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Hplc analysis of tea

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https://www.readbyqxmd.com/read/28433057/low-cost-humic-acid-bonded-silica-as-an-effective-solid-phase-extraction-sorbent-for-convenient-determination-of-aflatoxins-in-edible-oils
#1
Neng-Zhi Zhou, Ping Liu, Xiao-Chuan Su, Yan-Hua Liao, Ning-Sheng Lei, Yong-Hong Liang, Shao-Huan Zhou, Wen-Si Lin, Jie Chen, Yu-Qi Feng, Yang Tang
Aflatoxins (AFs) are highly toxic, mutagenic, carcinogenic, and teratogenic secondary metabolites produced by the toxigenic fungi Aspergillus flavus and Aspergillus parasiticus. AFs tend to contaminate a wide range of foods which is a serious and recurring food safety problem worldwide. Currently, immunoaffinity chromatography (IAC) has become the most conventional sample clean-up method for determining AFs in foodstuffs. However, IAC method is limited in the large-scale food analysis because it requires the use of expensive disposable cartridges and the IA procedure is time-consuming...
June 1, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28393854/transcriptomic-analysis-of-the-biosynthesis-recycling-and-distribution-of-ascorbic-acid-during-leaf-development-in-tea-plant-camellia-sinensis-l-o-kuntze
#2
Hui Li, Wei Huang, Guang-Long Wang, Wen-Li Wang, Xin Cui, Jing Zhuang
Ascorbic acid (AsA), known as vitamin C, is an essential nutrient for humans and mainly absorbed from food. Tea plant (Camellia sinensis (L.) O. Kuntze) leaves can be a dietary source of AsA for humans. However, experimental evidence on the biosynthesis, recycling pathway and distribution of AsA during leaf development in tea plants is unclear. To gain insight into the mechanism and distribution of AsA in the tea plant leaf, we identified 18 related genes involved in AsA biosynthesis and recycling pathway based on the transcriptome database of tea plants...
April 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28334752/monitoring-the-consistency-quality-and-antioxidant-activity-of-da-hong-pao-teas-by-hplc-fingerprinting
#3
Lin Wang, Ting Yan, Lanping Yang, Kexia Zhang, Jingming Jia
In the present study, a high performance liquid chromatography (HPLC) method was developed and validated for fingerprint profiling to evaluate the quality consistency of the Da Hong Pao tea. The chromatographic separation was performed on a USA Waters C18 column (4.6 mm × 250 mm, 5 μm, Waters-XBridge Shield RP 18) with gradient elution. The column temperature was maintained at 30°C and the detection wavelength was set at 278 nm. The results demonstrated that the developed HPLC method achieved the desired linearity, precision, accuracy and limit of quantification...
May 1, 2017: Journal of Chromatographic Science
https://www.readbyqxmd.com/read/28208888/haemoglobinopathies-and-%C3%AE-thalassaemia-among-the-tribals-working-in-the-tea-gardens-of-assam-india
#4
Anju Barhai Teli, Rumi Deori, Sidhartha Protim Saikia
INTRODUCTION: Prevalence of haemoglobinopathies and β-thalassaemia are very high in India but information about its status among the tribals working in the tea gardens of Assam is very less. AIM: The present study was carried out to determine the prevalence of haemoglobinopathies and β-thalassaemia among the tribals working in the tea gardens of Assam. MATERIALS AND METHODS: A total 1204 samples from the tribals working in tea gardens of Assam were analysed for both Complete Blood Count (CBC) and High Pressure Liquid Chromatography (HPLC) for detection of haemoglobinopathies and β-thalassaemia...
December 2016: Journal of Clinical and Diagnostic Research: JCDR
https://www.readbyqxmd.com/read/28193433/antioxidant-profiling-of-vine-tea-ampelopsis-grossedentata-off-line-coupling-heart-cutting-hsccc-with-hplc-dad-qtof-ms-ms
#5
Qingping Gao, Ruyi Ma, Lin Chen, Shuyun Shi, Ping Cai, Shuihan Zhang, Haiyan Xiang
Vine tea with strong antioxidant activity is commonly consumed as healthy tea/beverage. However, detailed information about its antioxidants is incomplete. Here, off-line hyphenation of heart-cutting high-speed countercurrent chromatography (HSCCC) with high performance liquid chromatography-diode array detector-quadrupole time-of-flight tandem mass spectrometry (HPLC-DAD-QTOF-MS/MS) were described for systematic profiling antioxidants in vine tea. At first, antioxidants were rapidly screened by 1,1-diphenyl-2-picryl-hydrazyl radical-high performance liquid chromatography (DPPH-HPLC)...
