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Murviel-lès-Montpellier, France

Symeonidou D.,French National Institute for Agricultural Research | Sanchez I.,French National Institute for Agricultural Research | Croitoru M.,Montpellier University | Neveu P.,French National Institute for Agricultural Research | And 6 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

The key discovery problem has been recently investigated for symbolical RDF data and tested on large datasets such as DBpedia and YAGO. The advantage of such methods is that they allow the automatic extraction of combinations of properties that uniquely identify every resource in a dataset (i.e., ontological rules). However, none of the existing approaches is able to treat real world numerical data. In this paper we propose a novel approach that allows to handle numerical RDF datasets for key discovery. We test the significance of our approach on the context of an oenological application and consider a wine dataset that represents the different chemical based flavourings. Discovering keys in this context contributes in the investigation of complementary flavors that allow to distinguish various wine sorts amongst themselves. © Springer International Publishing Switzerland 2016. Source

For the first time, we proposed a high-throughput method to quantify glutathione in grapes, musts and wines for all grape varieties using Stable Isotope Dilution Assay (SIDA). Indeed, the use of SIDA as a quantification method is essential to overcome the chemical instability of glutathione. In practice, glutathione was derivatized in-situ with N-ethylmaleimide to block the cysteine residue and to enhance its lipophilic properties. After quenching with acetic acid, samples were directly analyzed by LC-MS/MS (run of 13 min) in Multiple Reaction Monitoring mode using labeled glutathione as internal standard. The validation according to the International Organization of Vine and Wine recommendations demonstrated the high sensitivity (LOD = 45 μg L-1), accuracy (recovery = 112%) and intermediate reproducibility (RSD = 12%) of the method. This high-throughput method that requires only 1 mL of matrix, allowed us to analyze 70 samples per day for a moderate cost. © 2015 Elsevier Ltd. All rights reserved. Source

Bouisseau A.,French National Center for Scientific Research | Roland A.,NYSEOS | Reillon F.,NYSEOS | Schneider R.,NYSEOS | Cavelier F.,French National Center for Scientific Research
Organic Letters | Year: 2013

Due to its toxicity and presence in numerous food products, Ochratoxin A (OTA) has drawn attention for decades. This article summarizes the first synthesis of a labeled analogue of Ochratoxin α (OTα), one of the main products generated by the metabolization of OTA by microorganisms. This synthesis also led to a new labeled analogue of OTA with the deuteration located on the dihydroisocoumarin moiety allowing thus both the accurate quantification of OTA and OTα and the establishing of a reliable detoxification rate. © 2013 American Chemical Society. Source

Roland A.,NYSEOS | Bros P.,Institute Francais Of La Vigne Et Du Vin | Bouisseau A.,NYSEOS | Bouisseau A.,Max Mousseron Institute of Biomolecules | And 2 more authors.
Analytica Chimica Acta | Year: 2014

Ochratoxin A (OTA) exhibits potent nephrotoxic, carcinogenic and teratogenic effects and its maximum level in wines has been set to 2μgL-1 by regulation. Consequently, the analytical procedures for OTA determination in wines have to be both very sensitive and reliable. In this paper, we compared two quantification methods: the stable isotope dilution assay (SIDA) and the diastereomeric dilution assay (DIDA). For this purpose, non-natural analogues of OTA were synthesized: the labeled OTA (OTA-d4) as a diastereomeric mixture for the SIDA and one non-natural OTA's diastereomer (OTA-dia) for the DIDA. To quantify OTA in red grapes, musts or wines, the sample preparation was optimized using immunoaffinity column extraction and the analysis was performed by LC-MS/MS in Multiple Reaction Monitoring mode. A validation procedure in agreement with the International Organization of Vine and Wine recommendations was conducted. It appeared that SIDA quantification exhibited excellent sensitivity (LOD<1ngL-1), accuracy (recovery=98%), repeatability (RSD<3%) and intermediate reproducibility (RSD<4%) compared to quantification by DIDA. Indeed, DIDA method did not provide satisfactory results demonstrating that immunoaffinity extraction is exclusively selective for the natural OTA and not for its diastereomer, which therefore cannot be considered as a good internal standard for this particular method. © 2014 Elsevier B.V. Source

Dagan L.,NYSEOS | Reillon F.,NYSEOS | Roland A.,NYSEOS | Schneider R.,NYSEOS
Analytica Chimica Acta | Year: 2014

The 4-mercapto-4-methylpentan-2-one (4MMP) is a key aroma compound in wines, especially in Sauvignon Blanc ones. Its accurate quantification is quite difficult due to its traces levels and its reactivity in wine conferred by the thiol function. In this paper, we proposed a new method for its quantification in wine without any sample preparation, based on automated derivatization procedure by methoximation and SIDA-SPME-GC-MS/MS analysis. The derivatization procedure was adapted from a previously published method in order to decrease the amount of reagents and the volume of wine (only 3mL are required). The use of SPME and the detection conditions have also been optimized to reach the best sensitivity as possible. The method was then validated according to the International Organization of Vine and Wine recommendations and exhibited excellent performances. Indeed, this method allowed us to quantify the 4MMP in wine at traces levels (LOD=0.19ngL-1) with reproducible results (RSD<15%) and a very good accuracy (recovery=102%). © 2014 Elsevier B.V. Source

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