Decades-long organic tea production is distinguished by N deficiency: Evidence from soil and tea δ15N data

To investigate the possibility of identifying commercial organic teas from conventional teas based on their isotopic signatures, we sampled tea leaves and soil samples from three tea gardens in Pu'er, China, that underwent decades of certified organic cultivation and compared them with adjacent conventional gardens. We found that long-term organic tea cultivation increased the soil organic carbon and soil pH but significantly decreased the total N content of tea. Higher δ15N values were observed in the organic teas, but significant overlap existed with non-organic teas. The lower N content of the organic tea and contrasting pattern between the organic tea δ15N and soil δ15N suggested that the decline of the N availability could potentially act as a robust characteristic for discriminating between organic and non-organic tea cultivation systems. Further analysis implies that combining tea and soil N content with δ15N value is a promising approach to organic tea identification.

Quality analysis of steamed beef with black tea and the mechanism of action of main active ingredients of black tea on myofibrillar protein

In this study, we analyzed the tea polyphenol composition, volatile flavor composition and storage stability of steamed beef with black tea. The molecular docking and dynamics were used to elucidate the interaction mechanism between the active components of black tea and myofibrillar proteins. The highest content of caffeine (CAF) was found in black tea steamed beef products, followed by catechin (C), epicatechin gallate (ECG), epicatechin gallate (EGCG) and theaflavins (TF). Steamed beef with black tea showed low ΔE* value, low TBARS value, low carbonyl content as well as high sulfhydryl content during storage. The addition of C, CAF, ECG, EGCG and TF enhanced the oxidative stability of myofibrillar protein. In this study, the effects of active components of black tea on the oxidative stability of myofibrillar protein and their interactions were determined, which could provide a reference for the application of black tea and its active components in meat products. At the same time, it can provide new ideas for the development of new meat products.

A novel hybrid sensor array based on the polyphenol oxidase and its nanozymes combined with the machine learning based dual output model to identify tea polyphenols and Chinese teas

A novel sensor array was developed based on the enzyme/nanozyme hybridization for the identification of tea polyphenols (TPs) and Chinese teas. The enzyme/nanozyme with polyphenol oxidase activity can catalyze the reaction between TPs and 4-aminoantipyrine (4-AAP) to produce differences in color, and the sensor array was thus constructed to accurately identify TPs mixed in different species, concentrations, or ratios. In addition, a machine learning based dual output model was further used to effectively predict the classes and concentrations of unknown samples. Therefore, the qualitative and quantitative detection of TPs can be realized continuously and quickly. Furthermore, the sensor array combining the machine learning based dual output model was also utilized for the identification of Chinese teas. The method can distinguish the six teas series in China, and then precisely differentiate the more specific tea varieties. This study provides an efficient and facile strategy for the identification of teas and tea products.

and Camellia sinensis (L.) Kuntze extracts

BACKGROUND

Trichomonas gallinae is a parasite that causes canker and severe loss and death, especially in young pigeons. Metronidazole (MTZ) is the recommended drug for treating avian trichomoniasis. Due to drug resistance, non-chemical alternatives, such as medicinal plant extracts, are also considered possible therapies for this disease.

OBJECTIVES

This study compares the antitrichomonal effects of MTZ with extracts of Camellia sinensis and Ziziphus vulgaris on T. gallinae in vitro.

METHODS

Samples of T. gallinae were taken from infected pigeons. Multi-well plates with different concentrations (5, 10, 25, 50 and 100 µg/mL) of plant extracts were used for the in vitro study.

RESULTS

The minimum inhibitory concentration (MIC) of C. sinensis extract was 25 µg/mL over 24 h, compared to 50 µg/mL for MTZ. The MIC value of the Z. vulgaris extracts was 50 µg/mL.

CONCLUSIONS

The results suggest that the extracts of Z. vulgaris and C. sinensis, as potential natural agents, could have anti-avian trichomoniasis properties. This study also shows that MTZ, C. sinensis and Z. vulgaris are equally effective in preventing the growth of T. gallinae trophozoites in the culture.

YOLOv8-RMDA: Lightweight YOLOv8 Network for Early Detection of Small Target Diseases in Tea

In order to efficiently identify early tea diseases, an improved YOLOv8 lesion detection method is proposed to address the challenges posed by the complex background of tea diseases, difficulty in detecting small lesions, and low recognition rate of similar phenotypic symptoms. This method focuses on detecting tea leaf blight, tea white spot, tea sooty leaf disease, and tea ring spot as the research objects. This paper presents an enhancement to the YOLOv8 network framework by introducing the Receptive Field Concentration-Based Attention Module (RFCBAM) into the backbone network to replace C2f, thereby improving feature extraction capabilities. Additionally, a mixed pooling module (Mixed Pooling SPPF, MixSPPF) is proposed to enhance information blending between features at different levels. In the neck network, the RepGFPN module replaces the C2f module to further enhance feature extraction. The Dynamic Head module is embedded in the detection head part, applying multiple attention mechanisms to improve multi-scale spatial location and multi-task perception capabilities. The inner-IoU loss function is used to replace the original CIoU, improving learning ability for small lesion samples. Furthermore, the AKConv block replaces the traditional convolution Conv block to allow for the arbitrary sampling of targets of various sizes, reducing model parameters and enhancing disease detection. the experimental results using a self-built dataset demonstrate that the enhanced YOLOv8-RMDA exhibits superior detection capabilities in detecting small target disease areas, achieving an average accuracy of 93.04% in identifying early tea lesions. When compared to Faster R-CNN, MobileNetV2, and SSD, the average precision rates of YOLOv5, YOLOv7, and YOLOv8 have shown improvements of 20.41%, 17.92%, 12.18%, 12.18%, 10.85%, 7.32%, and 5.97%, respectively. Additionally, the recall rate (R) has increased by 15.25% compared to the lowest-performing Faster R-CNN model and by 8.15% compared to the top-performing YOLOv8 model. With an FPS of 132, YOLOv8-RMDA meets the requirements for real-time detection, enabling the swift and accurate identification of early tea diseases. This advancement presents a valuable approach for enhancing the ecological tea industry in Yunnan, ensuring its healthy development.

Assessing the health risks of heavy metals and seasonal minerals fluctuations in Camellia sinensis cultivars during their growth seasons

The risk assessment of heavy metals in tea is extremely imperative for the health of tea consumers. However, the effects of varietal variations and seasonal fluctuations on heavy metals and minerals in tea plants remain unclear. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to evaluate the contents of aluminum (Al), manganese (Mn), magnesium (Mg), boron (B), calcium (Ca), copper (Cu), cobalt (Co), iron (Fe), sodium (Na), zinc (Zn), arsenic (As), cadmium (Cd), chromium (Cr), nickel (Ni), and antimony (Sb) in the two categories of young leaves (YL) and mature leaves (ML) of tea (Camellia sinensis) cultivars throughout the growing seasons. The results showed significant variations in the contents of the investigated nutrients both among the different cultivars and growing seasons as well. Furthermore, the average concentrations of Al, Mn, Mg, B, Ca, Cu, Co, Fe, Na, Zn, As, Cd, Cr, Ni, and Sb in YL ranged, from 671.58-2209.12, 1260.58-1902.21, 2290.56-2995.36, 91.18-164.68, 821.95-5708.20, 2.55-3.80, 3.96-25.22, 37.95-202.84, 81.79-205.05, 27.10-69.67, 0.028-0.053, 0.065-0.127, 2.40-3.73, 10.57-12.64, 0.11-0.14 mg kg-1, respectively. In ML, the concentrations were 2626.41-7834.60, 3980.82-6473.64, 3335.38-4537.48, 327.33-501.70, 9619.89-13153.68, 4.23-8.18, 17.23-34.20, 329.39-567.19, 145.36-248.69, 40.50-81.42, 0.089-0.169, 0.23-0.27, 5.24-7.89, 18.51-23.97, 0.15-0.19 mg kg-1, respectively. The contents of all analyzed nutrients were found to be higher in ML than in YL. Target hazard quotients (THQ) of As, Cd, Cr, Ni, and Sb, as well as the hazard index (HI), were all less than one, suggesting no risk to human health via tea consumption. This research might provide the groundwork for essential minerals recommendations, as well as a better understanding and management of heavy metal risks in tea.

