Search Results (130)

To elucidate the regional flavor characteristics of sun-dried green tea (SDT) and their underlying influencing factors, a comprehensive analysis was conducted using metabolomics and flavoromics approaches. This study systematically examined SDT samples and their corresponding tea garden soils from 13 distinct regions in Yunnan Province. The results revealed that the SDT samples could be classified into two distinct groups based on their flavor profiles. Compared to the regions of Pa Sha (PS), Bang Dong (BD), Dong Ban Shan (DBS), Dong Guo (DG), Su Hu (SH), Gua Feng Zhai (GFZ), and Wu Liang Shan (WLS), the regions of Xin Nong (XN), Ba Ka Nuan (BKN), Mang Ang (MA), Man Nuan (MN), Bing Dao (BDao), and Bin Shan (BS) exhibited a significant upregulation of the tea polyphenols (TP)/free amino acids (FAA) ratio. The former group was characterized by a sweet mellow taste, while the latter displayed a stronger taste profile. Furthermore, the analysis of volatile compounds demonstrated that geraniol and linalool were significantly upregulated in the PS, BD, DBS, DG, BS, and BDao regions, which were associated with tender and floral aromas. In contrast, isophorone, 2-pentyl furan, 1-octanol, D-limonene, and benzaldehyde were markedly enriched in the XN, BKN, MA, MN, SH, GFZ, and WLS regions, contributing to sweet and honey-like aromatic profiles. Altitude and mineral element phosphorus are potential key factors affecting the regional flavor differences in SDT. Specifically, SDT cultivated at higher altitudes and in soils with elevated available phosphorus content exhibited a greater likelihood of accumulating sweet mellow and floral compounds. This study provides scientific evidence for understanding the characteristic flavor profiles of SDT across different regions, offering valuable insights into the factors contributing to regional flavor differentiation in tea production. Full article

Drying methods play a crucial role in the formation of green tea aromas. This study investigated the aroma characteristics and volatile component profiles of large-leaf green tea under hot-air drying, pan-fired drying, and sun drying. The results revealed significant differences in the sensory aroma characteristics and volatile components of the large-leaf green tea among the three drying methods. The pan-fire-dried green tea (PDGT) exhibited a distinct roasted aroma, while the hot-air-dried green tea (HDGT) and sun-dried green tea (SDGT) displayed a faint scent and lasting aroma characteristics, with the SDGT additionally featuring a noticeable sun-dried odor. A total of 48 differential volatile components were identified, among which β-Ionone, (E)-β-Ionone, 2,2,6-Trimethylcyclohexanone, Dihydroactinidiolide, BenzeneacetAldehyde, 2-Pentylfuran, 1,1,6-Trimethyl-1,2-dihydronaphthalene, δ-Cadinene, β-Myrcene, Geranylacetone, o-Cymene, 6-Methyl-5-hepten-2-one, (E)-β-Ocimene, and BenzAldehyde were identified as the primary contributors to the aroma differences among the three large-leaf green teas. Additionally, 43 differential volatile compounds were found to be significantly correlated with at least one of the aroma types (floral, sweet, green, faint scent, nutty, or roasted). The findings of this study provide a theoretical foundation for understanding the formation of aroma qualities in large-leaf green tea and offer valuable insights for improving its aromatic characteristics. Full article

