Search Results (455)

Anthracnose is a leaf fungal disease caused by multiple Colletotrichum species. Currently, the predominant deployment of chemical agents for anthracnose control increases ecological pollution risks and potential food safety concerns. The comprehension of the pathogenic mechanism and physicochemical properties of anthracnose is, therefore, essential for effective prevention and control. In this study, the pathogenic strain (pathogen) was isolated from the infected tea plant (Camellia sinensis) leaves and was identified as Colletotrichum gloeosporioides based on microscope observations and gene sequences. This fungus exhibited optimal growth at 28 °C and a pH of 6, with a lethal temperature threshold of 53 °C on PDA plate medium. The 80% tea saponin and 10% polymycin B could effectively inhibit its mycelium growth. Notably, the 10% polyoxin B exhibits a stronger inhibitory effect with an EC₅₀ value of 1.07 mg mL⁻¹. Following infection with Colletotrichum gloeosporioides, the resistant cultivar ‘Zhongcha 108’ exhibited higher levels of H₂O₂ and O₂⁻ than the susceptible ‘Longjing 43’, with later symptom onset and slower disease progression. Although the exogenous treatment of methyl jasmonate (MeJA) did not inhibit C. gloeosporioides directly, it significantly reduced lesion areas in ‘Longjing 43’ leaves caused by C. gloeosporioides. This treatment increased peroxidase and superoxide dismutase activities, but limited malondialdehyde content, thereby enhancing ‘Longjing 43’ resistance to the pathogen. The findings provide scientific guidance for the anthracnose prevention and control in tea gardens. Full article

The contents of secondary metabolites such as tea polyphenols, amino acids, caffeine, and volatile metabolites in fresh tea leaves are key factors determining the unique flavor and health attributes of finished tea products. However, differences in varieties, cultivation practices, and environmental conditions often lead to variations in these metabolites among fresh tea leaves, thereby affecting tea quality. In order to clarify the various internal and external factors that influence the formation of the quality of fresh tea leaves and their mechanism of action. This article mainly reviews the research on fresh leaf quality in the past decade. Firstly, it clarifies the molecular basis of metabolic differences among varieties. Then, it summarizes the regulatory mechanisms of underground (soil, microorganisms) and above-ground (light, temperature, humidity) environments on key metabolic pathways, and focuses on evaluating the effects of intercropping, fertilization, and other cultivation measures on improving tea quality. This review found that the specific gene expression of varieties, the transmission of environmental signals, and cultivation interventions jointly drive the synthesis and accumulation of tea polyphenols, amino acids, caffeine, and aroma substances. However, no one has ever systematically reviewed it. Therefore, it provides certain theoretical references for improving the quality of fresh leaves. Full article

Soybeans (Glycine max L.), a globally significant crop, play a critical role in economic, nutritional, and ecological systems, particularly in rotational farming due to their nitrogen-fixing capacity. This study investigated the residual effects of vermicompost (VC) and vermicompost tea (VCT) applied during a preceding corn cycle on subsequent soybean growth and productivity in an organic corn–soybean rotation. Soybeans were grown in raised beds previously treated with different VCT concentrations and combinations of VC+VCT, without additional fertilization during the soybean phase. Physiological traits, including leaf chlorophyll content (SPAD values) and stomatal conductance, were measured alongside biomass, yield, and plant leaves nutrient concentrations. VC+VCT treatments significantly increased biomass and yield, with VC1+VCT20 achieving the highest biomass (3.02 tons/ha) and yield (1.68 tons/ha). Leaf nutrient analysis revealed increased uptake of both macro- and micronutrients in amended treatments, while SPAD and stomatal conductance values remained consistently higher than in the control. Soil analyses confirmed improved nutrient retention and cation exchange capacity in amended plots, demonstrating the legacy benefits of organic inputs. Therefore, residual VCT and VC+VCT applications improved soybean productivity, nutrient acquisition, and physiological performance in rotational systems. By reducing reliance on synthetic fertilizers and enhancing soil fertility, this strategy supports climate-smart agriculture principles and contributes to SDG 2 (Zero Hunger), SDG 12 (Responsible Consumption and Production), and SDG 13 (Climate Action). Full article

