Frontiers in Sustainable Food Systems
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2024
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IF 3.7
Wang Qiwei,Shi Daliang,Hu Jiajing,Tang Jiahao,Zhou Xianxiu,Wang Lilei,Xie Jialing,Jiang Yongwen,Yuan Haibo,Yang Yanqin
Rolling plays an important role in shaping the characteristic quality of black tea. However, the dynamic alterations in volatile compounds during the rolling process remain unclear, which hampers the quality control of black tea. In this study, the dynamic changes of volatile compounds in Congou black tea throughout the rolling process were explored by a combination of GC-E-Nose and GC–MS analysis. The results of PCA and PLS-DA by GC-E-Nose revealed significant alterations in the volatile profiles, particularly at the 15-min rolling stage. A total of 82 volatile compounds including eight categories were identified in Congou black tea during the rolling process. The most abundant volatiles were aldehydes, alcohols, and esters. Through the integration of variable importance in the projection >1 and p < 0.05, 21 volatile compounds were pinpointed as pivotal volatiles responsible for distinguishing diverse rolling processes. According to their pathways, glycoside-derived volatiles (GDVs) (such as linalool and geraniol) and fatty acid-derived volatiles (FADVs) (such as (Z)-2-hexen-1-ol and hexanal) highlighted the pivotal role in the formation of the aroma of black tea during rolling process. GDVs, characterized by floral, honeyed, and fruity aromas, reached the lowest point at 35-min rolling and subsequently rebounded. FADVs exhibited an ascending trajectory during the initial 15-min rolling, followed by a downward trend. These findings provide invaluable insights into the aroma evolution during the rolling stage, offering strategies for enhancing the aroma quality of Congou black tea.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2025
·
IF 9
Iradukunda Blaise,Xinjie Liu,Jiafu Qu,Zhuoqing Lu,Xinyue Ma,Nan Xu,Xing Yan
This study aims to improve the applicability of green-synthesized nano zero-valent iron (GT-nZVI) for wastewater treatment under natural pH conditions by developing a novel -nZVI composite stabilized with polystyrene sulfonate (PSS) and green tea polyphenols (GT-nZVI@PSS) at different PSS/Fe mass ratios (0.01–0.5) for Pb(II) removal. Particular emphasis was placed on elucidating the influences of humic acid (HA) and sulfate ubiquitous constituents in wastewaters on Pb(II) removal performance, with the underlying mechanisms of their effects systematically clarified. Results demonstrated that GT-nZVI@PSS (PSS/Fe = 0.05) exhibited excellent Pb(II) removal at neutral pH, primarily driven by enhanced Pb(II) reduction and Pb 0 precipitation. This performance is mainly attributed to improved dispersibility resulting from the synergistic effects of PSS and tea polyphenols on the particle surface. HA and sulfate exerted opposing effects on Pb(II) removal by GT-nZVI@PSS. At low concentrations, HA enhanced Pb(II) uptake by increasing the surface negative charge, improving particle dispersion, and providing additional active sites for the formation of Fe–HA/Pb complexes. In contrast, sulfate inhibited Pb(II) removal by disrupting the polyphenol coating and forming surface sulfate–iron species and PbSO 4 precipitates, thereby accelerating passivation and reducing Fe release. However, at high concentrations, excessive HA molecules formed large aggregates that enveloped the particle surfaces, ultimately hindering Pb(II) access to the active sites of GT-nZVI@PSS. Conversely, high concentrations of sulfate promoted GT-nZVI@PSS corrosion, facilitating Fe 0 release and thereby enhancing Pb(II) removal. These findings highlight the crucial role of water matrix constituents in modulating the performance of GT-nZVI@PSS, as an eco-friendly and cost-effective material.
