JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2021
·
IF 5.279
Keying Zhang,Guang Zhu,Yunlong Wei,Li Zhang,Yizhong Shen
Accurately monitoring mercury ions (Hg2+) in food and agriculture-related matrixes (e.g., green tea) is of great significance to safeguard food safety. Here, we employed upconversion nanoparticles (UCNPs) and gold nanoparticles (AuNPs) to engineer a cysteine (Cys)-assisted anti-Stokes luminescence sensing platform (UCNPs–AuNPs) for precisely detecting residual Hg2+ in green tea through the competition effect. Initially, AuNPs could effectively quench the luminescence of UCNPs through the luminescence resonance energy transfer process, which was then interrupted by Cys-triggered AuNP aggregation via Au–S, thereby restoring UCNP luminescence. Interestingly, owing to the competition effect with AuNPs toward Cys, Hg2+ could weaken the luminescence restoring efficiency, achieving a Hg2+ concentration-dependent luminescence change. On this basis, a facile, reliable, and sensitive upconversion luminescence sensing platform for monitoring residual Hg2+ in green tea was successfully established. This study offers a novel insight into integrating the competition effect and anti-Stokes luminescence for food- and agriculture-related contaminant monitoring.
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高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Chao Xue,Wanling Cai,Xiulan Weng,Gary Owens,Zuliang Chen
The use of biomass for the synthesis of value-added products, such as functional nanomaterial for the removal of contaminants, is a challenge. In this study, hybrid bimetallic Fe/Ni nanoparticles and reduced graphene supported bimetallic Fe/Ni nanoparticles (Fe/Ni-rGO) were prepared via a one-step green synthesis using green tea extract, and thereafter evaluated for the simultaneous removal of rifampicin (RIF) and Pb(II) from aqueous solution. The efficiencies of Pb(II) and RIF removal by Fe/Ni-rGO were 87.5 and 96.8%, respectively. The removal performance of the hybrid Fe/Ni-rGO was better than either n Fe/Ni, rGO, or Fe-rGO. Detailed characterization and analyses of Fe/Ni-rGO indicated that both Fe and Ni nanoparticles were evenly distributed over the surface of rGO and that aggregation of Fe, Ni nanoparticles, and stacking of rGO in the hybrid were decreased. Furthermore, while LC-TOF-MS analysis showed that RIF was degraded into small-molecule fragments, XPS showed that Pb(II) was not reduced to Pb 0 . The major conditions impacting removal efficiency, adsorption kinetics, and fit to adsorption isotherm models were examined to better understand the removal mechanism. While the adsorption of both contaminants fit well a pseudo-second-order kinetic model, the adsorption of RIF fit the Freundlich isotherm model best, while the adsorption of Pb(II) fit the Langmuir isotherm model best. Thus, the removal mechanism of both contaminants firstly being chemical adsorbed onto the surface, while n Fe/Ni continues to participate in the catalytic reduction of RIF. Moreover, Fe/Ni-rGO could be reused and performed well for wastewater treatment , thus suitable as a practical resource recycling technology .
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FOOD CHEMISTRY
·
2021
·
IF 7.514
Hui Xue,Guowen Zhang,Tianfeng Han,Ruiling Li,Huilan Liu,Binghong Gao,Yonggang Tu,Yan Zhao
In this study, the improvement of gel properties and digestibility of the water-soluble polymer of tea polyphenol (TP)-egg white protein (TEP) under heat induction (HTEP), was studied. Results indicated that the particle size and turbidity of TEP increased with TP concentration, and the absolute value of ζ-potential decreased. After heat induction, the surface hydrophobicity of HTEP decreased with TP concentration, and the degree of protein aggregation increased. Microstructure and T 2 showed that the gel structure became compact and stable, and HTEP had a strong water-binding ability. The ionic and disulfide bonds were the main chemical bonds in HTEP. The hardness and disulfide bond increased, but the digestion of HTEP increased initially and then decreased (caused by the change of gel structure). Infrared spectroscopy indicated the mutual conversion of intermolecular and intramolecular β-sheets. In short, TP could modify egg white gel through forming stable disulfide bonds and dense gel network structures.