The genus Citrus consists of Tangerines (Citrus × reticulata), Mandarins (Citrus × reticulata), Oranges (Citrus × sinensis), Grapefruits (Citrus maxima), Lemons (Citrus × limon), and other citrus fruits. This study investigated the effects of 74 different citrus species and harvesting time on the quality of citrus dark tea using Hubei green brick tea as the raw material. Oranges (Citrus × sinensis) were found to outperform other species in improving the quality of citrus dark tea. Additionally, the impact of orange harvesting time (August to December) on the quality of orange dark tea was investigated by using the Peach leaf orange with the highest sensory score as the subject of the study. Results revealed that harvesting time can considerably impact the flavor quality of orange dark tea, but not its infusion color or scent. Specifically, the orange dark tea processed with September-harvested Peach leaf orange exhibited a strong fruity scent, a sweet and smooth flavor, and a harmonious tea and fruit aroma. With the delay of harvesting time, a downtrend was observed in the content of soluble proteins, flavonoids, hesperidin, synephrine, and limonin, as well as total volatile components, with the largest decrease in synephrine and flavonoids. However, the polysaccharide content increased in the peel of Peach leaf orange. Functional analysis revealed that the delay of harvesting time can diminish the inhibitory capacity of orange-dark tea on α-glucosidase and α-amylase. Organoleptic quality and physiological activity analysis demonstrated September as the optimal time for harvesting Peach leaf oranges for processing orange dark tea. Full article

Lycium barbarum L. bud tea and leaf tea are functional processed products made from L. barbarum buds and leaves with traditional green tea processing techniques. Based on an extensive targeted metabolomics technology, this study systematically analyzed the chemical composition of L. barbarum bud tea and leaf tea, identified their differential compounds, and explored the effects of water-extracted substances on the activities of pancreatic lipase and α-Amylase. The results showed that the contents of total phenols, total flavonoids, and chlorogenic acid in the bud tea were 36.09 ± 1.97 mg/g, 7.44 ± 0.31 mg/g, and 4.18 ± 0.10 mg/g, respectively, 66.25%, 34.78%, and 22.58% higher than those in the leaf tea, respectively. A total of 594 metabolites were identified through the metabolomics analysis, mainly including flavonoids, phenolic acid compounds, alkaloids, amino acids and their derivatives, organic acids, lignans and coumarins, terpenoids, ands steroid compounds. Among them, flavonoids, phenolic acids, alkaloids, and amino acids and their derivatives accounted for approximately 58%. Compared with the leaf tea, the bud tea was significantly enriched with flavonoids, phenolic acid compounds, nucleotide compounds, lignans, and coumarins. Delphinidin 3-O-galactoside, cyanidin-3-glucoside, and cyanidin-3-O-glucoside were identified as significantly differential metabolites. Both L. barbarum bud tea and leaf tea exhibited good inhibitory effects on pancreatic lipase and α-Amylase, with the highest inhibition rates being 68.71%, 77.33%, 76.08%, and 69.96%, respectively. The contents of anthocyanins and their derivatives, including delphinidin-3-O-galactoside, cyanidin-3-glucoside, cyanidin-3-O-glucoside, cyanidin-O-hexoside, delphinidin-O-hexoside, and delphinidin diglucoside, were positively correlated with the activities of the two enzymes. These results underpin functional exploration and quality standardization of L. barbarum bud/leaf tea products. Full article

Although colored-leaf tea germplasms can broaden product diversity and functional potential, such resources have been rarely reported in Korea. Herein, we comprehensively characterized Ku2, a newly discovered purple-green line of Camellia sinensis, and benchmarked it against the conventional green-leaf ‘Sangmok’. Five-year-old plants grown under identical open-field conditions were evaluated for growth characteristics, leaf pigmentation, biochemical composition, and antioxidant capacity. Ku2 exhibited a more vigorous growth habit with denser branching and produced leaves that were 11% longer and 17% wider than those of ‘Sangmok’, but chlorophyll concentrations were 29–33% lower. Young shoots of Ku2 in the first flush accumulated markedly higher levels of total polyphenols (+38%), anthocyanins (+78%), and total catechins (+35%), including a 70% increase in epigallocatechin-3-gallate. But amino acid and theanine contents were reduced to 30% and 25% of those in ‘Sangmok’, respectively. Consistent with its polyphenol enrichment, Ku2 extracts displayed superior radical-scavenging activity, with lower DPPH and ABTS IC₅₀ values (7.6 ± 0.5 and 11.6 ± 0.2 µg·mL⁻¹) than ‘Sangmok’ (10.1 ± 0.4 and 15.1 ± 0.1 µg·mL⁻¹), approaching ascorbic acid and Trolox standards. These findings highlight Ku2 as a valuable germplasm for developing premium Korean teas and for breeding colored-leaf cultivars enriched with health-promoting metabolites. Full article

