Search Results (88)

Oolong tea presents notable variations in taste profile and aroma characteristics under different cultivation conditions, particularly across altitudes. However, systematic investigations into the altitude-induced differences in key taste compounds and aroma composition remain limited. In this study, we examined six oolong tea cultivars, comparing their taste-related chemical constituents and aroma profiles under high- and low-altitude cultivation. Sensory evaluation, high-performance liquid chromatography (HPLC) and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) were employed to characterize these differences. Sensory evaluation revealed that high-altitude oolong teas exhibited enhanced umami, sweetness, and floral intensity. In most cultivars, the levels of free amino acids, polyphenols, and soluble sugar were relatively higher under high-altitude conditions. HS-SPME-GC-MS identified 55 common volatile organic compounds (VOCs), with terpenes and esters comprising the largest number of compounds. Identification by partial least squares discriminant analysis (PLS-DA) combined with relative odor activity value (rOAV) screening yielded 22 candidate differential volatile organic compounds. Floral monoterpenes, including linalool, linalool oxide II and geraniol, were consistently higher in high-altitude teas, whereas most other volatiles varied primarily with cultivar rather than altitude. These chemical patterns are consistent with the sensory finding of stronger floral intensity in high-altitude samples. This study provides theoretical insights for cultivar selection and quality improvement of oolong tea grown in high-altitude regions. Full article

The tea plant (Camellia sinensis (L.) O. Kuntze) is a globally important crop, yet its cultivation is continually challenged by a range of viral pathogens that can compromise plant health and product quality. In this study, eighteen symptomatic leaves were collected from the Hubei Province Tea Germplasm Resources Nursery, China, representing multiple cultivars and diverse genetic backgrounds. The samples were pooled into three groups and subjected to ribodepleted transcriptome sequencing. Analyses revealed a complex virome, with Tea plant necrotic ring blotch virus (TPNRBV) dominating Pools A and B, whereas Badnavirus betacolocalasiae was the most prevalent in Pool C. Functional enrichment of viral genes indicated involvement in multiple biological processes, including replication, host interaction, and metabolism. Notably, two previously uncharacterized viruses were identified: Tea plant-associated ourmia-like virus 1 (TeaOLV1) and Tea plant-associated rhabdo-like virus 1 (TeaRLV1). Phylogenetic reconstruction positioned TeaOLV1 within the Penoulivirus genus, while TeaRLV1 formed a distinct clade among plant-associated rhabdoviruses. Conserved motif analysis revealed typical viral domains, accompanied by lineage-specific variations in tea plants. Collectively, these findings enhance our understanding of the viral diversity in tea plants, provide refined taxonomic placement for newly identified viruses, and offer molecular insights into their evolutionary relationships and potential functional roles. Full article

Tea (Camellia sinensis (L). Kuntze) cultivation by smallholder out-growers has grown significantly. Recent government initiatives have expanded production from traditional tea growing regions. This study investigated how smallholder farmers perceive and prefer different commercial tea clones. It also looked at the factors that influence their choices across major tea-growing regions of Uganda. A structured questionnaire was administered to 324 randomly selected tea out-growers from Central, Western, Kigezi, and West Nile regions. Data was analyzed using descriptive statistics, a Tea Preference Index (rating clone attributes on a 1–5 scale), and a multivariate Probit (MVP) model to evaluate farmers’ choices and preferences. Clone 303/577 is the most cultivated, accounting for 59%. Adoption rates were high in West Nile (98%), Kigezi (77%), and Central (67%) regions. Clone 6/8 ranked second at 47%, while clone 100/5 had the lowest cultivation rate at 10%. The ranking of clones by preference was 303/577, 6/8, 108/82, 31/8, and 100/5. Key attributes influencing preferences included, yield potential, canopy width, post-plucking/pruning recovery rate, shoot tenderness and cup quality. Results showed that a farmers’ choice of clone 303/577 was significantly influenced by shoot density, gender and tea farming experience. For clone 108/82, the most important factors were quick recovery after plucking/pruning, education level and household size. This information is vital for agricultural policy, extension services, tea breeding and genetic improvement programs in the tea sector. Full article

