Chinese Journal of Chromatography
·
2021
·Vol. 39
·期 4
·349-356
·
IF 0
Qidong YU,Lan ZHANG,Wenmin ZHANG,Jiangfan YANG
Pyrethroids (PYs) have been widely used to control pests and prevent diseases in tea gardens. However, with the increasingly stringent pesticide testing standards in the import and export trade of tea, there is an urgent need for methods to detect trace amounts of PYs in tea. In this study, a covalent organic framework (COF) material TpBD with excellent thermal/chemical stability, high porosity, and a large specific surface area was prepared by a room-temperature solution-suspension approach (SSA). TpBD-coated solid phase microextraction (SPME) fibers were fabricated by coating the material on etched stainless-steel fibers by a simple physical coating method. The fibers were used in combination with gas chromatography-tandem mass spectrometry (GC-MS/MS) to establish a highly sensitive method for the detection of PYs. The enrichment factors of this method for cyfluthrin, cypermethrin, flucythrinate, fenvalerate, and deltamethrin were 702-2687. The method showed low LODs (0.1-0.5 ng/L), wide linear ranges (0.2-800 ng/L), good linearities (correlation coefficients ( R )≥0.9991) and acceptable repeatabilities (RSD≤11.0%, n =3). Green tea and oolong tea samples were analyzed using the developed method, and trace levels of the five PYs were successfully detected. The recoveries of the spiked PYs in the real green tea and oolong tea samples were in the range of 80.2%-109.5%. Experimental results showed that the established analytical method is suitable for the determination of PY pesticides in tea. Furthermore, the TpBD material was successfully prepared by the SSA method, demonstrating that the method has good universality and excellent potential for the simple synthesis of other COF materials.
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PubMed
Food Science and Technology
·
2022
·
IF 2.602
ZHU Wen,FANG Xin,WANG Wenfeng,XU Wencan,CHEN Wenjun,WU Shuang,HUANG Youyi,WANG Shengpeng
Thermophilic bacteria play an important role in aroma formation during pile-fermentation process of dark tea. With the aim to reveal the impact of thermophilic bacteria on volatile compounds in dark tea, Bacillus licheniformis (thermophilic bacteria) were inoculated into sun-dried green tea for spontaneous fermentation. In this study, headspace solid phase microextraction combined to gas chromatography mass spectrometry (HS-SPME-GC-MS), odor activity value (OAV), principal component analysis (PCA) and orthogonal partial least squares discrimination analysis (OPLS-DA) were employed to investigated the characteristics of volatile compounds during thermophilic bacteria pile-fermentation. According to HS-SPME-GC-MS, a total of 64 volatile compounds were identified. PCA revealed that tea samples could be clearly discriminated from each other. Furthermore, sulcatone, hexanoic acid, linalool, 2-methyl-trans-decalin, myrtenal, and α-ionone were found to play an important role in discrimination of tea samples, based on OPLS-DA. In addition, the OAV could effectively characterize the aroma contribution of volatile compounds during thermophilic bacteria pile-fermentation, and (Z)-linalool oxide (furanoid), α-ionone, (E)-2-nonenal, and linalool were the critical volatile compounds of aroma quality in dark tea. This study provides insight into volatile compounds characteristics during thermophilic bacteria pile-fermentation in dark tea.
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高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2019
·
IF 3.858
Yeqing Jia,Yahui Wang,Meng Yan,Qian Wang,Houjun Xu,Xuesheng Wang,Huanying Zhou,Yulan Hao,Manman Wang
A novel magnetic metal organic framework composite (Fe 3 O 4 @MOF-808) was synthesized by a facile solvothermal method and applied as an adsorbent for the magnetic solid phase extraction (MSPE) of benzoylurea insecticides (BUs) from tea beverages and juice samples. The prepared materials were characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), vibrating sample magnetometry measurements and N 2 adsorption-desorption experiments. The adsorption (adsorbent amount, extraction time and pH) and elution (elution solvent, elution volume and time) parameters were investigated in detail. Under the optimized experimental conditions, Fe 3 O 4 @MOF-808 exhibited simpler and better reusability than commercial C 18 , with an equivalent adsorption effect. Notably, π-π interactions, hydrophobic interactions and hydrogen bonding interactions contributed to the good adsorption of BUs by Fe 3 O 4 @MOF-808. Finally, a simple and sensitive method was established using Fe 3 O 4 @MOF-808-based MSPE coupled with high-performance liquid chromatography (HPLC). It provided low limits of detection (0.04–0.15 ng/mL), wide linear ranges (0.15–50 ng/mL) and satisfactory recoveries (84.6–98.3%). The proposed method was successfully applied for the fast and sensitive determination of BUs in tea beverages and juice samples.
