea. The developed method was validated with respect to linearity (R 2  > 0.992), low limit of detections (LODs, 0.49-3.16 µg/L), and satisfactory recoveries (61.8-127.6%) with a low relative standard derivations (RSDs, 1.1-16.4%), which was also validated for commercial milk. Six out of ten PAEs, i.e., diethylhexyl phthalate (DEHP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), diethyl phthalate (DEP), dihexyl phthalate (DHP), and diphenyl phthalate (DPP) were detected in Chinese bubble tea with concentrations ranging from not detection (ND) to 53.43 µg/L, while DEHP, DBP, DIBP, DEP, and dimethyl phthalate (DMP) were detected in commercial milk with concentrations ranging from ND to 110.58 µg/L. The respective average concentrations of DEHP in Chinese bubble tea and commercial milk were 19.40 and 23.46 µg/L, which were over two times that in drinking water quality standards of several countries including Israel, Korea, Oman, and Singapore (i.e., 8 µg/L). Calculated with human estimated daily intake (EDI), the average EDIs of five out of seven PAEs in bubble tea were higher than those in commercial milk. For example, the calculated EDI of DIBP in bubble tea was 5 times that in commercial milk, while their respective corresponding EDIs of DBP and DEHP were over 2.4 and 1.6 times. Based on estrogen equivalence (EEQ) with the unit of ng E2/L, the average EEQs of the ten PAEs in Chinese bubble tea and commercial milk were 14.26 and 17.06 ng E2/L, which were 52.8 and 62.3 times the observed effect concentration that could cause egg mortality of zebrafish. It is evident that the potential estrogenic effect of PAEs in bubble tea and commercial milk cannot be negligible. Given the fact that PAE contamination in bubble tea has been hardly investigated, such study is urgently to be performed in a global view., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Technological advances in tea production are critical to meet global demands for tea consumption. To illuminate differences in the scientific and commercial relevance of research programs between major tea-related research organizations around the world, we conducted a bibliometric analysis comparing the scientific outputs, including peer-reviewed publications and patents, of six major research organizations published between January 01, 2008 and July 11, 2020. For this competitive ranking analysis, we examined a number of papers, research topics, academic influence, capacity for development, capacity for collaboration, and capacity for technological innovation. Among the six research organizations, Anhui Agricultural University (in China) had the most publications, while the Chinese Academy of Agricultural Sciences, Tea Research Institute showed a higher capacity for development. The Council for Scientific and Industrial Research (in India) and the University of Shizuoka (Japan) both showed high academic influence, while the University of Shizuoka, Tea Research Association Tocklai and National Agriculture and Food Research Organization (Japan) showed a high capacity for collaboration. The Chinese Academy of Agricultural Sciences, Tea Research Institute applied for the most patents, while the Council for Scientific and Industrial Research applied for the most international patents. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of fermentation time and temperature on the content of high molecular weight polyphenol mitochondrial activation factors (MAFs) and other polyphenols in Congou black tea using high‐performance liquid chromatography (HPLC). There were two broad chromatographic peaks in the HPLC spectra of MAFs: MAFs‐1 (16.163 min) and MAFs‐2 (34.31 min); MAFs‐2 was satisfactorily analyzed by HPLC, with separation by paper chromatography. The MAFs‐2 contents increased gradually in different varieties of Congou black tea as the fermentation time and temperature increased; the maximum MAFs‐2 content was 5.11% in Xiaoxianghong 21‐3 after 8 hr of fermentation. The total polyphenols and catechins contents decreased, whereas the theabrownins contents increased as the fermentation time and temperature increased; the theaflavins and thearubigins contents in different Congou black teas showed different variation tendencies. Therefore, studies regarding changes in polyphenols during fermentation will help improve the quality of Congou black tea and enhance its health benefits. Novelty impact statement: A new method for the determination of MAFs‐2 by high‐performance liquid chromatography combined with paper chromatography was established. The content of MAFs‐2 increased initially and then stabilized as fermentation was continued from 2 to 8 hr, it increased gradually as the fermentation temperature was increased from 23 to 37°C. These results provide a new analytical method for MAFs in black tea and a theoretical basis and technical guidance for improving the quality of Congou black tea. [ABSTRACT FROM AUTHOR]

