Wine Authenticity Research Articles

Quo vadis non-targeted wine analysis?

Important challenges of wine authentication - for example the proof of wine varieties, the determination of the vintage or the geographical origin, the determination of certain practices (e.g. differentiation of barrel/chips storage) become more and more successfully investigated by non-targeted analytical approaches. Not only in relation to these open questions in wine authentication non-targeted approaches such as nuclear magnetic resonance and mass spectrometry offer enormous potential also in wine authentication due to their typical abilities as high-through put and screening technique. The adaptation from research into routine applications takes actually place in some instances (e.g. NMR) including wine analysis. In addition the combination of non-targeted and targeted approaches within the same run of analysis provides possibilities complementing or even substituting classical methodologies. Some examples, the general workflow and typical evaluation strategies will be presented and their possibilities and limits discussed. First results of a recent study on the NMR analysis with focus on variety verification and reproducibility of spectral data will be presented. Particular emphasis will be put on general open questions such as exchangeability of data, validation, standardisation options.

New approach for wine authenticity screening by a cumulative 1H and 2H qNMR

New methodological approach for rapid control of wine authenticity without sample preparation, based on the quantitative NMR spectroscopy (qNMR) of the protium 1H and deuterium 2H nucleus is suggested. The content of dominant (e.g. water, ethanol) and some minor (e.g. glycerol, organic acids) components of wine are determined from qNMR 1H spectra for authentication of molecular composition. The sum of all exchanging hydrogen atoms of wine's components provide the 1H signal with a chemical shift of 4.8 ppm. Accounting for their content from 1H spectrum allows us calculate the 2H isotopic content in wine water from integral intensity of corresponding signal in the 2H qNMR spectrum using an internal or external standard with a known content of the 2H isotope. The possible addition of water can be found from comparison of this value with values of surface and/or ground waters from corresponding viticulture areas. This approach was used for white and red wines from the Black Sea region (Krasnodar area & Crimea peninsula). The 2H contents in investigated wines range from 157 to 165 ppm. The maximum 2H isotope content in surface waters does not exceed 148 ppm. A qNMR measurement of wine according to the proposed approach takes some minutes, that significantly exceeds the laboriousness of methods based on IRMS/SIRA (e.g. δ13C, δ18O). The error of qNMR measurements is less than 2.0%. The qNMR screening of deuterium (2H) in ethanol can be used for detection of possible wine chaptalization. This approach is similar to the known SNIF-NMR method. The positive difference with this method is the use of minimal quantity of enriched 2H standard and measurement of integral intensities of all signals instead of heights. It allows to reduce measurements' time as well as to measure the 2H content of all fragments of ethanol molecules – CH3−, CH2−, OH-groups. The publication has been prepared with the support of the “RUDN University Program 5–100”.

Quantitative analysis and detection of chaptalization and watering down of wine using isotope ratio mass spectrometry

In early 1990's European Union has established new isotopic approach for detection of wine authenticity. In this article we setup the possibility of using new approach using new EIM – Module – IRMS (Ethanol Isotope Measurement – Module – Isotope Ratio Mass Spectrometry) instrumental technique and new analytical parameter δDn(δ2Hn) wine ethanol value, which represents δ2H value of non-exchangeable hydrogen stable isotope ratio in ethanol, with other isotopic species (δ18O values in wine water) to improve detection of illegal wine production practices such as addition of sugar and/or dilution with water. Total of 42 wine samples were analyzed. 10 wine samples (out of 42) were prepared from grapes by alcoholic fermentation and analyzed for δDn values of ethanol. 19 wine samples (out of 42) were collected from wine producers in Serbia plus 1 wine samples designated from United States was taken from Serbian market and analyzed for δDn values of ethanol, δ18O values in wine water and also δ13C values in wine ethanol. Furthermore 9 wine samples (out of 42) were taken from Hungarian market and analyzed for δDn values of ethanol, and also 3 wine samples (out of 42) were taken from Austrian market and analyzed for δDn values of ethanol. All experiments were done in 4 isotope laboratories located in US, Austria, Hungary and People's Republic of China. δDn values of ethanol were measured by using EIM Module connected to FlashHT 2000 pyrolizer (one laboratory – Imprint Analytics GmbH, Austria), while in other 3 laboratories (US – COIL – Cornell University, Stable Isotope Laboratory, Hungary – Isotoptech Ltd, Debrecen, Hungary and China – C.N.R.I.F.F.I. – China National Institute of Food and Fermentation Industries Limited) EIM Module was connected to TC/EA (High Temperature Conversion Elemental Analyzer). Peripherals in all laboratories were further interfaced with isotope ratio mass spectrometer. Furthermore δ18O values in wine water were measured by using Gas Bench II interfaced also with isotope ratio mass spectrometer (one laboratory – US). Obtained results from all 4 laboratories have shown that this new approach which uses δDn in wine ethanol is more effective in improving detection of illegal wine production practices (sugar enrichment and water dilution) and origin of ethanol, and also detecting the addition of corn or beet sugar, sugar syrup to wine, or dilution of grape must with water prior to alcoholic fermentation. Keywords: Wine authenticity; EIM – Module – IRMS; Stable Isotope; Isotope Ratio Mass Spectrometry; Wine; Watering; Chaptalization.

