查找使用阿拉丁产品的科研文献

Lady tasting tea revisited: A nanozyme-based artificial taste sensor for tea differentiation and brewing process analysis

Haili Wei,Shiyu Xia,Xueqing Sang,Juliana Gaithan Kauno,Zhiyong Dong,Yue Zhang,Jinfang Nie,Yali Yuan,Guobao Xu,Wenxin Niu

The “Lady Tasting Tea” is a classic experiment in statistics, often celebrated for its contribution to the field, though the lady’s extraordinary taste sensitivity is less frequently acknowledged. Herein, we developed a highly sensitive nanozyme-based artificial taste sensor, which differentiates teas and brewing processes, similar to the “Lady Tasting Tea” experiment. The sensor employs PdSb concave nanocubes, which exhibit enhanced peroxidase activity due to the oxophilicity of Sb, to construct a cross-responsive sensing platform that simultaneously identifies tea polyphenols and authenticates complex blank tea samples. With its multi-differentiation ability to simulate human taste, this platform objectively demonstrates the flavor differences in milk tea based on the order of milk and tea addition, providing reliable data to distinguish taste differences without subjective interference. Overall, this work presents a new approach for designing nanozyme-based sensing platforms to simulate human taste.

Smart evaluation of tea quality: machine learning-assisted SERS for white tea vintage authentication and grade classification

Qian Ye,Xianjin Zhang,Yuanyuan Yao,Yueliang Wang,Lifen Chen,Bingyong Lin,Hong Huang,Jianguo Xu,Xin Peng,Longhua Guo

Traditional sensory evaluation methods for tea—relying on empirical experience, visual colorimetry, and subjective taste perception—suffer from irreproducible inter-rater variability and inability to quantify bioactive markers, thus failing to establish scientifically verifiable quality standards. To address this, we developed an intelligent platform integrating surface-enhanced Raman scattering with machine learning for rapid and quantitative white tea analysis, enabling detection within just 20 min. Utilizing silver nano-coral substrates for signal enhancement and a 785 nm portable Raman spectrometer for full-spectrum data acquisition, we constructed a hybrid machine learning architecture featuring Random Forest for vintage classification (96% accuracy) and Gradient Boosting Regressor for epigallocatechin gallate (EGCG) quantification (R 2  = 0.98, the values of Root Mean Square Error, Mean Absolute Error, and Mean Square Error all approach zero). This approach established a definitive EGCG-content grading hierarchy: Yinzhen > Mudan > Gongmei > Shoumei, which is highly consistent with traditional sensory evaluation methods, while provides additional quantitative ability.

Occurrence and Residue Pattern of Phthalate Esters in Fresh Tea Leaves and during Tea Manufacturing and Brewing

Pingxiang Liu,Hongping Chen,Guanwei Gao,Zhenxia Hao,Chen Wang,Guicen Ma,Yunfeng Chai,Lin Zhang,Xin Liu

The residues of 16 phthalate esters (PAEs) in fresh tea leaves and made tea were determined via gas chromatography–tandem mass spectrometry to study their distribution and degradation characteristics during tea planting and processing. Five PAEs were detected in all fresh tea leaves, and higher concentrations were detected in mature leaves. The distribution of PAEs in fresh tea leaves ranged from 69.7 to 2244.0 μg/kg. The degradative percentages of ∑5PAEs during green tea manufacturing ranged from 61 to 63% and were significantly influenced by the drying process. The transfer rates of PAEs-D4 ranged from 5.2 to 100.6%. PAEs with a high water solubility showed the highest transfer coefficient in the range of 91.8–100.6%, whereas PAEs with a high log Kow showed a low leaching efficiency below 11.9%. These results benefit the risk evaluation and establishment of a maximum residue limit for PAEs in tea.