[Display omitted] • 3D paper-based microfluidic electrochemical device (3D-ePAD) was constructed. • Graphite-supported gold nanoparticles modified electrode was used as a working electrode. • Low-cost, disposable, simple, and miniaturized 3D-ePAD was performed for determination of GA in tea samples. The combination of µPAD with electrochemical transducers has gained advantages of miniaturization, high sensitivity, selectivity, simplicity of instrumentation, portability, rapid analysis, and so on. In this work, the development of a 3D paper-based microfluidic electrochemical device (3D-ePAD) for the determination of gallic acid (GA) was presented. The 3D-ePAD is composed of three electrodes (working, reference, and counter electrodes) in which the hydrophilic area of the working electrode was manually screen-printed and modified with graphite-supported AuNPs(AuNPs/C) ink. The evaluation of the electrochemical oxidation process of GA at modified and unmodified electrodes at 3D-ePAD indicated the improvement of anodic current responses at the AuNPs/C modified electrode which can be attributed to the intermolecular hydrogen-bonded network between AuNPs and GA. For quantitative determination of GA, the amperometric experiments were investigated under optimal conditions in which a linear relationship between the GA concentration and the recorded current was achieved. The sensor displays a good linear range of 1.0 to 100.0 μM and 0.1 to 2.0 mM for GA determination. The limit of detection (LOD) of 0.89 μM was achieved for GA by 3D-ePAD. Conclusively, the 3D-ePAD was performed successfully for the determination of GA in tea samples. [ABSTRACT FROM AUTHOR]

Objectives: Coffee, green tea, and caffeine are potential preventive factors for dementia, but the underlying evidence is insufficient. This study aimed to examine associations between the consumption of coffee, green tea, and caffeine and dementia risk in middle-aged and older people., Methods: This was a cohort study with an 8.0-year follow-up. Participants were community-dwelling individuals (n = 13,757) aged 40-74 years. A self-administered questionnaire survey was conducted in 2011-2013. Predictors were the consumption of coffee/green tea, from which caffeine consumption was estimated. The outcome was incident dementia obtained from the long-term care insurance database. Covariates were demographic factors, body mass index, physical activity, energy, smoking, drinking, and disease history. Adjusted hazard ratios (HRs) were calculated using Cox proportional hazards models. HRs were also calculated using a Cox model with delayed entry., Results: The number of dementia cases during the study period was 309. Participants with higher coffee consumption had lower HRs (adjusted p for trend = 0.0014), with the fifth quintile (≥326 ml/day) having a significantly lower HR (0.49, 95% confidence interval [CI]: 0.30-0.79) than the first quintile (<26 ml/day, reference). Similarly, participants with higher caffeine consumption had a significantly lower HR (adjusted p for trend = 0.0004) than the reference. The Cox model with delayed entry yielded similar results. These associations were significant in men, but not in women. Moreover, participants who consumed 2-2.9 cups/day and ≥3 cups/day of coffee had lower HRs (0.69, 95% CI: 0.48-0.98 and 0.53, 95% CI: 0.31-0.89, respectively) than those who consumed 0 cup/day. The association between green tea consumption and reduced dementia risk was significant (adjusted p for trend = 0.0146) only in the 60-69 years age subgroup., Conclusions: High levels of coffee and caffeine consumption were significantly associated with a reduced dementia risk in a dose-dependent manner, especially in men. Moreover, coffee consumption of ≥3 cups/day was associated with a 50% reduction in dementia risk., (© 2021 The American Geriatrics Society.)

