JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
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2020
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IF 3.004
Xinya Liu,Mengyuan Chen,Zilin Meng,Heng Qian,Sanbing Zhang,Runhua Lu,Haixiang Gao,Wenfeng Zhou
In this study, low-density deep eutectic solvent combined with dispersive liquid-liquid microextraction was applied to the extraction of five benzoylurea insecticides (BUs, including diflubenzuron, triflumuron, hexaflumuron, flufenoxuron, and chlorfluazuron) from beverages. Then the extracted and concentrated samples were analyzed and detected using the high-performance liquid chromatography combined with an ultraviolet detector. The DESs were synthesized by [P14,6,6,6]Cl as hydrogen bond acceptor and tetradecyl alcohol as hydrogen bond donor, and then characterized by Fourier transform infrared spectroscopy. In the experiment, the key factors affecting the extraction efficiency were screened by Plackett-Burman design and optimized with the central composite design. The extraction recovery rates were 85.91–95.12%. The limits of detection and correlation coefficients of the method were 0.30–0.60 μg L −1 and 0.9992–0.9997. Finally, the method was applied to determine the BUs in four beverage samples, and satisfactory recoveries, within the range of 76.87–101.19% were achieved. The present method has the potential to be applied to the detection of BUs in aqueous samples.
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CHEMICAL ENGINEERING JOURNAL
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2019
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IF 8.355
Qiong Ouyang,Fangying Kou,Nuanqin Zhang,Jintao Lian,Guoquan Tu,Zhanqiang Fang
Tea polyphenols (TP) are natural green organic compounds with chelating and reducing properties, which can promote the catalytic reaction, but the mechanism of promotion is still uncertain. In this paper, the chelation and reduction of TP were used to promote the degradation of lincomycin (LCM) by zero-valent iron Fenton-like reaction, and the mechanism of the two properties of TP was analyzed. The results showed that in the Fe 0 /H 2 O 2 system, the degradation rate of the reaction system was increased from 27% to 100% in two hours after the addition of TP, and the reaction rate was increased about 26 times. Moreover, the parameters of pH, Fe 2+ , ·OH, oxidation reduction potential (ORP) and so forth indicating that the chelating structure of TP and iron ions was formed under pH = 4–9, which obviously promoted the mutual conversion of Fe 3+ /Fe 2+ . It is propitious to the proper amount of iron dissolution in order to facilitate the continuous and efficient Fenton reaction. Under acidic conditions, the TP are more reductive due to the destruction of the chelate structure, which promotes the conversion of Fe 3+ to Fe 2+ or even zero-valent iron, significantly improves the Fe 3+ /Fe 2+ cycle capacity and increases the amount of OH produced.
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JOURNAL OF SURFACTANTS AND DETERGENTS
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2018
·Vol. 21
·期 3
·303-312
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IF 1.454
Zexia Fan,Zhiyu Deng,Tengfei Wang,Weipeng Yang,Kun Wang
Tea saponin (TS) is a relatively inexpensive natural nonionic surfactant extracted from parts of tea plants, which can be modified into an anionic surfactant to achieve better surface activity. In this paper, the synthesis of TS-based succinic acid sulfonate as an anionic foaming agent is described. TS used as the hydrophobic source was modified by maleic anhydride (MAH) and then reacted with sodium bisulfite. Orthogonal experiment of a 2-step reaction was designed and performed, resulting in 9 kinds of succinic acid tea-saponin sulfonate (STS). 4-Dimethylaminopyridine and tetrabutylammonium bromide were, respectively, used as catalyst for the esterification with MAH and the sulfonation with sodium bisulfite. During the synthesis process, N , N -dimethylformamide was employed as the solvent and ethyl acetate as the extractant. The molecular structure of STS was confirmed by infrared spectroscopy and mass spectrometry. The foaming property of STS was investigated through comparison with different kinds of common surfactants. The results show great prospects of these environmentally friendly anionic surfactants. Graphical
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FOOD CHEMISTRY
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2015
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IF 3.391
Fang-Yuan Fan,Meng Shi,Ying Nie,Yue Zhao,Jian-Hui Ye,Yue-Rong Liang
Tea catechins as a member of flavan-3-ols subclass with the same skeleton may behave differentially. This study investigated the chemical conversions of 8 catechins under heat treatment with the involvement of epimerization, hydrolysis and oxidation/condensation reactions. Three reactions were enhanced as temperature increased from 30 °C to 90 °C. The epimerization of non-gallated catechins was favored by epi-configuration but hindered by pyrogallol moiety, and the hydrolysis reaction of gallated catechins was facilitated by pyrogallol moiety. Epicatechin and epigallocatechin had the lowest thermostabilities due to epimerization and oxidation/condensation reactions respectively. Sufficient O 2 was not a precondition for the occurrence of chemical conversions of catechins under heat treatment. Non-enzymatic oligomerization occurred to epi type catechins and catechin under heat treatment, and dehydrodicatechins A were mainly responsible for the browning of epicatechin and catechin solutions. The evidence of generation of catechin oligomers provides a novel way to explain sensory change of tea and relevant products during thermal processing.