Alternaria species produce diverse secondary metabolites that act as critical virulence factors during plant pathogenesis. In cultivation areas of Chrysanthemum morifolium ‘Fubai’—a key cultivar for herbal tea—black spot disease caused by A. alternata manifests as necrotic leaf lesions progressing to wilting. Despite this disease’s economic impact, information on its associated toxins is limited, and the types of toxins produced by the black spot pathogen of Chrysanthemum morifolium ‘Fubai’ in particular remain unclear. Furthermore, whether toxins are present in the flowers when the leaves show symptoms is uncertain, but their inflorescence is not visibly infected. Using two previously characterized A. alternata strains (F16/F20) isolated from ‘Fubai’ in earlier studies, we demonstrated the concomitant production of altenuene (ALT) and tenuazonic acid (TeA) in both strains, with strain-specific yield variations (F20 TeA: 342.16 µg/mL vs. F16: 21.84 µg/mL; ALT: 0.28 µg/mL vs. 0.90 µg/mL). Time-course monitoring revealed coordinated accumulation of both toxins in inoculated petals, reaching 18.07 μg/g ALT and 2.59 µg/g TeA by day 9. Notably, these two toxins were detected only in flower samples from black spot-infected plants, and their concentrations correlated closely with disease severity in the leaves. Moreover, although the inflorescences did not display symptoms, both fresh and dried flowers retained detectable toxin levels. We established a technical system for the extraction and quantitative detection of the toxins ALT and TeA produced by the black spot pathogen in tea chrysanthemum. This work provides the first confirmation of ALT/TeA co-contamination in Chrysanthemum morifolium ‘Fubai’, revealing substantial dietary exposure risks through tea consumption. Our findings suggest that, from a food safety risk reduction perspective, integrated management strategies should be developed to minimize toxin contamination in tea chrysanthemum, including improved disease prevention measures and potential regulatory considerations. Full article

Tea saponin is a kind of natural non-ionic surfactant. Saponins were extracted from tea seed cake using an ultrasonic-assisted enzymatic method. The optimization of the tea saponin extraction procedure was conducted by using the response surface method to increase the yield. Study results indicated that the maximum yield of tea saponin was 69.81 mg/g under the optimum conditions of an enzyme concentration of 0.67%, a solvent-to-material ratio of 16.82 mL/g, an extraction temperature of 58.14 °C and an extraction time of 1.89 h. The surface activity experimental study results indicated that the critical micelle concentration of tea saponin was 0.5 g/L at 30 °C, and the lowest surface tension was 39.61 mN/m. The surface tension and CMC of tea saponin remained basically unchanged between 30 °C to 60 °C. When the pH of the solution was slightly acidic, the surface tension of tea saponin decreased significantly, while the CMC remained almost unchanged. Tea saponin has good salt and hard water resistance, and its surface tension decreases to a certain extent in both saltwater and hard water. The foam volume of tea saponin can reach 490 mL, with a half-life of 2350 s, and the foam is relatively stable. The combination of tea saponin and other surfactants has a certain synergistic effect. The critical micelle concentration of its complex system with the natural surfactant rhamnolipids can increase by 69.23%, and the surface tension can be reduced to a minimum of 22.56 mN/m. Moreover, by using the proposed method, the foam performance and stability of the system have been improved to a certain extent. This has significant practical significance for fully utilizing and developing waste camellia dried cake resources. Full article

The dried root of Sanguisorba officinalis L. (commonly known as Diyu) has been studied for its various pharmacological effects, including its antibacterial, antitumor, antioxidant, and anti-inflammatory activities. In the present study, primary cultured vascular endothelial cells (HUVECs) and isolated phenylephrine-precontracted rat thoracic aortic rings were examined to investigate the possible mechanism of a butanol extract of Diyu (BSO) in its vascular relaxant effect. HUVECs treated with BSO produced a significantly higher amount of nitric oxide (NO) compared to the control. However, its production was inhibited by pretreatment with N^G-nitro-L-arginine methylester (L-NAME) or wortmannin. BSO also increased the phosphorylation levels of endothelial nitric oxide synthase (eNOS) and Akt. In the aortic ring, BSO relaxed PE-precontracted rat thoracic aortic rings in a concentration-dependent manner. The absence of the vascular endothelium significantly attenuated BSO-induced vasorelaxation. The non-selective NOS inhibitor, L-NAME, and the selective inhibitor of soluble guanylyl cyclase (sGC), 1H-[1,2,4]-oxadiazolo-[4,3-α]-quinoxalin-1-one (ODQ), dramatically inhibited the BSO-induced relaxation effect of the endothelium-intact aortic ring. Ca²⁺-free buffer and intracellular Ca²⁺ homeostasis regulators (TG, Gd³⁺, and 2–APB) inhibited BSO-induced vasorelaxation. In Ca²⁺-free Krebs solution, BSO markedly reduced PE-induced contraction. Vasodilation induced by BSO was significantly inhibited by wortmannin, an inhibitor of Akt. Pretreatment with the non-selective inhibitor of Ca²⁺-activated K⁺ channels (K_Ca), tetraethylammonium (TEA), significantly attenuated the BSO-induced vasorelaxant effect. Furthermore, BSO decreased the systolic blood pressure and heart rate in a concentration-dependent manner in rats. In conclusion, BSO induces vasorelaxation via endothelium-dependent signaling, primarily through the activation of the PI3K-Akt-eNOS-NO signaling pathway in endothelial cells, and the activation of the NO-sGC-cGMP-K⁺ channels pathway in vascular smooth muscle cells. Additionally, store-operated Ca²⁺ entry (SOCE)-eNOS pathways and the inhibition of Ca²⁺ mobilization from intracellular stores contribute to BSO-induced vasorelaxation. Full article