Soursop (Annona muricata L.) fruit tea is a health‐beneficial product that promotes economic development and addresses the issue of excessive agricultural waste. Prolonging the shelf‐life of soursop fruit tea has been of scientific interest currently. This study evaluated the effects of three types of packaging materials of soursop fruit tea (e.g., paper, paper‐combined Polyetylen (PE), and aluminum‐combined PE) and different storage temperatures (5, 15, 30, and 45°C) on various product characteristics, total polyphenol content (TPC), total flavonoid content (TFC), total ascorbic acid (TAA), and 2,2‐diphenyl‐1‐picryl hydrazyl (DPPH)/2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) free radical scavenging capacity during 4 weeks of storage. The results revealed that the sample stored in aluminum‐combined PE packaging at 30°C retained most of the product's characteristics and nutritional values. This was evidenced by the moisture content of 2.49%, TAA of 3.9 ± 1.4 mg/100 g dry weight, TPC of 12.89 ± 0.47 mgGAE/g, TFC of 0.54 ± 0.004 mgQE/g, DPPH scavenging activity of 4.06 ± 0.02 mgAA/g, and ABTS scavenging activity of 13.34 ± 0.32 mgAA/g. Additionally, the microbiological quality of the sample met the standard of TCVN 9740:2013. Overall, the study highlights the importance of packaging materials and storage temperatures to maintain the nutritional quality of soursop fruit tea. It provides valuable insights into the suitable storage conditions for preserving the quality and health‐promoting effects of this product. [ABSTRACT FROM AUTHOR]

• Data of fermented tea samples was collected at-line by an industrial camera. • Catechins, theaflavins and chlorophylls were chosen as key quality indicators. • Correlations between color variables and quality indicators were established. • Spatial and temporal distribution of indicators was mapped and visualized. Fermentation is a key black tea processing step and makes an important contribution to quality formation. Current approaches to fermentation monitoring are costly or laboratory-based. Here, we first evaluated the potential of at-line computer vision for detecting fermentation quality in a tea factory. A self-built industrial camera was used to collect tea samples at various fermentation durations. The correlations of color variables that were extracted from the images with key quality indicators in the tea samples were verified. Subsequently, partial least-squares regression models based on the color variables showed high prediction accuracy with residual prediction deviation values of 4.13, 3.53, and 3.39 for catechins, theaflavins and chlorophylls, respectively. Finally, the spatial and temporal distributions of indicators during fermentation were mapped to visualize the fermentation quality. This study realized low-cost, at-line and real-time detection for black tea fermentation, which provides technical support for the industrial and intelligent production of black tea. [ABSTRACT FROM AUTHOR]

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Aiming at the current complex problem of the mechanized high-quality picking of tender tea buds, this paper designs a tender tea bud-picking manipulator. In the picking process, the quality of the petiole and leaf blade of the tender tea bud is crucial, as the traditional cutting picking method destroys the cell structure of the tender tea buds, resulting in rapid oxidation of the cuts, thus losing the bright green appearance and pure taste. For this reason, this paper draws on the quality requirements of tender tea buds and traditional manual picking technology, simulating the process of the manual picking action, putting forward a 'rotary pull-up' clamping and ripping picking method, and designing the corresponding actuating structure. Using PVDF material piezoelectric thin-film sensors to detect the clamping force of the tender tea bud picking, the corresponding sensor hardware circuit is designed. In addition, the finite element analysis method is also used to carry out stress analysis on the mechanical fingers to verify the rationality of the automatic mechanism to ensure the high-quality picking of tender tea buds. In terms of the control of the manipulator, an SMC-PID control method is designed by using MATLAB/Simulink 2021 and Adam 2020 software for joint simulation. The way to control the closed-loop system angle and angular velocity error feedback is by adjusting the PID parameters, which quickly converts the sliding mode control to the sliding mode surface. The simulation results show that the SMC-PID control method proposed in this paper can meet the demand in tender tea bud picking and simultaneously has high control accuracy, response speed, and stability. [ABSTRACT FROM AUTHOR]

