NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 11
·8791-8799
·
IF 3.201
Huazi Wang,Chaoran Liu,Xiaodong Huang,Chendi Jia,Yang Cao,Lu Hu,Runhua Lu,Sanbing Zhang,Haixiang Gao,Wenfeng Zhou,Donghui Xu
In the present study, a convenient, low-cost, sensitive and environmentally friendly method for the determination of four benzoylurea insecticides (BUs) in water and tea beverage samples was developed. The alkalized luffa sponge fibers (AL) were modified by the ionic liquid 1-hexadecyl-3-methylimidazolium bromide ([C16MIM]Br) through physisorption and used as the sorbent of dispersive solid-phase extraction (DSPE). The sorbent was characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The retained analytes were eluted using 200 μL of methanol and then quantified by high performance liquid chromatography-ultraviolet detection (HPLC-UVD). The influences of extraction parameters of [C16MIM]Br-AL-DSPE on the BUs were thoroughly studied. Under the optimal conditions, good linearity was observed over the concentration range of 1–500 ng mL−1, with coefficients of determination greater than 0.99. The limits of detection (LODs) of the developed method were 0.14–0.21 ng mL−1 in water and 0.19–0.23 ng mL−1 in tea beverage samples. Satisfactory recoveries were achieved in the range of 72.8–89.3%, with relative standard deviations lower than 10%. Finally, the established [C16MIM]Br-AL-DSPE-HPLC-UVD method was successfully applied for the determination of BU residues in environmental water and tea beverage samples.
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BIOMEDICAL CHROMATOGRAPHY
·
2018
·Vol. 32
·期 9
·e4281
·
IF 1.688
Peng-Cheng Guo,Hua-Dan Shen,Jiang-Ji Fang,Tian-Ming Ding,Xiao-Ping Ding,Jun-Feng Liu
An on-line high-performance liquid chromatography–biochemical detection (HPLC-BCD) method, in which compounds separated by HPLC were on-line reacted with enzyme and substrate solutions delivered by flow injection and the enzyme inhibition signal was collected by UV detection, was developed to rapidly screen α -glucosidase inhibitors from green tea extracts in this study. The chromatographic fingerprints and enzyme inhibition profiles of the different brands of green tea could be simultaneously detected by the on-line HPLC-BCD method. Enzyme inhibition profiles were detected by the UV detector at 415 nm based on the reaction of α -glucosidase and p -nitrophenyl α - d -glucopyranoside (PNPG). PNPG (1.25 m m ), α -glucosidase (0.4 U/mL) and the flow rate 0.07 mL/min were applied as optimized parameters to detect α -glucosidase inhibitors in green tea. Four components in green tea showed α -glucosidase inhibition action and three of them were identified as HHDP-galloyl glucose, (−)-epigallocatechin-3-gallate and (−)-epicatechin-3-gallate by HPLC–fourier-transform mass spectrometry (HPLC-FTMS). Two brands of green tea derived from Mengding and Enshi mountainous areas might be superior to the other samples in the prevention and treatment of diabetes owing to their stronger activities of enzyme inhibitors. The proposed on-line HPLC-BCD method could be used to rapidly identify the potential enzyme inhibitors in complex matrixes.
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COLLOIDS AND SURFACES B-BIOINTERFACES
·
2018
·
IF 3.997
Jie Zhang,Xiuli Ren,Xiaohan Tian,Peng Zhang,Zhenhua Chen,Xun Hu,Xifan Mei
Developing safe and effective stimuli-responsive nanocarriers is very important for tumor chemotherapy. In this work, bovine serum albumin (BSA) and green tea polyphenol (TP) were used to prepare glutathione (GSH) and enzyme (trypsin) responsive nanocarriers for doxorubicin (DOX). These nanocarriers were further modified with folate, briefly named as DOX@BSA-TP-FA NSs. The diameter of nanocarriers was about 220 nm. The DOX loading efficiency and loading amount were 86.4% and 23.5 wt%, respectively. The cellular uptake, apoptosis, and GSH and trypsin responsive release properties of these nanocarriers were investigated.