Objectives: The aim of this study was to provide a comprehensive overview of the nutritional and toxicological aspects of different forms of blueberry products (fresh blueberries, dried blueberries, supplements and herbal teas). Methods: Twelve aglycone and glycoside polyphenolic compounds, such as stilbenoids (resveratrol, astringin), flavonols (quercetin, rutin, isoquercitrin, quercitrin, kaempferol), flavanols (catechin, epicatechin), flavanone (hesperitin), flavone (luteolin), and forty chemical elements were analyzed using high-performance liquid chromatography coupled to a mass spectrometer and inductively coupled plasma mass spectrometry. Total phenolic and flavonoid content and antioxidant activity were also evaluated. Results: Different distributions of polyphenolic compounds were observed in the blueberry samples, with quercetin and its derivatives, as well as catechin and epicatechin, present in all samples. High concentrations of Ca, K, Mg and P (10–5800 mg/kg) were detected, followed by Fe and Mn at levels below the allowable limits in foods (425 and 500 mg/kg, respectively). The daily intake of polyphenols was quantified, and the estimated daily intake (EDI) was calculated for sixteen elements (including As, Cd, Cu, Fe, Ni, Pb, V and Zn). Hazard quotients (HQs), hazard index (HI) and cancer risk (CR) were assessed for carcinogenic and non-carcinogenic risks associated with the EDI of these elements in food products for both adults and young consumers. For all samples, HI values were below 1, and CR values were within acceptable limits. Conclusions: The diversity in polyphenolic profiles and elemental content in blueberry-based products was highlighted by this exploratory study. These findings are valuable for understanding the health benefits and risks of blueberry products. Full article

Atopic dermatitis is caused by various factors, including complex interactions between immune responses and imbalances in T helper cells. In order to resolve the side effects of steroid-based treatment and rapidly improve atopy symptoms, the development of preventive substances for new treatments and as food supplements is essential. Pulsatilla koreana Nakai (PKN) is traditionally used as an effective herbal medicine for pain relief, anti-inflammation, and edema, and dried PKN is boiled and drunk as a tea to prevent them; however, its effect on skin manifestations such as atopy are unclear. Therefore, we investigated the in vivo and in vitro effects of PKN extract on improving symptoms of atopy as a potential treatment. By evaluating dermatitis scores and conducting histopathological analysis in mice with Dermatophagoides farina-induced atopy-like pathology, we demonstrated that PKN extract alleviated atopy symptoms. Moreover, PKN extract restored a reduction in the protein levels of skin barrier-related factors in skin tissue. Through in vitro analysis, we examined the impact of PKN on JAK/STAT signaling in IL-4/IL-13-stimulated human keratinocytes and elucidated the mechanisms that suppress the levels of skin barrier factors and inflammation. PKN extract inhibited JAK/STAT phosphorylation stimulated by IL-4/IL-13. Furthermore, docking analysis of PKN constituents indicated binding to JNK1/2 and STAT3/6 and a subsequent inhibition of signal transduction. Therefore, this suggests that PKN extract has potential not only as a treatment but also as a food supplement to improve atopic dermatitis by strengthening skin barrier factors and inhibiting key signaling molecules. Full article