Определение подлинности и токсикологической безопасности пива и вин методом хромато-масс-спектрометрии

Определение подлинности и токсикологической безопасности пива и вин методом хромато-масс-спектрометрии

87Sr/86Sr isotopic ratios in vineyard soils and varietal wines from Douro Valley

The assessment of wine authenticity is of utmost importance in the current context of a growing market globalization. The strontium isotopic ratio 87Sr/86Sr is a well-established tool for dating and tracing the origin of rocks and minerals with special interest for wine traceability. A study was developed to examine the variation of 87Sr/86Sr in wines from Douro Valley taking into account the effects of vineyard location and grape variety. The 87Sr/86Sr of soils and wines from six vineyards were determined by using an ICP-MS based analytical procedure. A total of twenty-two monovarietal wines, obtained at micro vinification scale, from relevant white and red grapevine varieties for Douro region, were analysed. The range of 87Sr/86Sr values observed in soils and wines was of 0.708–0.725 and 0.711–0.717, respectively. The present study updates the scarce knowledge available on strontium isotopic ratios in soils and wines from Douro Valley, and its results will enlarge global databank on wine composition and support comparison with other world regions.

Investigation of geographic origin of wine from border regions: Results from investigation of two vintages

Investigation on discrimination of geographic origin in border areas is carried out by investigating and comparing authentic wine samples from the border areas of Austria, Czech Republic, Slovakia (and from Serbia) by applying different physico-chemical methods (e.g. IRMS, NMR, ICP-MS, ICP-OES, EPR, HPLC, UV-VIS, etc…). The comparison of the data sets from the participating countries and the different applied methods demonstrates, to which extent a differentiation can still be achieved in the border areas of the respective countries, which methods prove most efficient and sensitive and if a combination of methods leads to an increased sensitivity. Furthermore, we also investigate the potential causes for the differentiation, as the environment, different agricultural practices or enology. Analysis of two consecutive vintages shows significant variations between the two years, complicating direct comparison of regions beyond individual vintages. Still, several parameters are identified enabling correct and complete differentiation. However, some of them have been found to represent lab effects, whereas others are interpreted as resulting from different agricultural practices or environmentally driven. Only the latter two ones, if consistent, can be used for discrimination of geographic origin.

Investigation of geographic origin of wine from border regions: Potential limitations and possibilities of different analytical methods and combinations of methods to identify the correct side of the border

In the presented project the investigation on discrimination of geographic origin of wine in from border areas is carried out. Authentic wine samples from the border areas of Austria, Czech Republic, Slovakia (and from Serbia) are investigated and compared by applying different physico-chemical methods (e.g. IRMS, NMR, ICP-MS, ICP-OES, EPR, HPLC, UV-VIS, etc.). The comparison of the data sets from the participating countries and the different applied methods will show, to which extent a differentiation can still be achieved in the border areas of the respective countries, which methods prove most efficient and sensitive and if a combination of methods will lead to an increased sensitivity. Furthermore, we also investigate the causes for the potential differentiation, which might be environmentally determined, due to different agricultural and/or enological practices. Results from the first investigated vintage 2016 show a good separation of the respective geographic origins by isotope ratios and element concentrations as well as by other parameters. The relevant parameters for differentiation now have to be critically evaluated to exclude potential lab influences.