A sensor array based on a nanozyme with polyphenol oxidase activity for the identification of tea polyphenols and Chinese green tea

Green tea is popular among consumers because of its high nutritional value and unique flavor. There is often a strong correlation among the type of tea, its quality level and the price. Therefore, the rapid identification of tea types and the judgment of tea quality grades are particularly important. In this work, a novel sensor array based on nanozyme with polyphenol oxidase (PPO) activity is proposed for the identification of tea polyphenols (TPs) and Chinese green tea. The absorption spectra changes of the nanozyme and its substrate in the presence of different TPs were first investigated. The feature spectra were scientifically selected using genetic algorithm (GA), and then a sensor array with 15 sensing units (5 wavelengths × 3 time) was constructed. Combined with the support vector machine (SVM) discriminative model, the discriminative rate of this sensor array was 100% for different concentrations of typical TPs in Chinese green tea with a detection limit of 5 μM. In addition, the identification of different concentrations of the same tea polyphenols and mixed tea polyphenols have also been achieved. Based on the above study, we further developed a facile and efficient new method for the category differentiation and adulteration identification of green tea, and the accuracy of this array was 96.88% and 100% for eight types of green teas and different adulteration ratios of Biluochun, respectively. This work has significance for the rapid discrimination of green tea brands and adulteration.

Pollution indices of selected metals in tea (Camellia sinensis L.) growing soils of the Upper Assam region divulge a non-trifling menace of National Highway

The study investigated the influence of a National Highway (NH) traversing tea estates (TEs) on heavy metal (HM) contamination in the top soils of Upper Assam, India. The dispersion and accumulation of six HMs, viz. cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), and zinc (Zn), within tea-growing soils were assessed using diverse indices: contamination factor (CF), degree of contamination (DC), enrichment factor (EF), geo-accumulation index (Igeo), modified degree of contamination (MDC), Nemerow pollution index (PINemerow), pollution load index (PLI), potential ecological risk factor (Eri), and potential ecological risk index (RI). The order of HM prevalence was Fe > Mn > Zn > Ni > Cu > Cd. Elevated Cd levels near the NH prompted immediate attention, while Cd and Zn showed moderate pollution in CF, EF, and RI. The remaining metals posed minimal individual risk (Eri< 40), resulting in an overall contamination range of "nil to shallow," signifying slight contamination from the studied metals. From MDC values for investigated metals, it was found to be "zero to very low degree of contamination" at all locations except the vicinity of NH. Soil pollution, as determined by PLI, indicated unpolluted soils in both districts, yet PINemerow values indicated slight pollution. The statistical analysis revealed that there is a significant decrease in most of the indices of HM as the distance from NH increases. The application of multivariate statistical techniques namely Principal Component Analysis and Cluster Analysis showed the presence of three distinct homogenous groups of distances based on different indices. This investigation underscores NH-associated anthropogenic effects on TE soil quality due to HM deposition, warranting proactive mitigation measures.

A comprehensive multi-omics analysis, integrating proteomics and metabolomics, was employed to elucidate tea-induced stewed beef quality change mechanisms

To better understand the functional mechanism of four types of tea (green tea, black tea, jasmine tea, and dark tea) on the quality of stewed beef, changes in quality characteristics, proteomics, and metabolomics were investigated. Adding these four tea types decreased the pH value, L* value, shear force, and hardness of the stewed beef. Among these groups, black tea (BT) significantly improved the tenderness of the stewed beef. They have substantially impacted pathways related to protein oxidative phosphorylation, fatty acid degradation, amino acid degradation, and peroxisomes in stewed beef. The study identified that Myosin-2, Starch binding domain 1, Heat shock protein beta-6, and Myosin heavy chain four are significantly correlated with the quality characteristics of tea-treated stewed beef, making them potential biomarkers. Green tea (GT), black tea (BT), jasmine tea (JT), and dark tea (DT) led to the downregulation of 20, 36, 38, and 31 metabolites, respectively, which are lipids and lipid-like molecules in the stewed beef. The co-analysis of proteomics and metabolomics revealed that differential proteins significantly impacted metabolites associated with carbohydrates, amino acids, lipids, and other nutrients. This study determined the effects of four types of tea on the quality of stewed beef and their underlying mechanisms, providing valuable insights for applying of tea in meat products. At the same time, it can offer new ideas for developing fresh meat products.

Rolling forms the diversities of small molecular nonvolatile metabolite profile and consequently shapes the bacterial community structure for Keemun black tea

The detailed dynamics of small molecular nonvolatile chemical and bacterial diversities, as well as their relationship are still unclear in the manufacturing process of Keemun black tea (KMBT). Herein, mass spectrometry-based untargeted metabolomics, Feature-based Molecular Networking (FBMN) and bacterial DNA amplicon sequencing were used to investigate the dense temporal samples of the manufacturing process. For the first time, we reveal that the pyrogallol-type catechins are oxidized asynchronously before catechol-type catechins during the black tea processing. Rolling is the key procedure for forming the small molecular nonvolatile metabolite profile (SMNMetProf), increasing the metabolite richness, and then shaping the bacterial community structure in the KMBT manufacturing process, which decreases both molecular weight and molecular polarity of the small molecular nonvolatile metabolites. The SMNMetProf of black tea is formed by the endogenous enzymatic oxidation of tea leaves, rather than bacterial fermentation.

Changes in profiles of volatile compounds and prediction of the storage year of organic green tea during the long-term storage

In the present study, the volatile compounds in organic green tea with a continuous storage period (ranging from 1 to 16 years) were comprehensively analyzed and compared through SDE-GC-MS and chemometrics. The results revealed that the total of 124 volatiles were identified, and their total amount was increased with the prolongation of the storage years. Ketones, alcohols, esters, and aromatic hydrocarbons were the main types of volatiles in organic green tea, among which 26 volatile compounds were significantly correlated with storage years, and six volatile compounds that were most seriously affected by the storage years. The results of the support vector machine classification combined with multiple linear regression analysis showed that the content-period prediction model for the six volatile compounds can accurately predict the storage years of organic green tea. Therefore, this study offers novel insights into volatile compounds changes during the storage of green tea.

Microbial Fermentation Enhances the Effect of Black Tea on Hyperlipidemia by Mediating Bile Acid Metabolism and Remodeling Intestinal Microbes

Black tea (BT), the most consumed tea worldwide, can alleviate hyperlipidemia which is a serious threat to human health. However, the quality of summer BT is poor. It was improved by microbial fermentation in a previous study, but whether it affects hypolipidemic activity is unknown. Therefore, we compared the hypolipidemic activity of BT and microbially fermented black tea (EFT). The results demonstrated that BT inhibited weight gain and improved lipid and total bile acid (TBA) levels, and microbial fermentation reinforced this activity. Mechanistically, both BT and EFT mediate bile acid circulation to relieve hyperlipidemia. In addition, BT and EFT improve dyslipidemia by modifying the gut microbiota. Specifically, the increase in Lactobacillus johnsonii by BT, and the increase in Mucispirillum and Colidextribacter by EFT may also be potential causes for alleviation of hyperlipidemia. In summary, we demonstrated that microbial fermentation strengthened the hypolipidemic activity of BT and increased the added value of BT.

assamica) to climate conditions and change in China

Crop cultivation suitability plays a vital role in determining the distribution, quality, and production of crop and can be greatly affected by climate change. Therefore, evaluating crop cultivation suitability under climate change and identifying the factors influencing it can optimize crop cultivation layout and improve production and quality. Based on comprehensive datasets including geographical distribution points, climate data, soil characteristics, and topography, our study employed the MaxEnt model to simulate the potential distribution of Pu'er tea (Camellia sinensis var. assamica) cultivation suitability in Yunnan Province from 1961 to 2020. Furthermore, we assessed the consistency between the simulated suitable areas and the actual production of Pu'er tea. The results showed that precipitation of the warmest quarter, precipitation of the driest month, and average temperature in January were the three dominant environmental variables affecting the cultivation distribution of Pu'er tea. The high suitable areas for Pu'er tea cultivation in Yunnan Province were mainly distributed in the western and southern regions, accounting for 13.89% of the total area of Yunnan Province. The medium suitable areas are mainly distributed in the central and western regions of Yunnan Province, accounting for 20.07% of the total area of Yunnan Province. Over the past 60 years, the unsuitable area for Pu'er tea has increased, while the suitable area has shown a trend of migration to the southwest. Changes in precipitation and temperature were found to be the main drivers of the changes in the distribution of suitable areas for Pu'er tea. We also found a mismatch between the cultivation suitability and the actual production of Pu'er tea. Our study provides an accurate assessment and zoning analysis of the suitability of Pu'er tea cultivation in Yunnan Province, which can help optimize the layout of Pu'er tea cultivation and reduce potential climate risks.