A newly-discovered tea population variety processed Bai Mu Dan white tea: Flavor characteristics and chemical basis

Yanping Lin,Yibiao Huang,Su Zhou,Xiaolan Li,Yike Tao,Yani Pan,Xinyu Feng,Haowei Guo,Ping Chen,Qiang Chu

The quality of white tea (WT) is impacted by selected tea cultivars. To explore the organoleptic quality of a recently-discovered WT (“Caicha”, CC), HS-SPME/GC–MS and UPLC were employed to identify volatile and non-volatile compounds in tea samples. Multiple statistical methods demonstrated the distinctions between CC and four mainstream WT varieties from main producing areas. CC exhibited abundant volatile alcohol, terpenoids, ketone, aldehyde and ester, as well as non-volatile lignans and coumarins, phenolic acids and low-molecular carbohydrates. These substances combinedly contributed to the flavor attributes of CC, characterized by an intense herbal/citrus-like cleanness and flower/fruit-like sweetness, scarce in existing commercial WT varieties. Sensory evaluation corroborated these findings. In conclusion, we have processed a new tea variety (CC) with WT manufacturing technology, and discovered the unique cleanness and sweetness of it. This study enriches the raw material database for WT production and blending, and boosts the development of more premium WT varieties.

Aroma compositions of large-leaf yellow tea and potential effect of theanine on volatile formation in tea

Xiangyang Guo,Chi-Tang Ho,Wilfried Schwab,Chuankui Song,Xiaochun Wan

Large-leaf yellow tea (LYT) imparting unique toasty flavor is a traditional beverage in China. The volatile composition of LYT after full fire processing (FF-YT) was determined by different extraction methods. Steam distillation (SD), solid-phase microextraction (SPME) and headspace (HS) were applied for analysis of tea body notes, tea infusion and dry tea aroma, respectively. A total of 143 volatile compounds was identified by the three methods, of which SD-FF-YT, SPME-FF-YT, and HS-FF-YT extracts contained 100, 72, and 56 volatiles, respectively. Heterocyclics and aromatic compounds were the main volatile composition of LYT and might be contributors to its crispy-rice-like odor. l -Theanine was demonstrated to contribute to the formation of tea volatiles. N -Ethylacetamide, formed in the l -theanine only model thermal reaction, was probably involved in the LYT volatile formation. The current results provide new insight into l -theanine on aroma formation, although the detailed formation mechanism remains largely unknown.

Tea marinating-induced improvement of quality in roasted chicken: The potential relationship between tea, flavor, and hazardous substances

Ji Wang,Jing Che,Xu-Song Wang,Lei Qin,Xu-Hui Huang

The levels of flavor compounds and hazardous compounds are important indicators for evaluating high-temperature roasted food. In this paper, the effect of tea pre-marination on non-volatile compounds, volatile compounds, and hazardous compounds in roasted chicken. The results showed that the total content of key umami non-volatile compounds in roasted chicken marinated with green tea, white tea, and black tea increased by 17.43 % to 100.11 %. The content of alkenes, alcohols, aldehydes, and ketones in high-temperature roasted chicken marinated with oolong tea and yellow tea was increased. Different teas had varying inhibitory effects on hazardous compounds in high-temperature roasted chicken, while green tea exhibited the highest inhibition efficacy. The inhibition rates of green tea for ACY, 5-HMF, HCAs, and PAHs were 72.12 %, 69.87 %, 92.49 %, and 14.92 %, respectively. Flavonoids in tea may play an important role in the flavor enhancement and hazardous compounds inhibition of high-temperature roasted chicken.

The tea specific pretreatment methods for rapid detection of aflatoxin B1 and ochratoxin A on dark tea samples

Xu Wang,Xiaodan Li,Na Li,Ruidong Zi,Xin Hu,Yingying Qian,Yu Zhou

Matrix interference of dark tea was effectively eliminated by tea-specific clean-up. • Tea-specific pretreatment enabled rapid detections of AFB1 and OTA on tea sample. • A simple and cost-effective strategy was validated for rapid detection in dark tea. • Tea-specific pretreatment compatible with rapid test strips and instrumental analysis. Rapid test strips have been widely used for mycotoxins detection in foods; however, their application in tea is strictly limited by pronounced matrix interference. In this study, tea-specific cleaning methods were developed to enable rapid detection of aflatoxin B1 (AFB 1 ) and ochratoxin A (OTA) in dark tea and tea infusions. The proposed methods achieved recoveries ranging from 81.5% to 128.07% for AFB 1 and ranging from 80.05% to 131.48% for OTA. Method validation demonstrated robust accuracy and precision, with AFB 1 recoveries of 83.82%–110.00% (RSDs: 0.46%–12.74%) and OTA recoveries of 82.83%–118.47% (RSDs: 0.69%–11.74%). The limits of detection (LODs) were 1.14–2.52 μg/L for AFB 1 and were 1.13–3.04 μg/L for OTA in tea samples. The tea-specific clean-up effectively minimized matrix interference, yielding extracts compatible with rapid test strips for qualitative and quantitative testing. Overall, this study provides a simple, efficient and cost-effective strategy for improving the reliability of rapid mycotoxins detection in complex tea matrices.