Background: Dietary polyphenols, particularly flavonoids, have been associated with improved glycemic control and reduced risk of type 2 diabetes. Raspberry leaf (RL) is a rich but underexplored source of such bioactives, including ellagitannins, flavonoids, and phenolic acids. While raspberry fruit has received some attention in nutritional science, the metabolic effects of raspberry leaf—especially its influence on postprandial glucose and insulin responses—remain largely unstudied. Objective: This study is the first to investigate the acute effects of RL tea consumption on postprandial blood glucose and insulin levels in healthy individuals following intake of common dietary carbohydrates (sucrose and glucose). Methods: In a randomized crossover study, 22 healthy adults (12 males, 10 females) consumed 50 g of glucose or sucrose with or without 10 g of RL tea in four separate sessions. Blood glucose and insulin levels were measured at fasting and at 15, 30, 60, 90, and 120 min post-ingestion. A total of 37 polyphenolic compounds were identified in the RL infusion using LC–MS, following a 5-minute hot water extraction. The contents of ellagitannins, flavonoids, and phenolic acids were 38 mg, 7 mg, and 4 mg per 10 g of RL, respectively, contributing to a total polyphenol content of 50 mg per 10 g. Results: When RL tea was consumed with sucrose, postprandial blood glucose levels were significantly reduced at 15 and 30 min by 1.19 ± 0.88 mmol/L (25.59% reduction, p = 0.001) and 2.03 ± 1.05 mmol/L (43.57% reduction, p = 0.0004), respectively. Insulin concentrations were also significantly lower at 15 min (113.90 ± 59.58 pmol/L, p = 0.019), 30 min (161.76 ± 91.96 pmol/L, p = 0.0008), and 60 min (139.44 ± 75.96 pmol/L, p = 0.025). No significant differences were observed with glucose ingestion. Conclusions: This study provides the first clinical evidence that RL tea can blunt early postprandial glycemic and insulinemic responses to sucrose in healthy individuals. The data suggest that these effects are likely mediated by relatively low levels of polyphenols—particularly ellagic acid—through inhibition of carbohydrate-digesting enzymes such as α-glucosidase and β-fructofuranosidase. These findings support the potential of RL tea as a simple, dietary approach to modulate glucose metabolism and warrant further investigation in populations at risk for metabolic disorders. Full article

The inspection of the appearance quality of tea leaves is vital for market classification and value assessment within the tea industry. Nevertheless, many existing detection approaches rely on sophisticated model architectures, which hinder their practical use on devices with limited computational resources. This study proposes a lightweight object detection network, TeaAppearanceLiteNet, tailored for tea leaf appearance analysis. A novel C3k2_PartialConv module is introduced to significantly reduce computational redundancy while maintaining effective feature extraction. The CBMA_MSCA attention mechanism is incorporated to enable the multi-scale modeling of channel attention, enhancing the perception accuracy of features at various scales. By incorporating the Detect_PinwheelShapedConv head, the spatial representation power of the network is significantly improved. In addition, the MPDIoU_ShapeIoU loss is formulated to enhance the correspondence between predicted and ground-truth bounding boxes across multiple dimensions—covering spatial location, geometric shape, and scale—which contributes to a more stable regression and higher detection accuracy. Experimental results demonstrate that, compared to baseline methods, TeaAppearanceLiteNet achieves a 12.27% improvement in accuracy, reaching a mAP@0.5 of 84.06% with an inference speed of 157.81 FPS. The parameter count is only 1.83% of traditional models. The compact and high-efficiency design of TeaAppearanceLiteNet enables its deployment on mobile and edge devices, thereby supporting the digitalization and intelligent upgrading of the tea industry under the framework of smart agriculture. Full article