Rapid detection of ash content in black tea using a homemade miniature near-infrared spectroscopy

Ash is a testing index with both health inspection value and quality decision value, and it is an essential detection item in the import and export trade of tea. To realize the rapid and effective quantitative analysis of ash content in tea, this study proposed the use of a homemade miniature near-infrared (NIR) spectroscopy combined with multivariate analysis for the rapid detection of ash content in black tea. First, NIR data of black tea samples from different countries were acquired and optimized by the spectral preprocessing method. Then, the optimized pre-processed spectral data were used as features, and four feature wavelength selection algorithms, such as competitive adaptive reweighted sampling, iteratively retaining informative variables (IRIV), variable combination population analysis (VCPA)-IRIV, and interval variable iterative space shrinkage approach (IVISSA), were utilized to optimize the feature spectra. Finally, the support vector machine regression (SVR) algorithm was employed to construct the quantitative models of ash content in black tea by combining the optimal wavelengths obtained from the four feature selection methods mentioned above. The experimental results showed that the IVISSA-SVR model had the best performance, with correlation coefficient (Rp), root mean square errors of prediction (RMSEP), and relative prediction deviation (RPD) of 0.9546, 0.0192, and 5.59 for the prediction set, respectively. The results demonstrate that a miniature NIR sensing system combined with chemometrics as an effective analytical tool can realize the rapid detection of ash content in black tea.

Intercropped Flemingia macrophylla successfully traps tea aphid (Toxoptera aurantia) and alters associated networks to enhance tea quality

BACKGROUND

The tea aphid, Toxoptera aurantia is a destructive pest causing severe damage to the quality and yield of tea, Camellia sinensis. Relying on chemical insecticides to control this pest causes adverse ecological and economic consequences. Trap plants are an eco-friendly alternative strategy to mitigate pest damage on focal plants by attracting target insects and natural enemies. Yet, the utilization of trap plants in tea plantations remains limited. Besides, the effects of the trap plant on the tea aphid-ant-predator community and tea quality and yield are unknown.

RESULTS

Intercropped Flemingia macrophylla successfully trapped tea aphids and enhanced the complexity of aphid-ant-predator networks over three consecutive years compared to monoculture management. Moreover, F. macrophylla significantly increased the abundance of natural predators by 3100% and species richness by 57%. The increasing predators suppressed the aphid population and hampered its spillover to neighbouring tea plants. Consequently, F. macrophylla improved tea quality by an 8% increase in soluble sugar and a 26% reduction in polyphenols to amino acids ratio.

CONCLUSION

The study illustrated that F. macrophylla is a suitable trap crop for tea aphid control in tea plantations. This legume increases species nodes and strengthens multiple connections in aphid-associated communities through its cascade effects, improving tea quality. These findings shed light on the potential application of trap plants in tea plantations as an efficient integrated pest management (IPM) strategy. © 2023 Society of Chemical Industry.

UV-B application during the aeration process improves the aroma characteristics of oolong tea

Solar withering is essential for the aroma formation of oolong tea, but due to the rainy and humid weather in plantation areas, solar withering became insufficient which seriously limits high-grade oolong tea production. This study aims to investigate ultraviolet B (UV-B) effects on the aroma characteristics of oolong tea and its feasibility in improving tea aroma quality. Sensory evaluation, odorant quantitation, and aroma characteristic analysis suggested UV-B application during the aeration process provided similar effects as solar withering in improving the aroma quality of oolong tea. UV-B application significantly increased fruity and floral odorants (4-hexanolide, α-farnesene, and β-ocimene by 44%, 74%, and 37%, respectively), and decreased green and fatty odorants (hexanal, (E)-2-octenal, and (Z)-4-heptenal by 42%, 45%, and 27%, respectively). These indicate UV-B is crucial for the flowery and fruity aroma formation of oolong tea, which can be potentially applied to oolong tea production, especially under unsunny weather.

Unveiling the presence of fluoride in commercial tea infusion: Factors influencing its release and its adsorptive elimination by indigenously developed nanoadsorbents

Drinking tea, which is globally one of the most widely consumed beverages, is a potential source of fluoride toxicity. This research aimed at fluoride estimation in the infusions of commercial black tea and green tea samples, purchased from the local Indian market, systematic evaluation of the factors influencing the fluoride release and the adsorptive removal of fluoride using the indigenously developed nanoadsorbents. All the prepared infusions had fluoride content above the permissible WHO limits. Various factors, which affect the release of fluoride from tea leaves into the infusion include type of water, tea dosage and brewing time. The investigations revealed that, the fluoride content in the black tea infusions was much higher than the green tea infusions. Further, it also depended on the amount of tea leaves used for brewing. The fluoride, present in tea leaves, is released gradually and within just 1 min of brewing, the concentration of fluoride in the infusions was well above the permissible WHO limits. It was also observed that, the dried unprocessed tea leaves, when brewed in water, had high fluoride content. This further confirmed the presence of fluoride in tea infusion, which demands an efficient remediation technique. The developed nanoadsorbents exhibited efficient defluoridation of groundwater, and were therefore tested for their efficiency in defluoridating tea infusions as well. These nanoadsorbents could efficiently eliminate fluoride from both green and black tea infusions, bringing down the fluoride content below the WHO limits, thereby rendering the infusions safe. They exhibited rapid kinetics with high efficiency in adsorbing fluoride from tea infusions. These properties make them potential adsorbents for defluoridating tea infusion, which provides a probable solution to the problem of fluoride toxicity from drinking tea. This is one of the first reports on a technique for eliminating fluoride from tea infusions.

Epigallocatechin gallate (EGCG) nanoselenium application improves tea quality (Camellia sinensis L.) and soil quality index without losing microbial diversity: A pot experiment under field condition

Applying selenium (Se) fertilizer is the only way to alleviate soil Se deficiency. Although effects of nanoselenium foliar application on plant growth and stress resistance have been extensively investigated, soil application of nanoselenium on soil microorganisms and their relationship with crop quality and soil health remains unclear. In this study, a steady-state homogeneous nanoparticle of epigallocatechin gallate Se (ESe) was synthesized, and a pot experiment was conducted applying ESe at five concentrations (0, 1, 10, 50, and 100 mg kg-1) to the tea planattion soil. The study revealed a significant increase in Se concentration in soil and tea with ESe application and identified 2.43-7.8 mg kg-1 as the safe and optimal range for soil application. Specifically, the moderate dose of ESe improved the tea quality [reduced tea polyphenols (TP), increased free amino acids (AA), and reduced TP/AA] and soil quality index (SQI). Besides, in marure tea leaves, antioxidant enzyme activities [promote catalase (CAT) superoxide dismutase (SOD), and peroxidase (POD)] increased, while level of oxidative stress [malondialdehyde (MDA), hydrogen peroxide (H2O2) and superoxide anion (O2-)] decreased with ESe application. The 16S rRNA of the soil bacteria showed that ESe application significantly changed the community structure of soil bacteria but did not alter the diversity of the bacteria and the abundance of dominant taxa (phylum and genus levels). Statistical analysis of the taxonomic and functional profiles (STAMP) detected 21 differential taxa (genus level), mainly low-abundance ones, under the ESe application. Linear regression and random forest (RF) modeling revealed that the low-abundance bacterial taxa were significantly correlated with SQI (R2 = 0.28, p < 0.01) and tea quality (R2 = 0.23-0.37, p < 0.01). Thus, the study's findings suggest that ESe application affects soil and tea quality by modulating the low-abundance taxa in soil. The study also highlights the crucial role of low-abundance bacterial taxa of the rhizosphere in regulating soil functions under the ESe application.

