共查询到20条相似文献,搜索用时 281 毫秒
1.
R. Schindler R. Vonach B. Lendl R. Kellner 《Analytical and bioanalytical chemistry》1998,362(1):130-136
A new process control methodology for the simultaneous determination of sugars, alcohols and organic acids in wine based on multivariate evaluation of mid-IR transmission spectra of wine samples is presented. In addition to ethanol several lower level wine components (glucose, fructose, glycerol, citric-, tartaric-, malic-, lactic- and acetic acid) were determined. To establish a multivariate calibration model a set of 72 calibration solutions was prepared and measured, using a novel, fully automated sequential injection (SI) system with Fourier transform infrared (FTIR) detection. The resulting spectra were evaluated using a partial least square (PLS) model. The developed PLS model was then applied to the analysis of real wine samples containing 79–91 g L–1 ethanol, 5.9–8.1 g L–1 glycerol, 0.4–6.9 g L–1 glucose, 1.5–7.5 g L–1 fructose, 0.3–1.6 g L–1 citric acid, 1.0–1.7 g L–1 tartaric acid, 0.02–3.2 g L–1 malic acid, 0.4–2.8 g L–1 lactic acid and 0.15–0.60 g L–1 acetic acid, yielding results which were in good agreement with those obtained by an external reference method (HPLC-IR). The short analysis time (less than 3 min) together with high reproducibility makes the newly developed method applicable to process control and screening purposes (average of the standard deviations calculated from four repetitive measurements of six different real samples: ethanol: 0.55 g L–1, glycerol: 0.037 g L–1, glucose: 0.056 g L–1, fructose: 0.036 g L–1, citric acid: 0.020 g L–1, tartaric acid: 0.010 g L–1, malic acid: 0.052 g L–1, lactic acid: 0.012 g L–1 and acetic acid: 0.026 g L–1). 相似文献
2.
A procedure for the quantification of 9 organic acids, acetic, formic, citric, tartaric, lactic, malic, succinic, oxalic,
and fumaric, in alcoholic and alcohol-free beverages by reversed-phase HPLC on a Pronto-SIL C18 AQ (300 × 3 mm) column (3
μm) with the mobile phase 5 mM Li2SO4 (pH 3.00, H2SO4) at the rate 0.5 mL/min and conductometry detection. The analytical ranges made 5–200 mg/L for tartaric, malic, lactic and
acetic acids, 2–200 mg/L for the citric and fumaric, 10–400 mg/L for succinic, 15–400 for oxalic, and 20–200 for the formic
acids, and so the detection limits: 1 mg/L for tartaric, formic, malic and fumaric, 2 mg/L for lactic, acetic and citric,
5 mg/L for succinic, and 10 mg/L for oxalic acids. The analysis of alcoholic beverages takes 30–40 min, and of non-alcoholic
ones, 20–30 min; the standard deviation of the results of analyses does not exceed 5%. 相似文献
3.
Pinheiro AD Rocha MV Macedo GR Gonçalves LR 《Applied biochemistry and biotechnology》2008,148(1-3):227-234
A commercial strain of Saccharomyces cerevisiae was used for the production of ethanol by fermentation of cashew apple juice. Growth kinetics and ethanol productivity were
calculated for batch fermentation with different initial sugar (glucose + fructose) concentrations. Maximal ethanol, cell,
and glycerol concentrations were obtained when 103.1 g L−1 of initial sugar concentration was used. Cell yield (Y
X/S) was calculated as 0.24 (g microorganism)/(g glucose + fructose) using cashew apple juice medium with 41.3 g L−1 of initial sugar concentration. Glucose was exhausted first, followed by fructose. Furthermore, the initial concentration
of sugars did not influence ethanol selectivity. These results indicate that cashew apple juice is a suitable substrate for
yeast growth and ethanol production. 相似文献
4.
Negative effects on wine quality and productivity caused by stuck and sluggish fermentations can be reduced significantly, if such problems are detected early through periodic chemical analysis. Infrared spectroscopy (IR) has been used successfully for monitoring fermentations, since many compounds can be measured quickly from a single sample without prior treatment. Nevertheless, few applications of this technology in large scale winemaking have been reported, and these do not cover the entire fermentation from must to finished wine. In this work, we developed IR calibrations for analyzing the fermenting must at any stage of fermentation. The calibration model was obtained with multivariable partial least squares and proved effective for analyzing Cabernet Sauvignon fermentations for glucose, fructose, glycerol, ethanol, and the organic acids; malic, tartaric, succinic, lactic, acetic, and citric. Upon external validation we found an average relative predictive error of 4.8%. Malic acid showed the largest relative predictive error (8.7%). In addition, external validation found that insufficient data for these calibrations made the analysis of fermenting musts using other grape varieties less reliable. 相似文献
5.