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高影响因子
Journal of Cleaner Production
·
2025
·
IF 10
Weiwei Yu,Yuanxin Liu,Jianglin Tan,Yue Liang,Jiang Hu,Qing Tu,Shuo Yang,Ji Li,Sikai Zhao,Yang Liu,Xinyan Li,Yan Luo,Shiling Chen
The sulfate-based advanced oxidation processes (AOPs) are an emerging and efficient remediation technology in the water treatment field, but developing efficient and eco-friendly heterogeneous catalysts remains challenging. In this study, we synthesized chitosan/tea polyphenol-functionalized nanoscale zero-valent iron (CS/GT-nZVI) to activate low-toxicity sulfite species. Compared with traditional iron-based catalytic materials, CS/GT-nZVI effectively overcomes agglomeration and oxidation issues and exposes more active sites. The system achieved high degradation efficiency for the representative PPCPs, carbamazepine (CBZ). Furthermore, it demonstrated strong performance in pilot-scale tests, effectively treating CBZ in both wastewater purification tail water and pharmaceutical tailwater samples. Degradation pathways and corresponding ecotoxicological assessments revealed the toxicity of intermediate products generated during incomplete CBZ degradation, emphasizing the need for complete mineralization to mitigate ecological risks. This study provides a safe and cost-effective approach for mitigating PPCPs pollution sourced from urban water treatment system, with significant implications for enhancing water quality and ecological safety.
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高影响因子
FOOD CONTROL
·
2016
·
IF 3.388
Juan Wang,Shansong Huang,Ping Wang,Yaling Yang
A novel method, termed ionic liquid-based hollow fibre liquid phase microextraction (IL-HF-PLME), coupled with high-performance liquid chromatography (HPLC) was developed for separation and preconcentration of three phthalate esters (PAEs) in tea beverage . In the present study, ionic liquid 1-butyl-3-methy-limidazolium hexafluorophosphate ([BMIm]PF 6 ) was placed in the porous-walled polypropylene hollow fibre as the acceptor phase, and nonanol was used as the supported liquid membrane phase that accomplished extraction. Several important parameters influencing the extraction efficiency were investigated in detail. Under the optimized conditions, good linearity occurred in the range of 5–1000 ng mL −1 with the correlation coefficients values above 0.998. The limits of detection ranged from 0.67 to 1.73 ng mL −1 . Recoveries of three PAEs in two kinds of spiked tea beverage samples (PAEs, 10.0–100.0 ng mL) were between 94.2 and 103.4%, with relative standard deviations (RSDs) ranged from 1.77 to 3.02%. The enrichment factors were 200. The developed IL-HF-PLME method allowed the simple, rapid, and sensitive determination of phthalate esters in tea beverage samples with an extraction time of just 4 min.
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高影响因子
Journal of Cleaner Production
·
2019
·
IF 6.395
Qiong Ouyang,Fangying Kou,Pokeung Eric Tsang,Jintao Lian,Jingyi Xian,Jianzhang Fang,Zhanqiang Fang
Iron-based catalysts (GFe0.5) were successfully prepared from tea polyphenols (TP) and ferric trichloride and used as a heterogeneous Fenton-like catalyst for the degradation of lincomycin (LCM). The results showed that a GFe0.5 dosage of 0.01 g/L could completely degrade a 20 mg/L concentration of LCM in 90 min, and assessment of the toxicity to luminous bacteria showed that the GFe0.5/H 2 O 2 system effectively reduced the toxicity risk posed by this pollutant. The results of transmission electron microscopy , X-ray diffraction (XRD), Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and other characterisations showed that the synthetic material had a triangular structure similar to that of nonacarbonyldiiron, with Fe 2+ , Fe 3+ and organic groups attached to the triangular structure's surface. That is, the present environment-friendly synthesis produces an Fe-based material resembling a mixture of nonacarbonyldiiron and ferrous chloride. Free-radical capture and electron spin resonance experiments confirmed that ·OH was the main active free radical in the degradation mechanism of the iron-based material. Cyclic experiments, inductively coupled plasma and XRD characterisation of the materials after the reaction showed that the loss of free iron was the main reason for the decrease of activity. The free iron in the Fe-based material becomes bound during the reaction, which effectively avoids the excessive consumption of Fe 2+ in the prophase of the Fenton-like reaction, and is the key to both the efficient Fenton-like catalytic ability of GFe0.5, and to preventing the production of iron sludge .
