Search Results (147)

To explore the taste characteristics and flavor characteristics of Baiyun 0492 white tea, Fuyun 6 was used as a comparison to describe and analyze the taste of the tea by the standard tea sensory evaluation method and quantitative descriptive analysis. A total of 1083 nonvolatile metabolites were identified by ultrahigh-performance liquid chromatography and mass spectrometry (UPLC–MS–MS). N-Feruloyl tyramine, with strong biological activity, may be the specific metabolite of Baiyun 0492 white tea, and 3,4,5-tricaffeoylquinic acid, with a bitter taste, may be the specific metabolite of Fuyun 6 white tea. Most of the different metabolite contents were negatively correlated with the Baiyun 0492 and Fuyun 6 white tea grades. KEGG metabolic pathway analysis showed that Baiyun 0492 and Fuyun 6 white teas had higher enrichment levels of flavonoids, caffeine, amino acids and carbohydrate-related metabolic pathways. Correlation analysis using widely targeted metabolomics and quantitative taste description showed that most flavonoid differences and some amino acid and phenolic acid differences were significantly positively correlated with bitterness and astringency, including quercetin-3-o-rhamnoside (quercetin), L-arginine, 3,4,5-tricaffioylquinic acid, and neochlorogenic acid. Some soluble sugars were positively correlated with sweetness, including D-maltose and D-sucrose, which were the key taste components of Baiyun 0492 and Fuyun 6. These metabolites may be responsible for the taste characteristics of Baiyun 0492, which is characterized as sweet and mellow, while the taste of Fuyun 6 is mainly mellow. In this study, a wide range of targeted metabolomics techniques were used to screen out different metabolites related to the quality of Baiyun 0492 and Fuyun 6 white teas, providing a reference for clarifying the quality characteristics of Baiyun 0492. Full article

Background/Objectives: Gestational diabetes mellitus (GDM) is a major pregnancy complication with rising global prevalence. The Mediterranean Diet (MD) has shown metabolic benefits, but total adherence scores may obscure meaningful variation in dietary quality. This study aimed to investigate whether specific dietary patterns, identified within the MD framework, and their glycemic load (GL) are associated with GDM risk. Methods: This prospective cohort is part of the BORN2020 longitudinal study on pregnant women in Greece; dietary intake was assessed using a validated food frequency questionnaire (FFQ) at two time points (pre-pregnancy and during pregnancy). MD adherence was categorized by Trichopoulou score tertiles. GL was calculated for food groups using glycemic index (GI) reference values and carbohydrate content. Dietary patterns were identified using factor analysis. Logistic regression models estimated adjusted odds ratios (aORs) for GDM risk, stratified by MD adherence and time period, controlling for maternal, lifestyle, and clinical confounders. Results: In total, 797 pregnant women were included. Total MD adherence was not significantly associated with GDM risk. However, both food-specific GLs and dietary patterns with distinct dominant foods were predictive. GL from boiled greens/salads was consistently protective (aOR range: 0.09–0.19, p < 0.05). Patterns high in tea, coffee, and herbal infusions before pregnancy were linked to increased GDM risk (aOR = 1.96, 95% CI: 1.31–3.02, p = 0.001), as were patterns rich in fresh juice, vegetables, fruits, legumes, and olive oil during pregnancy (aOR = 2.91, 95% CI: 1.50–6.24, p = 0.003). A pattern dominated by sugary sweets, cold cuts, animal fats, and refined products was inversely associated with GDM (aOR = 0.34, 95% CI: 0.17–0.64, p = 0.001). A pattern characterized by sugar alternatives was associated with higher risk for GDM (aOR = 4.94, 95% CI: 1.48–19.36, p = 0.014). These associations were supported by high statistical power (power = 1). Conclusions: Within the context of the MD, evaluating both the glycemic impact of specific food groups and identifying risk-associated dietary patterns provides greater insight into GDM risk than overall MD adherence scores alone. Full article

The characteristic minty-like aroma of ‘Rucheng Baimaocha’ black tea (RCBT) enhances the tea’s unique flavor profile, driving high demand among consumers. The dynamic changes in key aroma compounds in minty-like RCBT were elucidated by sensory evaluation and gas chromatography olfactometry quadrupole time of flight mass spectrometry (GC × GC-O-Q-TOF-MS). The results indicated that during processing, the aroma of RCBT transitions from a fresh to floral, sweet, and minty-like aroma. Among the 189 identified volatile compounds, alcohols constitute the predominant category (over 50%), with 71 compounds identified as key differential compounds across all stages. Aroma analysis revealed that 28 compounds with odor activity values (OAV) > 1 were the primary contributors during RCBT processing. Notably, minty-like odorants in RCBT were primarily derived from the metabolic pathways of the methylerythritol phosphate (MEP) and mevalonic acid (MVA), lipid oxidation, and phenylalanine. These findings offer theoretical insights for improving unique black tea quality and optimizing processing techniques. Full article

