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LC/ MS-MS analysis of tea

Shuwei Zhang, Chun Yang, Emmanuel Idehen, Shi Lei, Lishuang Lv, Shengmin Sang
Black tea consumption has been associated with many health benefits including the prevention of cancer and heart disease. However, the chemical composition of black tea has not been fully explored. Most studies have examined different interactions between the four major tea catechins, and few studies have examined the interaction between catechins and other components in tea. In the present study, we tested our hypothesis that the ortho-dihydroxyl structure of chlorogenic acid (CGA) could react with the vic-trihydroxy structure of (-)-epigallocatechin 3-gallate (EGCG) and (-)-epigallocatechin (EGC) to generate theaflavin-type of compounds during black tea fermentation...
March 13, 2018: Journal of Agricultural and Food Chemistry
Oliver Kappenstein, Ingo Ebner, Carina Förster, Stephan Richter, Jürgen Weyer, Karla Pfaff, Andreas Luch
Polyamides (PA) are used in the production of various food contact materials (FCMs) and articles such as kitchen utensils and packaging material. Cyclic oligomers have been identified as potential migrants from PA. This study describes the development, validation and application of a multi-oligomer analytical method based on liquid chromatography-tandem electrospray mass spectrometry (LC-ESI-MS/MS) for the identification and quantification of eight cyclic oligomers of PA 6 and four PA 66 migrating from FCMs into food simulant B (3% acetic acid) and beverages...
March 6, 2018: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
Wojciech Koch, Wirginia Kukula-Koch, Łukasz Komsta
A comprehensive study on the composition and antioxidant properties of black tea samples with a chemometric approach was performed via LC-ESI-Q-TOF-MS, DPPH radical scavenging assay, and Folin-Ciocalteu assay (TPC). Marked differences between the teas from seven different countries (China, India, Iran, Japan, Kenya, Nepal, Sri Lanka) were shown. The Indian samples demonstrated the highest total catechin content (184.8 mg/100 mL), the largest TPC and DPPH scavenging potential (58.2 mg/100 mL and 84.5%, respectively)...
February 26, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Bingjun Qian, Lirong Yin, Xiaomin Yao, Yaoguang Zhong, Juan Gui, Feifeng Lu, Fuming Zhang, Jianhua Zhang
The saponins, as components of tea seed meal (TSM), are undesirable hemolytic components, and should be degraded for reducing their hemolytic activity in order to be used in animal feed. In this study, β-glucuronidase was verified to be a potent hydrolase of tea seed saponins to reduce their hemolytic activity, and a β-glucuronidase-producing Lactobacillus crustorum (L. crustorum) strain was screened from raw bovine milk. Next, solid-state fermentation with the isolated L. crustorum and a Bacillus subtilis natto strain, which can produce cellulase and hence improve the fermentation performance of tea seed meal, was processed for detoxification of tea seed meal...
February 20, 2018: FEMS Microbiology Letters
Xiujuan He, Xuecheng Zhao, Liping Gao, Xingxing Shi, Xinlong Dai, Yajun Liu, Tao Xia, Yunsheng Wang
There were several high concentrations of flavonoid components in tea leaves that present health benefits. A novel purple-leaf tea variety, 'Mooma1', was obtained from the natural hybrid population of Longjing 43 variety. The buds and young leaves of 'Mooma1' were displayed in bright red. HPLC and LC-MS analysis showed that anthocyanins and O-Glycosylated flavonols were remarkably accumulated in the leaves of 'Mooma1', while the total amount of catechins in purple-leaf leaves was slightly decreased compared with the control...
January 9, 2018: Scientific Reports
Xiu-Hua Meng, Chang Liu, Rong Fan, Li-Fang Zhu, Shi-Xiong Yang, Hong-Tao Zhu, Dong Wang, Chong-Ren Yang, Ying-Jun Zhang
Camellia fangchengensis Liang et Zhong, belonging to the genus Camellia sect. Thea (Theaceae), is an endemic tea species to the south and southwest areas of Guangxi province, People's Republic of China. Known as a wild tea plant, the leaves have been used for producing green tea or black tea by the local people of its growing area. HPLC and LC-MS analysis showed the leaves contain oligomeric catechins as major phenolic components. Further detailed phytochemical study led to the identification of five flavan-3-ol dimers (1-5) including two new ones, fangchengbisflavans A (1) and B (2) from the leaves of C...
January 10, 2018: Journal of Agricultural and Food Chemistry
Friederike Kühne, Oliver Kappenstein, Samira Straβgütl, Florian Weese, Jürgen Weyer, Karla Pfaff, Andreas Luch
It was the aim of the work described here to develop a validated analytical method for the determination of N-nitrosamines in food simulants. Here, we present the validation of a liquid chromatography-atmospheric pressure chemical ionisation-tandem mass spectrometry method for the determination of 13 N-nitrosamines in the food simulants deionised water, 3% acetic acid and 10% ethanol. Method validation encompassed linearity, LOD, LOQ, recovery, precision and stability of the N-nitrosamines. The method was found to be sufficiently rugged and suitable for routine analysis...