Although younger generations are not always given a prominent role in ethnobotanical surveys, studying intergenerational knowledge transfer should still be a primary interest, in the context of traditions’ erosion, globalization, disinterest and plant blindness. Our study was designed to describe the situation of knowledge transfer and to find potential solutions to counteract erosion by involving the children. This ethnobotanical survey involved students from primary and secondary schools of Valle Imagna (Bergamo, Italy) through different meetings and structured questionnaires to record their traditional knowledge on medicinal plants. The children were then asked to become an active part of the project by interviewing their families. All data recorded were archived in a database for statistical analysis. Students (number = 112) reported 41 plant species, with 36% reporting at least 3 species each. Forty percent of their use reports were related to exotic species or purchased plant material. The most reported species were Matricaria chamomilla L. and Camellia sinensis (L.) Kuntze with common preparations such as infusions from commercial products. Parents (n = 96) reported 76 species and grandparents (n = 35) 52. Statistical analysis showed correlation between traditional knowledge and age/gender, with older generations and female gender correlated to deeper knowledge. Our results suggest deep erosion and a clear lack of intergenerational knowledge transfer. However, our project serves as evidence of the concrete role ethnobotany holds in safeguarding the remaining cultural heritage of a territory, fostering preservation from the outset with the participation of younger generations. Full article

Background/Objectives: Camellia sinensis (L.) Kuntze or tea contains bioactive compounds such as catechin and caffeine, known for their antimicrobial and health-promoting properties. Colibactin-producing Escherichia coli are linked to genotoxicity in colon epithelial cells, potentially contributing to colorectal disease. This study aimed to evaluate the inhibitory effects of tea extracts (green, oolong, and black) and the phytochemicals catechin and caffeine on E. coli pathogenesis mediated by colibactin toxins, including transient infections, DNA damage, and cell cycle alterations in Caco-2 colon cells. Methods: Tea extracts were analyzed by HPLC for phytochemical content. Their antimicrobial activity against colibactin-producing E. coli (ATCC 25922) was assessed. Caco-2 cells were infected with the bacteria and treated with tea extracts or compounds. Cell viability was measured by MTT assay, DNA damage was measured by alkaline comet assay, and the expression of CDK-1, CDK-2, and Ki-67 genes was measurd by qRT-PCR. Results: Tea extracts and catechin inhibited colibactin-producing E. coli and significantly protected Caco-2 cells. Oolong tea showed the highest protection (90.78 ± 2.76%), with others maintaining viability above 80%. DNA damage was markedly reduced, and cell cycle regulation improved. All extracts upregulated CDK-1 and downregulated CDK-2, aiding in cell cycle restoration. Ki-67 expression indicated enhanced cell proliferation during infection. Conclusions: This study highlights new findings showing that tea extracts, including green, oolong, and black tea, as well as the tea compounds catechin and caffeine, can protect against DNA damage and help maintain the normal cell cycle of colon cells infected with E. coli-producing colibactin toxin. These results support their potential role in preventing and mitigating infections caused by such E. coli strains while promoting colon cell health. Full article

Green tea, derived from the unoxidized leaves of Camellia sinensis (L.) Kuntze, is one of the least processed types of tea and is rich in antioxidants and polyphenols. Among these, catechins—particularly epigallocatechin gallate (EGCG)—play a key role in regulating cell signaling pathways associated with various chronic conditions, including cardiovascular diseases, neurodegenerative disorders, metabolic diseases, and cancer. This review presents a comprehensive analysis of recent clinical studies focused on the therapeutic benefits and potential risks of interventions involving green tea extracts or EGCG. A systematic literature survey identified 17 relevant studies, classified into five key areas related to catechin interventions: toxicity and detoxification, drug pharmacokinetics, cognitive functions, anti-inflammatory and antioxidant properties, and obesity and metabolism. Findings from these clinical studies suggest that the health benefits of green tea catechins outweigh the potential risks. The review highlights the importance of subject genotyping for enzymes involved in catechin metabolism to aid in interpreting liver injury biomarkers, the necessity of assessing drug–catechin interactions in clinical contexts, and the promising effects of topical EGCG in reducing inflammation. This analysis underscores the need for further research to refine therapeutic applications while ensuring the safe and effective use of green tea catechins. Full article

Tea plant [Camellia sinensis (L.) O. Kuntze] is an economically important evergreen crop cultivated worldwide. While most tea plants have green leaves, albino cultivars with yellow or white young leaves have attracted growing interest due to their elevated levels of L-theanine, a key compound that enhances the umami flavor and overall quality of green tea. In this study, we characterized the morphological and biochemical traits of a novel albino tea cultivar, ‘Geumda’, developed in Korea. ‘Geumda’ exhibited yellow young shoots during the first flush and smaller leaves compared to the green-leaf standard cultivar, ‘Sangmok’. Although the catechin content of ‘Geumda’ was lower than that of ‘Sangmok’, it exhibited significantly higher levels of total amino acids, L-theanine, and arginine by 2.1-, 2.0-, and 9.8-fold, respectively. Transmission electron microscopy and gene expression analysis revealed that the elevated amino acid content in ‘Geumda’ was associated with impaired chloroplast development, leading to reduced chlorophyll content and diminished photosynthetic capacity. These findings suggest that ‘Geumda’, with its high concentrations of theanine and arginine and its impaired chloroplast development, represents a valuable genetic resource for the production of functional green teas enriched in umami flavor and beneficial health properties. Full article

