FOOD CHEMISTRY
·
2023
·
IF 8.8
Xiaoyu Yang,Zhichun Bi,Chenghui Yin,Shuyi Zhang,Donghui Song,Hui Huang,Yongxin Li
Tieguanyin (TGY) is one of top ten famous teas in China, but in the process of brand building there is the phenomenon of falsehood, thus harming the interests of consumers. To solve the adulterate problem of TGY, a colorimetric sensor array (CSA) based on peroxidase activity of nanozyme was constructed. Nanozymes can catalyze 3,3′,5,5′-tetramethylbenzidine (TMB) to 3,3′,5,5′-tetramethyl -[1,1′-bis(cyclohexyl)]-2,2′,5,5′-tetraene-4,4′-diimine (oxTMB), while the tea polyphenols (TPs) can inhibit this process, and the degree of inhibition varies significantly with the reaction time. We selected two nanozymes and three reaction time points to construct CSA. It can successfully distinguish TPs in TGY. The discriminative analysis can achieve: (1) distinction between TGY and adulterated tea, (2) discrimination of TGY in various seasons and seasonal adulteration in different degrees. The method constructed in this work is promising for both the class and quality differentiation of TGY and other teas with TPs as the main activity.
研究领域:
食品科学
·
分析化学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food Chemistry-X
·
2021
·
IF 5.182
Qing-Qing Cao,Yan-Qing Fu,Jie-Qiong Wang,Liang Zhang,Fang Wang,Jun-Feng Yin,Yong-Quan Xu
Roasting, a critical process for oolong tea, has been applied to Tieguanyin tea to improve flavor attributes. To investigate the effects of the roasting on the flavor of Tieguanyin , the global metabolomics analysis on the non-volatile and volatile components were proceeded. The weakening of bitterness and astringency, caused by roasting, may be attributed to the decreasing of flavonoids glycosides and procyanidins, whereas the enhancing of sweet aftertaste to the increasing of gallic acid. Besides, l -theanine flavan-3-ols adducts ( N -ehtyl-2-pyrrolidinone substituted flavan-3-ols) increased dramatically at 130 °C compared with 105 °C, with the reduction of l -theanine and flavan-3-ols. Meanwhile, high temperature hampered the volatiles’ diversity and intensity, resulting from the lowering of floral volatiles, i.e., β-ionone, jasmine, and nerolidol, yet the nitrogen-containing heterocyclic compounds increased, e.g., pyrroles and pyrazines. The results can help to comprehensively understand the influences of roasting technology on the flavor and chemistry of oolong tea.
研究领域:
食品科学
·
化学
·
代谢组学
✓ 已验证
DOI
PubMed
高影响因子
Biomass Conversion and Biorefinery
·
2023
·
IF 4
Zeng Xiang,Dai Huijia,Liu Bing,Wen Yao
In this study, the extraction process of Tieguanyin tea polyphenols was optimized and its hypoglycemic activity was tested. The response surface method was used to design the experiment to optimize the extraction process and explore the best extraction conditions. The extract was purified by AB-8 macroporous resin, and its hypoglycemic activity was studied by the inhibition rate of two enzymes (α-glucosidase and α-amylase). The optimum conditions of ultrasonic-assisted extraction of Tieguanyin tea polyphenols were as follows: material-to-liquid ratio of 40 mL/g, ultrasonic power of 240 W, and ultrasonic time of 30 min. The extraction rate of tea polyphenols was 13.82%, which was consistent with the predicted value of 13.78%. The purification experiment results showed that the purity of tea polyphenols was 50.62%. The IC 50 of Tieguanyin tea polyphenol extract on α-glucosidase and α-amylase was 1.93 × 10 −8 mg/mL and 7.65 × 10 −11 mg/mL, respectively, indicating that it could inhibit both of them. In this study, the optimum extraction process of Tieguanyin tea polyphenols was optimized and confirmed, and it was confirmed that Tieguanyin tea polyphenols had strong hypoglycemic activity.
研究领域:
食品科学
·
药理学
·
生物技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PAPERS
·
2026
·
IF 2.7
Chen Jun,Xiao Ke,Cai Shaoyu,Xu Mao,Kang Luo,Pei Shuchen
Antibacterial carbon dots (CDs) were synthesized from Tieguanyin tea to expand the functional applications of tea resources. The morphological, structural, and chemical properties of the CDs were systematically characterized by TEM, FT-IR, and XPS. These analyses confirmed that the CDs possess a well-defined graphite-like lattice and surface functional groups essential for interacting with bacterial cells. Notably, the tea-derived CDs exhibited potent antibacterial activity against clinically relevant drug-resistant pathogens, effectively overcoming existing resistance mechanisms. They showed strong inhibitory effects against S. aureus (MIC = 1.00 mg/mL) and E. coli (MIC = 1.20 mg/mL). The antimicrobial mechanism is attributed to the generation of reactive oxygen species (ROS) under illumination and electrostatic disruption of bacterial membranes driven by the cationic surface charge of the CDs. This study demonstrates the potential of tea as a promising platform for designing sustainable antibacterial nanomaterials, offering new insights into the integrated valorization of biomass resources and the mitigation of antibiotic resistance.
