Food Chemistry-X
·
2025
·
IF 8.2
Zixi Yang,Yanxia Xie,Yuanmin Zhu,Mengjie Lei,Xuemin Chen,Wenwen Jin,Chunhua Fu,Longjiang Yu
Ripened Pu-erh tea (RPT) is renowned for its distinctive flavor and health benefits. However, its complex fermentation process poses challenges in ensuring consistency in production. This study investigated RPT flavor formation through sensory evaluation, multi-omics analysis, and multivariate statistical approaches. By day 24, the tea exhibited a reddish-brown infusion and a mellow, thick taste (MT_RPT), achieving the highest sensory score (94.0, P < 0.05). Sixteen flavor-related chemical components exhibited significant changes ( P < 0.05). The contents of free amino acids, L -theanine, tea polyphenols, flavonoids, catechins, and thearubigins decreased. In contrast, the contents of total soluble sugars, caffeine, theobromine, epicatechin, and theabrownins (TBs) increased, reaching 74.1 mg/g, 65.38 mg/g, 3.13 mg/g, 3.33 mg/g, and 134.84 mg/g, respectively. Additionally, 33 nonvolatile metabolites (e.g., pelargonidin 3-O-glucoside, dihydroisorhamnetin, and puerarin) were significantly correlated with MT_RPT flavor (VIP > 1, |r| ≥ 0.8, P < 0.05) and influenced by key functional microbes, including Pantoea , Aspergillus , Brachybacterium , and Staphylococcus . By day 30, the infusion darkened, and sensory scores declined (81.4, P < 0.05), attributed to the dominance of Brevibacterium . This microbial shift reduced water-soluble pectin, free amino acids, and 11 metabolites while increasing TBs and theophylline (219.33 mg/g and 0.09 mg/g, respectively). Therefore, TBs were identified as a crucial indicator of optimal fermentation. Moreover, redundancy analysis indicated that the tea pile's central temperature, moisture content, and pH were essential fermentation parameters ( P < 0.05). These findings deepen our understanding of MT_RPT flavor development mechanisms and provide valuable insights into precise fermentation control.
研究领域:
食品科学
·
微生物学
·
代谢组学
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产品关联
DOI
PubMed
高影响因子
FOOD SCIENCE AND BIOTECHNOLOGY
·
2023
·
IF 2.9
Chen Xiaoqiang,Chen Tingting,Liu Jiayan,Wei Yan’an,Zhou Weilong
Tea polyphenols were used as substrates and oxidized successively by polyphenol oxidase and peroxidase to prepare theabrownins (TBs-dE). The conversion rate of catechins to TBs-dE was 90.91%. The ultraviolet and infrared spectroscopic properties and zeta potential of TBs-dE were characterized. TBs-dE is more stable at pH 5.0–7.0, about 25 °C or in dark environment. Ultraviolet light and sunlight can deepen its color due to the further oxidative polymerization. Mg 2+ , Cu 2+ , and Al 3+ had a significant effect on the stability of TBs-dE. The inhibitory rates of TBs-dE (1 mg/mL) against Staphylococcus aureus and Escherichia coli DH5α were 51.45% and 45.05%, respectively. After TBs-dE treatment, the cell morphology of both bacteria changed, some cell walls were blurred, and the cytoplasmic content leaked. The research results can provide theoretical support for the industrialization of theabrownins.