June 15, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28166943/cold-adaptive-thermogenesis-following-consumption-of-certain-pungent-spice-principles-a-validation-study
#6
Chaitanya Pandit, K R Anilakumar
Identifying a means to activate or potentiate thermogenic mechanisms through ingestion of dietary compounds have important implications in cold endurance and survival. Although many reports discuss the thermogenic potential of spices, it is surprising that none of the studies verify whether consumption of spices can improve cold endurance. In this study, we have attempted to evaluate if ingestion of certain spices can activate heat-generating mechanisms in the body such that a fall in. core body temperature (CBT) can be delayed or prevented when faced with a cold challenge...
February 2017: Journal of Thermal Biology
https://www.readbyqxmd.com/read/28109088/antioxidant-evaluation-and-composition-analysis-of-extracts-from-fuzhuan-brick-tea-and-its-comparison-with-two-instant-tea-products
#7
Qing-An Zhang, Xiao-Li Zhang, Yan-Ying Yan, Xue-Hui Fan
In this paper, the antioxidant capacities and compositions of two commercialized tea products and extracts from Fuzhuanbrick tea (FBT) were investigated using three HPLC methods comparing the retention times of injected standards. Principal component analysis and DPPH-spiking HPLC analysis were used to analyze correlation between antioxidant capacity and the compounds detected to screen which compounds contribute to antioxidant activity. Results indicated that all samples contained high amounts of polysaccharides, phenols, and flavonoids and had good antioxidant activity and a high level of correlation among them...
January 21, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28095717/functional-constituents-of-wild-and-cultivated-goji-l-barbarum-l-leaves-phytochemical-characterization-biological-profile-and-computational-studies
#8
Andrei Mocan, Gökhan Zengin, Mario Simirgiotis, Michaela Schafberg, Adriano Mollica, Dan C Vodnar, Gianina Crişan, Sascha Rohn
Goji (Lycium barbarum L.) leaves are emphasized as a functional tea or as dietary supplements. The phenolic compound profile, antioxidant, enzyme inhibitory, antimicrobial, and antimutagenic activities of leaf extracts from two selected cultivars in comparison with wild-growing plants have been evaluated. HPLC-DAD/ESI-ToF-MS analysis revealed the presence of phenolic acids and flavonoids with chlorogenic acid and rutin being the dominant compounds in the cultivated plants, whereas rutin and kaempeferol-3-O-rutinoside for wild growing ones...
December 2017: Journal of Enzyme Inhibition and Medicinal Chemistry
https://www.readbyqxmd.com/read/28071811/extraction-of-epigallocatechin-gallate-and-epicatechin-gallate-from-tea-leaves-using-%C3%AE-cyclodextrin
#9
Lu Cui, Yuxuan Liu, Ting Liu, Yahong Yuan, Tianli Yue, Rui Cai, Zhouli Wang
Use of organic solvents to extract phenolic compounds from plants may result in environmental pollution and cause health problems in persons. Replacing organic extraction solvents by green extracting agents without affecting the extraction yield is one of the most pressing problems to be solved. The aim of this study is to evaluate the capacity of β-cyclodextrin (β-CD) to recover phenolic compounds from tea leaves. The extract obtained using the ethanol/water mixture presented the highest total phenolic content, followed by those obtained using β-CD solution and water...
January 10, 2017: Journal of Food Science
https://www.readbyqxmd.com/read/28035976/meadowsweet-teas-as-new-functional-beverages-comparative-analysis-of-nutrients-phytochemicals-and-biological-effects-of-four-filipendula-species
#10
COMPARATIVE STUDY
Daniil N Olennikov, Nina I Kashchenko, Nadezhda K Chirikova
In recent years, the increased popularity of functional beverages such as herbal teas and decoctions has led to the search for new sources of raw materials that provide appropriate taste and functionality to consumers. The objective of this study was to investigate the nutritional, phytochemical profiles and bioactivities of possible functional beverages produced from F. ulmaria and its alternative substitutes (F. camtschatica, F. denudata, F. stepposa). The investigated decoctions were analyzed regarding their macronutrient, carbohydrate, organic acid, amino acid and mineral composition...