✓ 已验证
产品关联
DOI
高影响因子
npj Science of Food
·
2022
·Vol. 6
·期 1
·1-9
·
IF 7
Cao Qing-Qing,Wang Jie-Qiong,Chen Jian-Xin,Wang Fang,Gao Ying,Granato Daniel,Zhang Xuebo,Yin Jun-Feng,Xu Yong-Quan
Tieguanyin is one of the most consumed oolong teas because of its distinctive flavor. The brewing process is crucial for the flavor performance of traditional teas, thus the effects of brewing conditions, including water/tea ratio (R), brewing temperature (T), and time (S) on the sensory traits, chemical composition, and antioxidant activity of Tieguanyin tea infusion were investigated using quadratic orthogonal regression design. Results showed that R affected all the quality variables most, its reduction could lead to the promotion of tea infusion concentration, antioxidant activity, and taste intensity, which was favored by the tea consumers drinking tea almost daily (DTD) but unacceptable for those drinking tea hardly (DTH). Based on the optimization of brewing conditions in response surface methodology (RSM), we recommended several brewing schemes for diverse consume goals: R = 34 mL/g, T = 80 °C, S = 80 s for DTH; R = 39 mL/g, T = 100 °C, S = 127 s for DTO (the consumers drinking tea occasionally); R = 20 mL/g, T = 100 °C, S = 100 s for DTD; R = 26 mL/g, T = 100 °C and S = 127 s for the common consumers seeking for flavor and health benefits. These results would be helpful for tea consumers with multiple demands.
研究领域:
食品科学
·
茶叶科学
·
化学工程
·
消费者行为
✓ 已验证
产品关联
DOI
PubMed
高影响因子
npj Science of Food
·
2026
·
IF 9.7
Hu Xiaowen,Fang Jiaxin,Shao Shuaibo,Rui Zhenhan,Zhang Zhendong,Zheng Anru,Tian Caiyun,Zhou Chengzhe,Wan Zhelin,Wang Zhong,Guo Yuqiong
To characterize sensory differences among commercially available Chenxiang Tieguanyin with different labeled vintages and establish an objective discrimination method, Tieguanyin samples labeled from 5 to 40 years were analyzed using chemometrics and molecular sensory approaches. Amino acids and ester-type catechins decreased significantly with increasing labeled vintage, whereas theabrownin content increased steadily. Volatile profiles remained relatively stable between 10 and 25 years, while aroma characteristics gradually shifted from floral/fruity to aged, woody, and medicinal attributes, accompanied by enhanced mellowness and smoothness. A total of 22 key differential volatiles associated with labeled vintage were identified. Molecular docking and aroma recombination experiments were combined to systematically validate their contribution to the typical aged aroma of Tieguanyin. Among the machine-learning models, the convolutional neural network (CNN) exhibited the best classification performance, achieving 92.86% accuracy. This study provides an effective strategy for quality evaluation and labeled vintage discrimination of Chenxiang Tieguanyin.
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2025
·
IF 2.6
Desen Su,Yunyun Zheng,Minmin Huang,Ziqiang Chen,Lisong Chen,Meizhen Chen,Qinghua Yao
Depending on the manufacturing process, Tieguanyin tea (TGY) is classified into three main groups, light flavor type (LFT), heavy flavor type (HFT), and stale flavor type (SFT). However, the compositions and contents of volatile compounds among TGY types were still unclear. This study aimed to develop an efficient method for the nonselective determination of volatile compounds in teas via direct-headspace injection coupled with gas chromatography mass spectrometry (DHI-GC-MS), and to perform a comprehensive comparison among these teas. One hundred and twelve volatile compounds belonging to 9 classes were identified. Among them, 33 common volatiles from 4 categories (aldehydes, alcohols, ketones, and acids) were the dominant volatiles and accounted for 71.5%, 73.0%, and 71.8% of the total amount in LFT, HFT, and SFT, respectively. E-Nerolidol, ethanol, acetic acid, and some volatiles with five and six-carbon chains were the key chemicals to distinguish three different TGY teas. With PLS-DA analysis, distinct differences among different groups were observed. The results generated from this study may offer valuable insights for better grading of TGY teas.
研究领域:
食品科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food Chemistry-X
·
2023
·
IF 6.1
Yuan-Yuan Ma,Jie-Qiong Wang,Ying Gao,Qing-Qing Cao,Fang Wang,Jian-Xin Chen,Zhi-Hui Feng,Jun-Feng Yin,Yong-Quan Xu
Variations in the quality of brewing water profoundly impact tea flavor. This study systematically investigated the effects of four common water sources, including pure water (PW), mountain spring water (MSW), mineral water (MW) and natural water (NW) on the flavor of Tieguanyin tea infusion. Brewing with MW resulted in a flat taste and turbid aroma, mainly due to the low leaching of tea flavor components and complex interactions with mineral ions (mainly Ca 2+ , Mg 2+ ). Tea infusions brewed with NW exhibited the highest relative contents of total volatile compounds, while those brewed with PW had the lowest. NW and MSW, with moderate mineralization, were conducive to improving the aroma quality of tea infusion and were more suitable for brewing both aroma types of Tieguanyin . These findings offer valuable insights into the effect of brewing water on the sensory and physicochemical properties of oolong teas.
研究领域:
食品科学
·
茶叶研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）