查找使用阿拉丁产品的科研文献

Improving the utilization of summer tea leaves through steam explosion technology: flavor transformation and cold-brewing feasibility

Daoliang Wang,Zhibin Liu,Weiying Su,Yuan Lu,Xiaoxiao Feng,Yuan Liu,Jinsu Lin,Bo Wen,Meijuan Xiao,Li Ni

Summer tea leaves, characterized by thick cell walls, low aroma, and strong bitterness, are generally considered unsuitable for high-quality tea production. This study investigated the potential of steam explosion technology (SET), which exposes the leaves to high-pressure steam followed by rapid depressurization, for processing these leaves. Under optimal condition (0.6 MPa, 180 s), SET led to significant cell wall disruption, enhancing the release of polyphenols. Sensory analysis showed that steam-exploded tea achieved a flavor profile comparable to white tea made from spring leaves. GC–MS analysis revealed markedly increased extraction of desirable volatile compounds. UPLC-QTOF-MS confirmed that reductions in flavanols, phenolic acids, and caffeine (by up to 15.61 % ∼ 35.28 %) contributed directly to reduced bitterness. Furthermore, steam-exploded tea was suitable for cold-water brewing, achieving high extraction rates of key compounds compared to hot-water brewed tea. These findings highlight SET as a sustainable solution for enhancing summer tea quality and usability.

Metabolomics and sensory evaluation analyses for determining the effect of grades on taste quality of Liupao tea

Li Ya,Lu Mingfei,Pan Yuhua,Liang Jianfeng

In order to investigate characteristic marker metabolites and their grade-dependent variations in Liupao tea, non-volatile compounds from four grades of Liupao tea were analysed by combining sensory evaluation with UPLC-Q-TOF-MS based untargeted metabolomics. Sensory evaluation revealed that decreasing Liupao tea grade was accompanied by reduced stale flavour, gradual increases in bitterness and astringency, and an overall deterioration of sensory quality. In total, 4 099 non-volatile compounds were detected, of which 181 metabolites were common across all four grades. 14 significantly differential metabolites, including EC, EGC and L-theanine, displayed regular grade-related changes with Pearson correlation coefficients of |r| ≥ 0.7. Multivariate statistical analysis confirmed strong correlations between these 14 key compounds and both tea grade and sensory attributes. A PLS regression model built upon the 14 markers achieved an internal fitting R²of 0.9929. It should be noted that this model was trained solely on samples originating from a single tea garden, multi-sample external validation is required to verify its generalisability. This study provides theoretical references for unravelling flavour differences among differently graded Liupao tea.

Long effective tea tree oil/mesoporous silica sustained release system decorated by polyethyleneimine with high antibacterial performance

Huayao Chen,Zhichuan Shen,Peiting Wu,Hongjun Zhou,Li Hao,Hua Xu,Xinhua Zhou

Pyruvate is modified by tea/coffee metabolites and reversely correlated with multiple system atrophy and Parkinson's disease

Xu-Ying Li,Teng Xue,Hong Lai,Jing Dai,Fangda Peng,Fanxi Xu,Junge Zhu,Xian Li,Junya Hu,Wei Li,Raoli He,Lina Chen,Ying Chen,Chunguang Ding,Guoguang Zhao,Xianyang Chen,Qinyong Ye,Zhiheng Xu,Chaodong Wang

Introduction Multiple system atrophy (MSA) is a rapidly progressing neurodegenerative disorder. Although diverse biomarkers have been established for Parkinson's disease (PD), no widely accepted markers have been identified in MSA. Pyruvate and lactate are the end-product of glycolysis and crucial for brain metabolism. However, their correlation with MSA remains unclear. Moreover, it is elusive how lifestyles modify these metabolites. Methods To investigate the correlation and diagnostic value of plasma pyruvate and lactate levels in MSA and PD. Moreover, we explored how lifestyle-related metabolites interact with these metabolites in determining the disease risk. We assayed the 3 metabolites in pyruvate/lactate and 6 in the tea/coffee metabolic pathways by targeted mass spectrometry and evaluate their interactions and performance in diagnosis and differentiation between MSA and PD. Results We found that 7 metabolites were significantly different between MSA, PD and healthy controls (HCs). Particularly, pyruvate was increased in PD while significantly decreased in MSA patients. Moreover, the tea/coffee metabolites were negatively associated with the pyruvate level in HCs, but not in MSA and PD patients. Using machine-learning models, we showed that the combination of pyruvate and tea/coffee metabolites diagnosed MSA (AUC = 0.878) and PD (AUC = 0.833) with good performance. Additionally, pyruvate had good performance in distinguishing MSA from PD (AUC = 0.860), and the differentiation increased (AUC = 0.922) when combined with theanine and 1,3-dimethyluric acid. Conclusions This study demonstrates that pyruvate correlates reversely with MSA and PD, and may play distinct roles in their pathogenesis, which can be modified by lifestyle-related tea/coffee metabolites.

