Analytical Methods
·
2023
·
IF 3.1
Xinli Song,Yuqing Liu,Feiyan He,Yiyao Wu,Dongdong Wang,Hui Lv,Xueshan Wang,Zhongguan Sun,Canling Cheng,Kechao Liao,Yue Chen
Abstract The efficient extraction of phthalate acid esters (PAEs) is challenging due to their extremely low concentration, complicated matrices and hydrophilicity. Herein, hollow microspheres, as an ideal coating, possesses significant potential for solid-phase microextraction (SPME) due to their fascinating properties. In this study, multi-walled carbon nanotubes hollow microspheres (MWCNTs-HMs) were utilized as a fiber coating for the SPME of PAEs from tea beverages. MWCNTs-HMs were obtained by dissolving the polystyrene (PS) cores with organic solvents. Interestingly, MWCNTs-HMs well maintain the morphology of the precursors MWCNTs@PS. The layer-by-layer (LBL) assembly of MWCNTs on PS microsphere templates was ac-quired through electrostatic interactions. Six PAEs, di-ethyl phthalate (DEP), di-iso-butyl phthalate (DIBP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di-2-ethylhexyl phthalate (DEHP) and di-n-octyl phthalate (DOP), were selected as target analytes for assessing the efficiency of the coating for SPME. The stirring rate, sample solution pH and extraction time were optimized by using the Box-Behnken design. Under optimal working conditions, the proposed MWCNTs-HMs/SPME was coupled with gas chromatography-tandem mass spectrometry (GC-MS/MS) to achieve high enrichment factors (118–2137), wide linearity (0.0004-10 μg L-1), low limits of detection (0.00011-0.0026 μg L-1) and acceptable recovery (80.2%-108.5%) for the detection of PAEs. Therefore, the MWCNTs-HMs coated fibers are promising alternatives in the SPME method for the sensitive detection of PAEs at trace levels in tea beverages.
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CHEMOSPHERE
·
2023
·
IF 8.8
Zibin Pan,Rongrong Xie,Zuliang Chen
Acid Mine Drainage (AMD) contains various metal/metalloid ions such as Fe, Cu, and As, which all impact seriously on mine ecosystems. Currently, the commonly used chemical methods for treating AMD may cause secondary pollution to appear in the environment. In this study, one-step simultaneous biomass synthesis of iron nanoparticles (Fe NPs) using tea extracts for the removal of heavy metals/metalloids in AMD is proposed. Characterizations revealed that the Fe NPs presented severely agglomerated particles with an average particle size of 119.80 ± 4.94 nm, on which various AMD-derived metal(loid)s, including As, Cu, and Ni, were uniformly dispersed. The biomolecules participating in the reaction in the tea extract were identified as polyphenols, organic acids, and sugars, which acted as complexing agents , reducing agents, covering/stabilizing agents, and promoted electron transfer . Meanwhile, the best reaction conditions (reaction time = 3.0 h, volume ratio of AMD and tea extract = 1.0:1.5, concentration of extract = 60 g/L, and T = 303 K) were obtained. Finally, the simultaneous formation of Fe NPs and their removal of heavy metals/metalloids from AMD was proposed, mainly involving the formation of Fe NPs and adsorption, co-precipitation, and reduction processes of heavy metals/metalloids.
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Materials Express
·
2023
·Vol. 13
·期 4
·574-583
·
IF 0.7
Li Xiaochun,Li Guanli,Wu Mei,Pang Yongfeng,Nie Hui,Wu Shujie,Tang Xiaoxian,Luo Yanghe,Li Xiaolong
Gold-doped carbon dots (CDAu) were simply and quickly prepared via microwave procedure using fullerene as a precursor, a rapid detection method for chlorpyrifos was established using surface enhanced Raman scattering (SERS) combined with aptamer (Apt) controlled gold-doped
carbon dots catalytic reaction. As the result, the SERS intensity decreased due to the aptamer inhibited the CDAu catalytic reduction of chlorauric acid by glucose. However, in the presence of chlorpyrifos, SERS intensity increased linearly with the concentration of chlorpyrifos
in the range of 12.8–432.8 ng/L, the correlation coefficient was R
2 = 0.9961.