研究领域:
食品科学
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微生物学
·
化学
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产品关联
DOI
PubMed
高影响因子
Journal of Integrative Agriculture
·
2023
·
IF 4.8
Xiao-qiang CHEN,Jia-yan LIU,Xue-jun HUANG,Yan-an WEI,Rui-xiang SHAO,Ting-ting CHEN,Jian-chun XIE
Theabrownins (TBs) are the characteristic functional and quality components of dark teas such as Pu-erh tea and Chin-brick tea. TBs are a class of water-soluble brown polymers with multi-molecular weight distribution produced by the oxidative polymerisation of tea polyphenols during the fermentation process of dark tea, both enzymatically and non-enzymatically. TBs have been extracted and purified from dark tea all the time, but the obtained TBs contain heterogeneous components such as polysaccharides and caffeine in the bound state, which are difficult to remove. The isolation and purification process was tedious and uses a lot of harmful organic solvents. This has made it difficult to industrialise TBs. In this study, epigallocatechin (EGC), epigallocatechin gallate (EGCG), epigallocatechin gallate (ECG), EGC/EGCG (mass ratio 1:1), EGCG/ECG (mass ratio 1:1), EGC/ECG (mass ratio 1:1), EGC/ECG (mass ratio 1:1), EGC/ECG (mass ratio 1:1) and EGC/EGCG/ ECG (mass ratio 1:1:1) as substrates and catalyzed by polyphenol oxidase (PPO) and peroxidase (POD) in turn to produce TBs, named TBs-dE-1, TBs-dE-2, TBs-dE-3, TBs-dE-4, TBs-dE-5, TBs-dE-6 and TBs-dE-7. The physicochemical properties and the antibacterial activity and mechanism of TBs-dE (1-7) were investigated. Sensory and colour difference measurements showed that all seven tea browning samples showed varying degrees of brownish hue. Zeta potential in aqueous solutions at pH 3.0-9.0 indicated that TBs-dE (1-7) was negatively charged and the potential increased with increasing pH. The characteristic absorption peaks of TBs-dE (1-7) were observed at 208 nm and 274 nm by UV-visible(UV-vis) scanning spectroscopy. Fourier infrared spectroscopy (FT-IR) indicated that they were phenolic compounds. TBs-dE (1-7) showed significant inhibition of Escherichia coli DH5α ( E. coli DH5α). TBs-dE-3 showed the strongest inhibitory effect with MIC of 1.25 mg/mL and MBC of 10 mg/mL, followed by TBs-dE-5 and TBs-dE-6. These three TBs-dEs were selected to further investigate their inhibition mechanism. The results showed that TBs-dE inhibited bacteria by disrupting the extracellular membrane of E. coli DH5α, causing the leakage of contents and increasing the intracellular reactive oxygen content, resulting in abnormal cell metabolism due to oxidative stress. The TBs-dE was found to damage the extracellular membrane of E. coli DH5α, causing leakage of contents, and increase intracellular reactive oxygen content, resulting in abnormal cell metabolism due to oxidative stress. The results of the study provide a theoretical basis for the industrial preparation and product development of TBs.
研究领域:
食品科学
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微生物学
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化学
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药理学
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产品关联
DOI
高影响因子
JOURNAL OF FOOD PROCESSING AND PRESERVATION
·
2021
·Vol. 45
·期 10
·e15844
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IF 2.19
Xiaofen Wu,Tetsuo Ozawa,Yinhua Li,Jihua Duan,Kun Zhu,Jianan Huang,Zhonghua Liu,Keqin Wang
This study evaluated the effects of fermentation time and temperature on the content of high molecular weight polyphenol mitochondrial activation factors (MAFs) and other polyphenols in Congou black tea using high-performance liquid chromatography (HPLC). There were two broad chromatographic peaks in the HPLC spectra of MAFs: MAFs-1 (16.163 min) and MAFs-2 (34.31 min); MAFs-2 was satisfactorily analyzed by HPLC, with separation by paper chromatography. The MAFs-2 contents increased gradually in different varieties of Congou black tea as the fermentation time and temperature increased; the maximum MAFs-2 content was 5.11% in Xiaoxianghong 21-3 after 8 hr of fermentation. The total polyphenols and catechins contents decreased, whereas the theabrownins contents increased as the fermentation time and temperature increased; the theaflavins and thearubigins contents in different Congou black teas showed different variation tendencies. Therefore, studies regarding changes in polyphenols during fermentation will help improve the quality of Congou black tea and enhance its health benefits. Novelty impact statement A new method for the determination of MAFs-2 by high-performance liquid chromatography combined with paper chromatography was established. The content of MAFs-2 increased initially and then stabilized as fermentation was continued from 2 to 8 hr, it increased gradually as the fermentation temperature was increased from 23 to 37°C. These results provide a new analytical method for MAFs in black tea and a theoretical basis and technical guidance for improving the quality of Congou black tea.