A novel optimized eco-friendly simple spectrofluorimetric method for the determination of total catechins in green tea extract: Application to commercial tablet

Green tea extract (GTE) contains antioxidants that are present in green tea. The active constituents of green tea extract are catechins. This study demonstrates a spectrofluorimetric method for measuring GTE's catechin concentration based on its native fluorescence. To design a quick, sensitive, and ecological spectrofluorimetric approach, all features were investigated and adjusted. This method relies on determining the GTE ethanolic solution's native fluorescence at 312 nm after excitation at 227 nm. The calibration graph displayed a linear regression for values between 0.05 and 1.0 μg mL-1. The detection and quantification limits of the proposed technique were 0.008 and 0.026 μg mL-1, respectively. Two pure catechins present in GTE, (-)-epicatechin and (-)-epigallocatechin gallate, were examined by the proposed method. The analytical estimation of GTE in the pharmaceutical tablet was achieved effectively using this approach. An adequate degree of agreement was found when the findings were compared to those obtained by the comparative technique. Therefore, the novel strategy may be used in the GTE quality control study with minimal risks to people or the environment. The quantum yields of catechins were estimated. The validated technique was accepted by the International Council of Harmonization criteria.

Assessing tea plantations biophysical and biochemical characteristics in Northeast India using satellite data

Despite advancements in using multi-temporal satellite data to assess long-term changes in Northeast India's tea plantations, a research gap exists in understanding the intricate interplay between biophysical and biochemical characteristics. Further exploration is crucial for precise, sustainable monitoring and management. In this study, satellite-derived vegetation indices and near-proximal sensor data were deployed to deduce various physico-chemical characteristics and to evaluate the health conditions of tea plantations in northeast India. The districts, such as Sonitpur, Jorhat, Sibsagar, Dibrugarh, and Tinsukia in Assam were selected, which are the major contributors to the tea industry in India. The Sentinel-2A (2022) data was processed in the Google Earth Engine (GEE) cloud platform and utilized for analyzing tea plantations biochemical and biophysical properties. Leaf chlorophyll (Cab) and nitrogen contents are determined using the Normalized Area Over Reflectance Curve (NAOC) index and flavanol contents, respectively. Biophysical and biochemical parameters of the tea assessed during the spring season (March-April) 2022 revealed that tea plantations located in Tinsukia and Dibrugarh were much healthier than the other districts in Assam which are evident from satellite-derived Enhanced Vegetation Index (EVI), Modified Soil Adjusted Vegetation Index (MSAVI), Leaf Area Index (LAI), and Fraction of Absorbed Photosynthetically Active Radiation (fPAR), including the Cab and nitrogen contents. The Cab of healthy tea plants varied from 25 to 35 µg/cm2. Pearson correlation among satellite-derived Cab and nitrogen with field measurements showed R2 of 0.61-0.62 (p-value < 0.001). This study offered vital information about land alternations and tea health conditions, which can be crucial for conservation, monitoring, and management practices.

The application of demographic characteristics of Ectropis grisescens (Lepidoptera: Geometridae) in pest risk assessment of IPM

Ectropis grisescens Warren is one of the most important pests of tea plants. In this study, data on the development, survival, and fecundity of E. grisescens were collected at 15, 22, and 32 °C and analyzed by using the age-stage, two-sex life table. At 15 °C, the duration of the preadult period of E. grisescens was significantly prolonged (81.06 days), with high mortality (69.0%), and the proportion of emerged female adults was extremely low (7.0%). At 32 °C, the preadult period was significantly shortened (29.12 days), with high preadult mortality (74.0%), and a low proportion of emerged female adults (15.0%). At 22 °C, with low preadult mortality (24.0%), and a high proportion of emerged female adults (26.0%). The overall effects of the shorter preadult duration, higher preadult survival rate, higher proportion of emerged female adults, higher fecundity (F = 350.88 eggs/♀), and higher net reproductive rate (R0 = 91.23 offspring/individual) at 22 °C resulted in the highest values of the intrinsic rate of increase (r = 0.1054 days-1) and finite rate of increase (λ = 1.1112 days-1). Computer simulation showed that E. grisescens populations can increase much faster at 22 °C than at 15 and 32 °C. The weighted population size and cumulative weighted insect-days provided the dynamics necessary for estimating the damage potential of E. grisescens in devising economical pest management programs. Our results demonstrate that populations of E. grisescens were able to develop at a broad range of temperatures and adapt to the high temperatures. These finding can be utilized to improve the management of E. grisescens.

Tea intake and lung diseases: a Mendelian randomization study

Background

Existing studies on the relationship between tea intake and lung diseases have yielded inconsistent results, leading to an ongoing dispute on this issue. The impact of tea consumption on the respiratory system remained elucidating.

Materials and methods

We conducted a two-sample Mendelian randomization (MR) study to evaluate the associations between five distinct tea intake phenotypes and 15 different respiratory outcomes using open Genome-wide association study (GWAS) data. The inverse variance weighted (IVW) was used for preliminary screening and a variety of complementary methods were used as sensitivity analysis to validate the robustness of MR estimates. Pathway enrichment analysis was used to explore possible mechanisms.

Results

IVW found evidence for a causal effect of standard tea intake on an increased risk of lung squamous cell cancer (LSCC) (OR = 1.004; 95% CI = 1.001-1.007; P = 0.00299). No heterogeneity or pleiotropy was detected. After adjustment for potential mediators, including smoking, educational attainment, and time spent watching television, the association was still robust in multivariable MR. KEGG and GO enrichment predicted proliferation and activation of B lymphocytes may play a role in this causal relation. No causalities were observed when evaluating the effect of other kinds of tea intake on various pulmonary diseases.

Conclusion

Our MR estimates provide causal evidence of the independent effect of standard tea intake (black tea intake) on LSCC, which may be mediated by B lymphocytes. The results implied that the population preferring black tea intake should be wary of a higher risk of LSCC.

Chitosan-based topical formulation integrated with green-synthesized silver nanoparticles utilizing Camellia sinensis leaf extracts: A promising approach for managing infected wounds

This study explores the eco-friendly biosynthesis of silver nanoparticles (AgNPs) utilizing Camellia sinensis leaf extract. We assess their antioxidant and antibacterial properties. Furthermore, we impregnated AgNPs into 2 % chitosan (CHS) gel and assessed their wound-healing potential in Escherichia coli and Staphylococcus aureus infected wounds. Optimized AgNPs demonstrated a mean particle size of 36.90 ± 1.22 nm and a PDI of 0.049 ± 0.001. Green-synthesized AgNPs exhibited enhanced free radical inhibition (IC50: 31.45 μg/mL, 34.01 μg/mL, 27.40 μg/mL) compared to leaf extract (IC50: 52.67 μg/mL, 59.64 μg/mL, 97.50 μg/mL) in DPPH, hydrogen peroxide, and nitric oxide free radical scavenging assays, respectively. The MIC/MBC values of AgNPs against E. coli and S. aureus were 5 ppm/ 7.5 ppm and 10 ppm/ 15 ppm, respectively. Furthermore, our study showed that green-synthesized AgNPs at MIC significantly reduced the biofilm production of E. coli (70.37 %) and S. aureus (67.40 %). The CHS/AgNPs gel exhibited potent wound healing activities, comparable to a commercial cream with the re-epithelialization period of 8.16 ± 0.75. Histological analysis demonstrated enhanced skin regeneration with a thicker epidermal layer, well-defined papillary dermal structure, and organized collagen fibers. In summary, these findings hold promise for addressing bacterial infections, particularly those associated with biofilms-related wound infections.

Valorization of plant by-products in the biosynthesis of silver nanoparticles with antimicrobial and catalytic properties

Biosynthesis based on natural compounds has emerged as a sustainable approach for the production of metallic nanoparticles (MNP). The main objective of this study was to biosynthesize stable and multifunctional silver nanoparticles (AgNP) using different plant by-products as reducers and capping agents. Extracts obtained from Eucalyptus globulus, Pinus pinaster, Citrus sinensis, Cedrus atlantica and Camellia sinensis by-products, were evaluated. From all plant by-products tested, aqueous extract of eucalyptus leaves (EL), green tea (GT) and black tea (BT) were selected due to their higher antioxidant phenolic content and were individually employed as reducers and capping agents to biosynthesize AgNP. The green AgNP showed zeta potential values of -31.8 to -36.3 mV, with a wide range of particle sizes (40.6 to 86.4 nm), depending on the plant extract used. Green AgNP exhibited an inhibitory effect against various pathogenic bacteria, including Gram-negative (P. putida, E. coli, Vibrio spp.) and Gram-positive (B. megaterium, S. aureus, S. equisimilis) bacteria with EL-AgNP being the nanostructure with the greatest antimicrobial action. EL-AgNP showed an excellent photodegradation of indigo carmine (IC) dye under direct sunlight, with a removal percentage of up to 100% after 75 min. A complete cost analysis revealed a competitive total cost range of 8.0-9.0 €/g for the biosynthesis of AgNP.

