Fusing 1H NMR and Raman experimental data for the improvement of wine recognition models.

The present study proposes the development of new wine recognition models based on Artificial Intelligence (AI) applied to the mid-level data fusion of 1H NMR and Raman data. In this regard, a supervised machine learning method, namely Support Vector Machines (SVMs), was applied for classifying wine samples with respect to the cultivar, vintage, and geographical origin. Because the association between the two data sources generated an input space with a high dimensionality, a feature selection algorithm was employed to identify the most relevant discriminant markers for each wine classification criterion, before SVM modeling. The proposed data processing strategy allowed the classification of the wine sample set with accuracies up to 100% in both cross-validation and on an independent test set and highlighted the efficiency of 1H NMR and Raman data fusion as opposed to the use of a single-source data for differentiating wine concerning the cultivar and vintage.

Application of fuzzy algorithms in conjunction with 1 H-NMR spectroscopy to differentiate alcoholic beverages.

BACKGROUND: Recent statistics from the European Commission indicate that wine is one of the commodities most commonly subject to food fraud. In this context, the development of reliable classification models to differentiate alcoholic beverages requires, besides sensitive analytical tools, the use of the most suitable data-processing methods like those based on advanced statistical tools or artificial intelligence. RESULTS: The present study aims to establish a new, innovative approach for the differentiation of alcoholic beverages (wines and fruit distillates), which is able to increase the discrimination rate of the models that have been developed. A data dimensionality reduction step was applied to proton nuclear magnetic resonance (1 H-NMR) profiles. This stage consisted of the application of fuzzy principal component analysis (FPCA) prior to the development of classification models through discriminant analysis. The enhancement of the model's classification potential by the application of FPCA in comparison with principal component analysis (PCA) was discussed. CONCLUSION: The association of 1 H-NMR spectroscopy and an appropriate statistical approach provided a very effective tool for the differentiation of alcoholic beverages. To develop reliable metabolomic approaches for the differentiation of wines and fruit distillates, 1 H-NMR spectroscopic data were exploited in conjunction with fuzzy algorithms to reduce data dimensionality. The study proved the greater efficiency of using FPCA scores in comparison with those obtained through the widely applied PCA. The proposed approach enabled wines to be distinguished perfectly according to their geographical origins, cultivar, and vintage, and this could be used for wine classification. Moreover, 100% correctly classified samples were also achieved for the botanical and geographical differentiation of fruit distillates. © 2022 Society of Chemical Industry.

Applications of emerging stable isotopes and elemental markers for geographical and varietal recognition of Romanian and French honeys.

The research towards the identification of new authenticity markers is crucial to fight against fraudulent activities on honey, one of the top ten most falsified food commodities. This work proposes an association of stable isotopes and elemental content as markers for honey authentication, with respect to its floral and geographical origin. Emerging markers like isotopic signature of honey water alongside with carbon and hydrogen isotopic ratios of ethanol obtained from honey fermentation and Rare Earth Elements, were used to develop new recognition models. Thus, the efficiency of the discrimination potential of these emerging markers was discussed individually and in association. This approach proved its effectiveness for geographical differentiation (>98%) and the role of the emerging markers in these classifications was an essential one, especially of: (D/H)I, δ2H, δ18O, La, Ce and Pr. Floral recognition was realized in a lower percentage revealing the suitability of these markers mainly for geographical classification.

Testing the limits of FT-Raman spectroscopy for wine authentication: Cultivar, geographical origin, vintage and terroir effect influence.

FT-Raman spectroscopy represents an environmentally friendly technique, suitable for the analysis of high-water content food matrices, like wines, due to its relatively weak water bending mode in the fingerprint region. Based on metabolomics applied to FT-Raman spectra, this study presents the classifications achieved for a sample set comprising 126 wines, originated from Romania and France, with respect to cultivar, geographical origin and vintage. Cultivar recognition was successfully performed among four varieties (Sauvignon, Riesling, Chardonnay, Pinot Gris) while subtle particularities exiting between the Chardonnay wines, coming from the two countries, because of terroir influences were pointed out. The obtained separations of 100% in both initial and cross-validation procedure for geographical differentiation between the two origin countries, as well as, among the three Romanian areas (Transylvania, Muntenia and Moldova) were also discussed. Apart of this, the limitations and the importance of choosing a meaningful data set, in terms of representativity for each classification criterion, are addressed in the present work.