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高影响因子
INTERNATIONAL JOURNAL OF PHARMACEUTICS
·
2021
·
IF 5.875
Xingzi Lan,Yurong Liu,Yaqi Wang,Feng Tian,Xiaomin Miao,Han Wang,Yadong Tang
Preparing wound dressing with dual-delivery of antioxidant and antibacterial agents is highly desirable in clinical wound treatment. Herein, a series of coaxial nanofiber membranes loaded with antioxidant tea polyphenols (TP) in the core and antibacterial ε-poly (L-lysine) (ε-PL) in the shell layer were successfully fabricated by coaxial electrospinning. The physicochemical characterizations by transmission electron microscopy , inverted fluorescence microscopy and fourier transform infrared spectroscopy confirmed the formation of core-shell structure. The results of in vitro drug release indicated that ε-PL exhibited a fast release profile while TP released in a sustained manner, which is favorable to the achievement of quick bacteria inhibition in the initial phase as well as long-term antioxidant activity during wound healing. The antioxidant activity of coaxial nanofibers was found to be increased with the increment of TP content and incubation time . The antibacterial assays against Escherichia coli and Staphylococcus aureus demonstrated that the incorporation of ε-PL in the coaxial nanofibers led to strong antibacterial activity . Additionally, all the coaxial nanofibers possessed good cytocompatibility. Therefore, the prepared coaxial nanofibers simultaneously incorporated with ε-PL and TP are promising as potential wound dressing materials.
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PubMed
高影响因子
Foods
·
2025
·Vol. 14
·期 18
·3223
·
IF 5.1
Xianxiu Zhou,Jiajing Hu,Hongchun Cui,Jiahao Tang,Yongwen Jiang,Haibo Yuan,Jiahua Li,Yanqin Yang
Floral–fruity aroma Pu-erh tea (FFAPET) is highly valued by consumers for its distinctive and appealing fragrance. This study conducted a comprehensive investigation into the volatile components of FFAPET using advanced analytical techniques, including GC-O-MS, GC-MS/MS, aroma recombination, and omission tests. Compared with traditional stale aroma Pu-erh tea, FFAPET exhibited higher levels of alcohols and alkenes. Through GC-O-MS combined with OAV analysis, 10 key active-aroma compounds were identified in representative FFAPET samples. These compounds included (E, E)-2,4-heptadienal, phenylethyl alcohol, geraniol, (E,Z)-2,6-nonadienal, (Z)-4-heptenal, 2-phenethyl acetate, 2,2,6-trimethylcyclohexanone,D-limonene,β-ionone, and linalool, all of which made significant contributions to the development of the characteristic floral–fruity aroma profile. Tests involving aroma recombination and omission further confirmed that seven of these odorants played essential roles in defining the overall aroma of FFAPET. These findings offer valuable theoretical insights for the enhancement and regulation of Pu-erh tea flavor, particularly for the optimization of the floral–fruity aroma characteristics.
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PubMed
高影响因子
Journal of Future Foods
·
2026
·
IF 10.6
Ting Zhang,Zhiying Xu,Mengyang Wei,Xiao Liu,Manyou Yu,Yongqing Zhu,Xiaobo Tang,Shengxiang Chen,Yuanyuan Xiong,Yun Wang,Chen Xia,Chen Liu
Comparative profiling of aroma formation in piling and flowering Tibetan tea. • Stem decoction–assisted flowering enhanced fungal–floral and medicinal aromas. • Nine key volatiles were identified across Tibetan teas pile-fermentation types. • GC–O–MS and ROAV integrated with microbiome data to link aroma with taxa. • Thermophilic fungi and actinobacteria associated with the woody note. Solid-state fermentation can generate diverse aroma profiles, but the outcomes are often difficult to predict and standardize, which limits scalable production and intelligent quality control in fermented foods. Tibetan dark tea provides a relevant model because pile fermentation followed by flowering can produce distinct aroma styles. In this study, we compared four processing regimes to examine flowering under different pile fermentation levels: short piling (S1), tea stem decoction assisted flowering after short piling (S2), long piling (S3), and long piling followed by stem-decoction-assisted flowering (S4). Sensory evaluation revealed clear differences among regimes. S3 showed balanced woody and sweet notes, whereas S4 exhibited stronger medicinal notes together with fungal and floral impressions. GC-O-MS (gas chromatography-olfactometry-mass spectrometry), untargeted volatilomics, and ROAV (relative odor activity value) analysis identified nine key odorants with distinct trends across processes. Correlation analysis suggested that thermophilic fungi such as Thermomyces lanuginosus and heat-tolerant bacteria including Saccharopolyspora gregorii and Staphylococcus gallinarum were positively associated with woody-associated volatiles. In contrast, Leuconostoc, Weissella , and several proteobacteria taxa were negatively associated with grassy aldehydes such as hexanal. Overall, this study integrates sensory profiling, odorant prioritization, and microbiome association analysis to identify candidate odorant markers and associated microbial signatures, providing a basis for future process optimization and aroma quality control in flowering Tibetan dark tea. The framework may also inform aroma design and quality control for other solid-state fermented foods. Download: Download high-res image (183KB) Download: Download full-size image