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JOURNAL OF SEPARATION SCIENCE
·
2015
·Vol. 38
·期 8
·1263-1270
·
IF 2.737
Xingqiang Wu,Shuxuan Liang,Xusheng Ge,Yunkai Lv,Hanwen Sun
Dummy molecularly imprinted microspheres with danthron as template were synthesized and their performance was evaluated. Accelerated solvent extraction can rapidly and effectively remove template molecules from the microspheres. The microspheres were applied as a specific sorbent for solid-phase extraction of six anthraquinones from slimming tea, showing excellent affinity and high selectivity to danthron and the target analytes. The molecular recognition mechanisms were discussed by the experimental validation with IR spectroscopy. The sample was treated using accelerated solvent extraction followed by dummy molecularly imprinted microspheres solid-phase extraction. Under the optimized ultra high performance liquid chromatographic conditions, the six target analytes can be baseline separated in 8 min, and good linearity was obtained in a range of 0.1–40 μg/mL with the correlation coefficient ( r 2 ) of ≥0.9998. The method limit of quantification was in a range of 1–2 mg/kg, it can ensure analysis of anthraquinones at mg/kg level. The intra- and interday precision (RSD, n = 6) for the analysis of the six analytes in a slimming tea was less than 4.5 and 5.4%, respectively. The developed method can be applied for the selective extraction, effective separation, and rapid determination of six anthraquinones in slimming tea.
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EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY
·
2015
·Vol. 117
·期 7
·1008-1015
·
IF 1.812
Rong Shi,Yi Guo,Frank Vriesekoop,Qipeng Yuan,Shuna Zhao,Hao Liang
In this work we present a study of the influence of a stearic acid–surfactant–tea polyphenols complex (SSTC) on the oxidative and thermal stability of peanut oil under microwave heating and simulated deep fat frying. Changes of the quality parameters of all oil samples containing different SSTCs were very obvious, compared with those of pure peanut oil. Especially for the oil sample containing SSTC-P, the p-anisidine value decreased 48.89% and 14.90% after microwave heating and simulated deep fat frying. For K 232 , it decreased 36.90% and 33.18%, respectively. By GS–MS analysis, the content of unsaturated fatty acids in peanut oil containing SSTC-P was 8.7 times more than that in pure peanut oil after microwave treatment. As an efficient food antioxidant, the self-assembled complex of tea polyphenols in edible oil prepared by this novel method may have great market potential. Practical applications: Oxidation processes are one of the major problems encountered in oil consumption and storage. The addition of natural antioxidants is a major way to inhibit oxidation processes in edible oils. Tea polyphenols are excellent source of phenolic compounds, which have been reported to show good antioxidant activity. The results of this study suggest that oil-soluble tea polyphenols can be prepared based on a stearic acid–surfactant–tea polyphenols complex. The dispersion of SSTC into peanut oil can improve oxidative and thermal stability of edible oil. Therefore, the complex of tea polyphenols in edible oil may have great market potential of food antioxidant. Tea polyphenols solution was used as the aqueous phase. Stearic acid containing appropriate amount of surfactant were poured into a 50 mL centrifuge tube, and kept in a water bath maintained at 80°C and stirred at 500 rpm until a homogeneous clear solution was obtained. Then, the aqueous phase and the oil phase were mixed using a homogenizer at 26 000 rpm for 2 min to form a stable W/O emulsion. The resulting emulsion was frozen rapidly in liquid nitrogen, and lyophilized using a freeze-drying machine for 48 h. Finally, all of the stearic acid–surfactant–tea polyphenols complexes (SSTC) were obtained. The SSTC was dispersed in peanut oil. Oxidation products of the oil sample were analyzed by GC–MS under microwave heating.
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RSC Advances
·
2017
·Vol. 7
·期 80
·50430-50440
·
IF 3.108
Yongsheng Chen,Xiang Ma,Xiong Fu,Rian Yan
Adinandra nitida tea (Shiyacha) is a traditional eminent and flourishing tea with a long history in Southeast Asia. However, transformation of phytochemicals of A. nitida tea infusion during in vitro simulated digestions is vague. Herein, we investigated cellular antioxidant and antiproliferative activity of phytochemicals obtained from A. nitida tea infusion subjected to in vitro gastrointestinal conditions. Phenolic, flavonoid, flavonol, and anthocyanin contents found in A. nitida tea infusion were evaluated by normal colorimetric methods. Subsequently, the main compounds were determined by high-performance liquid chromatography. The antioxidant activity was evaluated based on peroxyl radical scavenging capacity (PSC), oxygen radical absorbance capacity (ORAC), and cellular antioxidant activity (CAA). The antiproliferative activity towards Caco-2 cells was determined by the cell methylene blue colorimetric assay. It was found that in simulated gastrointestinal fluids, the contents of phenolics and flavonols increased, whereas the contents of flavonoids and anthocyanins decreased. Moreover, the content of (−)-epigallocatechin and camellianin B increased, whereas that of L-epicatechin, quercitrin, and camellianin A decreased. Furthermore, the oxygen radical scavenging capacity and cellular antioxidant activity values increased, whereas the PSC values decreased. Most importantly, the gastrointestinal fluids of A. nitida tea infusion exhibited a strong antiproliferative activity towards Caco-2 cells and affected caspase 3/9 signaling pathway, and apoptosis induction might serve as the underlying mechanism for this antiproliferative activity. It can be concluded that A. nitida tea infusion may act as a potential intracellular antioxidant and colon cancer cell proliferation inhibitor.
