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Ftir analysis of tea extracts

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https://www.readbyqxmd.com/read/27154518/characterization-of-%C3%AE-glucosidase-immobilized-on-chitosan-multiwalled-carbon-nanotubes-mwcnts-and-their-application-on-tea-extracts-for-aroma-enhancement
#1
Akile Çelik, Ayşe Dinçer, Tülin Aydemir
β-Glucosidase was covalently immobilized on chitosan-MWCNTs carrier and its aroma enhancement effect in different tea samples was investigated. Chitosan-MWCNTs carrier was prepared by mixing chitosan with MWCNTs (5:1w/w) and characterization of prepared composite carrier was done by FTIR, TGA and SEM analysis. β-Glucosidase was covalently immobilized on the composite carrier after glutaraldeyde activation. After optimization of the immobilization conditions, immobilization yield was achieved as 95.22%. Optimum pH was found as pH 6...
August 2016: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/25818932/using-ftir-spectra-and-pattern-recognition-for-discrimination-of-tea-varieties
#2
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
https://www.readbyqxmd.com/read/25276215/optimization-of-cat-s-whiskers-tea-orthosiphon-stamineus-using-supercritical-carbon-dioxide-and-selective-chemotherapeutic-potential-against-prostate-cancer-cells
#3
Fouad Saleih R Al-Suede, Mohamed B Khadeer Ahamed, Aman S Abdul Majid, Hussin M Baharetha, Loiy E A Hassan, Mohd Omar A Kadir, Zeyad D Nassar, Amin M S Abdul Majid
Cat's whiskers (Orthosiphon stamineus) leaves extracts were prepared using supercritical CO2 (SC-CO2) with full factorial design to determine the optimum extraction parameters. Nine extracts were obtained by varying pressure, temperature, and time. The extracts were analysed using FTIR, UV-Vis, and GC-MS. Cytotoxicity of the extracts was evaluated on human (colorectal, breast, and prostate) cancer and normal fibroblast cells. Moderate pressure (31.1 MPa) and temperature (60°C) were recorded as optimum extraction conditions with high yield (1...
2014: Evidence-based Complementary and Alternative Medicine: ECAM
https://www.readbyqxmd.com/read/24234757/the-effect-of-structural-compositions-on-the-biosorption-of-phenanthrene-and-pyrene-by-tea-leaf-residue-fractions-as-model-biosorbents
#4
Zemin Xi, Baoliang Chen
To enhance the removal efficiency of polycyclic aromatic hydrocarbons (PAHs) by natural biosorbent, sorption of phenanthrene and pyrene onto raw and modified tea leaves as a model biomass were investigated. Tea leaves were treated using Soxhlet extraction, saponification, and acid hydrolysis to yield six fractions. The structures of tea leaf fractions were characterized by elemental analysis, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The amorphous cellulose components regulated the sorption kinetics, capacity, and mechanism of biomass fractions...
March 2014: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/23618259/preliminary-structural-characterization-and-antioxidant-activities-of-polysaccharides-extracted-from-hawk-tea-litsea-coreana-var-lanuginosa
#5
Xuejing Jia, Lihua Dong, Yong Yang, Shu Yuan, Zhongwei Zhang, Ming Yuan
Three polysaccharides were extracted from different leaf age Hawk teas (Litsea coreana var. lanuginosa) by hot water method. Preliminary structural characterization was conducted by physicochemical property, fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analyses. Antioxidant activities against 2,2-diphenyl-1-picryl-hydrazyl (DPPH), ferric reducing activity power (FRAP), hydroxyl radical and erythrocyte hemolysis were also evaluated. The physicochemical property analysis indicated significant differences in the three polysaccharides...
June 5, 2013: Carbohydrate Polymers
https://www.readbyqxmd.com/read/23603075/development-of-tea-extracts-and-chitosan-composite-films-for-active-packaging-materials
#6
Yong Peng, Yan Wu, Yunfei Li
The effects of 0.5%, 1% and 2% green tea extracts (GTE) and black tea extracts (BTE) on the physical, structural and antioxidant properties of chitosan films were investigated. Results showed that the addition of tea extracts significantly decreased water vapour permeability and increased the antioxidant ability of films. The DPPH radical scavenging ability of GTE films was stronger than that of BTE films in all food simulants (0%, 20%, 75% and 95% ethanol). The equilibration time in different food simulants decreased with the increased ethanol concentration...