The realization of the value of ecological products has led to an economic means for reducing carbon emissions in China. Tea is one of the most important cash crops and one of the most popular beverages in the world. Due to the complex the tea industrial chain, it is considered to be an industry with high carbon emissions. Ecological tea products with low-carbon attributes can be considered a linkage of ecology, economy, and society. Based on this, this paper presents research on low-carbon ecological tea (LCT). Herein, we construct the formational logic of low-carbon ecological products, explore the connotations of LCT, and form a conceptual pathway for realizing LCT to contribute to climate change mitigation and adaptation. This paper starts from the upstream, midstream, and downstream of the industrial chain; it establishes three value realization pathways that keep, as a priority, the promotion of ecological industrialization, focus on restoration to improve the ecology of the industrial chain, and innovate technology to expand the industrial chain. The pathways are a set of low-emission production solutions that use techniques to enhance carbon sequestration in soil, reduce the use of fertilizers and pesticides, and help shift to clean energy from low-emission sources in the stages of plantation, processing, and distribution. In the process of realizing LCT, the government plays an important role, and its support and guidance are needed. Based on stakeholder theory, this paper builds an implementation mechanism that focuses on the micro perspective (users, organizations), integrates the mesoscopic perspective (industry), and relies on the macro perspective (government). [ABSTRACT FROM AUTHOR]

This study presents a comprehensive analysis of the elemental profiles of tea leaves coming from plants grown in several European gardens, with a focus on the bioaccumulation of essential and potentially toxic trace elements in relation to processing and location of tea garden. Samples were collected from various gardens across Europe, including Portugal, the Azores, Germany, the Netherlands, and Switzerland. Elemental analysis was conducted on fresh tea leaves, dried leaves, and leaves processed for the production of green and black tea, along with soil samples from the root zones of tea plants. The results reveal no significant differences in elemental content based on the processing of tea leaves. However, distinct elemental profiles were observed among tea leaves of plants grown in gardens from different European regions. Utilizing chemometric and machine learning tools, the study highlights the potential of these elemental profiles for enhancing the traceability of tea products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Herein, a novel multifunctional enzyme β-glucosidase/xylanase/feruloyl esterase (GXF) was constructed by fusion of β-glucosidase and bifunctional xylanase/feruloyl esterase. The activities of β-glucosidase, xylanase, feruloyl esterase and acetyl xylan esterase displayed by GXF were 67.18 %, 49.54 %, 38.92 % and 23.54 %, respectively, higher than that of the corresponding single functional enzymes. Moreover, the GXF performed better in enhancing aroma and quality of Longjing tea than the single functional enzymes and their mixtures. After treatment with GXF, the grassy and floral odors of tea infusion were significantly improved. Moreover, GXF treatment could improve concentrations of flavonoid aglycones of myricetin, kaempferol and quercetin by 68.1-, 81.42- and 77.39-fold, respectively. In addition, GXF could accelerate the release of reducing sugars, ferulic acid and xylo-oligosaccharides by 9.48-, 8.25- and 4.11-fold, respectively. This multifunctional enzyme may have potential applications in other fields such as food production and biomass degradation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The study aimed to evaluate a food adhesive developed using tea polyphenols (TPs) with soybean protein isolate (SPI) to create a cohesive bond between soy protein gel and simulated fat. Upon the addition of 5.0 % TPs, significant increases in viscosity, thermal stability, and crystallinity were noted in adhesives, suggesting the formation of a cohesive network. Furthermore, TPs effectively enhanced adhesion strength, with the optimal addition being 5.0 %. This enhancement can be attributed to hydrogen bonding, hydrophobic and electrostatic interactions between TPs and SPI molecules. TPs induced a greater expansion of the protein structure, exposing numerous buried hydrophobic groups to a more hydrophilic and polar environment. However, excessive TPs were found to diminish adhesion strength. This can be attributed to enhanced reactions between TPs and SPI, where high molecular weight SPI-TPs cooperatively aggregate to form agglomerates that eventually precipitated, rendering the adhesive network inhomogeneous, less stable, and more prone to disruption., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Umami taste is a key criteria of green tea quality evaluation. The aim of this study was to comprehensively explore the key umami taste contributors in Longjing tea. The taste and molecular profiles of 36 Longjing green tea infusions were characterized by sensory quantitative descriptive analysis and LC-MS based metabolomics, respectively. By uni-/multi-variate statistical analysis, 84 differential compounds were screened among tea infusions with varied umami perceptions. Among them, 17 substances were identified as candidate umami-enhancing compounds, which showed significant positive correlations with umami intensities. Their natural concentrations were accurately quantified, and their umami taste-modifying effects were further investigated by taste addition into