extraction of caffeine from tea leaves

... Microwave-assisted extraction of tea polyphenols and tea caffeine from green tea leaves, Chemical engineering and processing 42, 129 – 133, 2003 [9] Carmen W Huie, A review of modern sample-preparation ... yield of MAE method 3.1.5 Comparison of the results of extraction with MAE and other methods Other extraction procedures (conventional heating reflux extraction method, ultrasoundassisted extraction ... five type of tea from Bao Loc, Lam Dong HPLC analysis of the extract showed the similarity of catechin compounds in all five tea origins, in which EGCG and ECG were the main components HAT tea, with...

Ngày tải lên: 22/07/2014, 10:21

... effective method for the extraction of bioflocculants from activated sludge, followed by steaming extraction SDS and washing extraction methods were ineffective because of low flocculating activity, ... analytical data of the polymer components shown in Table Conclusions Four different microbial polymer extraction methods (steaming extraction, NaOH extraction, SDS extraction, and washing extraction) ... amount of material other than protein Furthermore, the steaming- and washing-extracted polymers contained large amounts of phosphorus (of 3.2% and 3.6%, respectively) Table shows molar ratios of...

Ngày tải lên: 05/09/2013, 09:08

... combinations (sterile water instead of solvent) Residual solids from the described extraction treatment combinations were carried forward to examine the effects of the extraction conditions on sugar ... after extraction as well as sugar production and change in starch content after hydrolysis of residual extraction solids In a secondary experiment, fermentability of sugars produced from extraction ... conversion and ethanol production from ISP extraction residues Since the majority of sugars produced from residual solids that underwent anthocyanin extraction were in the form of the simple sugar glucose,...

Ngày tải lên: 05/05/2014, 08:39

... B: Extraction of curcumin from turmeric with different concentrations of ethanol C: Absorbance of the solvent by turmeric powder D: Effect of macerating hours on the extraction of curcumin from ... Programs of Guangzhou City (2009-T-17-1) and Guangdong Natural Science Fund (10151063101000002) References Fig Column-chromatographic extraction of curcumin from turmeric A: Extraction of curcumin from ... macerating method, the extraction efficiencies of different concentrations of ethanol was tested As shown in Fig 1B, the extraction rates of curcumin increased with ethanol concentrations from 40% to 80%,...

Ngày tải lên: 01/07/2014, 13:23

... the absence of these bands indicates that most of the lignin was removed So in RH cellulose the extraction procedures removed most of lignin polymers because of the disappearance of the lignin-associated ... step of mass loss Journal of Analytical and Applied Pyrolysis, 88, 151–165 Morán, J I., Alvarez, V A., Cyras, V P., & Vazquez, A (2008) Extraction of cellulose and preparation of nanocellulose from ... to determine the ash content of rice husk TGA scans were carried out from 35 to 700 ◦ C at a heating rate of 10 ◦ C min−1 and under inert atmosphere of N2 in a flux of 50 mL min−1 (TA Instruments...

Ngày tải lên: 08/10/2014, 06:05

... classical liquid liquid extraction (LLE) Microextraction techniques are characterized by the extraction of analytes from a given donor phase, into a minuscule volume of a selected acceptor phase ... 46 3.3.2 Preparation of surface modified sorbents 3.3 44 47 3.3.2.1 Preparation of APS 47 3.3.2.2 Preparation of UPS 47 3.3.2.3 Preparation of ZIPS 47 3.3.3 Characterization of sorbents and sorbent-containing ... Determination of EWC 48 References 49 RESULTS AND DISCUSSION 50 Preparation of sorbents 51 4.1.1 Preparation of APS and UPS 51 4.1.2 Preparation of ZIPS 53 4.2 EWC 54 4.3 Comparison of sorbents...

Ngày tải lên: 10/09/2015, 09:12

... thus the method may track both types of pixels, instead of just tracking the text pixels (Figure 2.11) 2.4.3 Signature-based Tracking Instead of using the SSD of intensity values, (Wernicke & Lienhart ... adapted from (Chen & Odobez 2005).) 51 Figure 2.26 The four main steps of text recognition (Figure adapted from (Casey & Lecolinet 1996).) 53 Figure 2.27 The results of projection profile ... provides a brief overview of the challenges of the different types of texts considered in this thesis We also review existing text extraction methods and identify some of the research gaps that...

Ngày tải lên: 12/09/2015, 11:24

... dividing lines of the domains of attraction of rain falling over the region The height of each point represents its intensity value The input of the watershed transform is the gradient of the original ... Flowchart of the proposed PPA detection method 70 4.2 Examples of (a) square structuring element with width of pixels (b) disk structuring element with radius of pixels 71 4.3 Output of ... 66 vii List of Figures LIST OF FIGURES 1.1 An example of color fundus image 2.1 Histogram of a bimodal image 2.2 Gradient vector flow [22] Left: deformation of snake with...

Ngày tải lên: 05/10/2015, 22:32

... in Table Total of 20 experiments were set up using the CCD matrix The yield extraction of mulberry values (Y) was taken as the response of the design experiment Design Expert software version ... extraction of the samples The effects of the extraction parameters such as temperature, weight and extraction time were investigated on the yield values The P- values show the significance of coefficients ... study proved that statistical experimental designs offer an efficient extraction yield optimization of mulberry fruits A maximum extraction yield of 1.15% was achieved with the following optimized...

Ngày tải lên: 02/08/2016, 13:37

... Northern blot of total RNA from spinach leaves (B) Western blot of total protein extract of spinach leaves, and (C) SDS/ PAGE of lg of recombinant protein purified from S frugiperda stained with ... blots of total RNA from spinach leaves, the same probe hybridized to a single band of % 2500 bp, corresponding to the length of the isolated cDNA (Fig 2A) Expression of the coding region of 6PF2K/Fru-2,6-P2ase ... ratio of 6PF2K activity to Fru-2,6-P2ase activity of the smaller form of the bifunctional enzyme was far lower than that of the larger form of the enzyme [11] This is reminiscent of the enzyme from...

