JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
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2020
·Vol. 100
·期 13
·4921-4929
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IF 2.614
Wanjun Gao,Jiagang Guo,Liang Xie,Chuanyi Peng,Lili He,Xiaochun Wan,Ruyan Hou
BACKGROUND The use of pesticides during tea plant cultivation helps agricultural production and prevents and controls pests, diseases and weeds. It is of the utmost importance to balance pesticide application with tea quality, safety and consumer health. The uptake of pesticides into plants may lead to the presence of residues that are hazardous to human health, especially for some foliar-applied insecticides. The movability or penetration behavior of a pesticide remains unknown after it has been sprayed on a tea leaf. RESULTS Two organophosphate (acephate, trichlorfon) and three neonicotinoid pesticides (imidacloprid, thiamethoxam and acetamiprid) were confirmed with respect to their removal from the treated fresh leaves of tea saplings via washing in a phytotron. Four of the targets have little penetrative ability into tea leaves, mainly existing (> 92%) on the tea leaf surface, except for trichlorfon (> 70%), for 30 days. With higher vapor pressures, trichlorfon and acetamiprid had relatively higher penetration ratios of 8.63–29.60% and 0.28–8.03% respectively. Two organophosphate insecticides were found to degrade more quickly, with lower final amounts of residues on and in the whole leaf compared to the neonicotinoid pesticides. In a field test, these residues could be reduced by 45–72% after a pre-harvest interval of 3 days, and by 16–89% after 7 days, when the fresh tea shoots were sprayed with 2 or 4 L m −2 water. CONCLUSION Pesticides with different structures have different penetration abilities on the tea leaf surface, and some pesticides in commercial tea can be reduced by spraying with water before fresh leaves are picked. © 2020 Society of Chemical Industry
研究领域:
农业科学
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食品安全
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植物科学
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DOI
PubMed
高影响因子
Advanced Science
·
2025
·
IF 14.1
He Wang,Yanjing Guo,Qing Liu,Jing Zhang,Qianlong Zhang,Mingying Yang,Qizhen Chen,Sheng Qiang,Bernal E. Valverde,Shiguo Chen
The tetramic acid moiety is a pivotal structural unit in numerous natural products. As an analogue of the simplest tetramic acid compound tenuazonic acid (TeA), sec-pentyl-TeA (S-TeA) exhibits double herbicidal activity of TeA. Here, this work identifies S-TeA as a novel natural product synthesized by Alternaria alternata and three other filamentous fungi. Chiral analysis confirm the absolute configuration of natural S-TeA as (5 S , 6 S ). Configuration-bioactivity studies reveal that natural (5 S , 6 S )-S-TeA is the eutomer and possesses the highest herbicidal activity among all tested diastereomers. Biosynthetic analyses demonstrate that threonine is the precursor to S-TeA, beginning with the production of 2-amino-3-methylhexanoic acid (AMHA) via eight enzymes from the branched-chain amino acid (BCAA) biosynthetic pathway, including threonine deaminase, 2-isopropylmalate synthase (IPMS), 3-isopropylmalate dehydratase (IPMDH), isopropylmalate dehydrogenase (ISMD), acetolactate synthase, ketol-acid reductoisomerase, dihydroxy acid dehydratase, and BCAA aminotransferase. Subsequently, AMHA undergoes acetylation and cyclization by non-ribosomal peptide synthetases to form S-TeA. Distinct differences in the biosynthetic pathways of S-TeA and TeA are identified. In vitro studies confirm the critical roles of three unique enzymes IPMS, IPMDH, and ISMD in S-TeA biosynthesis, which are absent in TeA biosynthesis. These findings provide a solid basis for developing S-TeA as a natural product herbicide.