December 26, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28035158/screening-and-purification-of-catechins-from-underutilized-tea-plant-parts-and-their-bioactivity-studies
#11
Ajay Rana, Eshita Sharma, Kiran Rawat, Ranjana Sharma, Sarika Verma, Yogendra Padwad, Ashu Gulati
Comparative investigation of major phytoconstituents was performed from various parts of tea plant viz. apical bud, subtending 1st-5th leaf, stem, coarse leaves, flowers, fruits and roots. From the results of comparative RP-HPLC-DAD analysis it was found that underutilized tea parts especially coarse leaves, flowers and fruits contains abundant amount of phenolics (17.5%) and catechins (4-5%). From these underutilized tea plant parts the catechins were extracted and purified and then screened for their anticancer, immunomodulatory effect and antimicrobial activity against food borne pathogens...
November 2016: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/27921291/evaluation-of-capillary-electrophoresis-for-the-analysis-of-rooibos-and-honeybush-tea-phenolics
#12
William J Arries, Andreas G J Tredoux, Dalene de Beer, Elizabeth Joubert, André de Villiers
Rooibos and honeybush are popular herbal teas produced from the shrubs of Aspalathus linearis and Cyclopia spp., respectively, which are indigenous to South Africa. Both herbal teas are rich in polyphenols and their consumption is associated with several health benefits, partly ascribed to their phenolic constituents. Quantification of phenolics in extracts and teas for quality control and research purposes is generally performed using HPLC, although dedicated and often species-specific methods are required...
March 2017: Electrophoresis
https://www.readbyqxmd.com/read/27818668/an-approach-based-on-hplc-fingerprint-and-chemometrics-to-quality-consistency-evaluation-of-matricaria-chamomilla-l-commercial-samples
#13
Agnieszka Viapiana, Wiktoria Struck-Lewicka, Pawel Konieczynski, Marek Wesolowski, Roman Kaliszan
Chamomile has been used as an herbal medication since ancient times and is still popular because it contains various bioactive phytochemicals that could provide therapeutic effects. In this study, a simple and reliable HPLC method was developed to evaluate the quality consistency of nineteen chamomile samples through establishing a chromatographic fingerprint, quantification of phenolic compounds and determination of antioxidant activity. For fingerprint analysis, 12 peaks were selected as the common peaks to evaluate the similarities of commercial samples of chamomile obtained from different manufacturers...
2016: Frontiers in Plant Science
https://www.readbyqxmd.com/read/27765257/composition-distribution-and-risk-of-total-fluorine-extractable-organofluorine-and-perfluorinated-compounds-in-chinese-teas
#14
Ruobing Zhang, Hong Zhang, Qingwu Chen, Ji Luo, Zhifang Chai, Jincan Shen
To explore the residual characteristics of fluorine and perfluorinated compounds (PFCs) in tea, the total fluorine (TF), extractable organofluorine (EOF) and PFCs in 19 Chinese commercial teas of five categories were measured using cyclic neutron activation analysis combined with HPLC-MS/MS. The results showed that fluorine mainly existed as inorganic fluorine in teas, and identified fluorine (∑PFCs quantified as F) only accounted for 0.023-0.41% of EOF, indicating that most EOF in tea were still unknown...
March 15, 2017: Food Chemistry
https://www.readbyqxmd.com/read/27697574/combination-of-hplc-ms-and-qams-as-a-new-analytical-approach-for-determination-of-saponins-in-ginseng-containing-products
#15
Andrey Stavrianidi, Elena Stekolshchikova, Anna Porotova, Igor Rodin, Oleg Shpigun
Conventional liquid chromatographic methods coupled with ultraviolet detection with low-wavelength range are lacking selectivity and sensitivity to determine both polar and less polar ginsenosides. Also the lack of standard substances for such quality control methods is leading to development of the approaches using single standard for quantitative analysis of multi-component system (QAMS). The objective of present study was to establish and compare for the first time liquid chromatography-ultraviolet detection and liquid chromatography-mass spectrometry QAMS methods for the simultaneous determination of protopanaxatriol-type and protopanaxadiol-type ginsenosides in a variety of ginseng products...
