Search results for "Extract"

Quantitative determination of sotolon in wines by high-performance liquid chromatography

1993

Sotolon (4,5-dimethyl-3-hydroxy-2(5H)-furanone) is a key flavour compound in the french flor-sherry “Vin jaune”. This compound was determined quantitatively by extraction of 25 ml of wine on a XAD-4 resin, elution with diethyl ether, separation by HPLC on a Lichrospher 100 Diol column, elution with dichloromethane/hexane (60/40) and UV detection at 232 nm. The amount of sotolon in “Vin jaune” (120 to 268 μg/l) was related to the development of the yeast film over a period of 6 years. Only 6 to 51 μg/l were found in the “Vin de paille” which is made with overmaturated grapes of the same Savagnin vine-plant but without development of yeasts, and 80 to 140 μg/l in “Tokai” which are partly grow…

High Performance Liquid Chromatography Analysis of Grape and Wine Polyphenols

2008

Representative champagne wine extracts for gas chromatography olfactometry analysis

1997

Gas chromatography olfactometry (GCO) analysis has proved to be a powerful method to determine key compounds of food aroma, but up to now few papers involving this technique in wine aroma studies were published. An accurate representation of the olfactory quality of the extracts is necessary to ensure the reliability of the conclusions resulting from such analyses. Three commercial champagne wines were used for this study. The champagne wine extracts were obtained from three different extraction methods:  adsorption on XAD resins, solvation in dichloromethane, and extraction by demixing ethanol. Thus the extracts were tested by a panel trained on champagne wines, using a profile descriptive…

Molecularly imprinted polymer solid phase extraction of fungicides from wine samples

2014

In order to preconcentrate iprodione fungicide in white wine samples, molecularly imprinted polymers (MIPs) specific for iprodione were synthesized using two polymerization approaches: precipitation (MIPp) and bulk polymerization (MIPb). A comparison of the performance of the MIPs and the corresponding non-imprinted polymers (NIPs) was conducted in batch studies. In this case, the MIPp revealed better recognition properties toward iprodione in wine samples than the MIPb. The MIPp and MIPb were then used as sorbents on solid phase extraction cartridges (MISPEp and MISPEb consecutively) in order to pre-concentrate iprodione from white wine samples. The optimization of the MISPE elution step w…

Application of finger span cross modality matching method (FSCM) by naive assessors for olfactometric discrimination of Gewürztraminer wines

2002

Abstract A gas-chromatography-olfactometric detection (GCO) using a direct estimation of odor intensities with the finger span (FSCM) was used to establish aroma profiles of three wines of gewurztraminer from different ‘terroirs’ of the Alsace region. The GCO-FSCM analyses of their hydroalcoholic wine extracts were performed using a group of untrained assessors. Forty-four olfactory signals were perceived by at least four assessors out of six and their intensities were scored in triplicate in each of the three wine extracts, amongst which ten of them were found discriminant between wines. The reliability of each assessor was studied on the basis of the finger span estimation repeatability, …

Comparison of different sample treatments for the analysis of ochratoxin A in must, wine and beer by liquid chromatography.

2004

Abstract Ochratoxin A (OTA) is a mycotoxin produced by some species of Aspergillus and Penicillium verrucosum. It has been found in foods and feed all over the world. There is a great concern about OTA because it is nephrotoxic and probably, carcinogenic to humans. Most of analytical methods developed for OTA in wine, beer and other products are based on LC with fluorescence detection (LC–FLD). In the present work, various procedures for extraction and/or clean-up for determination of OTA in musts, wine and beer by LC–FLD were compared: (1) dilution with polyethylen glycol 8000 and NaHCO3 solution and clean-up an on immunoaffinity column (IAC); (2) extraction with chloroform and IAC clean-u…

Increase of trans-resveratrol in typical Sicilian wine using β-Glucosidase from various sources

2008

β-Glucosidase (EC 3.2.1.21) (β-G) from different sources were tested to increase the trans-resveratrol in some Sicilian wines by hydrolysing resveratrol glucoside. β-G from Aspergillus niger mould was tested as a crude and purified enzyme, and compared with the same enzyme from Saccharomyces cerevisiae yeast. Specific purification served to eliminate collateral enzyme activities so that β-G could be used simply and economically. Aspergillus niger β-G produced trans-resveratrol increases of up to 75%, with no change in physico-chemical properties and bouquet, and an increase in health and nutritional properties. S. cerevisiae β-G raised free-terpenol levels, but impaired wine colour due to a…

Analysis of Contaminants in Beverages

2019

Abstract The main purpose of our researches, in the last years, was to develop reliable methods for the determination of emerging and old contaminants (Pt, Rh, V, Mo, polycyclic aromatic hydrocarbons (PAHs), etc.), at trace levels, in the solutions obtained from the mineralization or extraction of environmental and food matrices, because, in particular for metals, some of them cannot be readily analyzed using traditional method, for example, inductively coupled plasma-optical emission spectrometry and inductively coupled plasma with mass spectrometry techniques. Few data are available on the evaluations of Pt, Rh, V, and Mo concentrations, in food matrices, because have ever been carried ou…

A grape and wine chemodiversity comparison of different appellations in Burgundy: vintage vs terroir effects.

2013

Abstract This study aimed at assessing the ability of high resolution Fourier Transform Ion Cyclotron Resonance – Mass Spectrometry (FTICR–MS) to differentiate grapes and corresponding wines from distinct vineyards managed by a same producer, according to complex chemical fingerprints. Grape extracts (at harvest) and corresponding wines from four different vineyards, sampled immediately after the alcoholic fermentation over three successive vintages, were analysed by FTICR–MS. Thousands of metabolites that are specific to a given vintage, or a given class (wine, skin or must) could be revealed, thus emphasising a strong vintage effect. The same wines were reanalyzed after a few years in bot…

Incidencia de comunicación bucosinusal tras la extracción de 389 terceros molares superiores

2006

Podeu consultar la versió en anglès a http://hdl.handle.net/2445/117330