Food Chem
Biotechnology Research Institute, College of Agriculture and Life Sciences, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju 500-757, Republic of Korea. Electronic address:
Published: December 2014
A method for determining eight pesticide (cyhalothrin, flufenoxuron, fenitrothion, EPN, bifenthrin, difenoconazole, triflumizole, and azoxystrobin) residues in made green tea as well as a tea infusion (under various brewing water temperatures; 60, 80, and 100°C) using gas chromatography (GC) micro-electron capture detector (μECD) was developed and validated. The extraction method adopted the relatively commonly used approach of solid sample hydration, with the green tea hydrated before being extracted through salting out with acetonitrile followed by a cleanup procedure. The analytes were confirmed using GC-coupled to tandem mass spectrometry (GC/MS/MS) with a triple quadrupole. The linearity of the calibration curves yielded determination coefficients (R(2)) >0.995. Recoveries were carried out using blank samples spiked with all analytes at two levels. The results demonstrated that all pesticides were recovered within the range of 77-116% with a relative standard deviation (RSD) ⩽14%. The quantification limits of 0.015-0.03 mg/kg were lower than the maximum residue limits (MRLs) set by the Korea Food and Drug Administration (KFDA) for all analytes (0.05-10mg/kg). The infusion study indicated that cyhalothrin, flufenoxuron, and bifenthrin did not infuse into the tea brew from the made tea. Increases in brewing time resulted in increased transfer of azoxystrobin, fenitrothion, and difenoconazole from the made tea to the brew; however, this was not the case with triflumizole or EPN. We conclude that transfer of pesticides appeared to be dependent on their water solubilities and drinking a cup of tea is recommended to be at a water temperature of 60°C.
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http://dx.doi.org/10.1016/j.foodchem.2014.05.145 | DOI Listing |
Int J Biol Macromol
January 2025
College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen 361021, China; Research center of food biotechnology of Xiamen city, Xiamen, Fujian 361021, China. Electronic address:
In this study, polyethylene glycol 200 (PEG200) was employed as hydrogen bond acceptor, while organic acids served as hydrogen bond donors, to formulate poly-deep eutectic solvents (PDESs), which were utilized to pretreat tea stem. Specially, combining PEG200 and oxalic acid (OA) exhibited a notably high cellulose retention (82.03 %) and most efficient hemicellulose (97.
View Article and Find Full Text PDFEnviron Pollut
January 2025
Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, People's Republic of China; NHC Key Laboratory of Etiology and Epidemiology(Harbin Medical University); Joint Key Laboratory of Endemic Diseases(Harbin Medical University, Guizhou Medical University, Xi'an Jiaotong University); Center for Chronic Disease Prevention and Control, Harbin Medical University, Harbin, People's Republic of China. Electronic address:
Background: Skeletal fluorosis is a chronic metabolic bone disease caused by excessive accumulation of fluoride in the bones. Previous studies have found that when the intake of tea fluoride is similar, the prevalence of skeletal fluorosis varies greatly among different ethnic groups, which may be related to different genetic backgrounds. Single nucleotide polymorphisms (SNPs) of estrogen receptor 1 (ESR1) and collagen type 1 α1 (COL1A1) were strongly associated with bone metabolism as well as bone growth and development, but their association with the risk of skeletal fluorosis has not been reported.
View Article and Find Full Text PDFSci Total Environ
January 2025
School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, China. Electronic address:
This study comprehensively investigated the Cs signal in 294 sediment core samples from 132 lakes including reservoir and Gobi catchment in China. First, three Cs chrono-markers were observed: the 1963 peak corresponding to the maximum deposition of radioactive debris from global fallout, and two local sub-peaks corresponding to the time of the nuclear tests at Chinese Lop Nor site with a maximum in 1976, and to the Chernobyl accident in 1986. Second, the spatial distribution of sedimentation rates based on the 1963 Cs chrono-marker in Chinese lake sediment cores was studied.
View Article and Find Full Text PDFTalanta
January 2025
Department of Chemical Engineering, Jashore University of Science and Technology, Jashore 7408, Bangladesh.
Due to the larger pore structure, the macroporous material can be used as the immobilized carrier to not only increase the enzyme loading capacity, but also facilitate the transfer of reactants and substrates. Based on this, a three-dimensional ordered macro-microporous ZIF-8 (SOM-ZIF-8) was prepared using three-dimensional ordered stacked polystyrene spheres as the hard template. The morphology and structure of SOM-ZIF-8 were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and so on.
View Article and Find Full Text PDFJ Sep Sci
January 2025
School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China.
Tea saponin has garnered tremendous interest for its potential use in surfactant and drug synthesis. This research was designed to develop a technique based on pH-responsive switchable deep eutectic solvents (SDESs) for extracting tea saponins from Camellia oleifera seed meal. SDES synthesized from hexanoic acid and triethanolamine (1:1 molar ratio) offered the optimum extractive performance and the optimal conditions were obtained through single-factor experiments: 30 wt% water content in SDES, solid-liquid ratio of 1:30 g/mL, 60°C extraction temperature, 30 min extraction time, and acid volume of 1500 µL.
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