January 5, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/27693951/quality-assessment-of-marketed-chamomile-tea-products-by-a-validated-hptlc-method-combined-with-multivariate-analysis
#16
Etil Guzelmeric, Petar Ristivojević, Irena Vovk, Dušanka Milojković-Opsenica, Erdem Yesilada
Chamomile tea composed of dried flower heads of Matricaria recutita L. (Asteraceae) is one of the most popular single ingredient herbal teas. Tea industries, spice shops or public bazaars are mostly supplied chamomile as a raw material via cultivation or through nature-picking. However, one of the drawbacks of nature-picking is adulteration. This could be either due to false authentication of the plant materials by ingenuous pickers or intentional/unintentional substitution with other flowers resembling to chamomile in appearance during harvesting...
January 5, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/27681250/in-vitro-%C3%AE-glucosidase-inhibitory-activity-of-isolated-fractions-from-water-extract-of-qingzhuan-dark-tea
#17
Shuyuan Liu, Zhi Yu, Hongkai Zhu, Wei Zhang, Yuqiong Chen
BACKGROUND: Natural products have being used as potential inhibitors against carbohydrate-hydrolyzing enzymes to treat diabetes mellitus. Chinese dark tea has various interesting bioactivities. In this study, the active compounds from Qingzhuan dark tea were separated and their anti-diabetic activity was examined using an in vitro enzymatic model. METHODS: The chloroform, ethyl acetate, n-butanol, sediment and residual aqua fractions of a Chinese dark tea (Qingzhuan tea) were prepared by successively isolating the water extract with different solvents and their in vitro inhibitory activities against α-glucosidase were assessed...
September 29, 2016: BMC Complementary and Alternative Medicine
https://www.readbyqxmd.com/read/27633949/analysis-of-theanine-in-tea-camellia-sinensis-dietary-ingredients-and-supplements-by-high-performance-liquid-chromatography-with-postcolumn-derivatization-single-laboratory-validation-first-action-2016-10
#18
Maria Ofitserova, Sareeta Nerkar
An HPLC method with postcolumn derivatization was developed and validated for the determination of theanine content in tea dietary ingredients and supplements. A variety of common commercially available supplement forms such as powders, liquid tinctures, tablets, softgels, and gelcaps, as well as three National Institute of Standards and Technology Camellia sinensis Standard Reference Materials were investigated in the study. A simple extraction procedure using citrate buffer at pH 2.2 allowed for the analysis of theanine without additional cleanup or concentration steps, even at low ppm levels...
November 1, 2016: Journal of AOAC International
https://www.readbyqxmd.com/read/27596421/a-comparative-analysis-of-chemical-compositions-in-camellia-sinensis-var-puanensis-kurihara-a-novel-chinese-tea-by-hplc-and-uflc-q-tof-ms-ms
#19
COMPARATIVE STUDY
Yi-Fang Li, Shu-Hua Ouyang, Yi-Qun Chang, Ting-Mei Wang, Wei-Xi Li, Hai-Yan Tian, Hong Cao, Hiroshi Kurihara, Rong-Rong He
Camellia sinensis var. puanensis Kurihara (Puan tea) is a kind of ancient tea plant newly found in Jiangxipo and the surrounding areas of Puan County (Guizhou, China). People there always believe that drinking Puan tea is beneficial to the promotion of health and prevention of diseases. However, detailed information on its compositions has not been reported. Therefore, in this study, the varieties and contents of purine alkaloids and polyphenols in Puan tea were identified and determined by HPLC and UFLC-Q-TOF-MS/MS...
February 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/27589031/simultaneous-determination-of-eight-catechins-and-four-theaflavins-in-green-black-and-oolong-tea-using-new-hplc-ms-ms-method
#20
Wuqun Tao, Zhiguang Zhou, Bin Zhao, Tongyu Wei
A simple, rapid and accurate analytical method was developed for the analysis of eight tea catechins and four theaflavins simultaneously in three types of tea (green, black and oolong tea), using ultra high performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (HPLC-MS-MS) in multiple-reaction monitoring (MRM) mode. This method using HPLC-MS-MS in positive mode was performed on a CAPCELL PAK C18 MGIII (2.0mm×100mm, 3μm) column (Shiseido) with the mobile phase consisting of 0...
November 30, 2016: Journal of Pharmaceutical and Biomedical Analysis
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