Three acetate mutants of the yeast species Yarrowia lipolytica were screened using batch cultivation. The strain Y. lipolytica 1.31 was found to be the most suitable for citric acid production from raw glycerol, a by-product of biodiesel production
from rapeseed oil. At the initial concentration of glycerol of 200 g dm−3, the citric acid production of 124.5 g dm−3, yield of 0.62 g g−1, and productivity of 0.88 g dm−3 h−1 were achieved.
Presented at the 33rd International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 22–26 May
2006. 相似文献
6.
Summary Indirect UV detection in capillary zone electrophoresis (CZE) is frequently used for the determination of inorganic anions
and carboxylic acids. However, there are few reports on direct UV detection of these solutes in real samples. This paper describes
the use of direct UV detection of inorganic anions and organic acids in environmental samples using co-electroosmotic capillary
zone electrophoresis (co-CZE) at 185 nm. The best separation and detection of the solutes was achieved using a fused silica
capillary with an electrolyte containing 25 mM phosphate, 0.5 mM tetradecyltrimethylammonium bromide (TTAB) and 15% acetonitrile
(v/v) at pH 6.0. Four common inorganic anions (Cl−, NO2
−, NO3
− and SO4
2−) and 11 organic acids (oxalic, formic, fumaric, tartaric, malonic, malic, citric, succinic, maleic, acetic, and lactic acid),
were determined simultaneously in 15 min. Linear calibration plots for the test solutes were obtained in the range 0.02–0.5
mM with detection limits ranging from 1–9 μM depending on the analyte. The proposed method was successfully used to determine
inorganic anions and carboxylic acids in soil and plant tissue extracts with direct injection of the sample. 相似文献
7.
S. M. Sultan Aladdin M. Almuaibed A. Townshend 《Fresenius' Journal of Analytical Chemistry》1998,362(1):167-169
A new flow injection chemiluminescence method for the assay of medazepam is explored. The method involves the use of permanganate
in sulfuric acid for the oxidation of medazepam with the emission of chemiluminescence detected by a photomultiplier tube.
A simplex procedure was employed for optimising the conditions for high sensitivity detection, which were found to be 1.03
× 10–3 mol L–1 permanganate, 0.153 mol L–1 sulfuric acid and 3.43 mL min–1 flow rate. The linear calibration range was 3.7 × 10–5 to 1.7 × 10–3 mol L–1. The detection limit (3σ) and the sample throughput were 1.85 × 10–5 mol L–1 and 100 per hour, respectively. The relative standard deviation for 5 replicate determinations of 1.9 × 10–4 mol L–1 medazepam was 0.15%. Common excipients (starch, glucose, maltose, lactose) used in pharmaceutical preparations had no effect.
Received: 2 February 1998 / Revised: 20 May 1998 / Accepted: 25 May 1998 相似文献
8.
Karadjova IB Lampugnani L D'Ulivo A Onor M Tsalev DL 《Analytical and bioanalytical chemistry》2007,388(4):801-807
A rapid, accurate, and precise method is described for the determination of Pb in wine using continuous-flow hydride generation
atomic fluorescence spectrometry (CF-HGAFS). Sample pretreatment consists of ten-fold dilution of wine followed by direct
plumbane generation in the presence of 0.1 mol L−1 HCl and 1% m/v K3[Fe(CN)6] with 1% m/v NaBH4 as reducing agent. An aqueous standard calibration curve is recommended for Pb quantification in wine sample. The method
provides a limit of detection and a limit of quantification of 0.3 μg L−1 and 1 μg L−1, respectively. The relative standard deviation varies between 2–6% (within-run) and 4–11% (between-run) at 3–30 μg L−1 Pb levels in wine. Good agreement has been demonstrated between results obtained by CF-HGAFS and direct electrothermal atomic
absorption spectrometry in analyses of red and white wines within the concentration range of 9.2–25.8 μg L−1 Pb. 相似文献
9.