Comparative analysis of taste profiles and metabolic characteristics in white tea processed from wild and cultivated tea plants

Xingyun Zhao,Ping Li,Xueyin Luo,Liming Liu,Piyada Alisha Tantasawat,Xinjie Zheng,Hongmei Fu,Kaiguo Mao,Tingjian Meng,Xin Mei,Teerayoot Girdthai

BACKGROUND Wild tea trees represent valuable germplasm resources, with distinctive chemical characteristics and environmental resilience, but the biochemical basis underlying their flavor characteristics and potential contribution to white tea quality remain poorly understood. As a minimally processed tea, white tea provides a useful system for examining how differences among wild and cultivated raw materials are reflected in metabolite composition and sensory quality. RESULTS White teas produced from a wild super-large-leaf type (LWT), a wild small-leaf type (SWT), and the cultivated cultivar Fuding Dabai (FDDB) were evaluated using quantitative descriptive analysis and untargeted liquid chromatography–mass spectrometry metabolomics. Sensory assessment revealed significant differences among teas ( P < 0.05): LWT showed stronger bitterness and astringency, SWT greater sweetness, and FDDB more pronounced umami and mellowness. Metabolomic profiling annotated 1123 metabolites across 13 chemical classes. Principal component analysis separated wild and cultivated samples, explaining 55.21% of total variance, while orthogonal partial least squares discriminant analysis demonstrated robust discrimination ( R 2 Y = 0.999, Q 2 = 0.849). FDDB exhibited higher overall metabolite abundance, particularly flavonol glycosides and umami-related amino acids, whereas LWT accumulated more phenolic acids and bitter amino acids, and SWT was enriched in carbohydrates and sweet-tasting amino acids. Network and enrichment analyses further identified amino acid biosynthesis pathways as significantly associated with taste variation ( P < 0.05). CONCLUSION Taste differences between wild and cultivated white teas are closely linked to metabolite composition, especially amino acid metabolism. These findings provide a biochemical basis for evaluating wild tea germplasm and support breeding, raw material selection, and processing strategies aimed at improving specialty tea quality. © 2026 Society of Chemical Industry.

Systematic Comparison of Aroma Profiles and Tea Polysaccharide In Vitro Antioxidant Activities Among Six Anxi Oolong Tea Cultivars

Oolong tea is prized for its floral aroma and bioactive tea polysaccharides (TPS), yet the independent contribution of cultivar genetic background to aroma chemistry and TPS functionality remains unclear due to confounding effects from environment and processing. Here, we systematically compared volatile organic compound (VOC) profiles and in vitro antioxidant activities of TPS from six Anxi oolong tea cultivars all grown in the same tea garden and processed under identical Qingxiang oolong tea protocols. Using headspace solid-phase microextraction-gas chromatography-mass spectrometry, 39 VOCs were identified across cultivars. Huangjingui exhibited the highest total VOC content (69.01 μg·g−1) and the greatest number of compounds with relative odor activity values (rOAV) over 1. Principal component analysis and hierarchical clustering revealed clear metabolic separation among cultivars, with Daye Wulong displaying the most distinct metabolome. PLS-DA combined with rOAV screening identified 12 key differential volatiles that form the chemical basis of floral aroma. Preliminary in silico molecular docking predicted the strongest binding affinity between nerolidol and OR1A1 (−7.54 kcal/mol). Cultivar-specific high rOAV volatiles were characterized, including (E)-2-octenal and 1-phenyl-2-nitroethane in Tieguanyin, 2-phenylethyl-2-methylbutyrate and cis-3-hexenyl isovalerate in Maoxie, α-ocimene and cis-3-hexenyl benzoate in Daye Wulong, and (E,E,Z)-1,3,5,8-undecatetraene in Meizhan, suggesting their potential as chemical markers for cultivar authentication. Crude TPS yields ranged from 2.76% to 3.99%; Tieguanyin had the highest yield and Meizhan the lowest. TPS from Daye Wulong exhibited the strongest DPPH and ABTS+· scavenging capacities, with IC50values of 0.58 and 1.95 mg·mL−1, respectively, indicating the highest in vitro antioxidant activity among all tested samples. These results suggest that cultivar genetic background may be a primary determinant of both aroma metabolites and TPS bioactivity, providing a theoretical basis for cultivar selection and quality optimization in oolong tea production.