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Desalination and Water Treatment
·
2024
·
IF 1
Chunping Liu,Yongrui Pi,Guodong Ju,Zhaozhao Wang
A low-cost adsorbent, tea waste was activated by nitric acid and adsorption of Cu 2+ and direct sky blue 5B from aqueous solution was investigated. Response surface methodology (RSM) was used to study the adsorption process. The RSM results showed that temperature and concentration are major factors to modelling Cu 2+ and direct sky blue 5B adsorption, respectively. Higher temperature has a positive effect on the adsorption of Cu 2+ and direct sky blue 5B. Under the same temperature, the adsorption capacity was increased along with the concentration till maximum is attained both for Cu 2+ and direct sky blue 5B. The optimum condition of the RSM for Cu 2+ was determined as following: pH 4.5, 45°C, concentration of 1.5 × 10 –2 mol/L; for direct sky blue 5B, the optimal condition were pH 6.0, 25°C, 1.5 × 10 –2 mol/L. The equilibrium data during adsorption were modeled to Langmuir and Freundlich isotherms for Cu 2+ . For direct sky blue 5B, the equilibrium data were well presented by Freundlich isotherms. The maximum adsorption capacities were determined at 59.88 mg/g for Cu 2+ , 58.27 mg/g for direct sky blue 5B. The kinetic data fit to pseudo-second-order equation well with correlation coefficients larger than 0.99. The results strongly support that tea waste can be used as an economic and excellent adsorbent for the removal of Cu 2+ and direct sky blue 5B from contaminated water.
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JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2020
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IF 5.647
Yiqiao Xie,Jiawei Huang,Haojie Dong,Tong Wu,Ling Yu,Guoqiang Liu,Yang Yu
Dye decolorization is of crucial concern for effectively treating dye wastewater. In this study, rapid and effective decolorization of malachite green cationic dye was achieved by tea polyphenols and ferric ions under moderate conditions. Approximately 96.2% of decolorization efficiency could be obtained within the first 10 min at the initial dye concentration of 50 mg/L. The proposed method can perform excellently in a wide pH range of 5–9 and decolorization kinetics of malachite green under different solution pH were well fitted by the pseudo-second-order model. After the decolorization, only a slight reduction of tea polyphenols was observed, while the strength of peaks assigned to nitrogen-containing groups was significantly weakened, indicating that the N-demethylation reaction might occur during the decolorization process. The nucleophilic attack of deprotonated hydroxyl groups of tea polyphenols was proposed as the decolorization mechanism. The presence of ferric ions at an appropriate dosage could promote the deprotonation process and therefore enhance decolorization efficiency, while excess ferric ions in solution might compete with malachite green dye towards reductive sites on tea polyphenols. The findings from this study provided an economical and environmentally friendly technique for the effective decolorization of dye wastewater.
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FOOD CHEMISTRY
·
2026
·
IF 10.4
Linchi Niu,Yuning Feng,Shan Zhang,Zhizhen Fang,Rui Liang,Zhenxing Xu,Xujiang Shan,Qinghua Zhou,Haibo Yuan,Yongwen Jiang,Jia Li
458 lipids and 59 volatiles in black tea fermentation were analyzed by multi-omics. • 120 lipids and 27 FADVs were predominantly altered during black tea fermentation. • C18:2, C18:3-glycerophospholipids and glycolipids were potential aroma precursors. • Both non-enzyme auto-oxidation and enzyme oxidation formed FADVs in fermentation. • Simulated fermentation using crude enzyme and FA 18:2 yielded 9 FADVs with OAV > 1. Lipid metabolism and fatty acid-derived volatiles (FADVs) are crucial in black tea aroma formation. Herein, dynamic variations of 458 lipids and 59 volatiles during black tea fermentation were investigated by multi-omics using UHPLC-Q-Exactive/MS and GC–MS. 120 lipids and 27 FADVs were predominantly altered during fermentation. Glycerophospholipids and glycoglycerolipids harboring 18:2 and 18:3 fatty acyls were highlighted as potential aromatic precursors. Model experiments using linoleic acid revealed firstly that both non-enzyme auto-oxidation and enzyme oxidation participated in FADVs formation. 28 FADVs were generated at an abundance of 156.01 μg/L by non-enzyme oxidation. Whereas, 32 FADVs with an abundance of 215.01 μg/L were produced in simulated fermentation system containing crude enzyme, covering fatty aldehydes, esters, ketones, alcohols, furans, etc. Specifically, 9 FADVs exhibited odor activity value >1 in simulated fermentation, e.g., hexanal, 2-pentanone, heptanal, 2-pentylfuran, mainly imparting fresh, floral, fruity notes. This study provides novel insights into black tea aroma formation. Download: Download high-res image (290KB) Download: Download full-size image