Paulownia leaves and flowers have been used to prepare medicinal tea in traditional Chinese medicine; however, there has been no scientific validation of bioactive compounds so far. A systematic study is presented to establish a suitable drying protocol for leaf and flower tissues that may be useful in preserving bioactive compounds and retaining high antioxidant capacity. Additionally, a suitable drying protocol is commercially imperative for improving the shelf life of these tissues. In this study, P. elongata and P. fortunei juvenile leaves and flowers at two stages (pre- and post-anthesis stages) were subjected to five drying treatments to study the drying characteristics and were analyzed for total polyphenols, total flavonoids, and antioxidant capacity. Oven drying, sun drying, shade drying, freeze drying, and microwave drying were the five drying methods that were used to evaluate their efficacy on the drying characteristics and antioxidant potential. Fresh and dried tissues were analyzed for total polyphenols, total flavonoids, total tannins, total catechins, total monomeric anthocyanins, and total antioxidant capacity. A strong correlation was observed between the moisture content and total polyphenols (the lower the moisture content, the lower the polyphenols). Sun drying was the best method for Paulownia tissues based on color retention, moisture content, overall cost effectiveness, time, and antioxidant capacity. Shade drying was the second-best method based on the same parameters. No significant differences were observed between P. elongata and P. fortunei tissues in their total antioxidant capacity. Leaves and flowers at the pre-anthesis stage (stage 6) registered a higher level of total polyphenols, flavonoids, tannins, catechins, and resultant antioxidant capacity in comparison with flowers at stage 9 (the post-anthesis stage). Monomeric anthocyanins were highest in P. elongata flowers at stage 6. A strong correlation was observed between moisture content and the antioxidant levels of Paulownia tissues. Full article

The purpose of this paper is to determine the level of polycyclic aromatic hydrocarbons (PAHs) from medicinal plants and infusions prepared using them, as well as assess the transfer of these contaminants from plants to infusions. The separation of compounds was achieved using microwave extraction for dried plants and liquid–liquid extraction in the case of infusions. The extracts were cleaned using solid-phase extraction, and the compounds were analysed using gas chromatography coupled with mass spectrometry (GC-MS). Exposure to PAHs through tea infusion consumption was evaluated by calculating the estimated daily intake (EDI, ng/kg.bw/day) and Margin of Exposure (MOE). The average total content of PAHs varied from 277.22 ± 12.78 to 2466.46 ± 203.45 µg/kg in dry plants, and the compounds benzo[b]fluoranthene (BbF) and benzo[a]pyrene (BaP) were present in all samples. In the herbal tea infusions, the average total PAH content varied between 612.55 ± 46.12 ng/L and 2292.2 ± 140.24 ng/L. The observation was statistically checked using a two-sample paired test. The analysis revealed that PAHs could be split into those for which the content in the medicinal plants is significantly larger than in the infusions and those for which the difference is not significant. The average transfer rates of ∑16PAHs from plants to infusions varied from 7.25 to 32.86%. The MOE values confirmed that consumer exposure to PAHs via tea infusions is very low and safe for health. Full article

