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Karl Fraser Scott J. Harrison Geoff A. Lane Don E. Otter Yacine Hemar Siew-Young Quek Susanne Rasmussen 《Food chemistry》2012
Tea is the second most consumed beverage in the world and its consumption has been associated with numerous potential health benefits. Factors such as fermentation methods, geographical origin and season can affect the primary and secondary metabolite composition of tea. In this study, a hydrophilic interaction liquid chromatography (HILIC) method coupled to high resolution mass spectrometry in both positive and negative ionisation modes was developed and optimised. The method when combined with principal component analysis to analyse three different types of tea, successfully distinguished samples into different categories, and provided evidence of the metabolites which differed between them. The accurate mass and high resolution attributes of the mass spectrometric data were utilised and relative quantification data were extracted post-data acquisition on 18 amino acids, showing significant differences in amino acid concentrations between tea types and countries. This study highlights the potential of HILIC chromatography combined with non-targeted mass spectrometric methods to provide a comprehensive understanding of polar metabolites in plant extracts. 相似文献
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Pure d/l-theanine enantiomers were synthesized separately, and SEM was used for their crystal-structure observation. The novel enantiomeric separating method by HPLC was established using the chiral selector of β-CD in the mobile phase. Green tea, white tea, oolong tea, black tea and Pu-erh tea were tested for theanine enantiomers by different degrees of fermentation. The significantly higher d-enantiomeric proportion of theanine was found in white tea than the others, which was probably due to its specific processing step of withering. The effect of electrolyzed reduced water (ERW) on enantiomeric theanine and polyphenols in tea was explored. There was no change of theanine, but rather a loss of ECG (epicatechin gallate) and an increasing amount of GA (gallic acid). ERW also reduced tea cream, which contains significant amount of polyphenols, indicating its potential application in the tea-beverage industry. 相似文献
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根据茶叶之路的线路及特征,通过对茶叶之路沿途所建的晋商会馆的介绍,探讨了茶叶之路沿途晋商会馆的设立及作用,并总结了晋商会馆的分布特征,对茶叶之路的发展起到了推动作用。 相似文献
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本文阐述循环经济的理念在茶业生产中的应用。资源节约利用,产业持续发展和环境保护是区别传统茶业生产与循环农业模式的主要因素。金华市婺城区良好的气候条件、良种茶园的建设成果、茶叶生产加工机械化的普及改良和茶业标准化、组织化建设为发展茶业循环经济创造了有利的条件,但传统茶业生产根源的广泛性和循环经济意识的缺乏、及相应的支撑体系不完善也制约了茶业循环经济的发展。加大宣传,提高循环经济意识,加强循环茶业技术支撑和成熟模式的示范推广,完善保障体系,是推动茶业循环经济发展的重要途径。 相似文献
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Alessandro C. Martins Lais BukmanAlexandro M.M. Vargas Érica O. BarizãoJuliana C.G. Moraes Jesuí V. VisentainerVitor C. Almeida 《Food chemistry》2013
This study proposes a FRAP assay adapted to FIA system with a merging zones configuration. The FIA system conditions were optimised with the response surface methodology using the central composite rotatable design. The optimisation parameters studied were: the carrier flow rate, the lengths of the sample and reagent loops, and reactor length. The conditions selected in accordance with the results were: carrier flow rate of 1.00 ml/min, length of the loops 18.2 cm and length of the reaction coil 210.1 cm. The detection and quantification limits were, respectively, 28.6 and 86.8 μmol/l Fe2+, and the precision was 1.27%. The proposed method had an analytical frequency of 30 samples/h and about 95% less volume of FRAP reagent was consumed. The FRAP assay adapted to the FIA system under the optimised conditions was utilised to determine the antioxidant activity of tea samples. 相似文献