glutamic acid solution. Glutamic acid, aspartic acid, glutamine, theanine, phenylalanine, histidine, theogallin, galloylglucose, 1,2,6-trigalloylglucose significantly enhanced the umami taste. This study uncovered for the first time of some bitter amino acids and galloylglucose homologous series as important umami-enhancers, which provided a novel perspective into the tea taste., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Tea tree is a fluorine (F)-enriched plant, leading to much concern about the safety of drinking tea from tea tree (Camellia sinensis (L.) Kuntze). Tea tree is a perennial leaf-harvested crop, and tea production in China is generally categorized as spring tea, summer tea and autumn tea in its annual growth rounds. However, the seasonally dynamic changes of F content and accumulation in the leaves and its drinking safety are poorly understood. In this study, 85 tea varieties cultivated under the same conditions were investigated to analyze the seasonal variation of F content and it's relationships with F accumulation, aluminum (Al), calcium (Ca) and manganese (Mn) and hazard quotient (HQ) in young leaves (one bud and two leaves, YL) and mature leaves (canopy leaves, ML). The average F contents and accumulations were 350 mg kg -1 and 203 g ha -1 in YL, and they were 2451 mg kg -1 and 2578 g ha -1 in ML, respectively, with F mainly accumulated in ML. As the growing season progresses, the F content showed a gradual increase in YL, while a decrease in ML, inferring that F may be redistributed from mature leaves to young leaves. Additionally, the F content was quite different among tea varieties which are suitable for processing oolong tea, green tea, and black tea, with higher F accumulation in oolong tea varieties than in green and black tea varieties. Moreover, F content and accumulation could be obviously affected by the geographical origin of the tea tree varieties, with significantly higher F content in the varieties from F rich fluorite belts than other regions. Furthermore, F content and accumulation showed a significant positive correlation with the content of Al and Mn (p < 0.05). Based on a daily tea consumption of 8.7 g, the HQ was investigated to show that the proportion of tea leaves with HQ<1 made from spring, summer and autumn tender leaves of 85 varieties was 100 %, 90.6 % and 50.6 %, respectively, indicating that the tea with the best drinking safety comes from spring, followed by summer, and then autumn. This result suggests that it could be necessary to avoid planting tea trees in fluorite mining areas, choose low F tea tree varieties, and control the tenderness of fresh leaves in order to ensure the safety of tea drinking., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Endemic fluorosis has gained increasing attention as a public health concern, and the escalating risk of colitis resulting from excessive fluoride intake calls for effective mitigation strategies. This study aimed to investigate the potential mechanisms underlying the alleviation of fluoride-induced colitis by Tea polysaccharides (TPS). Under conditions of excessive fluoride intake, significant changes were observed in the gut microbiota of rats, leading to aggravated colitis. However, the intervention of TPS exerted a notable alleviating effect on colitis symptoms. Antibiotic intervention and fecal microbiota transplantation (FMT) experiments provided evidence that TPS-mediated relief of fluoride-induced colitis is mediated through its effects on the gut microbiota. Furthermore, TPS supplementation was found to modulate the structure of gut microbiota, enhance the relative abundance of Limosilactobacillus vaginalis in the gut microbiota, and promote the expression of short-chain fatty acid (SCFAs) receptors in colonic tissue. Notably, L. vaginalis played a significant role in alleviating fluoride-induced colitis and facilitating the absorption of butyric acid in the rat colon. Subsequent butyric acid intervention experiments confirmed its remarkable alleviating effect on fluoride-induced colitis. Overall, these findings provide a potential preventive strategy for fluoride-induced colitis by TPS intervention, which is mediated by L. vaginalis and butyric acid., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. All data needed to evaluate the conclusions in the paper are present in the paper and the Supplementary Materials. Additional data related to this paper may be requested from the corresponding authors., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Microbial fuel cells (MFCs) have the dual advantage of mitigating Cr(Ⅵ) wastewater ecological threats while generating electricity. However, the low electron transfer efficiency and the limited enrichment of active electrogens are barriers to MFCs advancement. This study describes the synthesis of the TP-PDA-RGO@CC negative electrode using tea polyphenol as a reducing agent and polydopamine-doped graphene, significantly enhances the roughness and hydrophilicity of the anode. The charge transfer resistance was reduced by 94%, and the peak MFC power was 1375.80 mW m -2 . Under acidic conditions, the Cr(Ⅵ) reduction rate reached 92% within 24 h, with a 52% increase in coulombic efficiency. Biodiversity analysis shows that the