Sensory-directed flavor analysis reveals the improvement in aroma quality of summer green tea by osmanthus scenting

Yujie Wang,Guojian Deng,Lunfang Huang,Jingming Ning

Flower scenting is an effective way to enhance the aroma of green tea (GT), including those osmanthus scented green tea (OSGT). However, the mechanism of aroma enhancement by scenting is still unclear. Here, the volatiles of GT, OSGT, and osmanthus were detected by GC–MS. The total volatile content of OSGT was significantly increased compared to GT, with the flowery and coconut aromas enhanced. Furthermore, 17 of 139 volatiles were responsible for the enhancement by GC–olfactometry and their absolute odor activity values (OAVs). Aroma recombination, omission and addition experiments showed that dihydro- β -ionone, (E) - β -ionone, (E, E) -2,4-heptadienal, geraniol, linalool, α -ionone, and γ -decalactone were the key aroma volatiles with flowery or coconut aromas. Additionally, the dynamics of the key volatiles (OAVs >1) from different scenting durations were analyzed, proving that the optimal duration was 6–12 h. This study provides new insight into the mechanism of aroma formation during OSGT production.

Strigolactones Regulate Secondary Metabolism and Nitrogen/Phosphate Signaling in Tea Plants via Transcriptional Reprogramming and Hormonal Interactions

Shuwei Yu,Hao Zuo,Ping Li,Litang Lu,Juan Li,Zhi Zhou,Shancen Zhao,Jianan Huang,Zhonghua Liu,MingZhi Zhu,Jian Zhao

Strigolactones (SLs) are known to regulate plant architecture formation, nitrogen (N) and phosphorus (P) responses, and secondary metabolism, but their effects in tea plants remain unclear. We demonstrated that the application of a bioactive SL analogue GR24 either to tea roots or leaves initially stimulated but later inhibited catechins, theanine, and caffeine biosynthesis. GR24 treatment also promoted the accumulation of flavonols and insoluble proanthocyanidins in a time- and dose-dependent manner. GR24 influenced flavonoid and theanine biosynthesis genes, such as up-regulating CsTT2c, CsMYB12, and CsbZIP1, modulating N-responsive and assimilation genes (CsNRT1,1, CsGSI/TS1, CsHRS1, CsPHR1, CsNLA1, and CsLBD37/38/39), and repressing N/P transport and signaling genes (CsPHO2, CsPHT1s, CsNRT2,2, CsHHO1, and CsWRKY38). GR24-induced changes in secondary metabolites were also observed in the leaves of tea plants. GR24-regulated CsLBD37a interacted with CsTT8a and CsTT2c, repressing catechins biosynthesis by interrupting MBW complex formation. GR24 regulated caffeine biosynthesis and regulator genes CsS40 and CsNAC7 and may thereby suppress caffeine production. GR24 altered the transcriptomic profiles of multiple hormone biosynthesis and signaling genes that potentially regulate tea characteristic metabolism and N/P signaling. This study provides new insights into SL-induced transcriptional reprogramming that leads to changes in N/P nutrition, secondary metabolism, and hormone signaling in tea plants.

Perceptual interactions of key aroma compounds in Fu brick tea: Odor threshold, sensory, and E-nose analysis

Xuexue Zheng,He Xie,Wenjie Fu,Chao Wang,Tengfei Hu,Xingchang Ou,Jian'an Huang,Zhonghua Liu,Qin Li

While extensive research has focused on the flavor of Fu brick tea (FBT), the perceptual interactions among its aromatic components remain unclear. To address this, twenty representative aroma compounds were selected from FBT to determine their thresholds and evaluate their interactions by analyzing threshold changes before and after mixing. The results revealed discrepancies between the determined thresholds and literature values, particularly for α -terpineol, methyl heptenone, and geranylacetone, which demonstrated ratios of 73.54, 6.62, and 6.41, respectively. Mixtures with similar aromas or structures exhibited synergy, whereas those with differing aromas or structures displayed masking effects. Additionally, the odor compound ( E )-nerolidol was added to the tea infusion at a concentration below its threshold level to investigate its impact on the overall aroma perception of FBT through sensory analysis and electronic nose assessments. The findings indicated that sub-threshold compounds could significantly influence the overall aroma profile of FBT.