Prospects for DNA authentication in wine production monitoring

Wines DNA authentication is a technological process of their authenticity verification by genetic identification of the main plant ingredient by means of molecular genetic analysis of the residual amounts of Vitis vinifera L nucleic acids extracted from end product cellular debris. The main aim of the research was the analysis of scientific and methodological approaches to the extraction of residual amounts of nucleic acids in wine raw materials and DNA authentication of wines for their subsequent application in solving the problem of determining wine products authenticity and place of origin. The prior art includes various approaches to the extraction of Vitis vinifera L. nucleic acids among which the three methods by Savazzini & Martinelli, Pereira and Bigliazzi can be named basically. Analysis of the effectiveness of different methods of DNA extraction from wines indicates the superiority of the Pereira method over other traditional methods of extraction in terms of DNA yield and quality. Besides, the nucleic acid extracted from wines is characterized as residual since its concentration is significantly reduced in a multi-stage wine production process. The yield of extracted nucleic acid also decreases as the wine ages. The use of microsatellite DNA loci designed for grapes genetic identification is one of the approaches applicable for wine DNA authentication.

Wine and grape marc spirits metabolomics.

Mass spectrometry (MS)-based and nuclear magnetic resonance (NMR) spectroscopic analyses play a key role in the field of metabolomics due to their important advantages. The use of metabolomics in wine and grape marc spirits allows a more holistic perspective in monitoring and gaining information on the making processes and thus it can assist on the improvement of their quality. This review surveys the latest metabolomics approaches for wine and grape marc spirits with a focus on the description of MS-based and NMR spectroscopic analytical techniques. We reviewed the literature to identify metabolomic studies of wine and grape marc spirits that were published until the end of 2017, with the key term combinations of 'metabolomics', 'wine' and 'grape marc spirits'. Through the reference lists from these studies, additional articles were identified. The results of this review showed that the application of different metabolomics approaches has significantly increased the knowledge of wine metabolome and grape marc spirits; however there is not yet a single analytical platform that can completely separate, detect and identify all metabolites in one analysis. The authentication and quality control of wines and grape marc spirits has to be taken with caution, since the product's chemical composition could be affected by many factors. Despite intrinsic limitations, NMR spectroscopy and MS based strategies remain the key analytical methods in metabolomics studies. Authenticity, traceability and health issues related to their consumption are the major research initiatives in wine and grape marc spirits metabolomics analysis.

Mineral Composition through Soil-Wine System of Portuguese Vineyards and Its Potential for Wine Traceability

The control of geographic origin is one of a highest priority issue regarding traceability and wine authenticity. The current study aimed to examine whether elemental composition can be used for the discrimination of wines according to geographical origin, taking into account the effects of soil, winemaking process, and year of production. The elemental composition of soils, grapes, musts, and wines from three DO (Designations of Origin) and for two vintage years was determined by using the ICP-MS semi-quantitative method, followed by multivariate statistical analysis. The elemental composition of soils varied according to geological formations, and for some elements, the variation due to soil provenance was also observed in musts and wines. Li, Mn, Sr and rare-earth elements (REE) allowed wine discrimination according to vineyard. Results evidenced the influence of winemaking processes and of vintage year on the wine’s elemental composition. The mineral composition pattern is transferred through the soil-wine system, and differences observed for soils are reflected in grape musts and wines, but not for all elements. Results suggest that winemaking processes and vintage year should be taken into account for the use of elemental composition as a tool for wine traceability. Therefore, understanding the evolution of mineral pattern composition from soil to wine, and how it is influenced by the climatic year, is indispensable for traceability purposes.

Polyphenol Fingerprinting Approaches in Wine Traceability and Authenticity: Assessment and Implications of Red Wines

Like any other food/feed matrix, regardless of the employed analytical method, wine requires authentication strategies; a suitable qualitative and quantitative analysis represents the fingerprint which defines its identity. Until recently, fingerprinting approaches using liquid chromatography applications have been regarded as an effective tool for the assessment of wines employing polyphenol profiles. These profiles are of considerable importance for grapes and wines as they influence greatly the color, sensory, and nutritional quality of the final product. The authenticity and typicity characters are fundamental characteristics, which may be evaluated by the use of polyphenol fingerprinting techniques. Under these conditions, the evolution of polyphenols during the red wine elaboration and maturation processes shows a high importance at the level of the obtained fingerprints. Moreover, the environment factors (vintage, the area of origin, and variety) and the technological conditions significantly influence wine authenticity through the use of polyphenol profiles. Taking into account the complexity of the matter at hand, this review outlines the latest trends in the polyphenol fingerprinting of red wines in association with the transformations that occur during winemaking and storage.