Apolygus lucorum is one of the main pests affecting tea quality. Chemical control is the primary method for managing this pest, but issues such as pesticide residues and the development of resistance are inevitable. The pest’s extensive host range holds significant practical implications for developing novel food baits. This study first investigated the preference of adult A. lucorum for tea branches under different conditions and various host plants by using the Y-tube olfactometer. Subsequently, the trapping efficacy of active tea volatile components and food baits was tested. The results revealed that adult A. lucorum exhibited a stronger preference for healthy and mechanically damaged tea branches, while they avoided branches infested with high densities of conspecifics. Adult A. lucorum showed significantly higher selection rates for Gossypium hirsutum, Vigna radiata leaf, Glycine max leaf, Phaseolus vulgaris, Lablab purpureus, and Brassica pekinensis compared with healthy tea branches. In field trials, three tea volatile baits showed effective trapping performance, (E,E)-α-farnesene, nonanal, and (Z)-3-hexenol. Three mixture baits of foods and tea plant volatiles, B. pekinensis + (Z)-3-hexenol, P. vulgaris + (E,E)-α-farnesene, and S. melongena + (Z)-3-hexenol, not only demonstrated high attractiveness but also maintained a residual effect period as long as 20 days. This study provides new insights and approaches for the integrated management of A. lucorum and offers technical support for the development of novel green pest control technologies in tea plantations. Full article

Lithocarpus litseifolius, a traditional sweet tea rich in dihydrochalcones, relies on plant nutrients for secondary metabolite accumulation. However, nutrient distribution patterns during leaf development and its relationship with secondary metabolites remain inadequately characterized. This study examined mineral elements, carbon and nitrogen metabolites, and primary dihydrochalcones in L. litseifolius leaves at various developmental stages, and analyzed their interrelationships. Mineral nutrients such as phosphate (P), potassium (K), magnesium (Mg), zinc (Zn), boron (B), and copper (Cu), along with trilobatin, were most abundant in the youngest leaves. Conversely, calcium (Ca), iron (Fe), sulfur (S), manganese (Mn), selenium (Se), sugars, soluble protein, amino acids, chlorophyll, and carotenoids predominantly accumulated in old leaves, paralleling the distribution of phlorizin. Nitrogen (N) and molybdenum (Mo) concentrations were higher in mature leaves. In young leaves, P, K, Mg, S, Mn, Zn, and B positively correlated with phlorizin and trilobatin, while N, chlorophyll, carotenoids, and fructose correlated negatively. Trilobatin was the primary contributor to hydroxyl radical (·OH) scavenging capacity. Redundancy analysis highlighted N, P, Mg, B, Zn, Cu, Fe, Mo, and Se as key mineral nutrients influencing phlorizin and trilobatin accumulation. These findings offer insights for mineral nutrient management and effective utilization of L. litseifolius. Full article

The objective of this study was to assess the content of selected elements—fluorine, calcium and inorganic phosphorus—in infusions prepared from selected commercial leaf teas available on the Polish market. A comprehensive analysis was conducted based on tea type and geographical origin. In addition, the Target Hazard Quotient (THQ) was calculated to estimate the non-carcinogenic health risk associated with fluoride intake from tea consumption. Methods: A total of 98 leaf tea samples were analyzed, including 55 black, 27 green, 9 oolong, and 7 white teas. Standardized brewing protocols were applied. Measured parameters included pH, calcium and inorganic phosphorus content, buffer capacity, and titratable acidity. Fluoride concentrations were determined using an ion-selective electrode. Statistical analysis was performed using non-parametric methods (Kruskal–Wallis ANOVA with DSCF post hoc test), and heatmaps were generated to illustrate the distribution of THQ across different models. Results: Black teas exhibited significantly lower pH values and higher titratable acidity, buffer capacity, and inorganic phosphorus levels compared to other tea types, indicating distinct physicochemical properties. Although all THQ values for fluoride remained well below the safety threshold (THQ < 1), the highest values were observed in elderly individuals with low body weight, particularly women consuming green tea, suggesting increased vulnerability in this subgroup. Conclusions: Among the analyzed samples, black teas demonstrated the most distinct chemical profile, characterized by the lowest pH and the highest acidity, buffer capacity, and fluoride and phosphorus content—especially in teas originating from Africa and Central Asia. While fluoride exposure from leaf tea infusions does not appear to pose a direct health risk, older adults, particularly low-weight women, may be more susceptible to potential non-carcinogenic effects and should moderate their intake of high-fluoride teas. Full article