Natural-origin edible gels are gaining attention as innovative carriers for bioactive compounds, offering consumer-friendly formats and potential to enhance stability and bioavailability. This study aimed to develop and characterize edible gels incorporating Camellia sinensis (L.) Kuntze extract using different plant-based gelling agents, including whole flaxseeds, ground flaxseeds, medium-size oatmeal, and coarse oatmeal. The physical properties of the gels were evaluated by rheological (flow curve) and pH studies. The phytochemical composition of the green tea extract and gels with this extract and the main phenolic compounds, including catechins, gallic acid, and caffeine, were evaluated by high-performance liquid chromatography. The biopharmaceutical properties of the prepared gels were evaluated by dissolution testing. Rheological analysis revealed that oat-based gels exhibited higher viscosity (up to 24.33 Pa·s) compared to flaxseed-based gels. Despite differences in consistency, no statistically significant differences were found in total phenolic release among gel formulations (p > 0.05), except for epigallocatechin, which showed significantly higher release from coarse oatmeal gels (p > 0.05). The findings suggest that both flaxseed- and oatmeal-based gels are promising natural carriers for green tea phytochemicals, offering standardized dosing and potential cognitive health benefits. Further studies are warranted to assess the in vivo bioavailability and long-term stability of these formulations. Full article

Matcha, a finely powdered green tea, has been cherished in Japan for centuries, used in the traditional tea ceremony and nowadays also valued for its health-promoting properties. Cultivated under shaded conditions to enhance chlorophyll production, which gives the typical vibrant green color, matcha is rich in important bioactive compounds, including caffeine, catechins, and theanine. This study analyzes three matcha grades—ceremonial grade 1 (G1), grade 4 (G4), and food grade (FG)—to assess variations in their metabolite profiles. The Bligh–Dyer method was employed to extract polar and non-polar metabolites from organic and hydroalcoholic phases. High-performance thin-layer chromatography (HPTLC) was used for qualitative metabolite analysis, while nuclear magnetic resonance (NMR) spectroscopy was employed for both qualitative and quantitative analyses. Results reveal a decreasing gradient of amino acids and caffeine from grade 1 to food grade, while other metabolites, such as polyphenols, display an increasing trend. These findings suggest that factors such as harvesting time and leaf maturity significantly influence matcha’s chemical composition, providing a scientific basis for its quality differentiation and potential nutraceutical uses. Full article

Distinguishing vegetation types from satellite images has long been a goal of remote sensing, and the combination of multi-source and multi-temporal remote sensing images for vegetation classification is currently a hot topic in the field. In species-rich mountainous environments, this study selected four remote sensing images from different seasons (two aerial images, one WorldView-2 image, and one UAV image) and proposed a vegetation classification method integrating hierarchical extraction and object-oriented approaches for 11 vegetation types. This method innovatively combines the Random Forest algorithm with a decision tree model, constructing a hierarchical strategy based on multi-temporal feature combinations to progressively address the challenge of distinguishing vegetation types with similar spectral characteristics. Compared to traditional single-temporal classification methods, our approach significantly enhances classification accuracy through multi-temporal feature fusion and comparative experimental validation, offering a novel technical framework for fine-grained vegetation classification under complex land cover conditions. To validate the effectiveness of multi-temporal features, we additionally performed Random Forest classifications on the four individual remote sensing images. The results indicate that (1) for single-temporal images classification, the best classification performance was achieved with autumn images, reaching an overall classification accuracy of 72.36%, while spring images had the worst performance, with an accuracy of only 58.79%; (2) the overall classification accuracy based on multi-temporal features reached 89.10%, which is an improvement of 16.74% compared to the best single-temporal classification (autumn). Notably, the producer accuracy for species such as Quercus acutissima Carr., Tea plantations, Camellia sinensis (L.) Kuntze, Pinus taeda L., Phyllostachys spectabilis C.D.Chu et C.S.Chao, Pinus thunbergii Parl., and Castanea mollissima Blume all exceeded 90%, indicating a relatively ideal classification outcome. Full article