Contents of ɑ-dicarbonyl compounds in commercial black tea and affected by the processing

The species and contents of ɑ-dicarbonyls in commercial black tea were examined, along with the effects of the manufacturing process and drying temperature on the formation of ɑ-dicarbonyls. Ten ɑ-dicarbonyls were quantified in commercial and in-process black tea samples by using UPLC-MS/MS and their derived quinoxalines. The ɑ-dicarbonyls content in commercial black tea decreased significantly (p < 0.05) in the following order: 3-deoxyglucosone > glucosone > 3-deoxypentosone = threosone > galactosone ≥ methylglyoxal = glyoxal ≥ 3-deoxygalactosone = 3-deoxythreosone = diacetyl. Except for 3-deoxyglucosone and 3-deoxygalactosone, a further eight ɑ-dicarbonyls were identified in all manufacturing steps of black tea. Except for the drying step, the rolling and fermenting played important roles in the formation of ɑ-dicarbonyls. The total contents of ɑ-dicarbonyls in black tea infusion ranged from 16.48 to 75.32 μg/g based on our detected ten ɑ-dicarbonyls.

Discovery of color compounds: Integrated multispectral omics on exploring critical colorant compounds of black tea infusion

The present study provided a highly efficient and systematic workflow for identifying colorants of food and beverage. Generally, the objective colorimeter and subjective human eye had different systems to identify colors, which makes the color description very challenging. Here, the Lab/LCH color system was applied to clearly illustrate color changes. Our workflow was applied to determine and verify the differential colorant substances between two groups of black tea infusions. Regarding color parameters, the infusions of black tea from Camellia sinensis and Camellia assamica differed significantly. The differential substances between black tea infusions were correlated to color parameters by mass spectrometry and nuclear magnetic resonance based multivariate statistical analysis and verified by machine learning tool. Pyroglutamic acid-glucose Amadori product, quercetin-3-O-glucoside, quinic acid and theabrownins were identified as main color contributors to black teas' color difference, which were also verified by addition test with standard black tea infusion.

Understanding the dynamic changes of volatile and non-volatile metabolites in black tea during processing by integrated volatolomics and UHPLC-HRMS analysis

Processing technology has an important effect on the flavor quality of black tea. However, the dynamic changes of volatile and non-volatile metabolites in black tea during processing are poorly understood. In this study, the volatile and non-volatile compounds during black tea processing were comprehensively characterized by integrated volatolomics and UHPLC-Q-Exactive/MS analysis. Volatile and non-volatile metabolites changed continuously throughout the processing process, especially during the withering stage. A total of 178 volatile metabolites and 103 non-volatile metabolites were identified. Among them, 11 volatile components with relative odor activity value greater than 1 (including dimethyl sulfide, 3-methylbutanal, 2-methylbutanal, β-myrcene, β-ocimene, linalool, methyl salicylate, β-cyclocitral, β-citral, citral, and β-ionone) were regarded as key aroma-active components responsible for finished black tea with sweet aroma. This study provides a comprehensive understanding of dynamic evolution trajectory of volatile and non-volatile metabolites during processing, which lays a theoretical foundation for the targeted processing of high-quality black tea.

Identification and pathogenicity of Fusarium spp. associated with tea wilt in Zhejiang Province, China

BACKGROUND

Tea is one of the most widely consumed beverages in the world, with significant economic and cultural value. However, tea production faces many challenges due to various biotic and abiotic stresses, among which fungal diseases are particularly devastating.

RESULTS

To understand the identity and pathogenicity of isolates recovered from tea plants with symptoms of wilt, phylogenetic analyses and pathogenicity assays were conducted. Isolates were characterized to the species level by sequencing the ITS, tef-1α, tub2 and rpb2 sequences and morphology. Four Fusarium species were identified: Fusarium fujikuroi, Fusarium solani, Fusarium oxysporum, and Fusarium concentricum. The pathogenicity of the Fusarium isolates was evaluated on 1-year-old tea plants, whereby F. fujikuroi OS3 and OS4 strains were found to be the most virulent on tea.

CONCLUSIONS

To the best of our knowledge, this is the first report of tea rot caused by F. fujikuroi in the world. This provides the foundation for the identification and control of wilt disease in tea plants.

Changes in the Antioxidant Potential of Camellia sinensis Cultures under the Influence of Phenolic Precursors

The viability, productivity and survival of higher plants under the adverse factors influence are largely determined by the functional activity of the antioxidant system. The aim of our work was to investigate changes in formation of high-molecular (superoxide dismutase and peroxidase) and low-molecular (phenolics, including flavanols and proanthocyanidins) antioxidants in callus culture of Camellia sinensis under influence of phenolic precursors (L-phenylalanine-3 mM, trans-cinnamic acid-1 mM, naringenin-0.5 mM). According to the data obtained, the effect of precursors on tea callus cultures did not lead to significant increasing of superoxide dismutase and peroxidase activity in most cases. However, it led to the increased accumulation of the total phenolics content, as well as flavanols and proanthocyanidins contents. For C. sinensis callus cultures, the most promising regulator of phenolic compounds was L-phenylalanine, in the presence of which its content increased almost twice. Thus, the exogenous effect of various precursors is possible to use for the targeted regulation of certain phenolics classes accumulation in plant cells.

Insights into the functional role of Actinomycetia in promoting plant growth and biocontrol in tea (Camellia sinensis) plants

Tea, a highly aromatic and globally consumed beverage, is derived from the aqueous infusion of dried leaves of Camellia sinensis (L.) O. Kuntze. Northeast India, encompassing an expansive geographical area between 24° and 27° N latitude and 88° and 95° E longitude, is a significant tea-producing region covering approximately 312,210 hectares. Despite its prominence, this region faces persistent challenges owing to a conducive climate that harbors the prevalence of pests, fungal pathogens, and weeds, necessitating agrochemicals. Helopeltis theivora, Oligonychus coffeae, and Biston suppressaria are prominent among the tea pests in this region. Concurrently, tea plants encounter fungal infections such as blister blight, brown root rot, and Fusarium dieback. The growing demand for safer tea production and the need to reduce pesticide and fertilizer usage has spurred interest in exploring biological control methods. This review focuses on Actinomycetia, which potentially safeguards plants from diseases and pest infestations by producing many bioactive substances. Actinomycetia, which resides in the tea rhizosphere and internal plant tissues, can produce antagonistic secondary metabolites and extracellular enzymes while promoting plant growth. Harnessing the biocontrol potential of Actinomycetia offers a promising solution to enhance tea production, while minimizing reliance on harmful agrochemicals, contributing to a more environmentally conscious and economically viable tea cultivation system.

Recent Progress Regarding Jasmonates in Tea Plants: Biosynthesis, Signaling, and Function in Stress Responses

Tea plants have to adapt to frequently challenging environments due to their sessile lifestyle and perennial evergreen nature. Jasmonates regulate not only tea plants' responses to biotic stresses, including herbivore attack and pathogen infection, but also tolerance to abiotic stresses, such as extreme weather conditions and osmotic stress. In this review, we summarize recent progress about jasmonaic acid (JA) biosynthesis and signaling pathways, as well as the underlying mechanisms mediated by jasmontes in tea plants in responses to biotic stresses and abiotic stresses. This review provides a reference for future research on the JA signaling pathway in terms of its regulation against various stresses of tea plants. Due to the lack of a genetic transformation system, the JA pathway of tea plants is still in the preliminary stages. It is necessary to perform further efforts to identify new components involved in the JA regulatory pathway through the combination of genetic and biochemical methods.