研究领域:
化学
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生物科学
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植物化学
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真菌学
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DOI
PubMed
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2023
·
IF 8.1
Yujiao Sun,Xushuang Yuan,Zhaojun Luo,Yungang Cao,Shuai Liu,Yang Liu
Liquid-state fermentation (LSF) of tea leaves is a promising way to obtain tea-based nutraceutical products rich in various bioactive compounds. In the study, the changes of bioactive compounds, tea pigments and complex metabolites from LSF of primary dark tea, green tea and white tea infusions with Aspergillus cristatus were determined. Chemical analyses revealed that soluble sugars, monosaccharide composition, total polyphenols, total flavonoids, free amino acids, soluble proteins and tea pigments were changed in different ways. An untargeted metabolomic analysis and ribonucleic acid sequencing (RNA-seq) based transcriptomic analysis were performed to investigate the metabolic differentiation and clarify the key differentially expressed genes (DEGs, fold change >2 and p < 0.05), showing that amino acid metabolism, carbohydrate metabolism and lipid metabolism were the most enriched pathways during A. cristatus fermentation of primary dark tea, green tea and white tea infusions. In addition, glycerophospholipid metabolism, linoleic acid metabolism and phenylalanine metabolism were greatly accumulated in the fermentation of primary dark tea and white tea infusions; Pyruvate metabolism, glycolysis/gluconeogenesis, fatty acid degradation, tyrosine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis and valine and leucine, isoleucine degradation were greatly accumulated in the fermentation of primary dark tea and green tea infusions; Starch and sucrose metabolism was greatly accumulated in the fermentation of green tea and white tea infusions; Galactose metabolism was significantly enhanced in the fermentation of primary dark tea infusion; Amino sugar and nucleotide sugar metabolism, sphingolipid metabolism and alanine, aspartate and glutamate metabolism were significantly enhanced in the fermentation of green tea infusion. Besides, some other pathways involving aminobenzoate degradation, biosynthesis of cofactors, pyrimidine metabolism, benzoxazinoid biosynthesis and phenazine biosynthesis, tropane, piperidine and pyridine alkaloid biosynthesis and flavone and flavonol biosynthesis also differed from each other. These findings support that A. cristatus plays a vital role in the biochemical and genetic regulation of metabolite profile, and could be considered a potential prospect for better use of A. cristatus on different kinds of tea materials.
研究领域:
食品科学
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微生物学
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分子生物学
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营养保健品
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产品关联
DOI
PubMed
高影响因子
Applied Food Research
·
2026
·Vol. 6
·期 1
·101723
·
IF 6.2
Dahe Qiao,Chun Yang,Xiaozeng Mi,Sihui Liang,Yan Guo,Juan Chen,Zhengwu Chen
Tea quality is synergistically shaped by raw material grade and processing, yet existing research has primarily focused on the processing stage, with systematic evaluations of the role of raw materials remaining insufficient. This study systematically investigated the flavor chemistry of the 'Qiancha 1′ (QC1) tea plant cultivar across tea types from multi-grade raw materials. Fresh leaves of QC1 (one-bud-one-leaf, one-bud-two-leaves, one-bud-three/four-leaves, open surface leaves) were processed into eight distinct tea products (green, black, oolong). Key taste components (catechins, theanine, caffeine, 20 amino acids, 18 flavonoids) were quantified via HPLC and LC-MS. Aroma volatiles (366 compounds) were analyzed using headspace solid-phase microextraction coupled with comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (HS-SPME/GC × GC-TOF-MS). Multivariate analysis revealed significant compositional shifts driven by raw material grade and processing. Tea from one-bud-two-leaves exhibited the highest theanine content. The curling process markedly increased amino acids and aroma volatiles while reducing catechins and flavonoids levels. Lipids and esters dominated the volatile profile. Thirty-eight key aroma-active compounds were identified, defining QC1′s characteristic floral, green, and fruity notes. This work provides a chemical basis for optimizing QC1 tea processing, recommending one-bud-one/two-leaf raw materials for curly green or black tea to enhance characteristic flavor quality.
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高影响因子
JOURNAL OF MOLECULAR STRUCTURE
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2025
·
IF 4.7
Xinrong Li,Shuliang Chen,Xianzhi Hu,Futing Zi
A key challenge in the recovery of Au ions from thiosulfate gold leaching solutions is the design of adsorbents with abundant active adsorption sites, exhibiting high affinity and selectivity toward Au(I), thus enabling its fast, high-purity, and large-capacity recovery. Guided by theoretical calculations, in this study a polychloromethylstyrene (PCMS) material capable of supplying additional charges was functionalized by triethylamine (TEA) to selectively recover gold from a thiosulfate leaching solution. The adsorption of Au(S₂O₃)₂³⁻ onto the functionalized PCMS–TEA followed pseudo-second-order kinetics and was consistent with the Langmuir isotherm model, suggesting a single-molecular-layer chemisorption process. PCMS–TEA exhibited a significant Au-ion loading capacity (81.50 kg/t), highlighting the potential of benzene rings to enhance the charge intensity of ionic adsorbents. Furthermore, PCMS–TEA exhibited good Au-ion selectivity in a copper–ethylenediamine–thiosulfate Au leaching solution. The adsorption mechanism of Au ions on PCMS–TEA involved ion exchange between Cl − in the adsorbent and Au(S 2 O 3 ) 2 3− complex ions. The visual analysis of density functional theory results, based on the Multiwfn and Visual Molecular Dynamics programs, confirmed the presence of a weak interaction between PCMS–TEA and Au(S 2 O 3 ) 2 3− , dominated by van der Waals forces. After five desorption cycles, the adsorption rate of Au ions was approximately 90%, and NaCl was used as the elution reagent. This study introduces a promising adsorbent for the selective recovery of Au ions from thiosulfate Au leaching solutions.
