The Influence of the Soil Profile on the Formation of the Elemental Image of Grapes and Wine of the Cabernet Sauvignon Variety.

The features for assessing the authenticity of wines by region of origin are studied, based on the relationship between the mineral composition of the wine, the grapes, and the soil profile (0 to 160 cm) from the place of growth of Cabernet Sauvignon grapes. Soil, grape, and wine samples were taken from the territories of six vineyards in the Anapa district of Krasnodar Territory, Russia. Using the methods of ICP-OES, thermal, and X-ray phase analysis, the soils were differentiated into three groups, differing in mineralogical and mineral compositions. The soil samples of the first group contained up to 31% quartz, the second group up to 25% quartz and 19% mixed calcite, and the third group up to 32% calcite and 15% quartz. The formation of the elemental image of the grapes was studied, taking into account the total content and mobile forms of metals in the soil. The territorial proximity of the vineyards did not affect the extraction of elements from the soil into the grape berry, and the migration of metals for each territory was selective. According to the values of the biological absorption coefficient, the degree of transition of metals from the soil to a berry was estimated. For K, Ti, Zn, Rb, Cu, and Fe in all berries, the coefficient was higher than 1.00, which means that the berry extracts contained not only mobile-form, but also difficult-to-dissolve metal compounds. The migration of macro-components from the soil to the berry was low, and amounted to 6-7% for Ca, 0.8-3.0% for Na, and 25-70% for Mg of the concentration of their mobile forms. For all territories, the maximum correlation between metal concentrations in grapes and soil was observed for samples from a depth of 0-40 cm. The discriminant model based on concentrations of Rb, Al, K, Sr, Co, Na, Pb, Ca, and Ni showed the formation of clusters in the territories of vineyard cultivation. The developed model allow the problems of identifying wines by region to be solved with high accuracy, using their elemental image.

Authentication of selected white wines by geographical origin using ICP spectrometric and chemometric analysis.

An important aspect of assessing the authenticity of wines is its geographical origin. The aim of the work is to authenticate by geographical origin according to the data of the ICP-spectrometric and chemometric analysis of elemental "images" of wines produced from white grape varieties Chardonnay, Riesling and Muscat grown in four regions of the Krasnodar Territory, Russia. The difference in the contents of Al, Ba, Ca and Rb in wines was found depending on the variety, and Al, Ba, Rb, Fe, Li, Sr - depending on the region of grape growth. Different models of the experimental data processing were used for attribution of the produced varieties of wine to the area of the grape's growth. The criterion for the quality of the constructed models was the accuracy of the attribution of a wine variety to the area of the grape's growth (%). Analysis of the elemental analysis data of 153 wine samples showed that in terms of attribution accuracy, automated neural networks (100 %) are preferred among machine learning methods, followed by support vector machines (98.69 %) and general discriminant analysis (94.77 %). The applied mathematical models enabled the revealing of the cluster structure of the analyzed wine varieties and their attribution to the area of a grape growth with high accuracy. Sr, Li and Fe concentrations in wines were found as the dominating predictors in the constructed models for definition of the geographical origin of wines. The combination of ICP-spectrometric analysis data with the capabilities of statistical modeling of machine learning methods focused on large-dimensional data made it possible to successfully solve small-dimensional problems of the definition of the geographical origin of wines by their elemental composition and variety.

Can Rare Earth Elements Be Considered as Markers of the Varietal and Geographical Origin of Wines?

The possibility of establishing the varietal and territorial affiliation of wines by the content of rare earth elements (REE) in them was studied. ICP-OES and ICP-MS with subsequent chemometric processing of the results were applied to determine the elemental image of soils containing negligible REE amounts, grapes grown on these soils, and wine materials of Cabernet Sauvignon, Merlot, and Moldova varieties produced from these grapes. To stabilize and clarify wine materials, the traditional processing of wine materials with various types of bentonite clays (BT) was used, which turned out to be a source of REE in the wine material. Discriminant analysis revealed that the processed wine materials were homogeneous within one denomination and that those of different denominations were heterogeneous with respect to the content of REE. It was found that REE in wine materials were transferred from BT during the processing, and thus they can poorly characterize the geographical origin and varietal affiliation of wines. Analysis of these wine materials according to the intrinsic concentrations of macro- and microelements showed that they formed clusters according to their varietal affiliation. In terms of their influence on the varietal image of wine materials, REE are significantly inferior to macro- and microelements, but they enhance their influence to a certain extent when used together.