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高影响因子
Foods
·
2026
·Vol. 15
·期 16
·2894
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IF 6
Chengjiang Wei,Weiwei Wu,Zhechen Han,Peng Zhang,Chenglong Li,Siqing Du,Qi Lin,Fuming Lin,Weijiang Sun
Wuyi rock tea (WRT) processed from dew-soaked leaves is often characterized by a pronounced grassy off-odor defect. However, the key odor-active compounds and their potential underlying mechanisms remain unclear. In this study, quantitative descriptive sensory analysis, GC–MS, GC–O, molecular docking, and aroma addition tests were used to systematically elucidate the chemical basis and potential perceptual mechanisms of the key grassy off-odor in WRT processed from dew-soaked leaves. The results showed that 16 volatile compounds were significantly associated with dew, among which (E,E)-2,4-heptadienal, octanal, hexanal, and heptanal were identified as the major odor-active compounds responsible for the grassy off-odor. The accumulation of these aldehydes may be associated with lipid peroxidation under the influence of dew. Aroma addition and omission tests confirmed that (E,E)-2,4-heptadienal contributed significantly to grassy off-odor formation and that additive effects existed among the four compounds. Molecular docking predicted that the four key odor-active compounds interacted with human olfactory receptors, including OR1A1 and OR10J5, through hydrogen bonds and hydrophobic interactions, thereby affecting grassy off-odor perception, with predicted binding energies below −4.7 kcal/mol. This study elucidated the effects of dew on the formation of the characteristic aroma of WRT and provides a scientific basis for tea quality regulation and processing improvement.
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FOOD RESEARCH INTERNATIONAL
·
2026
·
IF 8.8
Yingying Liu,Xue Wang,Yun Zhang,Danyang Zhang,Lei Zhu,Hongping Chen,Yunfeng Chai
2-Bromo- N,N -dimethylethanamine was used for fatty acids derivatization for the first time. • The derivatization method is simple, sensitive and exhibits minimal reagent residue. • The changes of 26 FFAs in different processing stages of black tea were profiled. • C16:0, C18:0, C18:2 and C18:3 displayed the most pronounced changes in black tea processing. As important precursors to aromatic substances in black tea processing, fatty acids deserve quantitative detection throughout the manufacturing procedure. We present a liquid chromatography/quadrupole orbitrap mass spectrometry method based on pre-column derivatization, which allows the simultaneous determination of 44 free fatty acids (FFAs, C3-C24). In this method, 2-bromo- N , N -dimethylethanamine was first used as a new derivatizing reagent. The derivatization system is simple and exhibits minimal reagent residue. After derivatization, the detection sensitivity of FFAs was increased by 2–4 orders of magnitude with satisfactory limit of quantitation (0.1–5 pg). Using this method, a total of 26 FFAs in black tea samples were identified and their dynamic changes at different processing stages were profiled. Among them, palmitic acid (C16:0), stearic acid (C18:0), linoleic acid (C18:2) and linolenic acid (C18:3) displayed the most pronounced changes in content and may therefore act as key indicators for monitoring black tea manufacture. Specifically, C16:0 and C18:0 exhibited a fluctuating downward trend (from 254.0 to 133.4 and 292.9 to 83.7 mg kg −1 , respectively), whereas C18:2 and C18:3 increased with fluctuations (from 18.8 to 55.0 and 13.6 to 69.2 mg kg −1 , respectively). Download: Download high-res image (142KB) Download: Download full-size image
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2026
·
IF 8.7
Hui Xu,Wendan Song,Anqi Duan,Wenqiang Ye,Yu Yang,Yeqing Yu,Naifu Wang,Yibin Zhou,Yiqun Du,Zhenyu Yu