研究领域:
材料科学
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环境化学
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冶金学
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吸附技术
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理论化学
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DOI
高影响因子
FOOD CHEMISTRY
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2026
·
IF 10.4
Ming Zhang,Bin Wang,Ishtiaq Ahmad,Jifang Miao,Shiguo Chen,Xingqian Ye
Chemical and flavor characteristics of Lingmu tea were systematically analyzed. • Processing reshaped aroma via redistribution of key odor-active compounds. • Taste profile changed with amino acids, organic acids, and polyphenols. • Antioxidant mechanism shifted from radical scavenging to reducing capacity. Lingmu tea is a traditional non- Camellia beverage, yet its chemical basis and processing-induced changes remain unclear. This study investigated the effects of processing on its composition, flavor, and antioxidant properties using metabolomic and sensory analyses. Processing significantly reduced free amino acids and flavan-3-ols such as epigallocatechin, while increasing complex polyphenols including terchebin and trigalloyllevoglucosan. Organic acids such as gallic acid and lactic acid also increased. Volatile analysis based on relative odor activity values showed that linalool (ROAV = 100) was the dominant aroma contributor in fresh leaves, whereas 1-octen-3-one (ROAV = 100) and dimethyl sulfide (ROAV = 61.75) showed higher contributions after processing. Notably, antioxidant activity exhibited a mechanistic shift from rapid radical scavenging to enhanced overall reducing capacity. These findings provide insights into the compositional and functional transformation of Lingmu tea during processing. Download: Download high-res image (139KB) Download: Download full-size image
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DOI
PubMed
高影响因子
Food Chemistry-X
·
2024
·
IF 6.5
Mengwan Li,Dan Liu,Tingting Han,Juan Li,Linbo Chen,Daxiang Li,Zhongwen Xie
Dali tea (DLT) made by wild tea plant ( Camellia taliensis) has been very popular in the market。However, the signature compounds and health benefits of DLT were not reported yet. To comprehensively understand metabolite signatures and potential health-function, the distinct metabolite signatures and hypoadiposity effect between DLT and Yunkang tea (YKT, made by Camellia sinensis var assamica cv. Yunkang 10) were comparative investigated. Our data found that catechins, and dimeric catechins were lower in DLT than YKT. In contrast, the levels of phenolic acid and amino acids were higher in DLT than YKT. An un-targeted metabolomics and a chemometric analysis indicated that flavonoid biosynthesis is a major pathway that distinguishes DLT from YKT. Additionally, chlorogenic acid, ellagic acid, arginine, tyrosine, and theanine were identified as characteristic metabolites of DLT. Furthermore, animal experiment showed that YKT performs better efficiency than DLT on alleviating hyperadiposity and renal damages in high-fat-diet induced obese mice.
研究领域:
食品科学
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营养学
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代谢组学
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药理学
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
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2025
·
IF 9.8
Chen Yang,Kaikai Wei,Minghui Xu,Zhaojun Wang,Chuanjian Cui,Qianying Dai,Guijie Chen,Ruyan Hou
This study investigated the sensory characteristics of black tea milk teas (BTMTS) and explored their key aroma qualities. Through sensory evaluation, the mouthfeel, taste, and aroma profiles of BTMTS were identified, and the sensory wheel for BTMTS was constructed. Combining three aroma extraction methods (SPME, SBSE, SAFE), the volatile components of milk tea were comprehensively extracted. A total of 47 volatile compounds were identified using GC–MS and GC-O, with flavor dilution factors ranging from 1 to 512. Additionally, 21 compounds were confirmed as aroma-active (OAV ≥ 1). Through recombination and omission studies, 19 key aroma-active compounds were identified, including geraniol, trans-β-ionone, dimethyl sulfide, linalool, δ-decalactone, etc. Alcohols, ketones, aldehydes, esters, and acids provided violet, honey, rose, almond-like, coconut candy, cheese, and creamy characteristics in BTMTS. This research offers valuable insights into the flavor characterization and evaluation of BTMTS.
