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FTIR of tea polyphenols

Lixue Dou, Bafang Li, Kai Zhang, Xin Chu, Hu Hou
Active edible films were prepared by incorporating tea polyphenols (TP) into gelatin and sodium alginate. The effects of 0.4%-2.0% TP (w/w, TP/gelatin) on physical, antioxidant, and morphological properties of gelatin-sodium alginate films were evaluated. Tensile strength (Ts), contact angle (CA), and cross-linking degree showed an enhanced trend as TP concentration in the film increased, whereas elongation at break (EAB) and water vapor permeability (WVP) possessed a decline trend. The light transmittance of the film was decreased by the incorporation of TP...
October 15, 2018: International Journal of Biological Macromolecules
Xiaoming Yuan, Yan He, Guangrong Zhou, Xiangwei Li, Aiwen Feng, Weiwei Zheng
Inhibiting component of therapy with (-)-epigallocatechin-3-gallate (EGCG) is low bioavailability of fresh tea polyphenols that outcome from insecurity under stomach related circumstances, insufficient transcellular transport. As needs are, fucose- carboxymethyl chitosan (FU-CMC) graft EGCG with gold nanoparticles (GNPs) (FU-CMC-EGCG-GNPs) nanocomposites were prepared and managed peritumorally to assess their anticancer action. The physicochemical properties of as-prepared nanocomposite were evaluated by FTIR spectroscopy, UV-visible absorption spectra, XRD, FESEM-EDX and HRTEM-SAD...
June 2018: Journal of Photochemistry and Photobiology. B, Biology
Ling Yu, Yewen Qiu, Yang Yu, Shanquan Wang
In this study, rapid decolorization of azo dyes was achieved by in situ-generated green tea extract-iron (GTE-Fe) chelate for the first time. When changing reaction conditions from the aerobic condition to the anaerobic condition, the decolorization efficiencies of two azo dyes, i.e., acid orange 7 (AO7) and acid black 1 (AB1), increased from 46.38 and 83.17 to 90.13 and 95.37%, respectively. The recalcitrant AO7 was then selected as the targeting pollutant in subsequent optimization and mechanism studies. Experimental evidences showed that the initial concentrations of AO7, Fe(III), and GTE are the key factors to optimize the decolorization efficiency...
June 2018: Environmental Science and Pollution Research International
Marija Perusko, Ayah Al-Hanish, Jelena Mihailovic, Simeon Minic, Sara Trifunovic, Ivana Prodic, Tanja Cirkovic Velickovic
Major green tea catechin, epigallocatechin-3-gallate (EGCG), binds non-covalently to numerous dietary proteins, including beta-lactoglobulin of cow's milk. The effects of glycation of proteins via Maillard reaction on the binding capacity for polyphenols and the antiradical properties of the formed complexes have not been studied previously. Binding constant of BLG glycated by milk sugar lactose to EGCG was measured by the method of fluorophore quenching. Binding of EGCG was confirmed by CD and FTIR. The antioxidative properties of the complexes were examined by measuring ABTS radical scavenging capacity, superoxide anion scavenging capacity and total reducing power assay...
October 1, 2017: Food Chemistry
Naga Pavan Kumar Chevala, Naga Thirumalesh Chevala, Kirubakaran Dhanakodi, Rama Rao Nadendla, Chandrashekara Krishnappa Nagarathna
BACKGROUND: Tea is an economic important crop with high medicinal value due to rich polyphenols content. In the present research we studied the accumulation of polyphenols of in vitro regenerated callus from anthers. OBJECTIVE: Callus induction of tea anthers and in vitro accumulation of phenolic compounds from the anther-derived callus. MATERIALS AND METHODS: Standardization of callus induction for tea anthers. In vitro generated callus was screened for in vivo accumulation of catechins and its isomers were screened by FC reagent staining technique...
July 2016: Pharmacognosy Magazine
Chuanyi Peng, Junjun Xi, Guijie Chen, Zhihui Feng, Fei Ke, Jingming Ning, Daxiang Li, Chi-Tang Ho, Huimei Cai, Xiaochun Wan
BACKGROUND: Brick tea usually contains very high fluoride, which may affect human health. Biosorbents have received much attention for selective removal of fluoride because of low cost, environmental friendliness, and relative safeness. RESULTS: In the present study, a highly selective fluoride tea waste based biosorbent, namely, aluminum (Al) oxide decorated tea waste (Tea-Al), was successfully prepared. The Tea-Al biosorbent was characterized by energy-dispersive spectrometry, Fourier transform infrared spectroscopy, powder X-ray diffraction and X-ray photoelectron spectroscopic analysis...