TP-PDA-RGO@CC anode could enrich electrogens, thereby boosting the electron generation mechanism at the anode and enhancing the reduction efficiency of Cr(Ⅵ) in the cathode chamber. This work emphasizes high-performance anode materials for efficient pollutant removal, energy conversion, and biomass reuse., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Enshi Yulu green tea (ESYL) is the most representative traditional steamed green tea in Enshi, Hubei. Different ESYL grades exhibit distinct flavors, tastes, and prices. In this study, a visual sensor based on 4-MPBA Au@AgNPs was developed for the rapid and accurate identification of ESYL grades. The recognition mechanism involved the binding of 4-MPBA Au@AgNPs with polyphenolic compounds in ESYL to form borate esters and the conversion of Ag + to Ag 0 , with the generated Ag 0 depositing on the surface of 4-MPBA Au@AgNPs. The results showed that the sensor can amplify the color differences of different grades of ESYL. The visual results were also validated by the partial least squares discriminant analysis model, demonstrating an enhancement in recognition accuracy from 68.2 % to 95.5 % compared to the original extraction solution. The colorimetric sensor developed in this study is expected to provide a new approach for traceability research of other foods., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Withering is the first and key process that influences tea quality, with light quality being a key regulatory factor. However, effects of withering light quality (WLQ) on transformation and formation pathways of tea aroma and volatile metabolites (VMs) remain unclear. In the present study, four WLQs were set up to investigate their effects on tea aroma and VMs. The results showed that blue and red light reduced the grassy aroma and improved the floral and fruity aroma of tea. Based on GC-MS/MS, 83 VMs were detected. Through VIP, significant differences, and OAV analysis, 13 key differential VMs were screened to characterize the differential impacts of WLQ on tea aroma. Further analysis of the evolution and metabolic pathways revealed that glycoside metabolism was the key pathway regulating tea aroma through WLQ. Blue light withering significantly enhanced glycosides hydrolysis and amino acids deamination, which was beneficial for the enrichment of floral and fruity VMs, such as geraniol, citral, methyl salicylate, 2-methyl-butanal, and benzeneacetaldehyde, as well as the transformation of grassy VMs, such as octanal, naphthalene, and cis-3-hexenyl isovalerate, resulting in the formation of tea floral and fruity aroma. The results provide theoretical basis and technical support for the targeted processing of high-quality tea., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

To explore the influence of tea trichomes on the quality of white tea, liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS), and headspace solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) were used to identify non-volatile and volatile compounds white tea without trichomes (WTwt) and pure trichomes (PT). It was found that the bitter and astringent compounds, caffeine (CAF), epigallocatechin gallate (EGCG), epicatechin gallate (ECG) and flavonol glycosides, were mainly enriched in the WTwt, with 16.3-fold, 47.1-fold and 28.7-fold decrease in CAF and EGCG and ECG, respectively, and the content of these compounds in PT were lower than the taste thresholds. In PT, kaempferol-3-O-(p-coumaroyl)-glucoside and kaempferol-3-O-(di-p-coumaroyl)-glucoside were non-volatile marker compounds, and decanal was significant aroma contributor with rOAV = 250.86. Moreover, the compounds in trichomes mainly contributed to the fruity and floral aroma of white tea, among which benzyl alcohol, (E)-geranylacetone, decanal, dodecanal and 6-methyl-5-hepten-2-one were the crucial aroma components, which were 2.1, 1.7, 1.8, 1.4 and 2.2 times as much as the WTwt in the PT, respectively. In conclusion, trichomes can improve the quality of white tea by reducing the bitterness and astringency, increasing the umami, as well as enhancing the fruity and floral aromas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Theabrownin (TB) is a dark brown pigment from Pu-erh tea or other dark teas. It is formed by further oxidization of theaflavins and thearubigins, in combination with proteins, polysaccharides, and caffeine etc. TB is a characteristic ingredient and bioactive substance of Pu-erh tea. However, the effects of TB on ulcerative colitis (UC) remains unclear., Purpose: This study aims to elucidate the mechanism of TB on UC in terms of recovery of intestinal homeostasis and regulation of toll-like receptor (TLR) 2&4 signaling pathway., Methods: The colitis models were established by administering 5% dextran sulfate sodium (DSS) to C57BL/6 mice for 5 days to evaluate the therapeutic and preventive effects of TB on UC. Mesalazine was used as a positive control. H&E staining, complete blood count, enzyme-linked immunosorbent assay, immunohistochemistry, flow cytometry, and 16S rRNA sequencing were employed to assess histological changes, blood cells analysis, content of cytokines, expression and distribution of mucin (MUC)2 and TLR2&4, differentiation of CD4 + T cells in lamina