This study constructed BS–TIDF composite systems with different levels of addition using large-leaf yellow tea insoluble dietary fiber (TIDF) and buckwheat starch (BS), and investigated their physicochemical properties, in vitro digestibility, and 3D printing characteristics. Dietary fiber is generally resistant to digestion and absorption in the upper gastrointestinal tract and therefore passes through the digestive system largely intact, contributing to satiety, accelerating intestinal transit, and increasing fecal bulk. The results showed that with increasing TIDF content, the L ⁎ value of the samples significantly decreased, the a ⁎ value first increased and then decreased, and the b ⁎ value markedly increased. The final viscosity increased from 4721.00 cP to 5374.00 cP, while the breakdown and setback values decreased. Textural properties, including hardness, cohesiveness, gumminess, chewiness, and resilience, were overall reduced, whereas adhesiveness increased. The microstructure became more compact, with cracks appearing at higher TIDF levels. Particle size first decreased and then stabilized; the short-range ordered structure of starch was weakened, and the relative crystallinity dropped from 11.54 to 6.60. The mobility of weakly bound water and free water was enhanced, promoting partial transformation of free water into bound water. Meanwhile, resistant starch (RS) content rose from 21.44% to 32.80%, and the predicted glycemic index (pGI) decreased from 74.70 to 61.76. In terms of 3D printing performance, formulations with 0–3% TIDF maintained good shape fidelity, whereas printing accuracy decreased when the addition level exceeded 6%. These findings provided a theoretical basis for dietary fiber–modified starch systems and the development of glycemic index (low-GI) and 3D-printed functional foods.
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FOOD CHEMISTRY
·
2026
·
IF 10.4
Jiahao Tang,Xianxiu Zhou,Jiajing Hu,Guangyue Hou,Yimin Yang,Yuhang Wang,Yongwen Jiang,Haibo Yuan,Yanqin Yang
Polysulfides constituted the most abundant category during black tea processing. • Final drying was identified as the most critical phase governing VSCs profile. • Methional and dimethyl sulfide were the most impactful aroma contributors. • Proposed pathway pinpointed methanethiol as core intermediate. Volatile sulfur compounds (VSCs) are crucial in defining the distinctive aroma profile of black tea. This study systematically investigated the dynamic evolution and formation mechanisms of VSCs throughout the black tea processing. Nine VSCs were identified and quantified, with polysulfides representing the most abundant category. PLS-DA effectively distinguished different processing stages (R 2 Y = 0.978 and Q 2 = 0.931), with drying identified as a critical phase influencing VSC profiles. OAV assessment revealed that methional (cooked potato-like) and dimethyl sulfide (cooked corn-like) were the predominant aroma contributors, with OAVs consistently exceeding 5000 and 3000, respectively. Methionine–glucose thermal reaction models further demonstrated that both reaction time and temperature critically govern the sequential generation and transformation of key VSCs. A plausible formation pathway was proposed, highlighting methionine as the key precursor and methanethiol as a core intermediate. These findings provide mechanistic insights for the targeted regulation of sulfur-related aroma formation during tea processing. Download: Download high-res image (184KB) Download: Download full-size image
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FOOD CHEMISTRY
·
2026
·
IF 10.4
Yuhang Zhang,Li Niu,Ruoxian Wang,Na Li,Juan Li,Mingzhi Zhu,Kunbo Wang
Compared with Baimudan, Baihaoyinzhen contained higher levels of amino acids, catechins and volatile compounds. • Compared with Baihaoyinzhen, Baimudan contained higher levels of phenolic acids, flavonols and flavones. • Isoschaftoside, salicylic acid and 4-hydroxybenzoic acid were key taste compounds in white tea. • Benzaldehyde, phenethyl alcohol and citral were shared key aroma compounds in white tea. In this study, fresh tea leaves were collected from five major white tea production regions in China and processed into Baihaoyinzhen (silver needle) and Baimudan (white peony). Electronic sensory technologies were used to characterize electronic sensory response profiles, while UHPLC-QqQ-MS and HS-SPME-GC–MS were used to quantify 18 amino acids, 52 polyphenolic compounds, and 64 volatile compounds. Overall, Baihaoyinzhen contained higher levels of volatile compounds, amino acids, and catechins than Baimudan. In contrast, Baimudan exhibited higher total contents of phenolic acids, flavonols and flavones than Baihaoyinzhen. Glu and Phe were linked to sweetness and astringency, respectively, whereas EGCG was consistently associated with astringency. Isoschaftoside, salicylic acid and 4-hydroxybenzoic acid were identified as key compounds associated with taste differences. For aroma, benzaldehyde, phenethyl alcohol and citral were identified as shared key aroma compounds in Baihaoyinzhen and Baimudan. These findings provide a multidimensional chemical basis for quality differentiation among Chinese white teas. Download: Download high-res image (180KB) Download: Download full-size image