Catechins are pivotal determinants of tea quality, with soil environmental factors playing a crucial role in the synthesis and accumulation of these compounds. To investigate the impact of changes in tea garden soil environments on the catechin content in sun-dried tea, this study measured the catechin content in soil samples and corresponding tea leaves from Nanhua, Yunnan, China. By integrating the variations in catechin content with those of 17 soil factors and employing COX regression factor analysis, it was found that pH, organic matter (OM), fluoride, arsenic (As), and chromium (Cr) were significantly correlated with catechin content (p < 0.05). Further, using the LASSO regression for variable selection, a model named LCLN-CA was constructed with four variables including pH, OM, fluoride, and As. The LCLN-CA model demonstrated high fitting accuracy with AUC values of 0.674, 0.784, and 0.749 for catechin content intervals of CA ≤ 10%, 10% < CA ≤ 20%, and 20% < CA ≤ 30% in the training set, respectively. The validation set showed AUC values of 0.630, 0.756, and 0.723, respectively, indicating a well-calibrated curve. Based on the LCLN-CA model and the DynNom framework, a visual prediction system for catechin content in Yunnan sun-dried tea was developed. External validation with a test dataset achieved an $Accuracy$ of 0.870. This study explored the relationship between soil-related factors and variations in catechin content, paving a new way for the prediction of catechin content in tea and enhancing the practical application value of artificial intelligence technology in agricultural production. Full article

Post-fermented Pu-erh tea (PFPT) is a microbial fermented tea characterized by unique sensory attributes and multiple health benefits. Aspergillus niger is the dominant fungus involved in the fermentation process and plays a significant role in imparting the distinct characteristics of PFPT. To investigate the role of Aspergillus niger in the fermentation of Pu-erh tea, this study inoculated unsterilized sun-dried green tea with Aspergillus niger isolated from Pu-erh tea to enhance the fermentation process. Metabolites and microbial communities in sun-dried green tea (CK), fortified fermented tea (TF), and naturally fermented tea (NF) were analyzed using non-targeted metabolomics, 16S rDNA, and internal transcribed spacer sequencing. Non-targeted metabolomics revealed that Aspergillus niger significantly altered the metabolite profile of the tea samples, identifying a total of 200 different metabolites, with 95 showing significant increases and 105 significant decreases, predominantly enriched in metabolic pathways associated with amino acid biosynthesis and degradation. High-throughput sequencing revealed that although the relative abundance of the fungal community remained largely unchanged, the inoculation of Aspergillus niger significantly increased the abundance of Bacillales and Pseudomonas within the bacterial community, thereby influencing the dynamic balance of the microbial ecosystem. Collectively, the inoculation of Aspergillus niger altered the composition of the microbial community and metabolic activities, resulting in changes to the content of amino acid-dominated metabolites, thereby enhancing the flavor profile and overall quality of Pu-erh tea. These findings provide important insights for optimizing the production processes of Pu-erh tea and the application of microorganisms in other fermented foods. Full article

Dry tea residue is a byproduct generated during the production, processing, and storage of tea leaves. The active ingredients and microbial composition of dried tea residue vary depending on different tea processing techniques. This study investigated the effects of six processed dry tea residues—green tea (G), black tea (B), raw Pu’er tea (Z), white tea (W), and ripe Pu’er tea (D)—at two addition ratios (5% and 10%) on the nutritional composition, fermentation quality, in vitro fermentation, and bacterial community of sweet sorghum (Sorghum bicolor) in the ensiling process. Compared to the control group (CK), the addition of tea residue significantly increased the crude protein (CP) content in silage by 17.9% to 180% (p < 0.05), and the content increased with increasing ratios of tea residue. The G10 treatment resulted in the highest CP content, reaching 16.4%. Including tea residue also influenced the ratio of ammonia nitrogen (NH₃-N) to non-protein nitrogen (NPN). Furthermore, the G and Z treatments at both addition levels increased the total phenolic content, DPPH free-radical scavenging activity, and total antioxidant capacity of the sweet sorghum silage. Except for the Z5 and W10 treatments, the addition of tea residue did not significantly affect in vitro dry matter digestibility. Overall, this study showed that incorporating tea residue could enhance the nutritional quality and antioxidant capacity of sweet sorghum silage, and the G5 treatment performed the best. The research results suggested that dried tea residues have potential as silage additives. Full article