Advanced glycation end products (AGEs) formed via glycation reactions negatively impact skin health by diminishing barrier function and elasticity and causing dullness. This study systematically evaluated the inhibitory and degradative capabilities of 24 cosmetic ingredients against AGEs using BSA-glucose and ELISA-based screening systems. We identified 21 ingredients that inhibit fluorescent AGEs, 22 that degrade AGEs-collagen crosslinks, and 19 with both properties. Further investigation of six key ingredients, including freeze-dried Rosa rugosa powder (Rosa rugosa cv. Plena) and freeze-dried Camellia sinensis flower powder (Camellia sinensis (L.) O. Kuntze), revealed their notable ability to degrade AGEs monomers and dimers. Freeze-dried Rosa rugosa powder achieved a 19% inhibition rate in an MGO-induced HDFs glycation model. Our findings provide valuable insights for selecting anti-glycation agents and developing effective anti-glycation products. Full article

Epigallocatechin-3-O-gallate (EGCG) is an important ingredient that indicates tea quality and has healthcare functions. Magnesium nutrition can improve the quality and yield of tea plants, but its regulatory role in the biosynthesis of EGCG in tea plants has not been clarified. Herein, we performed a comprehensive analysis of the metabolomics and transcriptomics of the shoots of ‘Huangdan’ at five magnesium concentrations: L1-L5 (0, 0.15, 0.45, 0.6, and 0.9 mmol/L mg²⁺, respectively). The results showed that the EGCG content of tea shoots treated with low magnesium concentrations was higher compared to those treated with high magnesium concentrations. The contents of related metabolites such as p-coumaric acid and cyanide in the EGCG synthesis pathway increased in the L4 and L5 treatment groups, while those of dihydroquercetin, dinnamic acid, and epicatechin increased significantly in the L2 and L3 treatment groups. Under the influence of magnesium treatment, the biosynthesis of EGCG was affected by a series of structural genes: CsPAL (HD.01G0005520), HD.02G0024350), Cs4CL (HD.15G0008250, HD.13G0010220), CsDFR (HD.04G0026220), CsANS(HD.12G0016700) with CsaroDE (HD.03G0002480)-positive regulation, and CsPAL (HD.13G0009900, HD.06G0008610), CsC4H (HD.06G0017130), Cs4CL (HD.02G0027390, HD.04G0003270), CsCHS (HD.10G0022640), CsCHI (HD.01G0011100), CsF3′H (HD.15G0015490), CsF3′5′H (HD.13G0004300), CsANS (HD.07G0023630), and Csaro B (HD.01G0028400) with CsSCPL (HD.01G0041070)-negative regulation. Transcription factors MYB 44 and WRKY 17 may play a key role in EGCG biosynthesis, which is significantly induced by magnesium nutrition in tea tree shoots. This study elucidates the effect of magnesium nutrition on EGCG biosynthesis in tea plants and provides key candidate transcription factors to provide a reference for further research on high-EGCG tea varieties to improve tea quality. Full article

This study utilized annual Fuding Dabaicha cuttings as the experimental subject, employing a nutrient solution cultivation technique to establish three distinct treatments: (1) CK: reference processing; (2) Cd: 20 mg/L CdSO₄ nutrient solution culture; (3) Cd + Se: 20 mg/L CdSO₄ + 1.5 mg/L Na₂SeO₃ nutrient solution culture. We measured and analyzed the electrolyte permeability, proline content, malondialdehyde (MDA) content, antioxidant-related indicators, photosynthesis-related indicators, Cd content in various organs, and transmission electron microscopy images depicting the distribution of Cd and Se elements within different organs of tea plants under these treatments after 30 days of processing, studying the regulatory role of selenium on the resistance mechanism of tea plants (Camellia sinensis) under cadmium stress. The findings are as follows: (1) Cd stress notably elevated the electrical conductivity, MDA content, and proline content of tea plants, whereas the Cd + Se₁ treatment significantly reduced the MDA and proline content under Cd stress; (2) the Cd stress treatment significantly increased the content of peroxides in the tea tree leaves and significantly decreased the activities of four antioxidant enzymes, SOD, POD, CAT, and Apx; the Cd + Se treatment significantly reduced the peroxide content in tea trees under cadmium stress and significantly increased the activities of SOD, POD, CAT, and Apx; (3) the Cd stress treatment significantly increased the values of certain chlorophyll fluorescence parameters and had no significant impact on the distribution of light energy, whereas the Cd + Se treatment significantly elevated the values of some chlorophyll fluorescence parameters and induced an uneven distribution of light energy; (4) the order of accumulation of Cd in different organs of the tea plants was as follows: root > stem > leaf, and the Cd + Se treatment significantly reduced the Cd content in various organs under Cd stress. In root cells, Cd and Se were predominantly located in the cell wall, plasma membrane, and vacuole membrane; in stem cells, they were primarily found in the cell wall and cytoplasm adjacent to the cell wall; in leaf cells, they were mainly distributed in the plasma membrane, cytoplasm, and vacuole. In conclusion, Cd treatment induced stress in tea plants, which resulted in a certain stimulatory effect on photosynthesis, but caused some damage to the photosynthetic apparatus in chloroplasts. The results of the Cd + Se treatment suggest that the interaction between Se and Cd can mitigate the toxicity experienced by tea plants under Cd stress. Full article