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Plants-Basel
·
2026
·Vol. 15
·期 14
·2125
·
IF 4.7
Wenjing Zhang,Yuting Li,Shuaibo Shao,Xingyuan Yao,Chengzhe Zhou,Zhong Wang,Yuqiong Guo
High-altitude environments provide a favorable basis for tea quality formation, but suitable processing parameters for high-altitude Oolong Tea (HAOT, Camellia sinensis (L.) O. Kuntze) remain unclear. This study optimized key processing parameters for HAOT using a three-factor, three-level orthogonal design involving withering method, shaking intensity and standing time. Sensory evaluation, quantitative descriptive analysis (QDA), macro-compositions determination, headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS), multivariate statistics and correlation analysis were used to clarify quality differences and their chemical basis. Leaf anatomical observation showed that high-altitude fresh leaves had a thicker cuticle and more compact mesophyll structure, suggesting the need for targeted processing regulation. Range analysis indicated that shaking intensity had the largest R value for sensory scores, followed by withering method, whereas standing time showed a comparatively small R value. The favorable combination was combined withering, heavy shaking (6 rounds) and 60 min standing, hereafter referred to as FHM. FHM showed the highest floral and fruity aroma scores and produced a mellow, full-bodied taste with a sweet aftertaste. It also contained significantly higher flavonoid and soluble sugar levels than the other processing combinations. A total of 65 volatile organic compounds were detected, with terpenoids and esters as the dominant classes. ROAV analysis identified geraniol, linalool, β-ionone, ( E )-nerolidol and benzaldehyde as representative major aroma-active compounds, while geraniol and linalool were especially prominent in FHM. Correlation analysis further linked flavonoids and soluble sugars with positive taste attributes, and linalool and geraniol with floral–fruity aroma. These results provide a practical basis for optimizing HAOT processing and improving product quality.
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高影响因子
Food & Function
·
2025
·
IF 5.4
Yina Huang,Yao He,Yunjie Cai,Yubin Cheng,Xunmei Shi,Jingyu He,Kesheng Wu,Hua Wei
Black tea is commonly used for tea beverage production and has been shown to be an effective natural ingredient to prevent experimentally induced colitis. However, there is limited evidence to show whether black teas of different origins demonstrate similar anti-inflammatory capacity in colitic mice. In this study, mice were daily administered with black tea extracts of lapsang, keemun or dianhong for 1 week prior to receiving 4% dextran sulfate sodium for inducing colitis. Both the lapsang and keemun extracts exhibited better anti-inflammatory effects than dianhong extract, as evidenced by the former two tea extracts that enhanced intestinal barrier functions (up-regulation of MUC2 and ZO-1 and increased population of goblet cells), and decreased colonic and serum pro-inflammatory cytokines. We deduced that GC might be a key contributor to the anti-colitis effects of black tea, potentially through synergistic interactions with other components at an optimal ratio to enhance anti-inflammatory efficacy. Fecal microbiome analysis showed that gut microbiome was differentially modulated by lapsang and keemun extracts. Their anti-colitic effects were dependent on gut microbiome as shown by the loss of such protection in DSS mice treated with broad-spectrum antibiotics (ABX) for significant microbiome alterations. Mechanistically, colonic transcriptomic analysis showed the differential impact of lapsang and keemun extracts on colitis via modulating gene expressions of IL-17 pathway and glutamatergic synapse, respectively. Further qPCR and immunohistochemistry assays verified aforementioned pathway modulation. Together, our study provided a roadmap for understanding the effects of different black tea types on colitis and for providing potential directions on nutritional modulation of colitis.
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高影响因子
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