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Food & Function
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2015
·Vol. 6
·期 6
·2008-2016
·
IF 2.791
Liang Zeng,Jingna Yan,Liyong Luo,Dongying Zhang
Disorders of blood lipid metabolism are the primary risk factors for many diseases. Recently, the effect of Pu-erh tea on blood lipid metabolism has received increasing attention. However, the mechanism underlying its ability to regulate blood lipid metabolism is unclear. We set out to study this through assessing the effects of Pu-erh tea aqueous extract (PTAE) on the central enzymes of blood lipid metabolism, including lipoprotein-associated phospholipase A2 (Lp-PLA2), lecithin: cholesterol acyltransferase (LCAT), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) and pancreatic lipase (PL). We find that the Lp-PLA2, HMRG and PL activities are inhibited by PTAE in a dose-dependent manner and that the LCAT activity tends to increase with increasing PTAE concentrations. Lineweaver–Burk plot analyses reveal that PTAE acts as a competitive inhibitor for HMGR and PL and as a noncompetitive inhibitor for Lp-PLA2. Moreover, we determine that its active ingredients include catechins, gallic acid, caffeine, free amino acids, and soluble sugar. However, the effect of each ingredient and whether any of them have synergistic effects are still unknown. The results suggest that Pu-erh tea has a potent ability to regulate blood lipid metabolism and knowledge of the mechanisms provides insights into its potential therapeutic application as an alternative hypolipidemic drug.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2013
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IF 2.596
Yuanfeng Wang,Yangyang Liu,Jianglei Huo,Tingtong Zhao,Jian Ren,Xinlin Wei
Four polysaccharides (TPS-F, TPS-V, TPS-S and TPS-M) were obtained from tea ( Camellia sinensis ) leaves by freeze-drying, vacuum-drying, spray-drying and microwave-vacuum drying, respectively. Their chemical composition and biological properties were comparatively studied. The results showed these TPS were similar in IR, UV absorption and distribution of molecular weight. However, they showed significant differences ( P < 0.05) in yields of crude polysaccharides and contents of protein and total polyphenols. Furthermore, morphological analysis showed their surface differed from each other in size and shape when viewed by SEM, from which surface of TPS-F was rough and porous, surface of TPS-S was evenly particles, and surfaces of the other two were similar to anomalistic bricks. In addition, the bioactivity of them was also evaluated. It was found TPS-F exhibited relatively better ability on metal chelating and superoxide radicals scavenging assays than others, and TPS-V exhibited higher ability on α-glycosidase and α-amylase inhibition assays than others with inhibitory percentages of 82.75% and 92.8%.