Chloranthus spicatus is one of the main scented tea varieties cultivated mainly in the Huangshan region, and dried flowers of these plants are mainly used for imparting a characteristic aroma to the tea. However, climatic variations in Huangshan limit its cultivation, with water deficit (WD) being the main limiting factor. The present study evaluated the effects of different WD intensities on the growth and physiological parameters of C. spicatus seedlings to determine the optimal soil moisture content for their large-scale cultivation. The experimental design comprised a control group (95–100%) and three treatment groups, namely mild WD (75–80%), moderate WD (55–60%), and severe WD (35–40%). Each treatment lasted 45 days and was given to 10 potted C. spicatus seedlings, with 3 replicates. Measurements were conducted for the shoot length and diameter; biomass; photosynthesis parameter; activities of antioxidant enzymes, namely superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT); and soluble protein (SP) and malonylaldehyde (MDA) contents of the seedlings. The results indicated that mild and moderate WD positively affected C. spicatus seedlings in terms of shoot length, diameter, biomass, root/shoot ratio, photosynthesis rate, intercellular CO₂ concentration, water use efficiency, and carboxylation efficiency. Moreover, the growth and photosynthesis were increased in the mild and moderate WD seedlings but decreased in the severe WD seedlings. Mild and moderate WD also led to a significant decrease in the antioxidant enzyme activities and the MDA content of seedlings (p < 0.05), all of which exhibited higher levels in severe WD seedlings. These results indicated that severe water stress restricted the growth of seedlings, while mild and moderate stress proved beneficial. SP content of the seedlings increased under mild and moderate WD but decreased under severe WD. We infer that the strong hydrophilicity of SPs in the seedlings results in the accumulation of water in plant cells, thus conferring resistance to drought stress. In conclusion, reducing the soil moisture content by 55–80% in the Huangshan region may be a promising strategy for boosting its cultivation. Full article

Bacterial cellulose (BC) is a biodegradable polymer resembling paper after being dried. It finds a growing number of applications in many branches of industry and in medicine. In the present study, BC was produced after Gluconacetobacter hansenii ATCC 23769 strain culture and used as a matrix for plant extracts (tulsi, brahmi, lemon, blackberry, nettle root, and nettle leave) and essential oils (cinnamon, sage, clove, mint, thyme, lemongrass, rosemary, lemon, anise, tea tree, lime, grapefruit, and tangerine), and the antimicrobial properties of these biomaterials was determined. The growth-inhibiting effects of plant extracts and essential oils combined with BC were analyzed against five Cronobacter species isolated from food matrix and two reference strains from the ATCC (513229 and 29544). Additional analyses were conducted for BC water activity and for its capability to absorb biologically active plant compounds. The cellulose matrix with a 50% extract from brahmi was found to effectively inhibit the growth of the selected Cronobacter strains. The other plant water extracts did not show any antimicrobial activity against the tested strains. It was demonstrated that BC soaked with thyme essential oil was characterized with the strongest antimicrobial activity in comparison to the other tested EOs. These study results indicate the feasibility of deploying BC impregnated with natural plant components as an active and environmentally-friendly packaging material. Full article

Introduction: The therapeutic effect of different doses of the traditional aqueous extract of dried leaves of yerba mate (Ilex paraguariensis A. St.-Hil.) was investigated in an experimental cataract model in chicken embryos. Methods and Results: LC-MS/MS analysis allowed the identification and quantification of 53 metabolites. In the hydrocortisone-induced cataract model, lenses were examined morphologically after treatment and parameters related to oxidative stress (total antioxidant/oxidant status (TAS/TOS), glutathione (GSH), and malondialdehyde (MDA)) were evaluated. Antiproliferative cell nuclear antigen (PCNA) and caspase-3 H-scores were determined and crystallin alpha A (CRYAA) gene expression in the lenses was measured by RT-PCR. The degree of cataract decreased in all treatment groups. While there was no significant difference in TAS levels compared to the negative control, TOS, GSH, and MDA levels were dose-dependently regulated. Treatment groups other than the high-dose group regulated the decrease in PCNA and the increase in caspase-3. CRYAA gene expression increased significantly only at the lowest dose. Conclusion: YM, which is becoming increasingly popular as a traditional tea, showed a therapeutic effect on hydrocortisone-induced cataracts in chicken embryos at relatively low doses. Full article