Application of fluorescence spectroscopy using classical right angle technique in white wines classification.

The potential of excitation - emission matrices (EEM) measurements using classical right angle technique, in conjunction with chemometrics, was prospected for white wine classification with respect to their cultivar and geographical origin. For this purpose, wines belonging to four cultivars (Chardonnay, Pinot Gris, Riesling and Sauvignon) from two different countries (Romania and France) were investigated. The excitation - emission matrices were statistically processed using parallel factor analysis (PARAFAC). According to Soft Independent Modeling Classification Analogy (SIMCA) model, for cultivar differentiation, only 3 out of 107 wine samples (1 Pinot Gris (Romania); 1 Riesling (Romania) and 1 Sauvignon (France)) were misclassified while for geographical origin assessment, only 2 wines (1 Romania and 1 France) were misclassified. This study  demonstrates the potential of excitation - emission fluorescence matrices spectroscopy using the classical right angle technique in wine authentication, without sample dilution.

1H NMR metabolomics applied to Bordeaux red wines.

The q-NMR metabolomics has already demonstrated its potential for classifying wines of different geographical origins, grape varieties, or vintages. This study focuses on the characterisation of Bordeaux red wines, seeking to discriminate them from others produced in the major French wine regions. A sampling of 224 commercial French wines was analysed by 1H NMR and forty compounds were quantified. Non-supervised and supervised statistical analyses revealed a singular imprint of Bordeaux wines in comparison with other French wines, with classification rates ranging from 71% to 100%. Within the Bordeaux vineyards, red wines from the different Bordeaux subdivisions were analysed from different vintages. Our results indicate that q-NMR metabolomics enables the differentiation of Médoc and Libournais vineyard highlighting the most discriminant constituents. In addition, the effects of wine evolution during bottle aging and vintage on Bordeaux red wines were pointed out and discussed.

Optimization of oxygen-18 ratio measurements by equilibration - Isotope ratio mass spectrometry using various water content matrices.

In the acknowledge method for the determination of oxygen isotope ratio from water, the oxygen-18 ratio (δ18O) quantification is performed on a relatively high amount of liquid solution. Recently, we proved that the oxygen-18 determinations can be made directly on a pasty matrix, using so called in situ measurements. In this paper, the accuracy of in situ measurements was demonstrated by the correspondence between δ18O values quantified in situ and those performed on the water, previously extracted from the pasty matrix itself. The use of matrices with various humidity (17-100% of water) allowed the construction of a model able to estimate the optimum amount of matrix requested for in situ equilibration according to its humidity. This study reveals that only 6 µL of liquid (water) is enough to obtain an accurate value and that, in the experimental configuration used, the minimum water content is 20% to obtain reliable and reproducible results.

Vine Water Deficit Impacts Aging Bouquet in Fine Red Bordeaux Wine.

The aim of this study was to investigate the influence of vine water status on bouquet typicality, revealed after aging, and the perception of three aromatic notes (mint, truffle, and undergrowth) in bottled fine red Bordeaux wines. To address the issue of the role of vine water deficit in the overall quality of fine aged wines, a large set of wines from four Bordeaux appellations were subjected to sensory analysis. As vine water status can be characterized by carbon isotope discrimination (δ13C), this ratio was quantified for each wine studied. Statistical analyses combining δ13C and sensory data highlighted that δ13C-values discriminated effectively between the most- and least-typical wines. In addition, Principal Component Analysis (PCA) revealed correlations between δ13C-values and truffle, undergrowth, and mint aromatic notes, three characteristics of the red Bordeaux wine aging bouquet. These correlations were confirmed to be significant using a Spearman statistical test. This study highlighted for the first time that vine water deficit positively relates to the perception of aging bouquet typicality, as well as the expression of its key aromatic nuances.