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FOOD CHEMISTRY
·
2023
·
IF 8.8
Xin Fang,Yanan Liu,Jingyi Xiao,Cunqiang Ma,Youyi Huang
High-performance liquid chromatography (HPLC), headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC–MS) and ultra-high performance liquid chromatography–Q-Exactive HF-X mass spectrometer (UHPLC–Q-Exactive HF/MS) were carried out to reveal dynamic changes of volatile and non-volatile compounds during the withering process of black tea. A total of 118 volatile organic compounds (VOCs) and 648 metabolites were identified in fresh and withered tea-leaves, respectively. Among them, 47 VOCs (OAV > 1.0) for the aroma formation, and 46 characteristic metabolites (VIP > 1.50, p < 0.01) selected through orthonormal partial least squares-discriminant analysis, indicated the withering contribution during black tea processing. Overall, the withering promoted alcohols, aldehydes, phenols, heterocyclic oxygen, hydrocarbons and halogenated hydrocarbons through relevant hydrolyzation, decomposition, terpene synthesis, and O -methylation. The hydrolyzation, O -methylation, condensation and N -acylation of kaempferol glycosides, quercetin glycosides, ester catechins, and gallic acid generated the accumulation of methoxyl flavonoids and flavonoid glucosides, dihydrokaempferol, syringic acid, theaflavins, and N -acylated amino acids, respectively.
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Frontiers in Microbiology
·
2018
·
IF 4.019
Lu Qinhua,Wang Yuchun,Li Nana,Ni Dejiang,Yang Yajun,Wang Xinchao
Colletotrichum, the causative agent of anthracnose, is an important pathogen that invades the tea plant (Camellia sinensis). In this study, 38 isolates were obtained from the diseased leaves of tea plants collected in different areas of Zhejiang Province, China. A combination of multigene (ITS, ACT, GAPDH, TUB2, CAL, and GS) and morphology analyses showed that the 38 strains belonged to two different species, namely, C. camelliae (CC), and C. fructicola (CF). Pathogenicity tests revealed that CC was more invasive than CF. In vitro inoculation experiments demonstrated that CC formed acervuli at 72 hpi and developed appressoria on wound edges, but CF did not develop these structures. Under treatment with catechins and caffeine, the growth inhibition rates of CF were remarkably higher than those of CC, indicating that the nonpathogenic species CF was more vulnerable to catechins and caffeine. Growth condition testing indicated that CF grew at a wide temperature range of 15–35°C and that the optimum temperature for CC growth was 25°C. Growth of both CC and CF did not differ between acidic and weakly alkaline environments (pH 5–8), but the growth of CC was significantly reduced at pH values of 9 and 10. Furthermore, the PacC/RIM101 gene, which associated with pathogenicity, was identified from CC and CF genomes, and its expression was suppressed in the hyphae of both species under pH value of 5 and 10, and much lower expression level was detected in CC than that in CF at pH 6. These results indicated that temperature has more important effect than pH for the growth of two Colletotrichum species. In conclusion, the inhibition by secondary metabolite is an important reason why the pathogenicity by CC and CF are different to tea plant, although the environmental factors including pH and temperature effect the growth of two Colletotrichum species.
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FOOD CHEMISTRY
·
2018
·
IF 4.946
Ying Zhou,Qiyuan Peng,Lanting Zeng,Jinchi Tang,Jianlong Li,Fang Dong,Ziyin Yang
After tea leaves, tea ( Camellia sinensis ) flowers are becoming a second tea plant resource because they contain not only functional metabolites similar to those found in tea leaves, but also predominant amounts of functional metabolites that only occur in tea leaves in small amounts. 1-Phenylethanol (1PE) is a predominant aroma compound found in tea flowers. A 1PE synthase in tea flowers was isolated, functionally characterized, and shown to have the highest catalytic efficiency for the conversion of acetophenone (AP). To determine why 1PE accumulates more in tea flowers than other plants, we compared their 1PE contents and used a stable isotope labeling method to elucidate the 1PE biosynthetic route. Supplementation with [ 2 H 8 ] l -phenylalanine and [ 2 H 5 ]AP suggested that most plants containing the enzyme/gene catalyzed the conversion of AP to 1PE. Furthermore, the availability of AP derived from l -phenylalanine was responsible for the difference in 1PE accumulation between tea flowers and other plants.