Ion chromatographic determination of organic acids in food samples using a permanent coating graphite carbon column 总被引:1,自引:0,他引:1
From the viewpoint of a graphite carbon column with excellent durability, it was applied to the ion chromatography (IC) of several organic acids. The carbon column was permanently coated with the cetyltrimethylammonium (CTMA) ion, and the elution behaviors of several organic acids (acetic acid, lactic acid, succinic acid, malic acid, tartaric acid, citric acid) and inorganic anions (Cl−, NO2−, NO3−, SO42−) were examined according to a non-suppressed IC coupled with conductivity detector, when an ion-exchange ability was given to the graphite carbon column. When salicylic acid and sodium salicylate were used as a mobile phase, each organic acid are analyzed approximately 10 min. But the separation of malic acid, chloride and nitrite was difficult. When benzoic acid and 2-amino-2-hydroxymethyl-1,3-puropanediol (tris aminomethane) were used as a mobile phase, tartaric acid and citric acid, etc. with large valency showed tendency to which the width of each peaks extended and retention time increased. However, it was possible to separate excellently for the analytes detected within 10 min. The developed method was then applied to the determination of organic acids in several food samples. 相似文献
10.
Panayot K. Petrov Jožica Majda Serafimovska Sonja Arpadjan Dimiter L. Tsalev Trajče Stafilov 《Central European Journal of Chemistry》2008,6(2):216-221
The influence of EDTA, carboxylic acids, amino-and hydroxocarboxylic acids, monosaccharides and humic substances on the generation
of arsines in hydride generation atomic absorption spectrometry (HGAAS) was investigated. EDTA (0.02 mol L−1), ascorbic acid (0.02 mol L−1) and glucose or fructose (0.2 mol L−1) are useful additives for levelling sensitivities for As(III), monomethylarsonate (MMA) and dimethylarsinate (DMA). The presence
of glycine, malonic, tartaric acids, BICIN and soil humin extracts leads to differences in analytical signal response between
these arsenic species. An analytical application to the determination of the sum of As(III), monomethylarsonate (MMA) and
dimethylarsinate (DMA) as well as the sum of toxicologically relevant hydride forming arsenic fraction As(III) + As(V) + MMA
+ DMA in EDTA soil/sediment extracts using continuous flow HGAAS was demonstrated. The limit of detection was 0.2 mg kg−1 As. Within-day and between-day precision were in the range 3–7% and 4–10%, respectively, for arsenic contents of 0.7–25 mg
kg−1, with recoveries 95–103%.
相似文献
11.
Organic acids, sugars, phenolic compositions and antioxidant capacities of orange juice and orange wine obtained from the cv. Kozan of Turkey were determined. High-performance liquid chromatographic methods were used to identify and quantify of these compounds. Three organic acids (citric, malic and ascorbic acids) and three sugars (sucrose, glucose and fructose) were determined. The major organic acid was found as citric acid. With regard to sugars, sucrose was present in the largest amounts for orange juice and wine. A total of 13 phenolic compounds were identified and quantified in orange juice and wine, including hydroxybenzoic acids (2), hydroxycinnamic acids (5), and flavanones (6). Hesperidin, narirutin and ferulic acid were the most abundant phenolic compounds in orange juice and wine. Antioxidant activities of orange juice and wine were measured using the DPPH• (2,2-diphenyl-1-picrylhydrazyl) assay, and the antioxidant capacity of orange juice was found to be higher than that of orange wine. 相似文献
12.
FT-IR with partial least squares (PLS) was used to establish a full calibration model for tartaric acid, malic acid, lactic acid, succinic acid, citric acid and acetic acid in wines, vinegars and spirits. Sample pre-treatment was not required except for filtering. 相似文献
13.
Luís C. Duarte Florbela Carvalheiro Joana Tadeu Francisco M. Gírio 《Applied biochemistry and biotechnology》2006,130(1-3):461-475
The combined effects of inhibitors present in lignocellulosic hydrolysates was studied using a multivariate statistical approach.
Acetic acid (0–6 g/L), formic acid (0–4.6 g/L) and hydroquinone (0–3 g/L) were tested as model inhibitors in synthetic media
containing a mixture of glucose, xylose, and arabinose simulating concentrated hemicellulosic hydrolysates. Inhibitors were
consumed sequentially (acetic acid, formic acid, and hydroquinone), alongside to the monosaccharides (glucose, xylose, and
arabinose). Xylitol was always the main metabolic product. Additionally, glycerol, ethanol, and arabitol were also obtained.