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Journal of Oleo Science
·
2017
·
IF 1.076
Yating Zhang,Lingbiao Gu,Fei Wang,Lingjun Kong,Huili Pang,Guangyong Qin
We specially carried out the subcritical butane extraction to separate abamectin from tea leaves. Four parameters, such as extraction temperature, extraction time, number of extraction cycles, and solid-liquid ratio were studied and optimized through the response surface methodology with design matrix developed by Box–Behnken. Seventeen experiments with three various factors and three variable levels were employed to investigate the effect of these parameters on the extraction of abamectin. Besides, catechins, theanine, caffeine, and aroma components were determined by both high-performance liquid chromatography and gas chromatography–mass spectrometry to evaluate the tea quality before and after the extraction. The results showed that the extraction temperature was the uppermost parameter compared with others. The optimal extraction conditions selected as follows: extraction temperature, 42°C; number of extraction cycles and extraction time, 1 and 30 min, respectively; and solid–liquid ratio, 1:10. Based on the above study, the separation efficiency of abamectin was up to 93.95%. It is notable that there has a quite low loss rate, including the negligible damage of aroma components, the bits reduce of catechins within the range of 0.7%–13.1%, and a handful lessen of caffeine and theanine of 1.81% and 2.6%, respectively. The proposed method suggested subcritical butane possesses solubility for lipid–soluble pesticides, and since most of the pesticides are attached to the surfaces of tea, thus the as-applied method was successfully effective to separate abamectin because of the so practical and promising method.
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Food Chemistry-X
·
2025
·
IF 8.2
Jian Ouyang,Ronggang Jiang,Huimin An,Xingchang Ou,Jing Wang,He Xie,Wenjie Fu,Jing Zhang,Hongyu Chen,Qi Liu,Juan Li,Haitao Wen,Ligui Xiong,Jian-an Huang,Zhonghua Liu
Rucheng Baimaocha ( Camellia pubescens ) black tea (RCBT) exhibits floral and sweet attributes with a unique minty-like aroma, distinguishing it from traditional and other innovative black teas. However, its key odorants remain unknown. In this study, gas chromatography-olfactometry (GC-O) combined with aroma extraction dilution analysis detected 26 aroma-active compounds (ACCs), of which 20 ACCs were quantified as odorants of RCBT infusion. In addition, aroma recombination models well simulated the overall aroma characteristics of RCBT infusion, which proved the accuracy of identification and quantification. Omission experiments showed that 12 key odorants played crucial roles in aroma formation of RCBT. Among these, four odorants (methyl salicylate, ( E , Z )-2,6-nonadienal, methyl geranate, and ( E )-2-nonenal), were of great importances for unique minty-like aroma, with significantly higher concentrations compared to other black tea varieties. This study offered a foundational theoretical framework for the processing and quality control of RCBT.
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Advanced Therapeutics
·
2024
·
IF 3.7
Kang Hu,Zhuo Huang,Qinying Tang,Danyang Chen,Lianxu Chen,Lu Chen,Guohua Jiang,Qianfei Huang,Langjie Chai,Hang Chen,Liang Guo,Bin Li
Currently, searching for safer and more effective approaches to promote skin wound healing and tissue regeneration is a significant research focus in the field of public health. Eliminating excessive reactive oxygen species (ROS) and using electrically active dressings to accelerate wound healing has gained significant attention. Herein, green tea-based carbon dots (GCDs) are synthesized from leaves of green tea and proven to possess strong antioxidant, antibacterial, and anti-inflammatory properties. Then, GCDs, polyvinyl alcohol (PVA), and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) are successfully constructed into a multifunctional conductive PVA-PEDOT:PSS/GCDs hydrogel (PPPCD) using a repeated freeze-thaw method for promoting skin wound healing. Highly electrical conductivity is imparted by introducing PEDOT:PSS, while antioxidant and antibacterial properties are conferred by GCDs. In vitro assays demonstrated the excellent biocompatibility of the hydrogel, as well as its ability to scavenge excessive ROS and promote cell migration. Furthermore, the hydrogel not only accelerates wound healing by promoting blood vessel formation and epidermal regeneration but also alleviating excessive inflammation in vivo. Overall, the developed hydrogel dressing demonstrates promising prospects for skin wound healing and offers a new perspective for tissue engineering.