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FOOD CHEMISTRY
·
2018
·
IF 4.946
Lu Wang,You Luo,Yanan Wu,Yan Liu,Zhenqiang Wu
There are both soluble and insoluble-bound forms of phenolics in tea-leaf products. In order to increase total soluble phenolics contents, guava leaves tea (GLT) was first fermented with Monascus anka and Saccharomyces cerevisiae , and then hydrolyzed with complex enzymes . The changes in phenolics profiles, antioxidant activities and inhibitory effect on α -glucosidase in processed GLT were investigated. Compared with the un-fermented GLT, fermentation and complex enzymatic processing (FE) significantly increased the total phenolics, total flavonoids, quercetin and kaempferol contents by 2.1, 2.0, 13.0 and 6.8 times, respectively. After the FE, a major proportion of phenolics existed in the soluble form. Quercetin was released in the highest amount among different phenolics. In addition, soluble phenolic extracts from GLT following FE exhibited a highest antioxidant activity and inhibitory effect on α -glucosidase. The paper suggested an improved method for processing GLT into high-value products rich in phenolics and flavonoids aglycones with enhanced health benefits.
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FOOD CONTROL
·
2025
·
IF 6.3
Yaqi Hu,Wei Sheng,Selorm Yao-Say Solomon Adade,Jun Wang,Huanhuan Li,Quansheng Chen
Tea polyphenols (TPs) and dihydromyricetin (DMY) are critical quality attributes of vine tea. This study developed a smartphone-based portable near infrared (NIR) device integrated with machine learning (ML) and deep learning (DL) approaches for rapid prediction of TPs and DMY in vine tea. NIR spectra of the vine tea samples were acquired using the developed portable device and smartphone software, while the contents of TPs and DMY were determined using UV–Vis spectrophotometer and high-performance liquid chromatography (HPLC). To accurately analyze the spectral data, various ML and DL models were evaluated and compared. Results indicate that DL models, including convolutional neural networks (CNN), long-short-term memory (LSTM) and CNN-LSTM, demonstrated superior predictive performance compared to traditional ML approaches in large sample environments. Thereinto, CNN-LSTM exhibited the optimal predictive performance for TPs (Rp = 0.9816; RPD = 5.24) and DMY (Rp = 0.9900; RPD = 7.11). Additionally, the optimal model 's validation performance are commendable, with a maximum coefficient of determination (0.9483 for TPs and 0.9625 for DMY). This demonstrates that the developed intelligent portable NIR instrument coupled with DL tools enables rapid on-site detection of vine tea quality components. Furthermore, it provides a potential strategy for real-time quality monitoring during vine tea online processing.
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JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
·
2024
·
IF 3.1
Yanyang Wang,Shanshan Gao,Gege Yang,Wenyi Zhu,Ying Lu,Mengyuan Tan,Yuancheng Peng,Hua Yang,Chunxia Song
A portable platform for the visual determination of F− and Al3+ was developed by combining FeNPs@g-C3N4 nano-enzyme and a smartphone. The FeNPs@g-C3N4 nano-enzyme with excellent peroxidase activity was synthesized through the in situ growth of Fe nanoparticles (FeNPs) on graphite-phase carbon nitride nanosheets (g-C3N4), which could catalyze H2O2 to oxidize TMB to blue oxide (oxTMB). The peroxidase activity of the FeNPs@g-C3N4 nano-enzyme could be inhibited by F−, and then restored by Al3+ because of the coordination reaction between Fe3+/Al3+ and F−. Furthermore, the solution color could be dynamically manipulated by changing the concentrations of F− and Al3+. Under optimal conditions, the developed method gave low detection limits of 2.43 nM for F− and 7.66 μM for Al3+. The cooperation of nano-enzyme and smartphone has greatly shortened the detection time and reduced the cost of detection, providing a new strategy for the on-site and convenient detection of F− and Al3+ in tea, and showed significant application potential in food safety evaluation.