propria, and changes in intestinal microbiota, respectively. Western blot was utilized to study the relative expression of tight junction proteins and the key proteins in TLR2&4-mediated MyD88-dependent MAPK, NF-κB, and AKT signaling pathways., Results: TB outstanding alleviated colitis, inhibited the release of pro-inflammatory cytokines, reduced white blood cells while increasing red blood cells, hemoglobin, and platelets. TB increased the expression of occludin, claudin-1 and MUC2, effectively restored intestinal barrier function. TB also suppressed differentiation of Th1 and Th17 cells in the colon's lamina propria, increased the fraction of Treg cells, and promoted the balance of Treg/Th17 to tilt towards Tregs. Moreover, TB increased the Firmicutes to Bacteroides (F/B) ratio, as well as the abundance of Akkermansia, Muribaculaceae, and Eubacterium&#95;coprostanoligenes&#95;group at the genus level. In addition, TB inhibited the activation of TLR2&4-mediated MAPK, NF-κB, and AKT signaling pathways in intestinal epithelial cells of DSS-induced mice., Conclusion: TB acts in restoring intestinal homeostasis and anti-inflammatory in DSS-induced UC, and exhibiting a preventive effect after long-term use. In a word, TB is a promising beverage, health product and food additive for UC., Competing Interests: Declaration of competing interest The authors declare that they have no known conflict of interest or individual connections that could have appeared to impact the work reported in this paper., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Studies on nitenpyram determination and behavior within tea remain limited despite its widespread use as a neonicotinoid. An organic-saving analytical approach tailored for the detection of nitenpyram in tea was established. Nitenpyram was extracted by boiling water and cleaned up by Cleanert PCX solid-phase. The average recoveries were 75.1-94.5 %, with relative standard deviations (RSDs) of 0.7-8.6 % for saving 34.5-88.6 % organic solvent. The limits of quantification (LOQs) were 0.002 mg·kg -1 in fresh tea shoots, 0.005 mg·kg -1 in made tea, and 0.001 mg·L -1 in tea brew, satisfying the current minimum Maximum Residue Limit (MRL). Nitenpyram dissipated rapidly with half-lives of 1.2-1.4 days at the recommended dosage (27 g a.i. ha -1 ) in two locations. Remarkably, 20-110 % of nitenpyram was leached out from made tea in different brewing modes. This work provides insights into nitenpyram's rational application in tea cultivation and offers considerations to institutions tasked with unestablished MRLs in tea., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

In this study, widely targeted metabolomics and chemometrics were utilized to comprehensively analyse the formation of taste compounds in Longjing green tea. A total of 580 non-volatile metabolites were identified by using ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry, and alterations in three metabolic pathways were investigated. Notably, the fixation process reduced phosphatidic acid levels, resulting in the formation of lyso-phosphatidylcholine and lyso-phosphatidylethanolamine, as well as the release of esterified polyunsaturated fatty acids. Baiye No.1 had high levels of L-glutamic acid and l-glutamine, while Longjing 43 showed elevated levels of flavones. Correlation analysis and sensory verification indicated that the specific concentration of L-leucine could decrease the umami of the tea. These findings advance our understanding of Longjing green tea quality improvement and cultivar development., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

N-Ethyl-2-pyrrolidinone-substituted flavan-3-ols (EPSFs) are a newly discovered compound class in tea with various bioactivities. This study aimed to develop a novel processing technique to enhance EPSF contents in white tea efficiently. Using optimal processing parameters of 125 °C and 30 min in a high-temperature sterilizing oven, total EPSF content significantly increased by 1.42-18.80-fold to 1.57-6.22 mg/g without impacting sensory characteristics. Metabolomics analysis revealed elevated levels of nucleosides, nucleotides, bases, theaflavins, flavonol aglycones, EPSFs, and most flavone-C-glycosides, as well as decreased levels of amino acids, procyanidins, theasinensins, several flavanols, and flavonol-O-glycosides after EPSF-enrichment treatment. Furthermore, the EPSF-enriched white tea exhibited notable anti-inflammatory effects, mitigating xylene-induced ear edema in mice and carrageenan-induced paw edema and cotton ball-induced granulomas in rats. This study developed a new processing technique for highly efficient enhancement of EPSFs in white tea and demonstrated that EPSF-enriched white tea has a potential to serve as effective anti-inflammatory dietary supplement., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