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高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2021
·Vol. 330
·期 3
·871-882
·
IF 1.371
Liu Jinxiang,Ge Yujie,Wang Guohua,Liu Yingjiu,Xu Xiaofeng
Uranium-containing wastewater poses a major threat to human health because of its toxicity and radioactivity. To address this issue, tea waste-derived porous biochar supporting the Fe–Mn bimetallic composite (FMBC) was fabricated using impregnation-pyrolysis and applied for U(VI) removal from aqueous solution. Batch experiments and characterization analysis were performed to investigate the adsorption properties and interaction mechanisms. Results showed that FMBC exhibit a maximum U(VI) removal capacity of 510.8 mg/g at pH = 5, T = 303 k, and t = 25 min. The kinetic and isotherm date fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model, respectively, indicating that uranium adsorption is dominated by chemical adsorption on FMBC. FTIR and XPS analyses further confirmed that the U(VI) adsorption mechanism by FMBC was attributed to surface complexation, π–π bonding, and reduction processes. In addition, the Cationic competitive adsorption experiment further highlighted the excellent selective performance of FMBC for U(VI) removal from aqueous solutions, which is important in radionuclides' pollution treatment.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2019
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IF 4.784
Wanli Zhang,Weibo Jiang
In the present study, the antioxidant and antibacterial chitosan/tea polyphenols-silver nanoparticles composite film (CS/TP-AgNPs) was developed via a novel one-pot method. The TP was added to the CS film not only as the reducing agent of AgNPs but also as the cross-linking agent and antioxidant. The AgNPs and nanocomposite films developed were characterized by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Besides, the physical, mechanical, antioxidant and antibacterial properties of the nanocomposite films were also analyzed. As the content of TP-AgNPs incorporation increased, the color of CS/TP-AgNPs nanocomposite film gradually shifted to brown, accompanied by an increase in opacity and thickness. The decrease in moisture contents and water vapor permeability of CS/TP-AgNPs nanocomposite film indicated that the TP-AgNPs varied the original bond between the CS-CS and CS-water. The denser cross-section of CS/TP-AgNPs nanocomposite film confirmed the enhanced mechanical properties. It is worth noting that CS/TP-AgNPs nanocomposite film exhibited more excellent antioxidant and antibacterial activity than CS film. This study developed the multi-functionality chitosan film by the simultaneous incorporation of AgNPs and TP and revealed the multiple effects of TP acting as reducing agent for AgNPs, cross-linking agent and antioxidant on chitosan film.
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高影响因子
MICROCHEMICAL JOURNAL
·
2019
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IF 3.206
Fengkai Shang,Yutian Wang,Junzhu Wang,Ling Zhang,Pengfei Cheng,Shutao Wang
The content of polycyclic aromatic hydrocarbons (PAHs) in tea has attracted widespread attention. In this study, the strategy of four-way fluorescence data coupled with third-order calibration method based on four way parallel factor analysis (four-way PARAFAC) was used to determine phenanthrene , naphthalene and acenaphthene in tea. A new method, introducing an additional temperature mode into the three-way fluorescence data set, was proposed to acquire a four-way data array. The feasibility of the method was validated by experiments. The four-way PARAFAC could give satisfactory analytical results for the determination of three PAHs in tea. The average spiked recoveries were (100.9 ± 7.8)% for phenanthrene, (94.6 ± 8.6)% for naphthalene, (96.0 ± 9.8)% for acenaphthene. The root-mean-square error of prediction (RMSEP) values were 0.495 μg L −1 for phenanthrene, 0.841 μg L −1 for naphthalene, 0.577 μg L −1 for acenaphthene. The average relative predictive errors (ARPE) values for three PAHs were <2.35%. The limits of detection (LOD) of three PAHs were between 0.026 and 0.14 μg L −1 . Generally, these results obtained by four-way PARAFAC were better than that of three-way PARAFAC. In addition, analytical figures of merit, such as Sensitivity, Selectivity and Analytical sensitivity, were calculated for three PAHs to evaluate the methods. The results demonstrated that the four-way PARAFAC was more suitable for the determination for three target analytes in this study.