Free Radical-scavenging Activity and Anthocyanin Profiles of Cabernet Sauvignon and Merlot Wines from Four Wine Grapegrowing Regions in China

The present study focused on the free radical-scavenging activity and anthocyanin profiles of Cabernet Sauvignon and Merlot wines produced from four different regions in China. The anthocyanin profiles in all wine samples were analysed by HPLC-MS/MS, while the free radical-scavenging activity was estimated by the DPPH assay. The results show that the contents of phenolic subclasses and the levels of antioxidant activity in all wine samples varied greatly among cultivars and environmental factors of vine growth, and these values were the most prominent in Yuquanling regional wines. As the main components in anthocyanins, the percentages of malvidin-3-O-glucoside and its derivatives showed differences within grape cultivars in the different regional wines; these monomeric anthocyanins (not present simultaneously in the four regional wines studied within grape cultivars) had concentrations below 10 mg Mv/L. The significant correlation was obtained between DPPH-scavenging ability and the total phenolic, flavonoid and anthocyanin content. It can be concluded that this information could be used as a biochemical marker for the authenticity of the single-cultivar red wines that were produced from the four regions above.

From the Field to the Bottle—An Integrated Strategy for Wine Authenticity

The wine sector is one of the most economically important agro-food businesses. The wine market value is largely associated to terroir, in some cases resulting in highly expensive wines that attract fraudulent practices. The existent wine traceability system has some limitations that can be overcome with the development of new technological approaches that can tackle this problem with several means. This review aims to call attention to the problem and to present several strategies that can assure a more reliable and authentic wine system, identifying existent technologies developed for the sector, which can be incorporated into the current traceability system.

Wine authentication: a fingerprinting multiclass strategy to classify red varietals through profound chemometric analysis of volatiles

The verification of the grape variety with chemical–analytical methods is one of the major challenges in wine authentication. Such strategies use multivariate data analysis and are expected to separate individual grape varieties; also, the classification models for a large number of varieties shall give accurate predictions. In the part II of a non-targeted fingerprinting study presented herein, special multiclass chemometric strategies for the classification of German and non-German red wine varieties available on the German market were tested. The obtained three-dimensional raw data of a standardised headspace solid phase microextraction (HS-SPME) online coupled with gas chromatography mass spectrometry (GC–MS) was used; a metabolomics software and data pre-treatment were applied. The feasibility of the approaches was determined with four botanical origins by testing the models with external samples (validation). In particular, suitable modelling of similar wine varieties was a discriminant strategy using one-versus-one models based on orthogonal partial least squares discriminant analysis under the direction of a decision tree: on average, 85–98% correct classification of external test samples through ten tests was achieved. In addition, soft independent modelling of class analogies confirmed the classification. Both statistical strategies may be recommended for further improving wine authentication.

Label free DNA-based optical biosensor as a potential system for wine authenticity

The diversity found among the Vitis vinifera L. species allows the production of wines with very different characteristics. The development of platforms suitable for food composition analysis is currently an emerging area. Among these, DNA biosensors have been developed for a wide variety of applications, ranging from food safety to authenticity. The main aim of this work was to study the detection capacity of the DNA-based optical biosensor using different V. vinifera matrices (leaf, must and wine). Genomic DNA was extracted from leaf, must and wine of three V. vinifera varieties and was tested on the long-period grating (LPG) DNA-based biosensor developed within our group. The biosensor was able to distinguish the varieties even using DNA extracted from complex matrices, revealing its potential to be applied in wine authenticity.

Graphic image of high quality wines

The objects of the research were samples of high quality wines of various types produced by the enterprises of the Krasnodar Territory, the Rostov Region and foreign producers of different grape varieties. The method of automatic titration of acids in wines was applied by coulometric generation of the base with the recording of the results of potentiometric indication on the computer. The influence of the grape variety and the duration of aging of table wine on the appearance of the titration curves was carried out using 77 technical grades and clones of grapes (44 red grapes and 33 white grapes) from the Anapsko-Tamanskaya zone of the Krasnodar Territory from 2001 to 2016. Grapes of the studied varieties were processed under the micro nodulation conditions according to two schemes. Dry table red wines were obtained by fermentation on the mash. Dry table white wines were produced using the high quality low-oxidized wines. The experimental studies confirming the individuality of the titration curves and the absorption spectra of wine samples for specific brands have been carried out. The principal possibility was shown of using the coordinates of the titration curve of a wine sample for establishing a relationship with the grape variety and the authenticity of the production of wines with the protected geographical indication and appellation of origin. To confirm the authenticity of the wine products, it was suggested to compare the data matrix with the coordinates describing the average titration curve of a specific wine product obtained by the manufacturer with a similar matrix obtained by the controlling party under the reproducibility conditions. When the appearance of the titration curves of red wines obtained from different grape varieties was identical, it was suggested to additionally apply a matrix of data describing the absorption spectrum in the visible region. Key words : organic acids, authenticity of wines, potentiometric titration curves, spectral characteristics DOI: http://dx.doi.org/10.15826/analitika.2018.22.3.003 (Russian) O.N. Shelud`ko 1,2 , N.K. Strizhov 2 , T.I. Guguchkina 1 , T.V. Guzik 2 1 Northern-Caucasian Federal Scientific Center for Horticulture, Viticulture, Winemaking. Russian Federation, 350901, Krasnodar, 40th Anniversary of the Victory st., 39 2 Kuban State Technological University, Russian Federation, 350072, Krasnodar, Moscow st.,2