August 2013: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/22904632/synthesis-of-silver-nanoparticles-by-using-tea-leaf-extract-from-camellia-sinensis
#7
Yuet Ying Loo, Buong Woei Chieng, Mitsuaki Nishibuchi, Son Radu
The development of the biological synthesis of nanoparticles using microorganisms or plant extracts plays an important role in the field of nanotechnology as it is environmentally friendly and does not involve any harmful chemicals. In this study, the synthesis of silver nanoparticles using the leaves extract of Chinese tea from Camellia sinensis is reported. The synthesized nanoparticles were characterized using UV-vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy...
2012: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/22801419/interaction-between-plectranthus-barbatus-herbal-tea-components-and-acetylcholinesterase-binding-and-activity-studies
#8
Pedro L V Falé, Lia Ascensão, M Luisa Serralheiro, Parvez I Haris
Plectranthus barbatus water extracts, have been used as herbal teas, for the treatment of various diseases. In a previous study it was demonstrated that antioxidant and anti-acetylcholinesterase active extract constituents and their metabolites were found in the plasma of rats after P. barbatus tea intraperitoneal administration. Consequently, a decrease in brain acetylcholinesterase activity occurred. The aim of the present research is to elucidate how P. barbatus extract components interact with acetylcholinesterase...
November 2012: Food & Function
https://www.readbyqxmd.com/read/21830482/synthesis-and-characterization-of-ammonium-functionalized-porous-poly-glycidyl-methacrylate-co-ethylene-dimethacrylate-monoliths-for-microscale-analysis-and-its-application-to-dna-purification
#9
A Bruchet, V Dugas, I Laszak, C Mariet, F Goutelard, J Randon
A systematic study of parameters affecting the nucleophilic addition of secondary and tertiary amines on reactive epoxy groups was conducted on porous polymer monoliths. Reaction of small amines like diethylamine (DEA) or triethylamine (TEA) on poly(glycidyl methacrylate-co-ethylene dimethacrylate) monoliths (poly(GMA-co-EDMA)) allows to prepare anion exchange media. This study aimed to determine optimal and suitable conditions to prepare anion-exchange porous monolith inside 100 microm internal diameter capillary...
June 2011: Journal of Biomedical Nanotechnology
https://www.readbyqxmd.com/read/19452062/a-hybrid-material-assembled-by-anthocyanins-from-a%C3%A3-a%C3%A3-fruit-intercalated-between-niobium-lamellar-oxide
#10
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
https://www.readbyqxmd.com/read/18347917/characterization-of-different-compost-extracts-using-fourier-transform-infrared-spectroscopy-ftir-and-thermal-analysis
#11
Teresa Carballo, Ma Victoria Gil, Xiomar Gómez, Fernando González-Andrés, Antonio Morán
Compost extract or "compost tea" is a liquid extract of compost obtained by mixing compost and water for a defined period of time. Compost tea contains nutrients and a range of different organisms and is applied to the soil or directly to plants with the principal aim of suppressing certain plant diseases. In addition, the application of compost tea supplies nutrients and organic matter to the soil. Thermal analysis and Fourier transform infrared spectroscopy (FTIR) are two widely applied analytical techniques for establishing the stability of compost, and although numerous studies have evaluated the capacity of compost tea to suppress plant diseases, there are no studies employing these techniques to characterize compost-tea...
November 2008: Biodegradation
https://www.readbyqxmd.com/read/12938375/-a-rapid-method-for-detecting-seven-kinds-of-american-ginseng-tea-bags-by-ftir-spectroscopy
#12
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
https://www.readbyqxmd.com/read/12373410/determination-of-caffeine-in-tea-samples-by-fourier-transform-infrared-spectrometry
#13
COMPARATIVE STUDY
Janina Ohnsmann, Guillermo Quintás, Salvador Garrigues, Miguel De La Guardia
A sustainable and environmentally friendly procedure has been developed for the FTIR determination of caffeine in tea leaf samples. The method is based on the extraction with ammonia and CHCl3 and direct determination of caffeine on the chloroform extracts using peak height absorbance measurements at 1658.5 cm(-1) and external calibration. The method provides a sensitivity of 0.2142 absorbance units mg(-1) mL and a limit of detection of 1 mg L(-1), corresponding to 0.002% m/m caffeine in tea leaves. As compared with a reference procedure, based on UV absorbance measurement at 276 nm after low pressure column chromatography, the developed procedure reduces the consume of CHCl3 by a factor of 10, that of NH4OH by a factor of 20 and avoids the use of diethyl ether and Celite...
October 2002: Analytical and Bioanalytical Chemistry
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