As a result of their metabolic processes, medicinal plants produce bioactive molecules with significant implications for human health, used directly for treatment or for pharmaceutical development. Chromatographic fingerprints with solvent gradients authenticate and categorise medicinal plants by capturing chemical diversity. This work focuses on optimising tea sample analysis in HPLC, using a model-based approach without requiring standards. Predicting the gradient profile effects on full signals was the basis to identify optimal separation conditions. Global models characterised retention and bandwidth for 14 peaks in the chromatograms across varied elution conditions, facilitating resolution optimisation of 63 peaks, covering 99.95 % of total peak area. The identified optimal gradient was applied to classify 40 samples representing six tea varieties. Matrices of baseline-corrected signals, elution bands, and band ratios, were evaluated to select the best dataset. Principal Component Analysis (PCA), k-means clustering, and Partial Least Squares-Discriminant Analysis (PLS-DA) assessed classification feasibility. Classification limitations were found reasonable due to tea processing complexities, involving drying and fermentation influenced by environmental conditions., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: M.C. García-ALvarez-Coque reports financial support was provided by Spain Ministry of Science and Innovation. Other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Albino tea has attracted increased attention due to its unique flavor. To reveal the difference in key metabolites constituting the important quality of different tea resources, amino acids and flavonoids profiles in three albino resources with different degrees of albinism and one normal green variety were comprehensively investigated. K-means analysis revealed 35 amino acids were significantly enriched in 'Jibai', while 3 and 2 were specifically accumulated in 'Huangjinya' and 'Anjibaicha', respectively. Based on OPLS-DA models, 40, 31 and 45 significantly differential flavonoids were determined in 'Huangjinya', 'Anjibaicha' and 'Jibai' compared to 'Fudingdabaicha', and most were down-regulated. Among them, 10, 5 and 13 differential flavonoids were exclusively found in 'Huangjinya', 'Anjibaicha' and 'Jibai', respectively, which may contribute to unique quality for different resources. The differential flavonoids and amino acids involved in their metabolic pathways were obviously different among four resources, resulting in the difference in tea quality and flavor., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The rapid development of nanozymes has offered substantial opportunities for the fields of biomedicine, chemical sensing, and food safety. Among these applications, multichannel sensors, with the capability of simultaneously detecting multiple target analytes, hold promise for the practical application of nanozymes in chemical sensing with high detection efficiency. In this study, Rh-decorated Pd nanocubes (Pd-Rh nanocubes) with significantly enhanced peroxidase-like activity are synthesized through the mediation of underpotential deposition (UPD) and subsequently employed to develop a multichannel colorimetric sensor for discriminating tea polyphenols (TPs) and tea authentication. Based on a single reactive unit of efficient catalytic oxidation of 3,3',5,5'-tetramethylbenzidine dihydrochloride (TMB), the nanozyme-based multichannel colorimetric sensor responds to each analyte in as short as 1 min. With the aid of principal component analysis (PCA) and hierarchical cluster analysis (HCA), various TPs and types of tea can be accurately identified. This work not only provides a new type of simply structured and highly active nanozymes but also develops a concise and rapid multichannel sensor for practical application in tea authentication and quality inspection., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This study aimed to investigate the biodegradation behaviour of starch/nanocellulose/black tea extract (SNBTE) films in a 30-day soil burial test. The SNBTE films were prepared by mixing commercial starch, nanocellulose (2, 4, and 6%), and an aqueous solution of black tea extract by a simple mixing and casting process. The chemical and morphological properties of the SNBTE films before and after biodegradation were characterized using the following analytical techniques such as field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and fourier transform infrared (FTIR). The changes in soil composition, namely pH, electrical conductivity (EC), moisture content, water holding capacity (WHC), soil respiration, total nitrogen, weight mean diameter (MDW), and geometric mean diameter (GMD), as a result of the biodegradation process, were also estimated. The results showed that the films exhibited considerable biodegradability (35-67%) within 30 days while increasing soil nutrients. The addition of black tea extract reduced the biodegradation rate due to its polyphenol content, which likely resulted in a reduction in microbial activity. The addition of nanocellulose (2-6% weight of starch) increased the tensile strength, but decreased the elongation at break of the films. These results suggest that starch nanocellulose and SNBTE films are not only biodegradable under soil conditions but also positively contribute to soil health, highlighting their potential as an environmentally friendly alternative to traditional plastic films in the packaging industry., (© 2024. The Author(s).)

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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)