The Changes in Metabolites, Quality Components, and Antioxidant Activity of Tea (Camellia sinensis) Infected with Exobasidium vexans by Applying UPLC-MS/MS-Based Widely Targeted Metabolome and Biochemical Analysis

Blister blight infection with Exobasidium vexans is one of the most destructive foliar diseases that seriously affect the quality and yield of tea. This research investigated the metabolite changes of healthy and infected leaves on tea cultivar 'Fuding Dabaicha' and further explored the potential antimicrobial substances against E. vexans infection. In total, 1,166 compounds were identified during the entire course of an infection, among which 73 different common compounds were significantly accumulated involved in the important antimicrobial substances of flavonoids and phenolic acids, including kaempferol (3,5,7,4'-tetrahydroxyflavone), kaempferol-3-O-sophoroside-7-O-glucoside, phloretin, 2,4,6-trihydroxybenzoic acid, galloylprocyanidin B4, and procyanidin C1 3'-O-gallate, which indicated that these metabolites might positively dominate resistance to E. vexans. Furthermore, relevant biological pathways, such as the flavone and flavonol biosynthesis, flavonoid biosynthesis, and phenylpropane pathways, were more closely related to resistance to E. vexans. Additionally, total flavonoids, phenolics, alkaloids, and terpenoids contributing to antimicrobial and antioxidant capacity were significantly altered during four different infection periods, especially the Leaf_S2 stage (the second stage of infection), in which the most concentration accumulated. The leaves affected by E. vexans infection at the second stage had the relatively highest antioxidant activity. Accordingly, this study provides a theoretical support for and comprehensive insights into the effects on the metabolite changes, tea quality components, and antioxidant activity of blister blight caused by E. vexans.

A Review on Rhizosphere Microbiota of Tea Plant (Camellia sinensis L): Recent Insights and Future Perspectives

Rhizosphere microbial colonization of the tea plant provides many beneficial functions for the host, But the factors that influence the composition of these rhizosphere microbes and their functions are still unknown. In order to explore the interaction between tea plants and rhizosphere microorganisms, we summarized the current studies. First, the review integrated the known rhizosphere microbial communities of tea tree, including bacteria, fungi, and arbuscular mycorrhizal fungi. Then, various factors affecting tea rhizosphere microorganisms were studied, including: endogenous factors, environmental factors, and agronomic practices. Finally, the functions of rhizosphere microorganisms were analyzed, including (a) promoting the growth and quality of tea trees, (b) alleviating biotic and abiotic stresses, and (c) improving soil fertility. Finally, we highlight the gaps in knowledge of tea rhizosphere microorganisms and the future direction of development. In summary, understanding rhizosphere microbial interactions with tea plants is key to promoting the growth, development, and sustainable productivity of tea plants.

A novel botybirnavirus with a unique satellite dsRNA causes latent infection in Didymella theifolia isolated from tea plants

IMPORTANCE

A novel botybirnavirus, infecting the tea plant pathogen Didymella theifolia and tentatively named Didymella theifolia botybirnavirus 1 (DtBRV1), together with an additional double-stranded RNA (dsRNA), was characterized. DtBRV1 comprises two dsRNAs (1 and 2) encapsidated in isometric virions, while dsRNA3 is a satellite. The satellite represents a unique specimen since it contains a duplicated region and has high similarity to the two botybirnavirus dsRNAs, supporting the notion that it most likely originated from a deficient genomic component. The biological characteristics of DtBRV1 were further determined. With their unique molecular traits, DtBRV1 and its related dsRNA expand our understanding of virus diversity, taxonomy, and evolution.

Consumption of herbal infusions/decoctions and tea in Greece: a Planeterranean perspective on the results of Hydria survey

BACKGROUND

The consumption of various herbal infusions was and is common in the traditional Mediterranean diet, and apparently are used in many other regions of the world outside of the Mediterranean region. The present study aimed to investigate the consumption of herbal infusions/decoctions and tea in a nationally representative sample of Greece, considering also their Planetary use.

METHODS

3951 adult participants of the HYDRIA Survey (2013-2014) were included from the 13 regions of Greece. The diet of participants was assessed by two 24-h dietary recalls (24-HDR) and the Food Propensity Questionnaire (FPQ). All food items were analyzed through the HYDRIA Food Composition Tables. Information on socio-demographics, lifestyle, and health characteristics during the baseline was also provided.

RESULTS

26.9% of herbal infusions and decoctions consumers are ≥ 75 years old, pensioners with a low level of education, and residents of urban areas. However, 22.2% of tea consumers belong to the 18-34-year age group, being employed with an intermediate level of education and living in an urban area. Elderly men and women use more herbal infusions/decoctions (55.4%; 40.6%) compared to tea (41.8%; 25.2%). According to FPQ, 7.1% of men and 9.7% of women use herbal infusions and decoctions four times or more per week, while 7.1 and 10.9% of men and women, respectively, consume tea at the same frequency. Green tea, mountain tea (Sideritis spp.), and black tea are reported most frequently. In addition, mountain tea (61.2%), black tea (60.3%), mixed herbal infusions/decoctions (58.4%), and sage (59.4%) are consumed mostly at breakfast, while chamomile was reported mainly at dinner or during the night (42.4%).

CONCLUSIONS

Based on the FPQ results, the moderate and high consumption of herbal infusions/decoctions and tea is low in Greece, especially among adults (18-64 years). Thus, our results indicate the existence of a generation gap to the attachment to the traditional Med Diet and the consumption of herbal infusions. The present study could encourage future research to focus on herbal infusions and decoctions consumption by other populations for cross-cultural comparison, as well as on emphasizing the value of consuming locally available herbs in a Planeterranean perspective.

Pyrrolizidine Alkaloids in Tea (Camellia sinensis L.) from Weeds through Weed-Soil-Tea Transfer and Risk Assessment of Tea Intake

Pyrrolizidine alkaloids (PAs) have been detected in tea and can threaten human health. However, the specific source of PAs in tea is still unclear. Here, 88 dried tea products collected from six major tea-producing areas in Anhui Province, China, were analyzed. The detection frequency was 76%. The content of total PAs in dried tea was between 1.1 and 90.5 μg/kg, which was all below the MRL recommended by the European Union (150 μg/kg). In the Shexian tea garden, PAs in the weeds and weed rhizospheric soil around tea plants and the fresh tea leaves were analyzed. Intermedine (Im), intermedine-N-oxide (ImNO), and jacobine-N-oxide (JbNO) were transferred through the weed-to-soil-to-tea route into the fresh tea leaves; only Im and ImNO were detected in dried tea samples. Potential risk of the total PAs in the tea infusion was assessed according to the margin of exposure method, and it might be a low concern for public health.

Catechin Composition, Phenolic Content, and Antioxidant Properties of Commercially-Available Bagged, Gunpowder, and Matcha Green Teas

The leaves of the Camellia sinensis plant are used to produce many different types of teas, and green tea is particularly noted for its health promoting properties which are attributed to high concentrations of phenolic compounds known as catechins. Green tea is available in forms such as bagged, gunpowder (rolled leaf), and matcha, a fine powder. This study evaluated the phenolic content, catechin composition, caffeine concentration, and antioxidant properties of fifteen commercially-available green teas with an emphasis on identifying differences between ceremonial and culinary matcha. Gunpowder and bagged green teas had higher total phenolic contents and greater CUPRAC (cupric ion reducing antioxidant capacity) and ORAC (oxygen radical absorbance capacity) antioxidant capacities than matcha teas. Among matcha samples, less expensive culinary teas had greater total phenolic contents and higher antioxidant capacities than ceremonial products. Hierarchical cluster analysis was used to determine similarities and differences in catechin composition and revealed that bagged and gunpowder green teas had the highest levels of the stereoisomers epi/catechin gallate, which correlated with their strong antioxidant properties. Bagged and gunpowder teas were the lowest cost products in this study, indicating that they are an economical choice for consumers who want a green tea beverage with high catechin content, although they generally had lower caffeine levels than matcha.

Comparison of Si-GA-PLS and Si-CARS-PLS build algorithms for quantitation of total polyphenols in black tea using the spectral analytical system

BACKGROUND

The objective of the current study was to compare two machine learning approaches for the quantification of total polyphenols by choosing the optimal spectral intervals utilizing the synergy interval partial least squares (Si-PLS) model. To increase the resilience of built models, the genetic algorithm (GA) and competitive adaptive reweighted sampling (CARS) were applied to a subset of variables.

RESULTS

The collected spectral data were divided into 19 sub-interval selections totaling 246 variables, yielding the lowest root mean square error of cross-validation (RMSECV). The performance of the model was evaluated using the correlation coefficient for calibration (RC ), prediction (RP ), RMSECV, root mean square error of prediction (RMSEP) and residual predictive deviation (RPD) value. The Si-GA-PLS model produced the following results: PCs = 9; RC  = 0.915; RMSECV = 1.39; RP  = 0.8878; RMSEP = 1.62; and RPD = 2.32. The performance of the Si-CARS-PLS model was noted to be best at PCs = 10, while RC  = 0.9723, RMSECV = 0.81, RP  = 0.9114, RMSEP = 1.45 and RPD = 2.59.