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FOOD CHEMISTRY
·
2024
·
IF 8.5
Fangying Cheng,Mianhong Chen,Zhihao Duan,Ying Zou,Yunxia He,Fanke Zeng,Yuan Yuan,Tiaokun Fu,Hao Tu,Ruyi Li,Jihua Li,Wei Zhou
Carrier-free nanodelivery systems are fully self-assembled from active ingredients through interactions, offering the advantages of green, safe, and large-scale manufacturing. To improve the dispersion of Citrus × limon ‘Rosso’ peel essential oil (CEO) in water and boost the biological activity of CEO and tea polyphenols (TP), self-assembled CEO-TP colloidal dispersions (CEO-TP Colloids) were fabricated through sonication without surfactants or carriers. The optimal CEO and TP concentrations in the CEO-TP Colloids were determined to be 10.0 and 20.0 mg/mL by particle size and stability analyzer, respectively. The CEO self-assembled with TP to form spherical nanoparticles through hydrophobic and hydrogen-bonding interactions, whereas the CEO in CEO-TP Colloids weakened TP intramolecular aggregation. Meanwhile, the CEO-TP Colloids showed synergistic effects with better antibacterial, cellular antioxidant, and anti-inflammatory activities than single components. This study opens up the possibility of carrier-free co-delivery of hydrophobic and hydrophilic active components developed into food-grade formulations with multiple bioactivities.
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FOOD RESEARCH INTERNATIONAL
·
2024
·
IF 7
Yao Chen,Yuan Li,Li-Lin Lin,Yue Liao,Huan Fang,Tong Wang
Lu’an Gua Pian (LAGP) tea is one of the most famous green teas in China. The quality of green tea is related to its picking periods, especially the green tea before Qingming Festival (usually April 6th) is highly praised as precious in the market. In this work, a simple and cheap indicator displacement colorimetric sensor array combined with smartphone was developed to rapidly identify LAGP picked during different picking periods. First, the chemical component contents of LAGP picked before and after Qingming Festival were analyzed. Second, a well-designed colorimetric sensor array was proposed based on the tea component contents differences. Finally, machine learning was used to process the array data taken by a smartphone. By comparison, the accuracy of the best model for the prediction set was 97%. Meanwhile, the multi-channel advantages of the sensing array were demonstrated by an ablation experiment. In addition, the method achieved an AGREE analysis score of 0.88, indicating that it was environmental-friendly.
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Plants-Basel
·
2024
·Vol. 13
·期 9
·1249
·
IF 4
Mengcong Zhang,Lixuan Zhang,Chengzhe Zhou,Kai Xu,Guangwu Chen,Linjie Huang,Zhongxiong Lai,Yuqiong Guo
The enzymatic reaction stage (ECS) of oolong tea processing plays an important role in the formation of the flavor quality of the oolong tea. To investigate the dynamic changes in the volatile and non-volatile components in the leaves of oolong tea during the ECS, metabolomic studies were carried out using the leaf samples collected at different stages of the ECS of Aijiao oolong tea. Out of the identified 306 non-volatile metabolites and 85 volatile metabolites, 159 non-volatile metabolites and 42 volatile metabolites were screened out as key differential metabolites for dynamic changes during the ECS. A multivariate statistical analysis on the key differential metabolites showed that the accumulations of most metabolites exhibited dynamic changes, while some amino acids, nucleosides, and organic acids accumulated significantly after turning-over treatment. The evolution characteristics of 27 key precursors or transformed VOCs during the ECS of Aijiao oolong tea were clarified, and it was found that the synthesis of aroma substances was mainly concentrated in lipids as precursors and glycosides as precursor pathways. The results revealed the dynamic changes in the flavor metabolites in the ECS during the processing of Aijiao oolong tea, which provided valuable information for the formation of the characteristic flavor of Aijiao oolong tea.