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Food Bioscience
·
2024
·
IF 4.8
Dianhui Wu,Ziqiang Chen,Yongxuan Lv,Lixia Yang,Hua Liu,Ran Qiu,Hengde Xu,Jianbo Li,Jian Lu,Guolin Cai
The utilization of mixed cultures of Saccharomyces and non -Saccharomyces cerevisiae strains to improve the quality and aroma complexity of wines has garnered considerable attention as of late. In this study, three non -S. cerevisiae strains exhibiting a strong β-glucosidase production capacity were screened from the yeasts preserved in the laboratory. Subsequently, the physiological characteristics of the strains were evaluated through growth curve analysis as well as alcohol and osmotic pressure tolerance experiments. Finally, the non -S. cerevisiae strain S14 ( Torulaspora delbrueckii ) was selected and applied to ferment Yuan'an yellow tea beer combined with S. cerevisiae S189. The results showed that the optimal fermentation performance was achieved when S14 was inoculated first, followed by the addition of S189 after 12 h of fermentation, with an S14:S189 ratio of 10:1. Mixed fermentation resulted in a significant increase in the concentration of volatile flavor compounds in beer, particularly terpenes, alcohols, esters, and acids, which exhibited levels of 520.98 μg/L, 5534.28 μg/L, and 1631.80 μg/L, respectively; these values were 299.25%, 32.45%, and 56.57% higher compared to purebred fermentation. Furthermore, mixed fermentation demonstrated an improvement in the antioxidant activity of beer, as evidenced by the increase in the comprehensive evaluation score (CES) from 1.86 to 2.89. Overall, these findings indicated the notable advantage of non -S. cerevisiae strain S14 in fermenting Yuan'an yellow tea beer.
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BIOTECHNOLOGY AND BIOPROCESS ENGINEERING
·
2015
·Vol. 20
·期 1
·157-167
·
IF 1.113
Chaudhary Narendra,Bhardwaj Jyoti,Hwang Jae-Ho,Seo Hyo-Jin,Kim Min-Yong,Shin Tai-Sun,Wee Ji-Hyang,Shin Yu-Lim,Kim Jong-Deog
Camellia sinensis L. O. Kuntze has traditionally been used in Asian countries as a stimulant, a diuretic, and to prevent obesity. Studies in green tea are well-documented in literature, though the potential of fruit from the plant has never been studied in details. In the present study, the anti-adipogenic effect of aqueous extract of green tea seed cake extract (GTE) were analysed in-vitro and the anti-obesity effects were determined in-vivo in murine model fed high-fat and high-carbohydrate diets. We found that GTE inhibited the lipid accumulation in 3T3-L1 adipocyte and significantly lowered body weight, body fat-pad weights, blood lipid, glucose, insulin, and leptin levels in mice fed high-fat and high-carbohydrate diets. GTE suppressed the expression of important adipogenic genes (PPARγ, C/EBPα, SREBP, LPL, aP2 and leptin) and lipid metabolism genes (FAS). Furthermore, GTE induced the levels of adiponectin in serum and adipose tissue, as well as AMP-activated protein kinase (AMPK) in liver tissue. These results suggested that GTE ameliorates its anti-obesity effect through multiple cells signaling pathways in diets induced obesity in mice.
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FOOD CHEMISTRY
·
2024
·
IF 8.5
Zifan Hu,Weiyang Sun,Jiaqi Guo,Xuan Wang,Li Yong,Lin Ren,Dejian Feng,Xiaoli Zou
Using high-performance liquid chromatography-mass spectrometry, fifteen bisphenols and halogenated phenols were simultaneously analyzed in tea for the first time in China. Response surface methodology was used to optimize sample preparation conditions based on QuEChERS. Finally, the limits of detection and the limits of quantification were 0.0200–0.173 μg/kg and 0.0892–0.770 μg/kg, respectively. The recoveries were 70 %–120 % for most compounds (except for some compounds at low spiked concentrations) with RSDs <20 %. Then 135 dried tea samples were analyzed. Bisphenol S, A and F were the predominant bisphenol contaminants with detection rates above 80 %, and the median level of bisphenol F (4.90 μg/kg) was even higher than that of bisphenol A (2.74 μg/kg). Bisphenol A ( p < 0.001) and bisphenol F ( p = 0.007) were significantly higher in black tea than in green tea. Hazard index was estimated and bisphenols in tea may pose potential risks to human health.
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