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FOOD RESEARCH INTERNATIONAL
·
2025
·
IF 8
Yingbin Zhang,Xuwei Chen,Dingding Chen,Li Zhu,Guoqing Wang,Zhongxiu Chen
The taste of Chinese green tea is highly diverse. In this study, a combination of unsupervised and supervised learning methods was utilized to develop a model for classifying and predicting typical Chinese green tea taste. Three clustering methods were assessed based on quantitative descriptive analysis (QDA) results, with the Hierarchical-K means method chosen to classify 88 tea infusions into seven distinct taste types. Electronic tongue sensors, near-infrared spectroscopy, and metabolomics, along with the analysis of key chemical constituents, were applied to construct various datasets as model data. The performance of four multivariate statistical methods and six artificial intelligence algorithms was compared across the three datasets. Dataset 3, comprising chemical components, taste activity value (Tav), and their ratios, achieved the highest accuracy. The random forest (RF) model achieved the highest accuracy (0.98) and Kappa value (0.97) in predictions. The results indicate that key chemical components, Tav, and their relationships are more critical for classifying green tea taste. This study can provide a more accurate representation and prediction of typical Chinese tea taste profiles from a consumer standpoint. Significant variations in sensory attributes and chemical composition were observed among the identified taste categories, with the MU type displaying the lowest TavTC (total Tav of catechins)/TavTAA (total Tav of amino acids) ratio, indicating the strongest umami and sweetness characteristics. The findings of this study offer the potential for the development of personalized tea products, thereby contributing to an enhanced consumer experience.
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FOOD RESEARCH INTERNATIONAL
·
2024
·
IF 7
Dongzhu Huang,Chenyi Sun,Yuhan Wu,Fangling Zheng,Qiqi Yang,Xinmeng Zhang,Qianying Dai,Xiaochun Wan,Qi Chen
This study aimed to investigate the effect of the combination of shaking and various anaerobic treatments on the aroma quality of gabaron oolong tea (GAOT) by chemical and sensory evaluation. The results showed that elevated anaerobic treatment harmed GAOT aroma, emphasizing undesirable attributes such as earthy, fatty, etc. A total of 85 volatiles were identified by gas chromatography-ion mobility spectrometry (GC-IMS), and the relationship between aroma attributes and volatiles were revealed by PLS regression projection and correlation network. Hexanal and octanal at inappropriate concentrations were main causes to the earthy attribute, while nonanal exhibited a potential masking effect against unpleasant attributes. Addition experiments and σ-τ plot analysis verified these associations. Furthermore, observing dynamic patterns of content changes of these three aldehydes in fresh leaves prior to tea thermal processing, providing references for future process optimization. These results provide a new direction for enhancing the quality of GAOT.
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Kuikun Gu,Xinyue Du,Xueying Song,Yu Wang,Zhongbao Luo,Xiaodong Yang,Mingzhe Zhang
The ternary metal oxides that combine two different metal cations is an interesting candidate as sensing material based on their interesting properties. Hence, ordered dendrite InWO 4 was successfully synthesized via a hydrothermal method, followed by the construction of an InWO 4 -rGO heterojunction to enhance detection capability for triethylamine (TEA) gas. The synthesized product underwent morphology and elemental composition analysis using various techniques. Gas sensing experiments revealed that the InWO 4 -rGO gas sensor, operating at the optimal temperature of 220 ℃, displayed a significantly improved response to 100 ppm TEA, with a high value of 59.5, in comparison to the pure InWO 4 gas sensor (11.5 at 250 ℃). Additionally, the recovery time was reduced from 184 s to 122 s. Based on experimental data and gas sensing reaction theory, this study attributes the improved gas sensing performance to the formation of p-n heterojunction, a larger specific surface area and rGO's catalytic effect. This study not only introduces a novel addition to the gas sensing material family but also promotes the development of advanced gas sensors.
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