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JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE
·
2019
·Vol. 56
·期 9
·4009-4015
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IF 1.85
Qin Hao,Li Bao-cai,Dai Wei-feng,Xiang Cheng,Qin Yi,Jiao Shi-yun,Zhang Mi
Volatiles have been regarded as active substances in many foods, whose chemicals can be analyzed by GC–MS qualitatively and quantitatively. However, the activities of volatiles are often studied as a whole, and it has no an effective method to determine that which molecule is active in volatiles by far. In order to identify the antioxidant molecules in volatiles, a rapid determination method was developed by GC–FID/MS combined with DPPH radical reaction in this study. Three antioxidant molecules were identified and validated among 20 components in rose tea infusion. Their activity validation and the methodological evaluation indicated this method could be used for distinguishing antioxidant molecules in volatiles rapidly and effectively.
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高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2019
·Vol. 411
·期 27
·7187-7196
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IF 3.286
Zhang De,Liang Pei,Ye Jiaming,Xia Jing,Zhou Yongfeng,Huang Jie,Ni Dejiang,Tang Lisha,Jin Shangzhong,Yu Zhi
Surface-enhanced Raman spectroscopy (SERS) has the potential to detect pesticide residues in agricultural products. However, some systemic pesticides, such as chlorpyrifos, can enter the plant tissue, and not just stay on the surface. Consequently, many SERS studies halted at practical application because of its complexity. In this work, SERS technology was used to detect chlorpyrifos residues in tea products at the semiquantitative level. A simple pretreatment method effectively avoided interference of other fluorescent substances, and all major peaks could be distinguished on the basis of a novel substrate. A principal component analysis algorithm was applied to form a regression model, and a nanogram detection limit was obtained. Furthermore, chlorpyrifos residues in the same tea products were also measured by gas chromatography–mass spectrometry, and the results show a small range of errors. From the comparative study of the two detection methods, the results suggest the great promise of SERS technology for rapid inspection of agricultural products.
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CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Xiulan Weng,Jing Wu,Li Ma,Gary Owens,Zuliang Chen
Graphene has a great potential in environmental remediation due to its unique physical and chemical properties. However, the relationships between synthetic conditions and contaminant removal are still unclear. In this study, a biogenic method was used for the reduction of graphene oxide (GO) using green tea extract and the reduced graphene oxide (RGO) produced was subsequently used to remove Pb(II) from aqueous solution. Hence, the impact of bioreduction synthetic conditions of RGO on Pb(II) removal efficiency was examined. The new findings included (1) that reduction of GO by green tea (GT) extract at a ratio of 2:1 (GO:GT), 80 °C and pH 8, led to a RGO material capable of removing 97.2% of a 10 mg·L −1 Pb(II) solution under the adsorption conditions of pH 4.5 and a RGO dose of 0.4 g·L −1 at 30 °C; (2) characterization results showed good dispersion of RGO, and removal of oxygen functional groups from GO, increased Pb(II) adsorption. Pb(II) removal efficiency was largely dependent on reduction conditions during synthesis of RGO; where efficient removal of oxygen-containing groups during reduction favored Pb(II) removal. Furthermore, during biogenic synthesis RGO was also capped by biomolecules such as polyphenols which decreased aggregation leading to enhanced Pb(II) removal efficiency.