研究领域:
食品科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2025
·
IF 9.8
Shan Zhang,Jinjie Hua,Linchi Niu,Haibo Yuan,Le Chen,Xujiang Shan,Qianting Zhang,Yuning Feng,Qinghua Zhou,Yongwen Jiang,Jia Li
Shaking-withering is a new technique in black tea manufacturing, which enables promoting aroma quality. Lipids are important tea aroma precursors. However, the lipids metabolism and its contribution to aroma formation of shaking-withering black tea (SBT) remain unknown. Herein, 436 lipids and 45 fatty acid-derived volatiles (FADVs) and their dynamic changes during SBT processing were investigated. Among them, 113 lipids and 29 FADVs (mainly floral/fruity fatty aldehydes and esters) were screened as critical compounds associated with shaking-withering. Key enzymes PLA, LOX and HPL showed enhanced activity/expression in SBT. Degradation of glycerophospholipids, glycoglycerolipids, and fatty acids were annotated as potential lipid metabolism pathways. Particularly, glycoglycerolipids containing 18:2, 18:3 fatty acyls, e.g., MGDG(18:2/18:3), DGDG(18:3/18:3), showed most predominate degradation after shaking and negative correlation with FADVs, and were highlighted as key potential aroma precursors in SBT. These results demonstrated that shaking may trigger greater glycoglycerolipids degradation and FADVs formation, contributing to SBT aroma improvement.
研究领域:
食品科学
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植物代谢
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2020
·
IF 6.306
Cheng Guo,Yijie Chen,Jing Li,Fuchao Zhan,Xianling Wei,Bin Li
Green tea nanoparticles (gTNPs) are considered as the precursors of tea cream, while the role of gTNPs in the process of tea cream formation remains obscure. This study indicated that gTNPs could be coated with epigallocatechin gallate (EGCG)-caffeine (CAF) complexes to form a ternary aggregate participating in tea cream formation. First, the ζ-potentials of gTNPs and EGCG-CAF complexes were adjusted by charge screening. Then, gTNPs were introduced into EGCG + CAF mixture solutions under different ζ-potential conditions to examine their effect on turbidity, particle size and components of mixture solutions. Finally, isothermal titration calorimetry (ITC) was applied to investigate the influence of gTNPs on the thermal effects of the interaction between EGCG and CAF. Our results reveal that hydrophobic interaction exceeded electrostatic repulsion to dominate the interaction between gTNPs and EGCG-CAF complexes at the low ζ-potential condition, thus forming the gTNPs/EGCG/CAF ternary aggregate.
研究领域:
食品科学
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纳米生物学
·
物理化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2022
·
IF 5.895
Mengru Li,Chi-Tang Ho,Jing Wang,Yuemeng Hu,Xiaoting Zhai,Liang Zhang,Xiaochun Wan,Xiaogen Yang
Theanine is a non-proteinogenic amino acid found in the tea plant Camellia sinensis. At an elevated temperature (>90 °C), it released two major volatile compounds 1-ethyl-1,5-dihydro-2H-pyrrol-2-one and N-ethylsuccinimide. Other products were identified, including 10 pyrroles and 12 amides/imides. The formation of the two major compounds was proposed to be initiated by the deamination of theanine and through the intermediate α-keto acid. In the presence of glucose, the two major products and many other volatiles from theanine thermal degradation were accelerated and further Maillard reactions occurred. A total of 56 compounds were identified in the model system of theanine and glucose, including 12 amides/imides, 16 pyrazines, 16 pyrroles and other N-heterocycles, and 12 furans and other O-heterocycles. Although most of the reaction products were detected in tea leaves and in their aqueous extract with or without the addition of theanine under the same experiment conditions, imides and amides were considerably suppressed, left only minute amounts, or were even no longer detectable. Pyrazines and pyrroles were also shown at reduced concentrations as a result of the interaction with tea components but to a lesser extent. A total of 16 and 12 pyrazines were identified in the theanine/glucose reaction system and tea leaves/aqueous extract after roasting, respectively. The results indicated that pyrazines and other main volatiles in roasted tea leaves were formed from the Maillard reactions of the aqueous fraction of tea leaves. Theanine participated in the formation of pyrazines in tea leaves under roasting conditions.
研究领域:
食品化学
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农业化学
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有机化学
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食品科学
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DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Ying Zhu,Yifan Gao,Yiqing Lu,Yuanhui Cheng
Highly efficient electrochemical interfaces are significant for the oxygen reduction reaction (ORR). However, previous efforts have been mainly paid to design catalytic sites with high intrinsic activity and neglect the electrode/electrolyte interfaces, especially the noncovalent interactions in the outer Helmholtz plane (OHP). Herein, an Fe–N–C single-atom catalyst is synthesized and acts as the model catalyst to demonstrate the effect of noncovalent interactions on the ORR performance. Two specific molecules of THA+ and TEA+ with different structures and functional groups have been selected to tune the OHP through noncovalent interactions. TEA+ can adjust the OHP, improve the oxygen diffusion coefficient, and increase the double-layer capacitance. Therefore, TEA+ enhances the activity, selectivity, and stability of Fe–N–C single-atom catalysts toward the ORR. This provides a new approach to finding new directions in designing electrochemical interfaces beyond the intrinsic catalytic sites in acidic electrolytes.
研究领域:
电化学
·
材料科学
·
催化
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）