The flavor-related metabolites and sensory quality of white tea produced by exogenous methyl jasmonate treated tea leaves

Qinghua Cheng,Shiqiang He,Xingzhu Duan,Yingjuan Chen

Methyl jasmonate (MeJA) is a well-established plant hormone utilized for flavor enhancement in agricultural products. This study systematically investigated its effects on white tea flavor by integrating analyses of both volatile and non-volatile compounds. Results indicated that MeJA treatment increased soluble sugar content and decreased tea polyphenol level, and also altered the composition of catechins and amino acids, particularly glutamic acid, affecting the overall taste profile of white tea. The content of the grassy-scented compounds (1-octen-3-ol, limonene, butanal, and (Z)-3-Hexen-1-ol acetate) was significantly decreased, while the content of pleasant aroma compounds (α-terpineol, α-ionone, phenylacetaldehyde) was significantly increased with MeJA treatment. A total of eight key compounds were identified as key contributors to the aroma of white tea. Our results systematically reveal the effect of MeJA on the flavor and quality of white tea, providing a scientific basis for the application of MeJA in tea.

In-vitro bioactivity evaluation and non-targeted metabolomic analysis of green tea processed from different tea shoot maturity

Chunhui Xu,Lu Liang,Tianming Yang,Lei Feng,Xuejin Mao,Yuanxing Wang

The chemical quality and biochemical properties of green tea processed from different tea shoot maturity has largely remained unexplored thus far. Total phenolic content, and total flavonoid content decreased during tea shoot maturation. Three in-vitro bioactivities, namely α-glucosidase and pancreatic lipase inhibitory and antioxidant activity showed a similar changing trend. A significant correlation between TPC and TFC, and these bioactivities was found. Non-targeted metabolomic analysis revealed that green tea processed from different tea shoot maturity had obvious differences. Variable importance analysis and S-plot gave 32 characteristic metabolites responsible for the discrimination of different green teas. Orthogonal partial least square analysis was used calculate the correlation coefficient between each characteristic metabolite and the values of three in-vitro bioactivities. Several important differential bioactive metabolites were obtained using the above analysis. This study explored the metabolic change in green tea during the process of tea shoot ripening, thus providing unique tea quality information for green tea production.

Caffeine is responsible for the bloodglucose-lowering effects of green tea and Puer tea extractsin BALB/c mice

Chong-Ye FANG,Xuan-Jun WANG,Ye-Wei HUANG,Shu-Mei HAO,Jun SHENG

The present study was designed to determine the effects of Puer tea and green tea on blood glucose level. Male BALB/c mice were administered green tea extract (GTE) or Puer tea extract (PTE), either intragastrically or in their drinking water. The major components of these teas are epigallocatechin gallate (EGCG) and caffeine, respectively. Blood glucose measurement results showed that mice fed intragastrically or mice that drank GTE, PTE or caffeine showed significantly lower blood glucose levels compared to the control group. However, EGCG exhibited no influence on the blood glucose levels. When caffeine was eliminated from the GTE and PTE, the effect on the blood glucose levels was abolished, but the effect was recovered when caffeine was re-introduced into the extracts. Evaluation of hematological and biochemical indices at the time of the greatest caffeine-induced decrease in blood glucose levels showed that the effect of caffeine was specific. Microarray analyses were performed in 3T3-L1 preadipocytes and mature adipocytes treated with 0.1 mg·mL −1 caffeine to identify factors that might be involved in the mechanisms underlying these effects. The results showed that few genes were changed after caffeine treatment in adipocytes, and of them only phospholipid transfer protein (PLTP) may be ralated to blood glucose. In conclusion, this study indicates that caffeine may be the key constituent of tea that decreases blood glucose levels, and it may be used to treat type 2 diabetes.