Tea polyphenol–iron nanocapsules for oxalic acid-triggered delivery of n-butylidenephthalide: a biorational strategy against Sclerotium rolfsii

Rui Zhang,Tongfang Jing,Peng Yi,Kaidi Cui,Leiming He,Xuewei Mao,Yuying Song,Lin Zhou

BACKGROUND Sclerotium rolfsii is a destructive soil-borne fungal pathogen distributed worldwide. Although n -butylidenephthalide (BP) exhibits strong inhibitory activity against S. rolfsii , its agricultural application is hampered by high volatility and poor water solubility. RESULTS To address these barriers, a pathogen-triggered delivery system was engineered using tea polyphenol–iron nanocapsules (TP@Fe NCs). The 277 nm core-shell capsules exhibited enhanced thermal stability and specific responsiveness to S. rolfsii , discharging 86.0% of the cargo under 1.0 m m oxalic acid (OA). In vitro assays confirmed superior bioactivity, with TP@Fe NCs exhibiting a significantly lower median lethal concentration (LC 50 ) of 13.34 mg/L compared to 21.53 mg/L for free BP. In glasshouse trials against peanut southern blight, TP@Fe NCs (300 mg/L) achieved a curative efficacy of 74.68%, significantly outperforming free BP (51.30%). Crucially, the formulation demonstrated excellent biosafety. Peanut seedlings treated with 200–300 mg/L TP@Fe NCs showed no phytotoxicity, maintaining emergence rates of 92.69% and normal root/stem development. Furthermore, acute toxicity tests on zebrafish (4.2–5.0 mg/L) revealed that while 5.0 mg/L free BP caused 100% mortality within 48 h, TP@Fe NCs maintained a > 90% survival rate over 96 h. CONCLUSION This study presents a biorational strategy for precise fungal control and develops an expandable and efficient framework for implementing eco-friendly nanopesticide systems toward sustainable agriculture. © 2026 Society of Chemical Industry.

Molecular mechanism of aroma compounds affecting the flavor of Dixu green tea and their interaction with olfactory receptors

Li Lei,Tian Di,Liu Zhengyi,Huang Yong,Zhang Xingyuan,Zhang Xiuqiong,Feng Ying

To investigate the dynamic changes in volatile organic compounds (VOCs) and their aroma contributions during the processing of Guangnan Dixu green tea, fresh leaves (XY), baked leaves (HQ), rolled leaves (RN), and dried tea (GC) were analyzed by headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS), combined with multivariate statistical analysis, odor activity value (OAV) evaluation, molecular docking, and molecular dynamics simulation. A total of 64 VOCs were identified across the processing stages, including alcohols, aldehydes, esters, ketones, alkanes, alkenes, and other compounds. Among them, 23 compounds showed OAV values > 1, indicating important contributions to the overall aroma profile. Multivariate analysis further identified four key differential aroma compounds in the dried tea, namely β-ionone, linalool, nonanal, and decanal. During processing, marked quantitative changes were observed in representative VOCs. For example, the relative content of Nonanal decreased from 210.69 µg/kg in XY to 53.61 µg/kg in RN, corresponding to a reduction of approximately 74.6%, while the proportion of aldehydes changed from 16.39% (XY) to 9.44% (HQ), then increased to 12.28% (RN) and 13.39% (GC). Molecular docking showed that the key VOCs exhibited favorable binding affinities toward olfactory receptors, with average binding energies ranging from − 4.95 to − 6.65 kcal/mol. Molecular dynamics simulations further demonstrated that the ligand–receptor complexes remained relatively stable over 100 ns, supporting the stability of these interactions. Overall, the results indicate that β-Ionone, linalool, nonanal, and decanal are key contributors to the characteristic aroma of Guangnan Dixu green tea, and that their dynamic changes during processing are closely associated with olfactory receptor interactions.

Standardized processing reconfigures regional raw material differences into distinct aroma-active compound profiles in raw Anhua dark tea

Jing Wang,Jiaqi He,Silei Bai,Yixiong Wang,Hengbin Yao,Xuehui Liu,Junhui He,Anhong Liu,Chao Wang,Zhonghua Liu,Jianan Huang