LC-MS Untargeted Protocol for the Analysis of Wine.

This chapter describes a protocol for the analysis of the metabolomic fingerprint of wine by liquid chromatography-mass spectrometry. The straightforward, optimized sample preparation procedure is limited to a single-step dilution with water or acetonitrile. The separation of wine analytes is carried out by two columns with orthogonal selectivity, including both reversed-phase (C18) and hydrophilic interaction (HILIC) chromatography, while the detection is assured by a high-resolution quadrupole time-of-flight mass spectrometer operating in negative and positive electrospray ionization mode, in order to obtain four different chromatograms for each sample. This validated protocol, or parts of it, could be applied in several oenological topic experimental designs, including wine quality and wine authenticity.

Phenolic Analysis and Theoretic Design for Chinese Commercial Wines' Authentication.

The phenolic data of 121 Chinese commercial dry red wines was processed with different statistical tools for varietal, regional, and vintage differentiation. A promising theoretical design was summarized, which might be helpful for wine authentication in practical situation.

Classification of Chinese wine varieties using 1H NMR spectroscopy combined with multivariate statistical analysis

In this study, the feasibility of discriminating grape varieties of Chinese red and white wines was investigated using 1H NMR spectroscopy in combination with a multivariate statistical procedure consisting of two steps: principal component analysis (PCA) plus linear discriminant analysis (LDA). Three grape varieties of red wines (Cabernet Sauvignon, Rose Honey, Cabernet Gernischt) and white wines (Ugni Blanc, Long Yan, Chardonnay) were examined, respectively. A segment-wise peak alignment was employed to handle peak misalignments of recorded 1H NMR spectra. Binning of the aligned 1H NMR spectra was performed for data reduction. The resulting bins were employed as input variables for the subsequent PCA and LDA analyses. The combination of PCA and LDA yielded in a sufficient discrimination of the examined grape varieties. The validity of the PCA/LDA model was confirmed by internal leave-one-out cross validation (LOOCV) as well as by external repeated double random cross validation (RDRCV). LOOCV and RDRCV led to average correct classification rates of 82% and 83% for red wine varieties, respectively, and 94% and 90% for white wine varieties, respectively. The results demonstrate that 1H NMR spectroscopy combined with multivariate analysis is an effective tool for verifying the authenticity of Chinese wines.

Evaluating Nanofiltration Effect on Wine 87Sr/86Sr Isotopic Ratio and the Robustness of this Geographical Fingerprint

When aiming to use the strontium isotopic ratio 87Sr/86Sr for the traceability and authentication of wine, it is crucial to understand the impacts of anthropogenic factors and technological processes on this parameter. A study was developed to evaluate the effect of nanofiltration (NF), a membrane process with several applications in oenology, on the isotopic ratio 87Sr/86Sr of wine, testing its robustness as geographical tracer. NF assays, for dealcoholisation, were carried out at laboratory scale with model solutions and white and red wines from Portuguese DO. High rejections to strontium (97%) and tartaric acid (> 70%) and low rejection to ethanol (< 10%) at 15 bar were observed in model solutions. Wines and NF-processed wines (17 bar; 2.1 L/min) were evaluated for physicochemical composition (including phenolic composition, chromatic characteristics and polysaccharides), multi-elemental composition and 87Sr/86Sr ratio by Q-ICPMS. The preferential membrane permeation of ethanol was associated with a slight increase in the quality parameters of the wine (anthocyanins and polysaccharides). High rejections to mineral elements, including heavy metals, were observed. Rejection to Sr was mostly higher than 95%. No significant differences in the 87Sr/86Sr of wines and corresponding permeate fractions were observed, suggesting that NF does not preclude the use of this parameter for wine traceability purposes.