Comparative study of ¹³C composition in ethanol and bulk dry wine using isotope ratio monitoring by mass spectrometry and by nuclear magnetic resonance as an indicator of vine water status.

The potential of wine (13)C isotope composition (δ(13)C) is presented to assess vine water status during grape ripening. Measurements of δ(13)C have been performed on a set of 32 authentic wines and their ethanol recovered after distillation. The data, obtained by isotope ratio monitoring by mass spectrometry coupled to an elemental analyser (irm-EA/MS), show a high correlation between δ(13)C of the bulk wine and its ethanol, indicating that the distillation step is not necessary when the wine has not been submitted to any oenological treatment. Therefore, the ethanol/wine δ(13)C correlation can be used as an indicator of possible enrichment of the grape must or the wine with exogenous organic compounds. Wine ethanol δ(13)C is correlated to predawn leaf water potential (R(2) = 0.69), indicating that this parameter can be used as an indicator of vine water status. Position-specific (13)C analysis (PSIA) of ethanol extracted from wine, performed by isotope ratio monitoring by nuclear magnetic resonance (irm-(13)C NMR), confirmed the non-homogenous repartition of (13)C on ethanol skeleton. It is the δ(13)C of the methylene group of ethanol, compared to the methyl moiety, which is the most correlated to predawn leaf water potential, indicating that a phase of photorespiration of the vine during water stress period is most probably occurring due to stomata closure. However, position-specific (13)C analysis by irm-(13)C NMR does not offer a greater precision in the assessment of vine water status compared to direct measurement of δ(13)C on bulk wine by irm-EA/MS.

Raman spectroscopy of white wines.

The feasibility of exploiting Raman scattering to analyze white wines has been investigated using 3 different wavelengths of the incoming laser radiation in the near-UV (325 nm), visible (532 nm) and near infrared (785 nm). To help in the interpretation of the Raman spectra, the absorption properties in the UV-visible range of two wine samples as well as their laser induced fluorescence have also been investigated. Thanks to the strong intensity enhancement of the Raman scattered light due to electronic resonance with 325 nm laser excitation, hydroxycinnamic acids may be detected and analyzed selectively. Fructose and glucose may also be easily detected below ca. 1000 cm(-1). This feasibility study demonstrates the potential of the Raman spectroscopic technique for the analysis of white wines.

(13)C/(12)C isotope ratios of organic acids, glucose and fructose determined by HPLC-co-IRMS for lemon juices authenticity.

High performance liquid chromatography linked to isotope ratio mass spectrometry via an interface allowing the chemical oxidation of organic matter (HPLC-co-IRMS) was used to simultaneously determine carbon 13 isotope ratio (δ(13)C) of organic acids, glucose and fructose in lime and lemon juices. Because of the significant difference between organic acids and sugars concentrations, the experimental protocol was optimised by applying a "current jump" to the IRMS device. The filament current is increased of 300µA during elution in order to enhance IRMS sensitivity. Then, analysis were performed on 35 lemon and lime fruits from various geographical origins and squeezed in the laboratory. An overall average δ(13)C values of -25.40±1.62‰, -23.83±1.82‰ and -25.67±1.72‰ is found for organic acids mixture mainly made up of citric acid, glucose and fructose, respectively. These authentic samples allowed the definition of a confidence domain to which have been confronted 30 commercial juices (24 "pure juices" and 6 coming from concentrate). Among these 30 samples, 10 present δ(13)C values outside the defined range revealing an added "C4" type organic acids or sugars, addition not specified on the label that is not in agreement with EU regulation.

Potential of ion chromatography coupled to isotope ratio mass spectrometry via a liquid interface for beverages authentication.