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高影响因子
POLYMER DEGRADATION AND STABILITY
·
2026
·
IF 8.1
Yi-Zi Wang,Shao-Peng Zhao,Han-Qiao Zhang,Tao Chen,Jiang-Yu Li,Peiqi Yu,Yu Han,Yue Ren,Chuntai Liu,Changyu Shen
Although antioxidants such as vitamin E (VE) and tea polyphenols have been employed to enhance the oxidation resistance of ultra-high molecular weight polyethylene (UHMWPE) for artificial joint applications, the long-term oxidative behavior of tea polyphenol-stabilized, crosslinked UHMWPE under real-time shelf aging remains insufficiently understood. In this study, the performance evolution of crosslinked UHMWPE containing VE, epigallocatechin gallate (EGCG), and lipid-soluble EGCG ( ls EGCG) was investigated after 7 years of real-time shelf storage. Notably, the EGCG-stabilized UHMWPE exhibited a markedly higher crosslink density (≥ 40% increase compared with the VE group) and superior tribological performance, with the coefficient of friction reduced by 16‒35%. Furthermore, it reduced the fraction of submicron wear particles (≤ 1 µm), lowering the potential risk of osteolytic inflammation. The enhanced stabilization efficacy of tea polyphenols, particularly EGCG, originates from their polyphenolic hydroxyl groups, which could effectively quench free radicals and preserve crosslink network during long-term storage. Overall, these findings demonstrate that tea polyphenols represent a durable and effective antioxidant strategy for UHMWPE, with significant potential to extend the clinical service life of joint implants.
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高影响因子
Food Bioscience
·
2026
·
IF 6.2
Xifan Zhan,Xinying Wang,Md Mehedi Hassan,Fangling Jiang,Jiaying Xu,Yuan Zhang,Shanghua Li,Sha Zou,Hongfa Liu,Yi Xu,Quansheng Chen
Pesticide residues in tea pose significant health risks to consumers. This research focuses on developing a surface-enhanced Raman scattering (SERS) sensor using a solid-phase substrate made of Au@Ag@PVP nanoparticles (NPs), combined with machine learning chemometric techniques, for the rapid detection of trichlorfon, carbendazim, and clothianidin in tea. Au@Ag@PVP NPs were immobilized onto anodic aluminum oxide (AAO) filter membranes via vacuum filtration, yielding densely packed NPs that generate strong electromagnetic hot spots, thereby increasing SERS sensitivity. Raman spectra of tea infusions containing different concentrations of pesticides were acquired and analyzed using three machine-learning algorithms. Among these models, competitive adaptive reweighted sampling-partial least squares (CARS-PLS) demonstrated superior predictive performance, with Rc = 0.9950, Rp = 0.9942, and RPD = 9.2893 for trichlorfon; Rc = 0.9955, Rp = 0.9942, and RPD = 9.1010 for carbendazim; and Rc = 0.9981, Rp = 0.9957, and RPD = 9.7523 for clothianidin. This approach enables the rapid, quantitative detection of pesticide residues with minimal sample preparation and high sensitivity, representing a practical method for monitoring tea safety.
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高影响因子
FOOD CHEMISTRY
·
2026
·
IF 10.4
Dong Wang,Xinrui Huang,Yan Liu,Lian He,Xiaoqin Wu,Fan Wu,Liyong Luo,Liang Zeng
Dali-variety ( Camellia taliensis (W. W. Sm.) Melch.) black tea (DLBT) possesses distinctive tropical fruit and citrus aromas, yet its key aroma compounds and formation mechanism remain unclear. To address this, we employed a molecular sensory science approach. GC–MS identified 143 volatiles across 10 DLBT samples, from which 21 aroma-active compounds were screened via GC-O/AEDA. OAV calculations further pinpointed 9 key aroma compounds. Reconstitution and omission experiments definitively identified octanal as the primary source of the tropical fruit note, while linalool, nonanal, and decanal were crucial for the sweet citrus character. Dynamic profiling of volatiles, enzyme activities and gene expression during processing identified withering and drying as key stages for DLBT's unique aroma. Water stress during withering rapidly upregulates the activities of fatty acid metabolic enzymes and the expression levels of related genes, promoting the accumulation of key aroma precursors and laying the material foundation for the final aroma.
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PubMed
高影响因子
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