The inhibitory action of acetic acid on growth, on glucose consumption and on all product formation rates was found to be
significant (p≤0.05), as well as formic acid inhibition on xylose consumption and biomass production. Hydroquinone negatively affected biomass
productivity and yield, but it significantly increased xylose consumption and xylitol productivity. Hydroquinone interactions,
either with acetic or formic acid or with both, are also statistically signficant. Hydroquinone seems to partially lessen
the acetic acid and amplify formic acid effects. The results clearly indicate that the interaction effects play an important
role on the xylitol bioprocess. 相似文献
14.
S. Garrigues F. J. Rambla M. de la Guardia 《Fresenius' Journal of Analytical Chemistry》1998,362(1):137-140
A comparative study has been carried out between a horizontal Attenuated Total Reflectance (h-ATR) cell and a Cylindrical
Internal Reflection (CIR) cell (CIRCLE cell). Both cells were employed for the determination of glucose, fructose, sucrose
and total sugar in soft drinks and fruit juices using absorbance measurements at two resolution values (4 and 8 cm–1). Data were processed by Partial Least Squares regression (PLS). Using a resolution of 4 cm–1, mean relative errors of prediction from 0.6% to 1.3% were obtained using the horizontal-ATR and from 0.6% to 2.8% using
the CIRCLE cell resulting in a limit of detection from 0.03% in the case of sucrose to 0.21% for total sugar for the h-ATR
and from 0.06% for sucrose to 0.13% for glucose using the CIRCLE cell. Both cells provided appropriate figures of merit, but
the analytical sensitivity obtained using the h-ATR cell was three times higher than that obtained using the CIRCLE cell.
Received: 8 December 1997 / Revised: 16 February 1998 / Accepted: 23 February 1998 相似文献
15.
Hoffmann I. Muenze R. Dreyer I. Dreyer R. 《Journal of Radioanalytical and Nuclear Chemistry》1982,74(1-2):53-61
Ion mobilities of different99mTc- and99Tc chelates prepared by reduction of pertechnetate by Sn(II) in the presence of citric, malic, tartaric, gluconic, and α-hydroxyisobutyric
acid as ligands have been measured by means of electrophoresis without supporting material. All the chelates investigated
proved to be anions in the pH range of 2–7. Both the Tc(V)- and Tc(IV) compounds with the same ligand including the99mTc preparation show identical ion mobilities and dissociation characteristics. 相似文献
16.
Magdalena Rakicka Zbigniew Lazar Anita Rywińska Waldemar Rymowicz 《Chemical Papers》2016,70(11):1452-1459
Inulin and glycerol were used as substrates for efficient erythritol and citric acid production by newly engineered Yarrowia lipolytica strains. Hydrolysis of inulin by the Y. lipolytica Wratislavia K1 strain was established by expressing the Kluyveromyces marxianus INU1 gene. Erythritol was produced in two stages: inulin was used for biomass formation, followed by erythritol biosynthesis initiated by glycerol addition. The highest titer of erythritol obtained, 120.9 g L?1 with the yield of 0.6 g g?1, was produced by the K1 INU 6 strain. Moreover, the K1 INU 6 strain in fed-batch culture produced a high amount of citric acid: 105.2 g L?1 after 235 h from 200 g L?1 of inulin. Maximum activity of inulinase during this culture was 14000 U g?1 of cell dry mass. The presented study proves the potential of new Y. lipolytica transformants for efficient erythritol and citric acid production from inexpensive raw materials such as inulin and glycerol. 相似文献
17.
Application of FT-MIR spectrometry in wine analysis 总被引:1,自引:0,他引:1
By means of liquid Fourier transform-middle infrared spectrometry, it is possible to analyse wine and must within 90 s simultaneously on a significant number of important parameters like alcohol, relative density, extract, sugar-free extract, refraction, conductivity, glycerol, total phenols, reducing sugar, fructose, glucose, sucrose, total acid, pH value, volatile acid, total SO2 and tartaric acid, malic acid, lactic acid and citric acid. Within a short time, it is possible to obtain information on the chemical composition of the product and it is useful to monitor the changes in chemical composition from beginning of grape ripening, must and fermentation to finished wines. Additionally, it is possible to obtain a fingerprint of the products which can serve as an identity check for quality management and production control. In the first part, a sample set with 327 typical German wines from 1989 to 2001 were analysed using Fourier transform-middle infrared spectrometry (FT-MIR) and also with different reference methods. In the second part, the results of a Ring test with 52 typical wines from each of 13 German wine regions are discussed. The results from this study demonstrated that a calibration model could be transferred between FT-MIR machines with the same hardware. The inter-laboratory reproducibility proved to be satisfactory and the instrument results were comparable with those obtained by the “classical reference methods”. 相似文献
18.