New tools for the determination of characteristic parameters for food authentication are requested to prevent food adulteration from which health concerns, unfair competition could follow. A new coupling in the area of compound-specific carbon 13 isotope ratio (δ(13)C) analysis was developed to simultaneously quantify δ(13)C values of sugars and organic acids. The coupling of ion chromatography (IC) together with isotope ratio mass spectrometry (IRMS) can be achieved using a liquid interface allowing a chemical oxidation (co) of organic matter. Synthetic solutions containing 1 polyol (glycerol), 3 carbohydrates (sucrose, glucose and fructose) and 12 organic acids (gluconic, lactic, malic, tartaric, oxalic, fumaric, citric and isocitric) were used to optimize chromatographic conditions (concentration gradient and 3 types of column) and the studied isotopic range (-32.28 to -10.65‰) corresponds to the values found in food products. Optimum chromatographic conditions are found using an IonPac AS15, an elution flow rate of 0.3mLmin(-1) and a linear concentration gradient from 2 to 76mM (rate 21mMmin(-1)). Comparison between δ(13)C value individually obtained for each compound with the coupling IRMS and elemental analyzer, EA-IRMS, and the ones measured on the mixture of compounds by IC-co-IRMS does not reveal any isotope fractionation. Thus, under these experimental conditions, IC-co-IRMS results are accurate and reproducible. This new coupling was tested on two food matrices, an orange juice and a sweet wine. Some optimization is necessary as the concentration range between sugars and organic acids is too large: an increase in the filament intensity of the IRMS is necessary to simultaneously detect the two compound families. These first attempts confirm the good results obtained on synthetic solutions and the strong potential of the coupling IC-co-IRMS in food authentication area.

Authenticity of carbon dioxide bubbles in French ciders through multiflow-isotope ratio mass spectrometry measurements.

A procedure to detect whether carbon dioxide was added to French ciders has been developed. For this purpose, an optimised and simplified method is proposed to determine (13)C/(12)C isotope ratio of carbon dioxide (δ(13)C) in ciders. Three critical steps were checked: (1) influence of atmospheric CO2 remaining in the loaded vial, (2) impact of helium flush, (3) sampling speed. This study showed that atmospheric CO2 does not impact the measurement, that helium flush can lead to isotopic fractionation and finally, that a fractionation occurs only 5h after bottle opening. The method, without any other preparation, consists in sampling 0.2 mL of cold (4 °C) cider in a vial that is passed in an ultrasonic bath for 10 min at room temperature to enhance cider de-carbonation. The headspace CO2 is then analysed using the link Multiflow®-isotope ratio mass spectrometer. Each year, a data bank is developed by fermenting authentic apples juices in order to control cider authenticity. Over a four year span (2008-2011), the CO2 produced during the fermentation step was studied. This set of 61 authentic ciders, from various French production areas, was used to determine a δ(13)C value range of -22.59±0.92‰ for authentic ciders CO2 bubbles. 75 commercial ciders were analysed with this method. Most of the samples analysed present a gas δ(13)C value in the expected range. Nevertheless, some ciders have δ(13)C values outside the 3σ limit, revealing carbonation by technical CO2. This practice is not allowed for organic, "Controlled Appellation of Origin" ciders and ciders specifying natural carbonation on the label.

Intrinsic ratios of glucose, fructose, glycerol and ethanol 13C/12C isotopic ratio determined by HPLC-co-IRMS: toward determining constants for wine authentication.