China is the place of origin and main producer of black tea worldwide, with Dianhong (DH), Chuanhong (CH), and Keemunhong (KH) being the famous Chinese black teas. The contents of various odor components in black teas differ with their origins. However, the effects of these differences on the presentation of distinctive odor characteristics in various products remain unclear. We aimed to elucidate the odor characteristics and odor compounds of these three black teas; to this end, we performed a sensory evaluation and multivariate statistical analysis based on comprehensive two-dimensional gas chromatography–mass spectrometry (GC×GC-MS) results. The sensory evaluation revealed that the odor characteristics of DH were floral and fruity, whereas sweet and herbal-like odors were more intense in CH and QH. A total of 119 volatile compounds were detected, with alcohols, aldehydes, and esters being the main volatile compounds. Among them, 41 volatile compounds were identified with an odor activity value (OAV) of >1, and 24 of them were selected through principal component analysis, hierarchical cluster analysis, and orthogonal partial least squares discriminant analysis as marker substances to distinguish the three teas; thus, 24 volatile compounds are important odor compounds of DH, CH, and QH. Full article

The development of black tea quality is the outcome of the synergistic interaction between tea cultivars and the ecological environment of the production area, including factors such as climate, soil, and cultivation practices. Nevertheless, within a specific geographical region, systematic analysis of the environmental regulation mechanisms governing processing adaptability and quality formation among different cultivars remains insufficient. This study evaluated six Camellia sinensis cultivars from the Jingshan region of Hangzhou, China, integrating non-targeted metabolomics, sensory profiling, bioassays, and molecular docking to elucidate cultivar-specific quality attributes. Non-volatile metabolomics identified 84 metabolites linked to color and taste, including amino acids, catechins, flavonoid glycosides, and phenolic acids. Sensory and metabolite correlations revealed that amino acids enhanced brightness and imparted fresh-sweet flavors, while catechins contributed to bitterness and astringency. Specific metabolites, such as 4-hydroxybenzoyl glucose and feruloyl quinic acid, modulated color luminance. Volatile analysis identified 13 aroma-active compounds (OAV ≥ 1), with 1-octen-3-ol, phenylacetaldehyde, and linalool endowing JK with distinct floral-fruity notes. Molecular docking further demonstrated interactions between these volatiles and olfactory receptors (e.g., OR1A1 and OR2J2), providing mechanistic insights into aroma perception. These findings establish a robust link between cultivar-driven metabolic profiles in black tea, offering actionable criteria for cultivar selection and quality optimization in regional tea production. Full article

Summer green tea often suffers from an inferior flavor, attributed to its bitterness and astringency. In this study, an integrated shaking and piling process was performed to improve the flavor of summer green tea. The results demonstrated a significant improvement in the sweet and kokumi flavors, accompanied by a reduction in umami, astringency, and bitterness following the treatment. Additionally, the yellowness and color saturation were also enhanced by the treatment. A total of 146 non-volatile metabolites (NVMs) were identified during the study. The elevated levels of sweet-tasting amino acids (L-proline, L-glutamine, and L-threonine), soluble sugars, and peptides (such as gamma-Glu-Gln and glutathione) contributed to the enhanced sweetness and kokumi. Conversely, the decreased levels of ester-catechins, flavonoid glycosides, and procyanidins resulted in a reduction in umami, astringency, and bitterness. Furthermore, the decreased levels of certain NVMs, particularly ascorbic acid and saponarin, played a crucial role in enhancing the yellowness and color saturation of the summer green tea. Our findings offered a novel theoretical framework and practical guidelines for producing high-quality summer green tea. Full article