Tea plants Camellia sinensis (L.) O. Kuntze consume substantial quantities of water and nutrients during the flowering period, which can adversely affect the yield and quality of tea plants. Therefore, the effects of thidiazuron, carbaryl, ethephon, and lime sulphur on flower buds and flower abscission in tea plants were investigated. The photosynthetic characteristics and biochemical components, the electrical conductivity of leaves, and the occurrence of insect pests and frost damage in the tea plants were assessed following the exogenous application of these chemicals. The results showed that 0.015, 0.03, and 0.06% thidiazuron, 0.08% ethephon, and 2.0 and 3.0% lime sulphur significantly promoted tea flower buds and flower abscission. Thidiazuron notably increased the concentrations of total amino acids, caffeine, catechin, and soluble sugar in tea leaves while reducing leaf electrical conductivity to some extent. Additionally, it also suppressed the occurrence of Empoasca onukii Matsuda (Hemiptera: Cicadellidae) and Apolygus lucorum Meyer-Dür (Hemiptera: Miridae). Furthermore, thidiazuron enhanced both the length and weight of tea shoots the following early spring. Application of 3.0% lime sulphur enhanced chlorophyll a and b, carotenoid, catechin, and caffeine and decreased the number of Aleurocanthus spiniferus Quaintanca (Hemiptera: Aleyrodidae) on the tea plants. However, no significant differences in frost damage were observed across treatments. Overall, exogenous application of the chemicals, particularly thidiazuron, effectively reduced flower production, altered key biochemical components, controlled tea pests, and ultimately enhanced tea productivity. Full article

Green tea catechins (GTCs) are a group of bioactive polyphenolic compounds found in fresh tea leaves (Camellia sinensis (L.) O. Kuntze). They have garnered significant attention due to their diverse health benefits and potential therapeutic applications, including as antioxidant and sunscreen agents. Human skin serves as the primary barrier against various external aggressors, including pathogens, pollutants, and harmful ultraviolet radiation (UVR). Skin aging is a complex biological process influenced by intrinsic factors such as genetics and hormonal changes, as well as extrinsic factors like environmental stressors, among which UVR plays a pivotal role in accelerating skin aging and contributing to various dermatological conditions. Research has demonstrated that GTCs possess potent antioxidant properties that help neutralize free radicals generated by oxidative stress. This action not only mitigates cellular damage but also supports the repair mechanisms inherent in human skin. Furthermore, GTCs exhibit anti-carcinogenic effects by inhibiting pathways involved in tumor promotion and progression. GTCs have been shown to exert anti-inflammatory effects through modulation of inflammatory signaling pathways. Chronic inflammation is known to contribute significantly to both premature aging and various dermatological diseases such as psoriasis or eczema. By regulating these pathways effectively, GTCs may alleviate symptoms associated with inflammatory conditions. GTCs can enhance wound healing processes by stimulating angiogenesis. They also facilitate DNA repair mechanisms within dermal fibroblasts exposed to damaging agents. The photoprotective properties attributed to GTCs further underscore their relevance in skincare formulations aimed at preventing sun-induced damage. Their ability to screen UV light helps shield underlying tissues from harmful rays. This review paper aims to comprehensively examine the beneficial effects of GTCs on skin health through an analysis encompassing in vivo and in vitro studies alongside insights into molecular mechanisms underpinning these effects. Such knowledge could pave the way for the development of innovative strategies focused on harnessing natural compounds like GTCs for improved skincare solutions tailored to combat environmental stresses faced by the human epidermis. Full article