High-performance liquid chromatography linked to isotope ratio mass spectrometry (HPLC-co-IRMS) via a Liquiface© interface has been used to simultaneously determine (13)C isotope ratios of glucose (G), fructose (F), glycerol (Gly) and ethanol (Eth) in sweet and semi-sweet wines. The data has been used the study of wine authenticity. For this purpose, 20 authentic wines from various French production areas and various vintages have been analyzed after dilution in pure water from 20 to 200 times according to sugar content. If the (13)C isotope ratios vary according to the production area and the vintage, it appears that internal ratios of (13)C isotope ratios (R((13)C)) of the four compounds studied can be considered as a constant. Thus, ratios of isotope ratios are found to be 1.00 ± 0.04 and 1.02 ± 0.08 for R((13)C(G/F)) and R((13)C(Gly/Eth)), respectively. Moreover, R((13)C(Eth/Sugar)) is found to be 1.15 ± 0.10 and 1.16 ± 0.08 for R((13)C(Gly/Sugar)). Additions of glucose, fructose and glycerol to a reference wine show a variation of the R((13)C) value for a single product addition as low as 2.5 g/L(-1). Eighteen commercial wines and 17 concentrated musts have been analyzed. Three wine samples are suspicious as the R((13)C) values are out of range indicating a sweetening treatment. Moreover, concentrated must analysis shows that (13)C isotope ratio can be also used directly to determine the authenticity of the matrix.

Determination of quinacrine dihydrochloride dihydrate stability and characterization of its degradants.

Although quinacrine dihydrochloride dihydrate is a widely used drug substance, a comprehensive determination of its stability profile is lacking. In this work, an integrative approach is implemented to determine the drug stability both in the solid state and aqueous solutions, identify the impurities that can be found in the active pharmaceutical ingredient, and evaluate the associated toxicity risks. Thermal analyses pointed out a two-step dehydration of the solid state. This phenomenon seems to be consistent with the organization of the water molecules in the crystal structure and results in the destruction of the lattice. Seven related compounds of quinacrine have been identified by liquid chromatography-ion trap mass spectrometry. The main thermal degradant both in the solid state and the solution corresponds to the N-deethyl compound, whereas quinacrine tertiary amine oxyde appears to be a signal impurity of oxidative stress in solution. Moreover, two photolytic impurities can be formed in solution either by aromatic amine cleavage or via O-demethylation. Additionally, using computational approaches, the analysis of the potential toxicity of the impurities compared with the parent compound one shows that ketone and O-demethyl derivatives may exhibit specific toxicity profiles.

Quantification method and organoleptic impact of added carboxymethyl cellulose to dry white wine.

Following the resolution Oeno 2-2008 of the OIV, "Organisation Internationale de la Vigne et du Vin", the addition of carboxymethyl cellulose (CMC) in wines at a concentration lower than 100 mg L-1 is authorized in the EU (RCE 606-2009). In order to control this level, a method has been elaborated to quantify CMC addition at the maximum limit authorized. It is based on the absorbance level of a coloured complex obtained by the addition of a solution of 2,7-dihydronaphthalene in concentrated sulfuric acid to a dry white wine that has been dialyzed; the proposed method has a quantification limit of 60 mg L-1 with a 40 mg L-1 uncertainty. Despite these relatively high values, the method is, nevertheless, suitable for its purpose. Some wines, elaborated and CMC supplemented, allowed one to test the CMC quantification method, in real conditions of wine production. All the measurements provide a CMC quantification at the expected level, within the uncertainty. These samples, sets of treated and untreated wines, were submitted to sensory evaluation to assess the impact of CMC addition to wine. At the maximum authorized level, no significant difference was detected by the 20 expert panel under quality control requirements. Moreover, some experiments, performed to determine the concentration threshold at which the CMC effect is noticeable, showed that even at a level 15 times higher than the maximum amount authorized, CMC has no impact on the taste or the nose of the wines.

Characterization and quantification of grape variety by means of shikimic acid concentration and protein fingerprint in still white wines.

Protein profiles, obtained by high-performance capillary electrophoresis (HPCE) on white wines previously dialyzed, combined with shikimic acid concentration and multivariate analysis, were used for the determination of grape variety composition of a still white wine. Six varieties were studied through monovarietal wines elaborated in the laboratory: Chardonnay (24 samples), Chenin (24), Petit Manseng (7), Sauvignon (37), Semillon (24), and Ugni Blanc (9). Homemade mixtures were elaborated from authentic monovarietal wines according to a Plackett-Burman sampling plan. After protein peak area normalization, a matrix was elaborated containing protein results of wines (mixtures and monovarietal). Partial least-squares processing was applied to this matrix allowing the elaboration of a model that provided a varietal quantification precision of around 20% for most of the grape varieties studied. The model was applied to commercial samples from various geographical origins, providing encouraging results for control purposes.