CONCLUSION

The build model's prediction ability was amended in the order PLS < Si-PLS < CARS-PLS when full spectroscopic data were used and Si-PLS < Si-GA-PLS < Si-CARS-PLS when interval selection was performed with the Si-PLS model. Finally, the developed method was successfully used to quantify total polyphenols in tea. © 2023 Society of Chemical Industry.

Uptake and translocation of organic pollutants in Camellia sinensis (L.): a review

Camellia sinensis (L.) is a perennial evergreen woody plant with the potential for environmental pollution due to its unique growth environment and extended growth cycle. Pollution sources and pathways for tea plants encompass various factors, including atmospheric deposition, agricultural inputs of chemical fertilizers and pesticide, uptake from soil, and sewage irrigation. During the cultivation phase, Camellia sinensis (L.) can absorb organic pollutants through its roots and leaves. This review provides an overview of the uptake and translocation mechanisms involving the absorption of polycyclic aromatic hydrocarbons (PAHs), pesticides, anthraquinone (AQ), perchlorate, and other organic pollutants by tea plant roots. Additionally, we summarize how fresh tea leaves can be impacted by spraying pesticide and atmospheric sedimentation. In conclusion, this review highlights current research progress in understanding the pollution risks associated with Camellia sinensis (L.) and its products, emphasizing the need for further investigation and providing insights into potential future directions for research in this field.

Azorean Black Tea (Camellia sinensis) Antidermatophytic and Fungicidal Properties

The treatment of dermatophytoses, the most common human fungal infections, requires new alternatives. The aim of this study was to determine the antidermatophytic activity of the aqueous Azorean Black Tea extract (ABT), together with an approach to the mechanisms of action. The phytochemical analysis of ABT extract was performed by HPLC. The dermatophytes susceptibility was assessed using a broth microdilution assay; potential synergies with terbinafine and griseofulvin were evaluated by the checkerboard assay. The mechanism of action was appraised by the quantification of the fungal cell wall chitin and β-1,3-glucan, and by membrane ergosterol. The presence of ultrastructural modifications was studied by Transmission Electron Microscopy (TEM). The ABT extract contained organic and phenolic acids, flavonoids, theaflavins and alkaloids. It showed an antidermatophytic effect, with MIC values of 250 µg/mL for Trichophyton mentagrophytes, 125 µg/mL for Trichophyton rubrum and 500 µg/mL for Microsporum canis; at these concentrations, the extract was fungicidal. An additive effect of ABT in association to terbinafine on these three dermatophytes was observed. The ABT extract caused a significant reduction in β-1,3-glucan content, indicating the synthesis of this cell wall component as a possible target. The present study identifies the antidermatophytic activity of the ABT and highlights its potential to improve the effectiveness of conventional topical treatment currently used for the management of skin or mucosal fungal infections.

leaves extract for spectroscopic estimation of ofloxacin and ciprofloxacin in commercial formulations

The current study describes the biogenic synthesis of two metal oxides zinc oxide (ZnO), aluminum oxide (Al2O3) nanoparticles using Camellia sinensis, and Origanum vulgare L. leaves extract, respectively. The synthesized metal oxide nanoparticles were investigated using spectroscopic and microscopic techniques to confirm the formation of their nanostructures. Accurate and precise spectrofluorometric probes were proposed for the quantification of Ofloxacin (OFX) and Ciprofloxacin (CPFX) in their bulk and commercial formulations. The extraordinary properties of Zinc oxide and aluminum oxide nanoparticles (ZnONPs and Al2O3NPs) enhance the fluorescence intensity in the presence of 0.5 mL and 1.0 mL of sodium dodecyl sulfate (SDS, 1.0% w/v) as organizing agent for the detection of OFX and CPFX, respectively. The optical detection of both drugs at λex/em range 250-700 nm displayed linearity with a main correlation coefficient >0.999 at 1-300 (OFX-SDS-ZnONPs) and 0.5-100 (OFX-SDS-Al2O3NPs) ng mL-1,10-400 (CPFX-SDS-ZnONPs) and 0.1-50 (CPFX-SDS-Al2O3NPs) ng mL-1. The detection and quantification limits were found to be 0.04, 0.03, and 0.02, 0.04 ng mL-1, 0.13, 0.10, and 7.24, 0.09 ng mL-1 for the above-mentioned fluorescence systems, respectively. The suggested spectrofluorometric probes were validated and potentially applied for the estimation of OFX and CPFX in their bulk and commercial formulations.

Improved phyllosphere microbiome composition of tea plant with the application of small peptides in combination with rhamnolipid

BACKGROUND

Small peptides play a crucial role in plant growth and adaptation to the environment. Exogenous small peptides are often applied together with surfactants as foliar fertilizers, but the impact of small peptides and surfactants on the tea phyllosphere microbiome remains unknown.

RESULTS

In this study, we investigated the effects of small peptides and different surfactants on the tea phyllosphere microbiome using 16S and ITS sequencing. Our results showed that the use of small peptides reduced the bacterial diversity of the tea phyllosphere microbiome and increased the fungal diversity, while the use of surfactants influenced the diversity of bacteria and fungi. Furthermore, the addition of rhamnolipid to small peptides significantly improved the tea phyllosphere microbiome community structure, making beneficial microorganisms such as Pseudomonas, Chryseobacterium, Meyerozyma, and Vishniacozyma dominant populations.

CONCLUSION

Our study suggests that the combined use of small peptides and surfactants can significantly modify the tea phyllosphere microbiome community structure, particularly for beneficial microorganisms closely related to tea plant health. Thus, this preliminary study offers initial insights that could guide the application of small peptides and surfactants in agricultural production, particularly with respect to their potential for modulating the phyllosphere microbiome community in tea plant management.

Characterization of different grades of Jiuqu hongmei tea based on flavor profiles using HS-SPME-GC-MS combined with E-nose and E-tongue

In order to distinguish different grades of Jiuqu hongmei tea (black tea), four different grades of Jiuqu hongmei tea were used as materials in this study: Super Grade (SuG), First Grade (FG), Second Grade (SG), and Third Grade (TG). HS-SPME-GC-MS combined with electronic nose (E-nose) and electronic tongue (E-tongue) technology was used to detect and analyze tea samples. The results showed that 162 volatile substances were identified, mainly alcohols, followed by hydrocarbons, aldehydes, ketones and esters. Twenty-nine volatile compounds were found in all grades of tea samples. The results of heat map analysis showed that the relative contents of five volatile compounds in different grades of Jiuqu hongmei tea were positively correlated with the grades of Jiuqu hongmei tea. By orthogonal partial least squares discriminant analysis (OPLS-DA), 35 different compounds of SuG and FG, 30 different compounds of SG and TG, 34 different compounds of FG and SG were found. Overall, the results indicated that there were significant differences in volatile compounds among different grades of Jiuqu hongmei tea, and the use of HS-SPME-GC-MS combined with E-nose and E-tongue could provide a scientific reference method as an effective tool for detecting flavor characteristics of other types of black tea grades.

Metabolic responses of tea (Camellia sinensis L.) to the insecticide thiamethoxam

BACKGROUND

Thiamethoxam (TMX) is insecticidal, but also can trigger physiological and metabolic reactions of plant cycles. The objective of this work was to evaluate the physiological and metabolic effect of TMX on tea plants and its potential benefits.

RESULTS

In this study, dose of TMX (0.09, 0.135 and 0.18 kg a.i./ha) were tested. Except for peroxidase (POD) and glutathione S-transferase (GST), chlorophyll, carotenoid, catalase (CAT) and malondialdehyde (MDA) were significantly affected compared with the controls. The CAT activity was increased by 3.38, 1.71, 2.91 times, respectively, under three doses of TMX treatment. The metabolic response between TMX treatment and control groups on the third day was compared using a widely targeted metabolomics. A total of 97 different metabolites were identified, including benzenoids, flavonoids, lipids and lipid-like molecules, organic acids and derivatives, organic nitrogen compounds, organic oxygen compounds, organoheterocyclic compounds, phenylpropanoids and polyketides, and others. Those metabolites were mapped on the perturbed metabolic pathways. The results demonstrated that the most perturbation occurred in flavone and flavonol biosynthesis. The beneficial secondary metabolites luteolin and kaempferol were upregulated 1.46 and 1.31 times respectively, which protect plants from biotic and abiotic stresses. Molecular docking models suggest interactions between TMX and flavonoid 3-O-glucosyltransferase.