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

Background:Sweet Tea (Lithocarpus polystachyus Rehd.), a traditional ethnobotanical medicine, contains phlorizin, a dihydrochalcone compound with antioxidative and anti-inflammatory properties. Given the critical role of oxidative stress and inflammation in age-related macular degeneration (AMD), this study tested the hypothesis that phlorizin mitigates oxidative damage and inflammation in AMD models, thereby offering therapeutic potential. Materials and Methods: Adult retinal pigmented epithelial cells (ARPE-19) were pre-treated with phlorizin (0.01–0.1 μM) and subjected to oxidative stress induced by ultraviolet A (UVA) radiation or sodium iodate (NaIO₃). Cell viability, reactive oxygen species (ROS) production, MAPK/NF-κB signaling, and the level of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) and pro-angiogenic factors (VEGF, MMP2, MMP9) expression were assessed using MTT assays, fluorescence imaging, Western blotting, and RT-qPCR. In vivo, a laser-induced choroidal neovascularization (CNV) mouse model was used to evaluate phlorizin’s effects on CNV formation and vascular leakage via fundus photography and fluorescence angiography. Result: Phlorizin significantly enhanced cell viability, reduced ROS production, inhibited MAPK/NF-κB activation, and downregulated inflammatory and angiogenic mediators. In vivo studies confirmed the reduced CNV formation and vascular leakage following the phlorizin treatment. Conclusions: Phlorizin demonstrated significant protective effects against oxidative stress and inflammation, highlighting its therapeutic potential for treating AMD. Full article

Leaf-vegetable sweet potatoes incurred significant losses during storage, which resulted in a shortened shelf life and reduced commercial value. This study investigated the effects of tea polyphenols (TPs) fumigation and microporous packaging (MP) during 10 days at 10 °C and 90–95% RH. The results indicated that the preservation effects followed the order TP + MP > MP > TP > CK, with the TP + MP treatment effectively controlling the degradation rate of chlorophyll and delaying leaf yellowing. In addition, TP + MP treatment increased the activity of antioxidant enzymes, especially catalase (CAT) and ascorbate peroxidase (APX), and also enhanced non-enzymatic systems (flavonoids, total phenolics, and ascorbic acid). Pearson’s correlation analysis showed a positive correlation between the decline in postharvest quality of leaf-vegetable sweet potatoes and the increase in reactive oxygen species (ROS) levels. This study provided a robust theoretical and technical foundation for the development of effective postharvest preservation strategies for leaf-vegetable sweet potatoes. Full article

Active packaging using an edible coating could be an essential and sustainable alternative solution to preserve the properties of fruits and to prevent food loss and food waste. Fruits generate significant food wastes and losses. Reducing food waste is a global priority. For this research, nature-based solutions (NBSs) were applied, using micro-sized chitosan (CsMPs) and selenium microparticles (SeMPs), which are green-synthesized from black tea leaf extracts, and thyme essential oil. In this study, the effects of the new generation active food preservative coating agents formed from combinations of micro-sized chitosan (CsMPs) and selenium (SeMPs), and thyme essential oil (Oil) on the quality of “0900 Ziraat” sweet cherry fruits after harvest were investigated. After the fruits were coated with edible colloid solution, they were stored at 4 °C and 21 °C for 20 days, and quality parameter analyses were performed on days 0, 5, 10, 15, and 20. As a result of this study, it was determined that the application of CsMPs + SeMPs and the subsequent application of CsMPs + SeMPs + Oil from colloid solution coatings reduced weight loss, respiration, and decay rates. Also, it was determined that these applications were the most effective in preserving color values (L*, chroma, and hue), fruit firmness, total soluble solid (TSS) amount, acidity content and total phenolics, anthocyanin, and antioxidant capacity. These results show that CsMPs + SeMPs and CsMPs + SeMPs + Oil applications can be used as edible coatings to preserve the quality of sweet cherry fruits and extend their shelf life after harvest. This study’s results will contribute to obtaining micro-sized composite coating agents/agents produced with new technology to extend the shelf life. Full article

Objectives: Hydration is essential for overall health; therefore, this study aimed to identify associations between hydration status and beverage consumption, anthropometric measures, and urine biochemical analyses in Polish adults. Poland was chosen due to potential regional dietary habits and hydration patterns that may influence hydration status. Methods: A total of 337 participants completed a beverage frequency questionnaire (FFQ). Blood pressure (BP), anthropometric parameters, and body composition were measured. Urine samples were analyzed for specific gravity (USG), osmolality (Uosm), and potential hydrogen value (pH). Hydration status was assessed using the WUT model (weight, urine color, thirst level), classifying participants into two groups: dehydrated (2-3 WUT components) and properly hydrated (0-1 WUT component). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Results: Approximately 50% of participants (n = 165) exhibited dehydration symptoms, including higher thirst levels, darker urine, and elevated USG and Uosm (p ≤ 0.05). Dehydrated individuals more frequently reported fatigue (p = 0.009), headaches (p = 0.024), and heavy legs (p = 0.002). Higher BMI (OR: 1.49), waist circumference (OR: 1.79), USG (OR: 2.29), and Uosm (OR: 1.75) increased dehydration risk. Conversely, greater consumption of tea (OR: 0.52) and non-carbonated mineral water (OR: 0.45), higher total body water (OR: 0.49), and handgrip strength (OR: 0.81) were linked to lower dehydration risk. Four dietary patterns were identified: Reasonable, Unhealthy, Minimalist, and Loving Sweet Beverages. Conclusions: Multifactorial hydration assessment, combined with preventive strategies such as regular fluid intake and weight management, may improve hydration. The WUT model and Venn diagram provide a practical tool for hydration assessment in clinical and public health. Full article