Effects of must concentration techniques on wine isotopic parameters.

Despite the robustness of isotopic methods applied in the field of wine control, isotopic values can be slightly influenced by enological practices. For this reason, must concentration technique effects on wine isotopic parameters were studied. The two studied concentration techniques were reverse osmosis (RO) and high-vacuum evaporation (HVE). Samples (must and extracted water) have been collected in various French vineyards. Musts were microfermented at the laboratory, and isotope parameters were determined on the obtained wine. Deuterium and carbon-13 isotope ratios were studied on distilled ethanol by nuclear magnetic resonance (NMR) and isotope ratio mass spectrometry (IRMS), respectively. The oxygen-18 ratio was determined on extracted and wine water using IRMS apparatus. The study showed that the RO technique has a very low effect on isotopic parameters, indicating that this concentration technique does not create any isotopic fractionation, neither at sugar level nor at water level. The effect is notable for must submitted to HVE concentration: water evaporation leads to a modification of the oxygen-18 ratio of the must and, as a consequence, ethanol deuterium concentration is also modified.

Alternative method for the quantification by gas chromatography triacylglycerol class analysis of cocoa butter equivalent added to chocolate bars.

Directive 2000/36/EC allows chocolate makers to add up to 5% of only six specific cocoa butter equivalents (CBEs) to cocoa butter (CB). A quantification method based on triacylglycerol (TAG) class analysis by gas chromatography with an unpolar column was set up for routine control purposes of chocolate bars. Mixtures of CBEs/CB were elaborated according to a Placket-Burman experiment design and analyzed by gas chromatography. A matrix was built with the normalized values of TAG classes (C50, C52, C54, and C56) of pure CBs of various origins, homemade CB/CBE mixtures (1 CB type), and mixtures containing CBE with CBs of various origins. A multivariate calibration equation was computed from this matrix using a partial least-squares regression technique. CBE addition can be detected at a minimum level of 2%, and the mathematical model allows its quantification with an uncertainty of 2% with respect to the cocoa butter fats. The model has also been applied for deconvolution and quantification of each CBE of a CBE mixture in chocolate bars.

[Methods of use and behavior of cocaine addicts consulting medical-legal emergency units in Paris. Clinical aspects and urinary toxicology profile]. / Modes d'usage et comportements du cocaïnomane consultant aux urgences médico-judiciaires de Paris. Aspect clinique et profil toxicologique urinaire.

OBJECTIVE: Establish the epidemiological characteristics and urinary toxicological profiles of a population of cocaine addicts under police custody. METHOD: A series of 60 cocaine addicts consulting the medico-legal emergency unit of the Hôtel-Dieu hospital in Paris was studied prospectively on the following elements: clinical characteristics, method of cocaine administration and association with other licit or illicit substances. Urinary toxicological analysis, using immuno-chemistry and chromatography linked to a mass spectrometer was systematically proposed to each patient. RESULTS: Half of the 17 to 26 year-old patients declared having consumed cocaine for the past 2 to 5 years. Inhalation of the vapours and the intravenous route were used more than the cigarette or nasal route. The majority of 26 to 35 year-olds were multi-drug addicted, generally associating cocaine, heroine and tobacco. Analysis of the urine provided an objective assessment of the cocaine consumption of these persons under police custody in Paris. CONCLUSION: Screening for urinary toxicity gives better knowledge on the consumption of addictive products by the person in whom urine was sampled. This study was conducted in cocaine addicts under police custody, and for the majority were social misfits. In this population, the consumption of crack by inhalation predominated.