January 19, 2018: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
Masahiro Umehara, Koji Yanae, Hiroko Maruki-Uchida, Masahiko Sai
(-)-Epigallocatechin-3-O-gallate (EGCG), the major catechin present in green tea, exhibits potent antioxidant activity. We thereby investigated the presence of unknown components bearing the (-)-epigallocatechin (EGC) moiety in fresh tea leaf samples. Initially, liquid chromatography tandem mass spectrometry (LC-MS/MS) was employed to examine fresh tea leaves of the Yabukita, the most popular tea cultivar in Japan, which suggested the presence of the EGC phenylpropanoid derivatives, (-)-epigallocatechin-3-O-p-coumaroate (EGCpCA) and (-)-epigallocatechin-3-O-caffeoate (EGCCA)...
December 2017: Food Research International
Noelia Pallarés, Guillermina Font, Jordi Mañes, Emilia Ferrer
The aim of the present study was to develop a multimycotoxin liquid chromatography tandem mass spectrometry (LC-MS/MS) method with a dispersive liquid-liquid microextraction procedure (DLLME) for the analysis of AFs, 3aDON, 15aDON, NIV, HT-2, T-2, ZEA, OTA, ENNs, and BEA in tea beverages and to evaluate their mycotoxin contents. The proposed method was characterized in terms of linearity, limits of detection (LODs), limits of quantification (LOQs), recoveries, repeatability (intraday precision), reproducibility (interday precision), and matrix effects to check suitability...
November 29, 2017: Journal of Agricultural and Food Chemistry
Jia Li, Jinjie Hua, Qinghua Zhou, Chunwang Dong, Jinjin Wang, Yuliang Deng, Haibo Yuan, Yongwen Jiang
As important biomolecules in Camellia sinensis L., lipids undergo substantial changes during black tea manufacture, which is considered to contribute to tea sensory quality. However, limited by analytical capacity, detailed lipid composition and its dynamic changes during black tea manufacture remain unclear. Herein, we performed tea lipidome profiling using high resolution liquid chromatography coupled to mass spectrometry (LC-MS), which allows simultaneous and robust analysis of 192 individual lipid species in black tea, covering 17 (sub)classes...
November 7, 2017: Journal of Agricultural and Food Chemistry
Zhaotang Ding, Sisi Jia, Yu Wang, Jun Xiao, Yinfei Zhang
In order to study the response of tea plants to P stress, we conducted the ionomic and metabolomic analysis by ICP-OES, GC-MS and LC-MS. The results demonstrated that P was antagonistic with S, and was cooperative with Cu, Zn, Mn and Fe under P-deficiency. However, P was antagonistic with Mn, Fe and S, and was cooperative with Cu and Zn under P-excess. Moreover, P-deficiency or excess reduced the syntheses of flavonoids and phosphorylated metabolites. P-deficiency decreased the amount of glutamate and increased the content of glutamine, while P-excess decreased the content of glutamine...
September 14, 2017: Plant Physiology and Biochemistry: PPB
Dongqiang Hu, Yingying Fan, Yanglan Tan, Ye Tian, Na Liu, Lan Wang, Duoyong Zhao, Cheng Wang, Aibo Wu
Xinjiang jujubes (Zizyphus rhamnaceae) are important agro-economical foods with the highest planting area and yields in China; however, black spot disease and contaminated Alternaria toxins have unfortunately caused a decline or loss of jujube nutritional quality in recent years. In this study, we used ultrahigh-performance liquid chromatography coupled to Orbitrap high-resolution mass spectrometry to profile both Alternaria toxins and components in three representative Xinjiang jujubes, Hami Huang, Hetian Jun, and Ruoqiang Hui...
September 18, 2017: Journal of Agricultural and Food Chemistry
Mukesh Meena, Prashant Swapnil, R S Upadhyay
Alternaria species produce various sorts of toxic metabolites during their active growth and causes severe diseases in many plants by limiting their productivity. These toxic metabolites incorporate various mycotoxins comprising of dibenzo-α-pyrone and some tetramic acid derivatives. In this study, we have screened out total 48 isolates of Alternaria from different plants belonging to different locations in India, on the basis of their pathogenic nature. Pathogenicity testing of these 48 strains on susceptible tomato variety (CO-3) showed 27...