Understanding how leaf maturity affects the flavor attributes of green tea is crucial for optimizing harvest timing and processing strategies. This study comprehensively characterized the flavor profiles of Fudingdabai green teas at three distinct leaf maturity stages—single bud (FDQSG), one bud + one leaf (FDMJ1G), and one bud + two leaves (FDTC2G)—using a multimodal approach integrating electronic nose, electronic tongue, HS-GC-IMS, relative odor activity value (rOAV) evaluation, and machine learning algorithms. A total of 85 volatile compounds (VOCs) were identified, of which 41 had rOAV > 1. Notably, 2-methylbutanal, 2-ethyl-3,5-dimethylpyrazine, and linalool exhibited extremely high rOAVs (>1000). FDQSG was enriched with LOX (lipoxygenase)-derived fresh, grassy volatiles such as (Z)-3-hexen-1-ol and nonanal. FDMJ1G showed a pronounced accumulation of floral and fruity compounds, especially linalool (rOAV: 7400), while FDTC2G featured Maillard- and phenylalanine-derived volatiles like benzene acetaldehyde and 2,5-dimethylfuran, contributing to roasted and cocoa-like aromas. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis revealed significant enrichment in butanoate metabolism and monoterpenoid biosynthesis. Random forest–SHAP analysis identified 20 key flavor markers, mostly VOCs, that effectively discriminated samples by tenderness grade. ROC–AUC validation further confirmed their diagnostic performance (accuracy ≥ 0.8). These findings provide a scientific basis for flavor-driven harvest management and the quality-oriented grading of Fudingdaibai green tea. Full article

Global climate warming and freshwater scarcity are intensifying water stress in agricultural fields, severely constraining sustainable agricultural development. As a typical C3 perennial cash crop, tea (Camellia sinensis) is naturally suited to low-latitude regions with abundant heat and evenly distributed precipitation, and it is highly sensitive to environmental factors such as temperature and moisture. In northern hilly tea-producing areas, tea plantations often encounter multiple challenges including uneven rainfall distribution and poor soil water retention, resulting in prominent water supply–demand imbalances that critically limit stable and efficient tea production. To explore efficient water-saving irrigation strategies adapted to such ecological conditions, this study was conducted in the Yushan Tea Plantation, Rizhao City, Shandong Province, China. Based on field monitoring data across three growing seasons (spring, summer, and autumn) from 2021 to 2023, five irrigation treatments were evaluated: conventional sprinkler irrigation (CK), drip irrigation (D), micro-sprinkler irrigation (W), drip irrigation with straw mulching (SD), and micro-sprinkler irrigation with straw mulching (SW). Actual crop evapotranspiration (ET_c act) was estimated using the soil water balance method, and actual fresh tea leaf yield (FTLY) and crop water productivity (CWP) were measured. Results showed that the SW treatment significantly improved both FTLY and CWP across all three seasons, with summer FTLY in 2022 increasing by 56.58% compared to CK and maximum CWP in spring and autumn reaching 0.916 kg/m³, demonstrating excellent stability and adaptability. Among all irrigation strategies, the SW treatment also exhibited the best regression fitting and yield prediction accuracy. The regression model validated by leave-one-out cross-validation (LOOCV) for the SW treatment demonstrated strong robustness and reliability (R² = 0.734; RMSE = 208.12 kg/ha; MAE = 183.31 kg/ha). Notably, the samples with the largest prediction errors across all treatments were nearly all associated with the highest or near-highest ET_c act values, indicating that model accuracy tends to decrease under extreme evapotranspiration conditions. The results show the synergistic effect of irrigation–mulching integration on enhancing CWP in northern perennial tea systems, providing empirical evidence and theoretical support for developing efficient irrigation strategies in hilly tea-growing regions of Northern China. Full article

Toona sinensis (“Heiyouchun”) is a traditional Chinese woody vegetable, the leaves of which can also be processed into tea, known for its distinctive flavor and diverse bioactivities. However, the effects of leaf maturity and processing methods on its phytochemical composition and functional properties remain unclear. In this study, metabolomic analysis revealed 35 significantly different metabolites between tender and mature leaves, with higher concentrations of flavonoids, flavonoid glycosides, limonoids, and amino acids in tender leaves. Additionally, comparative analysis revealed that black tea fermentation preserves bioactive compounds more effectively than hot-air drying, particularly in tender leaves. In vitro activity assays showed that toon leaf tea extracts exhibited significant antioxidant and hypoglycemic effects, with black tea fermented tender leaves displaying the most potent bioactivity. Correlation analysis further confirmed a strong positive relationship between flavonoid/polyphenol content and bioactivity. These findings provide a theoretical foundation for optimizing processing techniques to enhance the functional properties of toon leaf tea. Full article