Fresh leaves from seven regions were processed under identical conditions. • Processing reshaped aroma composition and amplified regional differences. • OAV and multivariate analysis identified 17 region-specific odorants. • Molecular docking suggested different receptor binding capacities among key odorants. Whether standardized tea processing homogenizes regional raw material differences or reconstructs them into distinct aroma profiles of raw Anhua dark tea (RADT) remains unclear. In this study, fresh leaves from seven regions were processed under identical manufacturing conditions to separate the effects of raw material origin from manufacturing process. Sensory evaluation showed that standardized processing did not eliminate regional aroma differences; instead, the resulting tea infusions retained distinct aroma attributes across regions, including roasty/smoky, stale/woody, floral, fruity, and green/fatty notes. GC-O/MS and quantitative analysis identified 48 odorants in fresh leaves and 82 odorants in RADT infusions, indicating that processing substantially reshaped the aroma composition. Alcohols, aldehydes, and terpenoids derived from fresh leaves generally decreased, whereas processing associated acids, phenols, lactones, and heterocyclics increased. Multivariate analysis identified 45 processing responsive odorants, including newly formed heterocyclics, ( E , E )-2,4-heptadienal, and ( E )- β -ionone. By integrating odor activity value with multivariate discrimination, 17 regional key odorants were identified, demonstrating that standardized processing reconfigured regional raw material differences into distinct aroma-active compound combinations rather than homogenizing them. Molecular docking revealed different predicted binding capacities between representative key odorants and selected olfactory receptors, with cedrol and ( E )- β -ionone showing stronger predicted receptor interactions than smaller linear aldehydes, suggesting that regional aroma differences in RADT may also involve receptor level recognition. Overall, these findings reveal that standardized processing acts as a transformative filter that reshapes regional raw material differences into distinct aroma profiles in RADT. Download: Download high-res image (184KB) Download: Download full-size image

Potential of tea polyphenols to ameliorate the quality of beef meatballs during frozen storage and its action mechanism

Yu-Xin Xie,Qiu-Yue Ma,Qian-Da Xu,Nan Chen,Wei-Cai Zeng

Frozen storage is commonly used for preservation of meat products, but it may cause some quality deterioration, due to the repeatedly forming of ice crystals in meat. Effects and action mechanism of tea polyphenols (TP, from 0 to 0.30 g/kg) on the quality of beef meatballs during freeze-thaw cycles were investigated in present study. TP significantly reduced thaw loss of beef meatballs by 36.62% and improved texture (hardness increased by 21.13%, chewiness increased by 18.88%). Low-field nuclear magnetic resonance analysis revealed that TP restricted the conversion of immobilized to free water, decreasing free water by 7.42% and increasing immobilized water by 7.43%. Freezing temperature curve and microstructure image results demonstrated that TP facilitated the rapid formation of uniformly distributed, smaller ice crystals in beef meatballs. After freeze-thaw cycles, TP significantly decreased the content of free sulfhydryl and carbonyl groups of myofibrillar protein, enhanced its surface hydrophobicity and decreased its solubility. Furthermore, multispectral (including fluorescence and infrared spectroscopy) analysis combined with molecular docking indicated that TP could significantly caused a more unfolded secondary structure of myofibrillar protein and expose its hydrophobic centers due to their molecular interaction through hydrogen bonds and hydrophobic interactions. All results suggest that TP show the potential to ameliorate the quality of frozen meat products.

Multiple carbon quantum dots-enhanced excitation-emission matrix fluorescence strategy for accurate vintage discrimination of Anhua dark tea

Ye He,Wu Wang,Xu-Dong You,Yao Chen,Xiao-Zhi Wang,Tong Wang,Hai-Long Wu,Ru-Qin Yu

Accurate discrimination of dark tea vintages is crucial for quality assurance and market value assessment. In this study, a multiple carbon quantum dots-enhanced excitation-emission matrix (MCQDs-EEM) fluorescence strategy was developed for the rapid identification of Anhua dark tea from different production years. Three functional carbon quantum dots with complementary responses to pH, tea polyphenols, and amino acids were combined into an integrated fluorescent chemical sensor, generating enhanced and information-rich fluorescence fingerprints upon interaction with tea infusions. The MCQDs-EEM dataset was decomposed using the Alternating Trilinear Decomposition (ATLD) algorithm, which revealed four chemically significant components that showed differences in Anhua dark tea from thirteen different years. Based on the MCQDs-EEM data, partial least squares discriminant analysis (PLS-DA) and k -nearest neighbors ( k- NN) models were constructed. The PLS-DA model achieved 100% classification accuracy for both the training and test sets, while the k -NN model attained accuracies of 96.59% and 100%, respectively. These results demonstrate clear superiority over the traditional fluorescence strategy based on carbon quantum dots (CQDs-FL), which relies on the splicing of three distinct emission spectra. The MCQDs-EEM strategy not only simplifies the implementation process but also demonstrates higher accuracy, which can be regarded as an effective tool for tea vintage authentication and quality control.