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高影响因子
FOOD CHEMISTRY
·
2018
·
IF 4.946
Wenwen Deng,Long Yu,Xiao Li,Jia Chen,Xuanxuan Wang,Zixin Deng,Yuxiu Xiao
A series of new hydrophobic deep eutectic solvents (DESs), which are liquid at room temperature and have high density (>1.4 g mL −1 ), were synthesized using hexafluoroisopropanol (HFIP) as hydrogen-bond donor and l -carnitine/betaine as hydrogen-bond acceptor. Then these hydrophobic DESs were used as extraction solvents to establish dispersive liquid-liquid microextraction (DLLME) method for extraction of pyrethroids. The DES extraction phase was in the bottom after DLLME, being easy to be collected for analysis. After optimization by one-variable-at-a-time and response surface methodology, the enrichment factors of 265–360 were achieved for five pyrethroids. The proposed DLLME method coupled with HPLC has good performance: linear ranges of 0.25/0.5/1–100/200/400 ng/mL ( r ≥ 0.9990), limits of detection of 0.06–0.17 ng mL −1 , relative recoveries of 85.1–109.4%, intra-day and inter-day RSDs below 7.5%. The novel DLLME method is simple, rapid, highly efficient and eco-friendly for extraction of pyrethroids in real tea beverages and fruit juices.
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EUROPEAN FOOD RESEARCH AND TECHNOLOGY
·
2012
·Vol. 236
·期 2
·303-310
·
IF 1.566
Chen Guan-Lin,Hu Kun,Zhong Nan-Jing,Guo Juan,Gong Yu-Shi,Deng Xiao-Ting,Huang Ying-Si,Chu Da-Ke,Gao Yong-Qing
The total antioxidant capacity and total polyphenol content of 9 tea juices were examined following in vitro digestion model. Results show that there was a significant variation in total antioxidant capacity [16,392.30 ± 111.64–22,340.23 ± 46.73 μmol VC/L (DPPH), 3,194.24 ± 14.76–13,795.07 ± 37.46 μmol Trolox/L (ABTS), 2,540.61 ± 59.79–7,951.57 ± 31.91 μmol Trolox/L ferric reducing antioxidant power (FRAP)] and total polyphenol content (265.84 ± 9.52–876.62 ± 6.59 μg GAE/mL). Following the in vitro digestion, most of the juices of antioxidant capacities and 7 juices of the total polyphenol content were decreased. Before the in vitro digestion, a highly positive correlation was found between the total polyphenol content and FRAP value. After the gastric phase of digestion, there was a very strong positive linear correlation between the total polyphenol content and total antioxidant capacity. After the duodenal phase of digestion, the correlation between the total polyphenol content and total antioxidant capacity was very weak, and also, a very weak linear correlation was found between the antioxidant assays.
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Journal of the Iranian Chemical Society
·
2015
·Vol. 13
·期 2
·331-337
·
IF 1.087
Fan Chunlei,Pan Qinhe,Li Qun,Wang Liyuan
In this work, cloud point-TiO 2 /sepiolite composites–octyl alcohol extraction combined with UV–vis spectrometry was applied to analyze nickel in real samples. Trace nickel was separated and preconcentrated with PAN as chelating agent, and TiO 2 /sepiolite composites—octylphenoxypolyethoxyethanol (TX-114)—octyl alcohol as extraction agent. Factors influencing extraction efficiency, such as concentrations of TX-114 and octanol, type of the desorption on the extraction system, concentration of chelating agent, pH, incubation temperature, incubation time and conditions of phase separation were investigated and optimized systematically. The results showed that TiO 2 /sepiolite composites exert significant effects on the extraction efficiency; especially nickel concentration is very low. Under the optimal conditions, the absorbance signal is linear with nickel concentration in the range of 0.02–3 mg L −1 and the detection limit was 5 μg L −1 . The developed method was successfully applied to the determination of nickel in natural products of Baisha green tea and coconut water in Hainan.
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危险品化学品经营许可证（带存储）