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Current Research in Food Science
·
2024
·
IF 6.2
Shan Zhang,Le Chen,Linchi Niu,Haibo Yuan,Xujiang Shan,Qianting Zhang,Yuning Feng,Qinghua Zhou,Yongwen Jiang,Jia Li
Lipids are important tea aroma precursors. Due to the complexity of black tea processing involving both enzymatic and thermal reactions, the role of lipids in black tea aroma formation remained unclear. Herein, the dynamic changes of lipids and volatiles during black tea processing were simultaneously analyzed by lipidomics and volatolomics using ultra-high-performance liquid chromatography coupled to Q-Exactive Orbitrap mass spectrometry (UHPLC-Q-Exactive) and gas chromatography-tandem mass spectrometry (GC-MS/MS). The lipidomics method was validated in linearity, reproducibility, and recovery, which showed a high reliability. A total of 374 lipids and 88 volatiles were detected. Among them, 362 lipids and 29 fatty acid-derived volatiles (FADVs) were significantly altered depending on different processing stages. During the enzyme-driven stages of black tea processing (withering, rolling and fermentation), monogalactosyldiacylglycerol (MGDG), phosphatidylcholine (PC), and phosphatidylethanolamine (PE) were largely downregulated (<0.33 folds). Instead, in the non-enzymatic drying steps of black tea processing, triacylglycerol (TG), diacylglycerol (DG), and phosphatidic acid (PA) were mainly degraded (<0.24 folds). MS/MS fragmentation revealed that these most prominently degraded lipids were structurally enriched with fatty acyl (FA) 18:2 and 18:3 residues, such as MGDG (18:2/18:3), PC (18:2/18:2), PE (18:1/18:2), TG (18:3/18:3/18:3), DG (18:3/18:3), PA (18:3/18:3). Correlation analysis showed significant negative correlation between these lipids and FADVs such as aliphatic aldehydes, alcohols, ketones, and esters, etc. These most prominently degraded lipids were highlighted as the key potential aroma precursors during black tea processing, which were possibly oxidized and degraded into volatiles through enzyme- and thermal-driven pathways at different processing stages.
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TALANTA
·
2018
·
IF 4.244
Yayun Zhao,Yuhai Tang,Jun He,Yuan Xu,Ruixia Gao,Junjie Zhang,Tie Chong,Li Wang,Xiaoshuang Tang
Novel water-compatible magnetic molecularly imprinted polymers were developed. The magnetic core was firstly grafted by methyl acrylate and ethanediamine to increase the number of amino groups, which could immobilize more templates and form high-density recognition sites. Dopamine was adopted as functional monomer and crosslinker to retighten templates and prepare hydrophilic polymers. The characterization, adsorption capability, selectivity, and reusability were investigated in detail. The limit of detection and quantification of the method were 0.01 μg mL −1 and 0.038 μg mL −1 . The experimental results exhibited that the resultant nanomaterials had high crystallinity , satisfactory magnetic property, fast kinetics, favorable adsorption capacity, excellent specificity, and pleasing recovery after a mild elution. In addition, the recoveries of the proposed method at four spiked levels analysis were between 98.4% to 101.3%. The obtained imprinted nanoparticles were used as sorbents for selective separation and determination of chlorogenic acid in Honeysuckle tea.
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FOOD CHEMISTRY
·
2024
·
IF 8.5
Lin Zeng,Yan-Qing Fu,Ying Gao,Fang Wang,Shuang Liang,Jun-Feng Yin,Marie-Laure Fauconnier,Lijing Ke,Yong-Quan Xu
In this study, widely targeted metabolomics and chemometrics were utilized to comprehensively analyse the formation of taste compounds in Longjing green tea. A total of 580 non-volatile metabolites were identified by using ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry, and alterations in three metabolic pathways were investigated. Notably, the fixation process reduced phosphatidic acid levels, resulting in the formation of lyso-phosphatidylcholine and lyso-phosphatidylethanolamine, as well as the release of esterified polyunsaturated fatty acids. Baiye No.1 had high levels of L-glutamic acid and l -glutamine, while Longjing 43 showed elevated levels of flavones. Correlation analysis and sensory verification indicated that the specific concentration of L-leucine could decrease the umami of the tea. These findings advance our understanding of Longjing green tea quality improvement and cultivar development.
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