CONCLUSION

Thiamethoxam spray positively promoted the physiological and metabolic response of tea plants. And this work also provided the useful information of TMX metabolism in tea plants as well as rational application of insecticides. © 2023 Society of Chemical Industry.

Tea green leafhopper-induced synomone attracts the egg parasitoids, mymarids to suppress the leafhopper

BACKGROUND

The tea green leafhopper, Empoasca flavescens is the most important pest of tea plants in China. Mymarid attractants based on herbivore-induced plant volatiles (HIPVs) from leafhopper feeding and oviposition-induced plant volatiles (OIPVs) were formulated and tested as a novel pest control agent against the leafhopper in tea plantations.

RESULTS

Results showed that two mymarid species, Stethynium empoascae and Schizophragma parvula, had a reducing effect on leafhopper populations. The HIPVs and OIPVs were identified and bioassayed to screen the key synomones showing strong attraction to the mymarids. They were formulated into different blends, of which Field Attractant 1, comprising linalool, methyl salicylate, (E)-2-hexenal, perillen and α-farnesene at ratio of 1:2:3:58:146 (20 mg/lure), showed the strongest attraction to the mymarids. In field trials with the attractant, the average parasitism rate (60.46 ± 23.71%) of tea leafhoppers by the two mymarids in the attractant-baited area was significantly higher than that (42.85 ± 19.24%) in the CK area. Also, the average leafhopper density (46 ± 30 per 80 tea shoots) in the attractant-baited area was significantly lower than that (110 ± 70 per 80 tea shoots) in the CK area.

CONCLUSION

This study showed that a synthetic blend of key volatiles from HIPVs and OIPVs at an optimal ratio can be formulated into an attractant with the potential to attract and retain wild mymarid populations to suppress leafhopper populations in infested tea plantations, so as to reduce or avoid the spraying of insecticides. © 2023 Society of Chemical Industry.

Variations in physicochemical characteristics, antioxidant activity, phenolic and volatile profiles, and sensory attributes of tea-flavored Chardonnay wine during bottle aging

A novel Chardonnay wine flavored with either green tea or black tea was subjected to bottle aging for 9 months, and the physicochemical properties, antioxidant capacity, total phenolic content, volatile content and sensory properties were monitored. There were 272 phenolic and non-phenolic compounds characterized in the aged Chardonnay wines, including newly formed 9, 1, 3 and 8 phenolic compounds and 10, 6, 1 and 6 non-phenolic compounds after aging for 1, 3, 6 and 9 months, respectively. For all the aged wines, catechin was determined as the most abundant phenolic compound, and epigallocatechin mainly contributed toward the antioxidant power. A total of 54 volatile compounds were identified in the aged Chardonnay wines, including 17 odor-active compounds. The aging process diminished floral and fruity odors, but intensified green odor. The consumer study revealed the highest consumer liking for 1% (w/v) black tea infused wine. This study revealed the quality and bioactivity of this novel flavored wine type during aging which is critical to understand the shelf-life and functionality of the product.

Incidental nanoparticles in black tea alleviate DSS-induced ulcerative colitis in BALB/c mice

As the dominant herbal drink consumed worldwide, black tea exhibits various health promoting benefits including amelioration of inflammatory bowel diseases. Despite extensive studies on the tea's components, little is known about the bioactivities of nanoparticles (NPs) which were incidentally assembled in the tea infusion and represent the major components. This study investigated the alleviative effects of black tea infusion, the isolated black tea NPs, and a mixture of caffeine, epigallocatechin-3-gallate, gallic acid and epicatechin gallate on dextran sodium sulfate (DSS)-induced ulcerative colitis. The results showed that both the black tea infusion and the NPs significantly alleviated colitis, suppressed the mRNA levels of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β, and suppressed the DSS-induced loss of cell-cell junction proteins (e.g., E-cadherin, ZO-1, and claudin-1) and increase of p-STAT3. The mixture of four tea components, which is the analogue of bioactive payloads carried by the NPs, was much less effective than the tea infusion and NPs. It shows that the NPs elevate the efficiency of polyphenols and caffeine in black tea in restoring the intercellular connection in the intestine, inhibiting mucosal inflammation, and alleviating ulcerative colitis. This work may inspire the development of tea-based therapeutics for treating inflammatory bowel diseases and have wide influences on value-added processing, quality evaluation, functionalization, and innovation of tea and other plant-based beverages.

Animal efficacy study of a plant extract complex (BEN815) as a potential treatment for COVID-19

In a short time, several types of injectable and oral therapeutics have been developed and used to effectively manage patients with coronavirus disease 2019 (COVID-19). BEN815 is an improved mixture of three extracts (Psidium guajava, Camellia sinensis, and Rosa hybrida) recognized by the Ministry of Food and Drug Safety of Korea as a health food ingredient that alleviates allergic rhinitis. The current animal efficacy study was performed to assess its probability of improving COVID-19 symptoms. BEN815 treatment significantly increased the survival of K18-hACE2 transgenic mice and reduced viral titers in the lungs at 5 days post infection (DPI). Furthermore, the lungs of the treated mice showed mild tissue damage at 5 DPI and nearly complete recovery from COVID-19 at 14 DPI. BEN815 appears to be an effective and minimally toxic anti-SARS-CoV-2 agent in mice and has potential for clinical applications.

Could Natural Products Help in the Control of Obesity? Current Insights and Future Perspectives

Obesity is a global issue faced by many individuals worldwide. However, no drug has a pronounced effect with few side effects. Green tea, a well-known natural product, shows preventive effects against obesity by decreasing lipogenesis and increasing fat oxidation and antioxidant capacity. In contrast, other natural products are known to contribute to obesity. Relevant articles published on the therapeutic effect of natural products on obesity were retrieved from PubMed, Web of Science, and Scopus. The search was conducted by entering keywords such as "obesity", "natural product", and "clinical trial". The natural products were classified as single compounds, foods, teas, fruits, herbal medicines-single extract, herbal medicines-decoction, and herbal medicines-external preparation. Then, the mechanisms of these medicines were organized into lipid metabolism, anti-inflammation, antioxidation, appetite loss, and thermogenesis. This review aimed to assess the efficacy and mechanisms of effective natural products in managing obesity. Several clinical studies reported that natural products showed antiobesity effects, including Coffea arabica (coffee), Camellia sinensis (green tea), Caulerpa racemosa (green algae), Allium sativum (garlic), combined Ephedra intermedia Schrenk, Thea sinensis L., and Atractylodes lancea DC extract (known as Gambisan), Ephedra sinica Stapf, Angelica Gigantis Radix, Atractylodis Rhizoma Alba, Coicis semen, Cinnamomi cortex, Paeoniae radix alba, and Glycyrrhiza uralensis (known as Euiiyin-tang formula). Further studies are expected to refine the pharmacological effects of natural products for clinical use.

Fluoride and Aluminium in Tea (Camellia sinensis L.)-Tea Quality Indicators and Risk Factors for Consumers

In recent years, the quality and sourcing of tea have gained importance in Europe, but information remains scarce. The aim of this study was to determine the concentrations of fluoride (F-) and total aluminium (Al) species in infusions of commercially available teas in Slovenia, and thus in Europe, and to relate them to tea quality and their impact on consumer safety. F- concentrations were determined using a fluoride-ion-selective electrode and Al concentrations using inductively coupled plasma optical emission spectroscopy. A comparison of the results obtained for four selected tea samples using the calibration curve and a standard addition technique showed good agreement, with no interferences caused by the sample matrix. The concentrations of 35 commercial teas ranged from 0.34 to 4.79 and 0.51 to 8.90 mg/L for F- and Al, respectively. The average concentrations of the two elements followed the same descending order: black filter > green filter > black leaves ≈ green leaves. Single and multivariate statistical methods supported the categorisation of teas by packaging but not by type, with tea in filter bags being more expensive than loose tea. The linear relationship between F- and Al concentrations in infusions (C(Al) = 1.2134 · C(F-)) allows for the determination of one element and estimation of the other, leading to a significant reduction in laboratory effort and cost. This research advances tea assessment by proposing Al concentration alongside F- as a quality indicator and provides the basis for tea-monitoring protocols. Finally, the daily consumption of larger quantities of tea (≈1 L) with elevated F- and Al concentrations could potentially pose a health risk.