研究领域:
食品科学
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分析化学
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茶叶科学
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产品关联
DOI
高影响因子
ENVIRONMENT INTERNATIONAL
·
2025
·
IF 9.7
Jianrong Han,Changqian Liu,Zhiyuan Chen,Fengkai Ruan,Fanzheng Xue,Lingxiao Ye,Yi Yu,Zhenghong Zuo,Chengyong He
Metabolic-associated fatty liver disease (MAFLD), linked to lipid dysregulation, poses global health risks. 2,2′,3,4,4′,5′-hexachlorobiphenyl (PCB138) is a persistent organic pollutant that poses potential threats to liver health due to its environmental persistence and bioaccumulation. Theabrown (TB), a natural compound extracted from black tea, exhibits lipid-lowering and antioxidant properties, but its protective effects on PCB138-induced liver injury have not been thoroughly investigated. Following a biphasic experimental design, juvenile male C57BL/6J mice were subjected to chronic PCB138 exposure (100 μg/kg, oral gavage every other day) for 48 weeks, with subsequent administration of TB (225 mg/kg/day) for an 8-week recovery duration. Long-term PCB138 exposure resulted in elevated liver/body weight ratio, hepatic triglyceride/cholesterol accumulation, and histopathological lipidosis, confirming MAFLD progression. Mechanistically, chronic oral exposure to PCB138 induced multi-organ dysregulation, characterized by: (i) intestinal barrier disruption, (ii) gut microbiota dysbiosis, (iii) disruption of the gut-liver bile acid axis accompanied by hepatic accumulation of lithocholic acid (LCA), taurolithocholic acid (TLCA), taurodeoxycholic acid (TDCA), and glycodeoxycholic acid (GDCA), and (iv) upregulated hepatic fatty acid synthase (FASN) expression, thereby accelerating de novo lipogenesis. TB administration for another 8 weeks attenuated these MAFLD manifestations, evidenced by mitigated hepatic lipidosis, repaired intestinal defenses, microbiota normalization, and bile acids rebalance. Using alpha mouse liver 12 (AML12) cells, we demonstrated that GDCA activated sterol regulatory element-binding protein 1 (SREBP1) expression, promoting lipogenesis. This study establishes long-term environmental PCB138 exposure as a driver of MAFLD via gut-liver axis activating lipogenic pathways and microbial-metabolic crosstalk. TB emerges as a potential protective agent by targeting bile acids-mediated SREBP1/FASN signaling, offering insights into environmental pollutant toxicity mitigation and MAFLD management.
研究领域:
环境毒理学
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肝病学
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营养科学
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微生物学
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药理学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2022
·
IF 6.056
Lijuan Ma,Yuxi Peng,Liping Du,Linqi Zhang,Wenzhe Tong,Yanru Weng,Dongguang Xiao,Huiling Zhang,Jihong Huang
As a typical Chinese tea, Pu-erh tea attracts much attention due to its unique flavor formed by taste and aroma compounds. To study the effects of taste compounds on the aroma release, model solutions containing five typical methoxyphenolic compounds (MCs) and main taste compounds with different concentrations were prepared based on the analysis of Pu-erh tea samples. GC-MS results indicated that the release of five MCs was inhibited by theabrownin, tea polysaccharide, tea polyphenol and catechins. The release of 1,2-dimethoxybenzene, 3,4-dimethoxytoluene and 1,2,3-trimethoxy-5-methyl-benzene was promoted by gallic acid under a low concentration (≤4 mg/g). Statistically, gallic acid had the most significant effect on the release of MCs. Isothermal titration calorimetry suggested that hydrogen bonds and hydrophobic effects had potential contributions to the interaction between taste and aroma compounds. This work will provide the research basis for revealing the formation mechanism of tea flavor.
研究领域:
食品科学
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化学
·
农业科学
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产品关联
DOI
高影响因子
Foods
·
2024
·Vol. 13
·期 5
·753
·
IF 4.7
Xiaomei Wen,Shanjie Han,Jiahui Wang,Yanxia Zhang,Lining Tan,Chen Chen,Baoyu Han,Mengxin Wang
The storage period of tea is a major factor affecting tea quality. However, the effect of storage years on the non-volatile major functional components and quality of green tea remains largely unknown. In this study, a comparative analysis of organic green teas with varying storage years (1–16 years) was conducted by quantifying 47 functional components, using electronic tongue and chromatic aberration technology, alongside an evaluation of antioxidative capacity. The results indicated a significant negative correlation between the storage years and levels of tea polyphenols, total amino acids, soluble sugars, two phenolic acids, four flavonols, three tea pigments, umami amino acids, and sweet amino acids. The multivariate statistical analysis revealed that 10 functional components were identified as effective in distinguishing organic green teas with different storage years. Electronic tongue technology categorized organic green teas with different storage years into three classes. The backpropagation neural network (BPNN) analysis demonstrated that the classification predictive ability of the model based on the electronic tongue was superior to the one based on color difference values and 10 functional components. The combined analysis of antioxidative activity and functional components suggested that organic green teas with shorter storage periods exhibited stronger abilities to suppress superoxide anion radicals and hydroxyl radicals and reduce iron ions due to the higher content of eight components. Long-term-stored organic green teas, with a higher content of substances like L-serine and theabrownins, demonstrated stronger antioxidative capabilities in clearing both lipid-soluble and water-soluble free radicals. Therefore, this study provided a theoretical basis for the quality assessment of green tea and prediction of green tea storage periods.
研究领域:
食品科学
·
化学工程
·
神经网络
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农业化学
·
植物科学
✓ 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）