August 18, 2017: Scientific Reports
Imran Nazir, Nisar Ur Rahman, Zunaira Alvi, M Hafizur Rahman, Jandirk Sendker, Tao Zhang, Neil Frankish, Helen Sheridan
Diabetes mellitus is a chronic disease and one of the most important public health challenges facing mankind. Fagonia cretica is a medicinal plant used widely in the Punjab in Pakistan. A recent survey has demonstrated that traditional healers and herbalists frequently use this plant to treat diabetes. In the current study, the traditional medicine was prepared as a tea, and the profile of the main metabolites present in the traditional medicine was analysed via LC/MS/MS. The extract was shown to contain a number of phenolic glycosides including quercetin-3-O-rutinoside, kaempferol-3-O-rutinoside, kaempferol-3-O-glycoside, kaempferol-3(6'-malonylglucoside), isorhamnetin-3-O-rutinoside, and isorhamnetin 3-(6″-malonylglucoside) in addition to two unidentified sulphonated saponins...
October 2017: Planta Medica
Zejun Jiang, Hui Li, Xiaolin Cao, Pengfei Du, Hua Shao, Fen Jin, Maojun Jin, Jing Wang
A rapid and sensitive method based on modified QuEChERS for hymexazol determination in 26 plant-derived foods using liquid chromatography tandem-mass spectrometry (LC-MS/MS) was developed. Variables affecting the separation (LC column, mobile phase additives) and clean-up effects of various dispersive phases, such as PSA, C18, GCB, MWCNTs, PEP-2, Al2O3, Florisil, and PVPP were evaluated. The method was validated using 26 matrices at spiked levels of 0.01 or 0.02, 0.05, 0.1, and 0.5mg/kg (0.05, 0.2, 0.5, and 1...
August 1, 2017: Food Chemistry
Dasharath P Oulkar, Sandip Hingmire, Arnab Goon, Manjusha Jadhav, Bharat Ugare, Ahammed Shabeer Thekkumpurath, Kaushik Banerjee
A sensitive and accurate LC with tandem MS (MS/MS)-based method was developed and validated for the analysis of the herbicide glyphosate, its metabolite aminomethylphosphonic acid (AMPA), and glufosinate after derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl) in various plant matrixes. The method also covers direct analysis of the glufosinate metabolites 3-methylphosphinicopropionic acid (3-MPPA) and N-acetyl-glufosinate (NAG). The homogenized samples were extracted with 0.1% formic acid in water-dichloromethane (50 + 50)...
May 1, 2017: Journal of AOAC International
Chun-Hong Nie, Shi-Ming Wan, Tea Tomljanovic, Tomislav Treer, Chung-Der Hsiao, Wei-Min Wang, Ze-Xia Gao
BACKGROUND: Intermuscular bones (IBs) and ribs both are a part of skeletal system in teleosts, but with different developing process. The chemical composition of fish IBs and ribs as well as the underlying mechanism about their development have not been investigated. In the present study, histological structures showed that one bone cavity containing osteoclasts were existed in ribs, but not in IBs of Megalobrama amblycephala. We constructed the first proteomics map for fish bones including IBs and ribs, and identified the differentially expressed proteins between IBs and ribs through iTRAQ LC-MS/MS proteomic analysis...
February 10, 2017: BMC Genomics
Snehasis Jana, Himanshu Rastogi
BACKGROUND AND OBJECTIVES: Melatonin is a popular dietary supplement and also considered as pharmaceutical product for sleep disorders. Caffeic acid and quercetin are widely distributed in leafy vegetables, fruits, tea extract, and both are used as natural antioxidant. There is an immense concern for health researchers to study the herb/food-drug interactions of melatonin. It is mainly metabolized by CYP1A2 in human so that herbs/foods containing cytochrome P450 (CYP) inhibitors can affect pharmacokinetics of melatonin...
October 2017: European Journal of Drug Metabolism and Pharmacokinetics
Madeleine Gross, Stefan Asam, Michael Rychlik
An enzyme-linked immunosorbent assay (ELISA) for the Alternaria mycotoxin tenuazonic acid (TeA) was evaluated by comparative analysis of naturally contaminated sorghum grains and sorghum-based infant food, using a stable isotope dilution LC-MS assay (SIDA; limit of detection (LOD) 1.0 μg/kg) as the reference method. LODs of the ELISA were 30 μg/kg in sorghum grains and 220 μg/kg in sorghum-based infant cereals. With SIDA, 100% of the samples (n = 28) had been positive for TeA in a concentration range of 6-584 μg/kg (mean 113 μg/kg)...
February 2017: Mycotoxin Research
Qiao-Ying Chang, Guo-Fang Pang, Chun-Lin Fan, Hui Chen, Fang Yang, Jie Li, Bi-Fang Wen
GC-MS, GC-tandem MS (MS/MS), and LC-MS/MS were used to mathematically define the degradation profiles of pesticide residues in two field trials. Nineteen pesticides were studied in the first field trial and 11 in the second. The results of the field trials demonstrated that the degradation profiles of pesticide residues in green tea can be described with power functions to successfully estimate the amount of time, following pesticide application, pesticide residues appearing in tea in concentrations at and/or above the maximum residue limit (MRL) decrease to concentrations below the MRL...
November 1, 2016: Journal of AOAC International
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