March 2017: Journal of the Science of Food and Agriculture
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
Changyan Xu, Xiaomei Shi, An Ji, Lina Shi, Chen Zhou, Yunqi Cui
There has been an upsurge of green reductants for the preparation of graphene materials taking consideration of human health and the environment in recent years. In this paper, reduced graphene oxides (RGOs) were prepared by chemical reduction of graphene oxide (GO) with three green reductants, L-ascorbic acid (L-AA), D-glucose (D-GLC) and tea polyphenol (TP), and comparatively characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectra, Raman spectra and electrical conductivity analysis...
2015: PloS One
C D Kanakis, Imed Hasni, Philippe Bourassa, P A Tarantilis, M G Polissiou, Heidar-Ali Tajmir-Riahi
The effect of milk on the antioxidant capacity of tea polyphenols is not fully understood. The complexation of tea polyphenols with milk proteins can alter the antioxidant activity of tea compounds and the protein secondary structure. This study was designed to examine the interaction of β-lactogolobulin (β-LG) with tea polyphenols (+)-catechin (C), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG) and (-)-epigallocatechin gallate (EGCG) at molecular level, using FTIR, CD and fluorescence spectroscopic methods as well as molecular modelling...
August 1, 2011: Food Chemistry
Allison Derenne, Vincent Van Hemelryck, Delphine Lamoral-Theys, Robert Kiss, Erik Goormaghtigh
Polyphenolic compounds are an important part of human diet and regular consumption of fruits, vegetables and tea is associated with reduced risk of cancer. Dietary polyphenols display a vast array of cellular effects but the large number of data published in the literature makes it difficult to determine the main mechanisms of action associated and to identify molecules with original mechanisms. Therefore, there is an increasing demand for more systemic approaches in order to obtain a global insight of the biochemical processes mediated by polyphenols...
January 2013: Biochimica et Biophysica Acta
Yong-Seo Park, Mi-Kyung Lee, Buk-Gu Heo, Kyung-Sik Ham, Seong-Gook Kang, Ja-Yong Cho, Shela Gorinstein
This study was conducted in order to compare the nutrient and chemical contents of two Korean teas: traditional Chungtaejeon tea (CTJ) with that of green tea (GT). Main bioactive compounds and the antioxidant activities using four radical scavenging assays (ABTS, CUPRAC, FRAP and DPPH) in methanol and acetone extracts of both teas were determined. It was found that the contents of vitamin C, amino acids and total nitrogen in CTJ were lower than that of GT (p < 0.05). Caffeine, reducing sugar and chlorophyll contents in CTJ were similar to GT...
June 2010: Plant Foods for Human Nutrition
Monthana Chitpan, Xiaoyong Wang, Chi-Tang Ho, Qingrong Huang
The binding processes of thearubigin, which is one of the two major polyphenols (the other one is theaflavin) that gives black tea its characteristic color and taste, to the bovine serum albumin (BSA) surface have been investigated by quartz crystal microbalance with dissipation monitoring (QCM-D). The mass and thickness of the thearubigin adlayer on BSA surfaces at various thearubigin concentrations, salt concentrations, and pH values have been determined by QCM-D using the Voigt model. Our results show that the adsorption isotherm of thearubigin on the BSA surface can be better described by the Langmuir model than the Freundlich model, suggesting that the thearubigin adsorption on the BSA surface is dominated by specific interactions, such as electrostatic interaction and hydrogen bonding, as evidenced by the stronger thearubigin adsorption at pH below the isoelectric point (pI) of BSA and shifts in the positions of both amide bands in the FTIR spectra of the BSA surface with and without thearubigin adsorption...
December 12, 2007: Journal of Agricultural and Food Chemistry
Kalyan S Ghosh, Tushar K Maiti, Joy Debnath, Swagata Dasgupta
We report the effect of the natural polyphenolic compounds from green tea on the catalytic activity of Ribonuclease A (RNase A). The compounds behave as noncompetitive inhibitors of the protein with inhibition constants ranging from 80-1300 microM. The dissociation constants range from 50-150 microM for the RNase A-polyphenol complexes as determined by ultraviolet (UV) and circular dichroism (CD) studies. We have also investigated the changes in the secondary structure of RNase A on complex formation by CD and Fourier transformed infrared (FTIR) spectroscopy...
November 15, 2007: Proteins
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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