Multidimensional analysis of the interaction of volatile compounds and amino acids in the formation of sensory properties of natural wine.

The content of free amino acids and aroma compounds present in wine and dependent on the grape variety, conditions of its growing and technology of production form its consumer properties. In this paper, the structure of interactions of amino acids and volatile organic compounds in 150 samples of natural dry red and white wines produced in the Krasnodar region, Russia, (2010-2013) was studied. The aim of this work was to comparatively evaluate the contribution of volatile compounds and amino acids to the sensory properties of wines by using regression, canonical, covariance, factor analyses, as well as principal component analysis. The list of volatile compounds, i.e., acetaldehyde, ethyl acetate, methanol, the total content of higher alcohols, acetic acid, and furfural, and such amino acids as arginine, proline, threonine was selected based on their influence on sensory properties of wines. The concentrations of volatile compounds and amino acids in wines were determined by gas chromatography and capillary electrophoresis, respectively. Sensory evaluation was conducted by experts with professional experience in wine tasting. Application of statistical methods allowed to establish intra- and inter-group correlations among amino acids and volatile compounds as well as between the groups of these compounds, which determined sensory properties of wines. More than 80% of the variability of the sensory assessment of wines is determined by the degree of relationship between the selected amino acids and volatile compounds; the contribution of amino acids to this indicator is 4.5-fold higher. The results obtained can be used to predict the sensory assessment of red and white wines based on the levels of volatile compounds and amino acids.

Data on the influence of clarification and stabilization with bentonite clays on the elemental composition of red wines determining their varietal affiliation.

The research data on the effect of bentonite clays (BT) in the process of clarification and stabilization on the elemental composition determining the varietal affiliation of wines are analyzed in the article. The initial objects were three untreated wine samples produced from Cabernet Sauvignon, Merlot and Moldova grape varieties in the Krasnodar Territory. Clarification and stabilization of untreated wine samples was carried out with 32 samples of BT of various degrees of dispersion and trademarks. The concentrations of metals, i.e., macro- and microelements, in bentonite clays, untreated and treated wine samples were determined by ICP-OES and ICP-MS methods. The results of the influence of stabilization and clarification of various wines with 32 BT on their elemental composition based on the concentrations of 16 micro- and macroelements isolated chemometrically from 39 elements are shown in the article. The elemental composition of the initial wine varieties as well as wine samples obtained after their clarification and stabilization (32 samples per each variety) was established based on the results of three parallel measurements. The aim of the study was to assess the contribution of macro- and microelements to the formation of the elemental image of wines determining their varietal affiliation. Using discriminant analysis and principal component analysis, the presence of cluster structures in treated and untreated wine samples was established in accordance with their varieties with respect to the concentrations of isolated macro- and microelements. The role of microelements was shown to be higher than that of macroelements in the formation of varietal image of wines. The combination of the most informative macro- and microelements in determining the cluster structure of wine samples increases the possibilities of assessing the intravarietal similarity and intervarietal differences of wines.

Data on the sensory evaluation of the dry red and white wines quality obtained by traditional technologies from European and hybrid grape varieties in the Krasnodar Territory, Russia.

The analysis of data on the sensory evaluation of the quality of wines obtained using traditional technologies in the Krasnodar Territory, Russia, was carried out using the statistical ranking criteria - the Spearman and Kendall correlation coefficients, as well as the positional analysis - Cronbach's alpha. Data on the sensory evaluation of 60 samples of natural dry red and white wines are presented, among which 20 are white wines, 40 are red wines produced in 2010-2015. Eleven specialists aged between 32 and 66 years (the average age was 50 years; 4 females and 7 males) participated in the sensory evaluation procedure. All participants are considered experts in the field of wine, work in the wine industry and have professional experience in the field of sensory analysis. The results of the consistency study of expert evaluations, the reliability of the general score scale, as well as the analysis of the loyalty of experts in the wine quality assessment are presented in the article. The reliability of the proposed loyalty scale is shown, i.e., the scale of the sum of scores given by each expert in the evaluation of the quality of wines. The database on the sensory evaluation of the quality of wines, obtained for all wine samples using positional analysis, makes it possible to assess the contribution of each of the 60 wine samples to their ranking by mean scores. The data may be of interest to scientists and oenologists for the wine quality assessment.