Ngày tải lên: 22/02/2014, 04:20

... extracting grammars from a Treebank A feature structure is a way of representing grammatical information Formally feature structure consists of a specification of a set of features, each of which is ... feature structure of a new node created by substitution inherits the union of the features of the original nodes The top feature of new node is the union of the top features (f1 ∪ f) of the two original ... Insertion Grammars, one variation of TAG formalism for his extraction system from English Penn Treebank Xia et al (2000) developed the uniform method of a grammar extraction for English, Chinese...

Ngày tải lên: 23/03/2014, 18:20

... automatically The objects concerned wilh the extraction of cues from spectra, segmentation, manner-class sequencing and display of constituent structure, repairing effects of lenition and assimilation are ... cues are calculated from fast Fourier transforms (FFTs) of speech signals in terms of total amplitude or energy distribution ED across low, middle and high frequency parts of the vocal range and ... computable only after segmentation from the length in slices from boundary to boundary, 579 normalising this length using the JSRU database of the relative durations of segments in different manner...

Ngày tải lên: 31/03/2014, 04:20

... may often be used with determiners in the general domain Hosaka, Junko and Umetsu, Ryo 2002 Toward the extraction of protein-protein interaction information from immunology literature Proc of ... network of human genes for high-throughput analysis of gene expression Nature Genetics, 28: 21-28 Yakushiji, Akane, et al 2001 Event extraction from biomedical papers using a full parser Proc of PSB, ... NP/NPL to the left of the "activat*" phrase • Extract the highest NP/NPL "ACK-2" Preliminary Evaluation We applied our extraction rules to two sets consisting of the parsing outputs from 100 sentences:...

Ngày tải lên: 31/03/2014, 20:20

... the Institute of Natural Product Chemistry, VAST, and at the herbarium of the College of Pharmacy, Chungnam National University, Korea Extraction and isolation Dried and powdered leaves (3.7 kg) ... identified by Prof Dr Tran Minh Hoi, Institute of Ecology, Biological Resourses, Vietnamese Academy of Science and Technology (VAST) Voucher specimens (No 2539) are deposited at the herbarium of the Institute ... 17.5 and 21.3 A 1H-1H COSY experiment allowed analysis of their spin systems and assignments of their proton resonances The assignment of their corresponding carbons, made by a HMQC spectrum...

Ngày tải lên: 03/04/2014, 15:20

... is noticeable that the glycosilation of flavonoids often results in 127 the reduction of biological activities regardless of the types of aglycones and types of linkage (C- or O-glycosides) possibly ... placed the sugar moiety at 3-O position, and the connection of the coumaroyl moiety to C-6” of glucose was judged from the HMBC correlation from the two proton signals at H 4.05 (strong) and 4.3 (weak) ... J Chem., Vol 41, No (2003) The air-dried leaves were collected in the suburbs of Hanoi, and identified by a botanist Prof Vu Van Chuyen (Hanoi College of Pharmacy, Hanoi in 2002 RP HPLC: Dionex...

Ngày tải lên: 03/04/2014, 15:20

... through use of fractional separators or at the point of extraction by stepwise alterations of pressure and temperature Figure 6: A) Structure of isolated component, B) 1H NMR spectrum of isolated ... was charged with 300 g of glass from a LCD panel (Figure 2D) cut into 10 cm x cm segments Typical extraction took place at a pressure of 250 bar and 40°C with a flow rate of 40 g/min, the collector ... bar and 40ºC the extraction recovery from complete screens was poor, 0.1% of the total liquid crystal present The removal of a resin seal from the outer edge of the LCD did not significantly increase...

Ngày tải lên: 28/04/2014, 10:50

... Detail of the measured data set of Figure 4, (b) reconstruction of the response of the first-order ceiling reflection using the Radon transform method, (c) the result of subtracting (b) from (a) ... Conservatory of Music in The Hague, at the Department of “Art of Sound.” During the summer semester of 2001, he fulfilled the “Edgard Varese” guest professorship at TU Berlin In 2004, he held a Guest Professor ... data set of Figure 4, (b) reconstruction of the response of the first-order ceiling reflection using the cylindrical harmonics decomposition method, (c) the result of subtracting (b) from (a) 10...

Ngày tải lên: 22/06/2014, 19:20

... modification of the original CTAB protocol of Doyle and Doyle [2] and other CTAB methods designed for extraction of DNA from plant material [1, 3, 4, 7, 8, 12]) CTAB (1-2 %) extraction buffers often ... artefact of the method conclusion, the protocol described provided DNA good quality by a quick method of extraction from tree species which have often been a problem regarding extraction of their ... DNA but only from in vitro culture and not from other sources of plant material The method of Sul and Korban [12] was originally designed for extracting DNA from in vitro cultures of apple tree,...

Ngày tải lên: 08/08/2014, 14:21

... flow rate of 1.5 mL/min and UV detector of 295 nm 2.4 Extraction of a-tocopherol and g-oryzanol from rice bran using solvent extraction A g sample of rice bran was extracted using 100 mL of hexane ... of temperature The effect of temperature on the extraction was studied at a constant pressure of 48 MPa, using a CO2 flow rate of 0.45 mL/min and at temperatures from 45 to 65 1C The results of ... 12 show that extraction rate is increasing in the beginning of extraction, since there is a lot of concentration gradient of substances in bulk fluid and interior of rice bran The extraction rate...

Ngày tải lên: 17/08/2014, 21:37