The present study investigated the dynamics changes in physicochemical properties and non-volatile metabolites during Bulang pickled tea fermentation. A combination of artificial sensory evaluation, chemical-physical analysis, ultra performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UPLC-QTOF-MS), and multivariate statistical analysis were employed to examine the differences among four fermentation stages of Bulang pickled tea. The bitterness, astringency, sweetness after taste, sourness and fermentation taste tended to increase with fermentation. The highest lactic acid bacteria, aerobic bacteria, total titratable acidity, total soluble sugar, total polyphenols, and total flavonoids were recorded at the second month of fermentation, while fungi, total free amino acids, total antioxidant capacity and hydroxyl free radical scavenging capacity increased with fermentation. Mantel test demonstrated significant associations between lactic acid bacteria /fungal communities and taste characteristics. UPLC-QTOF-MS analysis led to the identification of 35 differential non-volatile metabolites, predominantly comprising heterocyclic compounds, organic acids with their derivatives, and flavonoids. Nine non-volatile metabolites are related to antioxidant activity, and morin, malvidin and 7-methylxanthine exhibit relatively strong antioxidant activity. This study provides comprehensive insights into the non-volatile metabolites and antioxidant function of Bulang pickled tea. Full article

To develop and utilize Folium Artemisia argyi (FAA) tea resources, UPLC-MS/MS, HS-GC-IMS, and HS-SPME/GC×GC-TOFMS were adopted to analyze its volatile and non-volatile compounds, when harvested from March to June, in combination with its antioxidant activity. Here, 1742 volatile compounds and 8726 non-volatile compounds were identified, with 75 differential volatile metabolites and 36 key flavor compounds screened. Notably, 1-octen-3-one, (E)-2-octenal, (E)-2-undecenal, and heptanal were identified as major contributors to the sweet, fruity, green, and herbal aromas, and the concentration of them was highest in June-harvest FAA tea. Furthermore, metabolomics revealed that there were 154 non-volatile differential metabolites in FAA tea at four harvest times, which were mainly related to amino acid biosynthetic pathways. Samples harvested in June also showed the strongest antioxidant capacity, which was positively correlated with D-xylitol, L-glutamic acid, honokiol, and costunolide. These findings highlight June as the optimal harvest time, providing FAA tea with superior flavor and enhanced antioxidant properties, underscoring its potential as a valuable resource for functional food development. Full article

To investigate the flavour evolution mechanism of raw Pu-erh tea (RPT) during storage, the volatile and non-volatile compounds of RPT with different storage years (1–10 years) from the same raw material origin, manufacturer, and storage location in Wenshan Prefecture, Yunnan Province, were systematically analysed by HPLC, HS-SPME-GC-MS, and OAV. The results showed that both cluster analyses based on non-volatile and volatile compounds could classify RPT of different storage years into three ageing cycles, with key turning points in the third and eighth years of storage, which is also accompanied by the colour changing from green to orange or brown, the aroma changing from a faint scent to woody and ageing, the astringency diminishing, and the sweet and mellow increasing. Theophylline was identified as the potential marker of RPT stored 1–3 years, while (−)-catechin gallate, (−)-gallocatechin gallate, quercetin, and rutin as those for a storage of 9–10 years. The volatile compounds indicate a general trend of an initial increase followed by a decrease. Forty-four key aroma compounds (OAV ≥ 1) were identified. Eucalyptol, β-Caryophyllene, 2-Amylfuran, Copaene, Estragole, and α-Terpinene originated as potential markers for RPT stored 1–3 years, while (Z)-Linalool oxide (furanoid), α-Terpineol, Terpinen-4-ol, and cis-Anethol were for RPT stored 8–10 years. This study revealed the flavour characteristics and quality changes of RPT over the course of storage, and constructed a sensory flavour wheel, providing theoretical underpinnings for the quality control and assessment of RPT. Full article