Application of a pH Feedback-Controlled Substrate Feeding Method in Lactic Acid Production 总被引:1,自引:0,他引:1
Substrate concentration in lactic acid fermentation broth could not be controlled well by traditional feeding methods, including
constant, intermittent, and exponential feeding methods, in fed-batch experiments. A simple feedback feeding method based
on pH was proposed to control pH and substrate concentration synchronously to enhance lactic acid production in fed-batch
culture. As the linear relationship between the consumption amounts of alkali and that of substrate was concluded during lactic
acid fermentation, the alkali and substrate in the feeding broth were mixed together proportionally. Thus, the concentration
of substrate could be controlled through the adjustment of pH automatically. In the fed-batch lactic acid fermentation with
Lactobacillus lactis-11 by this method, the residual glucose concentration in fermentation broth was controlled between 4.1 and 4.9 g L−1, and the highest concentration of lactic acid, maximum cell dry weight, volumetric productivity of lactic acid, and yield
were 96.3 g L−1, 4.7 g L−1, 1.9 g L−1 h−1, and 0.99 g lactic acid per gram of glucose, respectively, compared to 82.7 g L−1, 3.31 g L−1, 1.7 g L−1 h−1, and 0.92 g lactic acid per gram of glucose in batch culture. This feeding method was simple and easily operated and could
be feasible for industrial lactic acid production in the future. 相似文献
19.
E. A. Zakharova M. L. Moskaleva Yu. A. Akeneev E. S. Moiseeva G. B. Slepchenko N. P. Pikula 《Journal of Analytical Chemistry》2011,66(9):848-853
The method of potentiometric titration with a copper electrode is used for the determination of the total acidity and concentration
of citric acid (CA) in identifying the adulteration of wines. The procedure is suitable for the determination of citric acid in wines in the
range from 0.1 to 3.5 g/L in the presence of 30-fold amounts of tartaric, acetic, malic, succinic acids and a 10-fold amount
of oxalic acid after the separation of organic carboxylic acids on an AV-17-8 anion exchanger. The procedure was developed
and certified for the potentiometric determination of the mass fraction of citric acid in table wines and wine materials with
an error not exceeding 20%. The criteria (mass fraction of citric acid, the percentage of citric acid in the total acidity,
and the shape of the curves of potentiometric titration) were proposed for revealing the adulteration of the acid composition
of wines. 相似文献
20.
Contamination by Brettanomyces is a frequent problem in many wineries that has a dramatic effect on wine aroma and hence its quality. The yeast Brettanomyces/Dekkera is involved in the formation of three important volatile ethylphenols—4-ethylphenol, 4-ethylguaiacol and 4-ethylcatechol—that
transmit an unpleasant aroma to wine that has often been described as ‘medicinal’, ‘stable’ or ‘leather’. This study proposes
an in situ derivatisation and headspace solid-phase microextraction– gas chromatography coupled to mass spectrometry method
to determine the three ethylphenols in red Brettanomyces-tainted wines. The most important variables involved in the derivatisation (acetic anhydride and base concentration) and
the extraction (extraction temperature and salt addition) processes were optimised by experimental design. The optimal conditions
using 4 mL of wine in 20-mL sealed vials were 35 μL of acetic anhydride per millilitre of wine, 1 mL of 5.5% potassium carbonate
solution and 0.9 g of sodium chloride and the extraction was performed with a divinylbenzene–carboxen–poly(dimethylsiloxane)
fibre at 70 °C for 70 min. Then, the performance characteristics were established using wine samples spiked with the ethylphenols.
For all compounds, the detection limits were below the odour threshold reported in the literature and they were between 2
and 17 μg L−1 for 4-ethylguaiacol and 4-ethylphenol, respectively. Intermediate precision (as relative standard deviation) was acceptable,
with values ranging from 0.3 to 12.1%. Finally, the method was applied in the analysis of aged Brettanomyces-tainted wines. 相似文献