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Ftir spectrum of tea

Dong-yu Li, You-ming Shi, Shi Lai Yi
For better determination of the chemical components in the Puer black tea, Fourier transform infrared spectroscopy was used for obtaining vibrational spectra of Puer black tea at different aging time. Fourier transform infrared (FTIR) spectra indicated that the chemical components had change in Puer black tea at different aging time. The leaf of Puer black tea was a complex system, its Fourier transform infrared spectrum showed a total overlap of each absorption spectrum of various components. Each band represented an overall overlap of some characteristic absorption peaks of functional groups in the Puer black tea...
July 2015: Guang Pu Xue Yu Guang Pu Fen Xi, Guang Pu
Jian-xiong Cai, Yuan-feng Wang, Xiong-gang Xi, Hui Li, Xin-lin Wei
In order to classify typical Chinese tea varieties, Fourier transform infrared spectroscopy (FTIR) of tea polysaccharides (TPS) was used as an accurate and economical method. Partial least squares (PLS) modeling method along with a self-organizing map (SOM) neural network method was utilized due to the diversity and heterozygosis between teas. FTIR spectra results of tea extracts after spectra preprocessing were used as input data for PLS and SOM multivariate statistical analyses respectively. The predicted correlation coefficient of optimization PLS model was 0...
2015: International Journal of Biological Macromolecules
Jing-Ming Ning, Zheng-Zhu Zhnag, Sheng-Peng Wang, Xiao-Chun Wan, Xin-Sheng Zeng
Infrared spectra of Pu'er raw tea and Pu'er ripe tea were investigated using Fourier transform spectroscopy, in order to exploit a rapid method for discrimination of aging period for Pu' er tea samples. The results showed that the two kinds of Pu'er teas shared a similar woveform of infrared spectrum. However, due to the variations of aging time, leading to different chemical composition in pu'er teas, both Pu'er raw tea and ripe tea displayed corresponding different characteristic peaks. And the extent of aging of Pu'er tea had a significant relationship with optical density and waveforms of absorption peaks in the wave number range of 1 120-1 570 cm(-1) and 400-853 cm(-1), suggesting that the extent of aging of Pu'er tea may be identified by infrared spectrum technology rapidly and simply...
September 2011: Guang Pu Xue Yu Guang Pu Fen Xi, Guang Pu
Yanan Chen, Yang Doo Lee, Harindra Vedala, Brett L Allen, Alexander Star
Single-walled carbon nanotubes (SWNTs) possess unique electronic and physical properties, which make them very attractive for a wide range of applications. In particular, SWNTs and their composites have shown a great potential for chemical and biological sensing. Green tea, or more specifically its main antioxidant component, epigallocatechin gallate (EGCG), has been found to disperse SWNTs in water. However, the chemical sensitivity of this SWNT/green tea (SWNT/EGCG) composite remained unexplored. With EGCG present, this SWNT composite should have strong antioxidant properties and thus respond to reactive oxygen species (ROS)...
November 23, 2010: ACS Nano
Angela Albuquerque Teixeira-Neto, Ana Lucia Shiguihara, Celly M S Izumi, Marcos Augusto Bizeto, Fabrice Leroux, Marcia L Arruda Temperini, Vera R Leopoldo Constantino
Organic-inorganic hybrid materials can be prepared dispersing organic species into well-defined inorganic nanoblocks. This paper describes the immobilization of natural dyes from the extract of the Brazilian açaí-fruit into two types of layered hexaniobate precursors derived from H(2)K(2)Nb(6)O(17): (i) colloidal dispersion of niobate exfoliated nanoparticles and (ii) niobate pre-intercalated with tetraethylammonium cations (TEA(+)). The restacking of exfoliated particles in the presence of açaí anthocyanins promotes their intercalation and produces stacked layers showing large basal spacing (ca...
June 7, 2009: Dalton Transactions: An International Journal of Inorganic Chemistry
Xiang-Ping Zhou, Gang Liu, You-Ming Shi, Qin Dong
In the present paper, Fourier transform infrared spectroscopy (FTIR) was used to determine unzymic and zymic Pu'er tea of different grade produced in Simao, Yunan Province. Because of the different processing technology, different proportion of chemical constituents exists in the unzymic and zymic Pu'er tea. And although there is a great mass of similarity in infrared spectrum, the results still show differences in the characteristic peaks of infrared spectrum between unzymic and zymic Pu'er tea. And there is also obvious difference between unzymic Pu'er tea of different grade or zymic Pu'er tea of different grade...
March 2008: Guang Pu Xue Yu Guang Pu Fen Xi, Guang Pu
Su-qin Sun, Qun Zhou, Hei-wun Leung, Hin-wing Yeung
A rapid and non-destructive method, was used to identify seven commercial American Ginseng Tea bags by Fourier-transform infrared spectroscopy (FTIR) in this paper. It could be seen from the results, that each sample has its own characteristic infrared spectrum. Also, the seven tea bags could be divided into two groups: one is made from pure Ginseng powders, and the other is made by Ginseng extractives and additives. The information of additives used by factories could be identified by IR spectra. For example, some factories use glucose, and the others use sucrose as the additives...
August 2002: Guang Pu Xue Yu Guang Pu Fen Xi, Guang Pu
Andrea Edelmann, Bernhard Lendl
The interaction of polyphenols (tannins) with proline-rich proteins (gelatin) has been studied using an automated flow injection system with Fourier transform infrared spectroscopic detection to gain insight into chemical aspects related to astringency. In the perception of astringency, a major taste property in red wines and other beverages such as beer, tea, or fruit juices, an interaction between proline-rich salivary proteins and tannins present in the sample takes place. To study this interaction, agarose beads carrying gelatin (a proline-rich protein) were placed in the IR flow cell in such a way that the beads were probed by the IR beam...
December 11, 2002: Journal of the American Chemical Society
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