Pattern recognition analysis applied to classification of Galician (NW Spain) wines with Certified Brand of Origin Ribeira Sacra

In 39 red wines from Galicia (NW Spain), some trace elements were determined by atomic spectroscopy. Data were processed using multivariate chemometric techniques involving principal component analysis, discriminant analysis and K nearest neighbours to develop a typification for wine samples of Ribeira Sacra origin. The wines with Certified Brand of Origin (CBO) Ribeira Sacra can be differentiated from the wines of two other CBOs from Galicia: Ribeiro and Valdeorras. The latter CBOs make wines with the same grape variety; hence they are possible substitutes for falsification of Ribeira Sacra wines owing to their similar organoleptic properties. By means of multivariate techniques of data exploration, two main groups of samples (Ribeira Sacra and non-Ribeira Sacra wines) were observed. Exploratory analysis results were confirmed using supervised procedures of data classification. Using lithium and iron content as key features, a satisfactory classification was achieved. © 1999 Society of Chemical Industry     

Volatile profile and differentiation between Albariño wines from different origins

Commercial Albariño wines from different subzones of Certified Brand of Origin ‘Rías Baixas’ (NW Spain) were analysed over four consecutive harvests. The contents of monoterpenes, volatile phenols, alcohols, sulphur compounds, acetates, fatty acids and ethyl esters were determined by gas chromatography (flame ionisation detector and flame photometric detector) and gas chromatography–mass spectrometry. These white wines presented high concentrations of free monoterpenes, volatile phenols, acetates, and ethyl esters, while the levels of sulphur compounds, known as default compounds, were very low. All the wines were elaborated from Albariño grapes, but they were produced by different enological practices, such as skin contact and by carrying out malolactic fermentation or not. No significant differences were found between wines from the same subzone and from different vintages. The results obtained, and confirmed by Principal component and linear discriminant analysis, showed a differentiation among these wines as a function of the Galician subzone of origin.     

Biogenic Amine Content in Red Wines from Different Protected Designations of Origin of Southern Italy: Chemometric Characterization and Classification

Biogenic amines are contaminants naturally present in wines. Their occurrence is influenced by several factors including oenological and agricultural practices, grape variety, and geographical origin. For these reasons, they have been chosen as marker to characterize and classify 56 Italian red wines belonging to four protected designations of origin (PDO) from Southern Italy. Principal component analysis and cluster analysis were applied on data obtained by HPLC/RF in order to highlight the natural grouping of samples. Afterward, linear discriminant analysis and partial least squares were used to classify the wines according to their PDO. Biogenic amines are demonstrated to be a reliable and useful marker for the characterization and classification of the four Southern Italian PDOs investigated. Both the linear discriminant analysis (LDA) and the partial least squares discriminant analysis (PLS-DA) achieved 100 % of wines correctly classified and predicted. Therefore, the determination of these compounds in red wines can play an important role in wine quality assessment, by providing information for the prevention of potential detrimental effects on health and for the characterization of PDO labeled wines.     

Polyphenolic composition of Spanish red wines made from Spanish Vitis vinifera L. red grape varieties in danger of extinction

Phenolic composition, chromatic characteristics, and antioxidant activity of young wines made from three minority red grape varieties (Moravia Dulce, Rojal and Tortosí) cultivated in the Spanish region of Castilla-La Mancha were studied over two vintages. Phenolic contents were affected by both grape variety and vintage, whereas phenolic profiles were mainly affected by grape cultivar, thus allowing their differentiation The anthocyanin profiles of Moravia Dulce and Tortosí wines were dominated by malvidin 3-glucoside, whereas peonidin 3-glucoside was in Rojal wines. The flavonol profile of Rojal and, in a lesser extent, Tortosí wines were dominated by B-ring di-substituted flavonols (mainly quercetin-type flavonols). In contrast, B-ring tri-substituted flavonols (mainly myricetin-type) predominated in Moravia Dulce wines. All studied wines had high quantities of total resveratrol, especially Rojal and Moravia Dulce wines, although they mainly occurred as cis-isomers. Rojal wines always appeared as the most different single-cultivar wines in all parameters in this study, being characterized by the lowest content of almost all families of phenolic compounds. With regard to the colour characteristics, all the studied wines had normal values to be considered young red wines except for Rojal wines, which should be considered as rosé wines. Finally, all wines showed remarkable antioxidant activity, closely connected with their phenolic content. The results suggest that Moravia Dulce and Tortosí grape cultivars could be appropriate raw materials for the elaboration of quality young red wines, whereas Rojal grapes could be for rosé wines.     

Lychee Variety Discrimination by Hyperspectral Imaging Coupled with Multivariate Classification

This current study was carried out to investigate the ability of hyperspectral imaging (HSI) technique and multivariate classification for the differentiation of lychee varieties. A total of 122 lychee samples from three varieties (“Baila,” “Jizhui,” and “Guiwei”) were used. The relationship between reflectance spectra and lychee varieties were established. Principal component analysis (PCA) was implemented on the region of interest (ROI) image to reduce data dimensionality and visualize the cluster trend. The first two principal components (PCs) explained over 97 % of variances of all spectral bands. Linear (soft independent modeling of class analogy (SIMCA) and partial least square discriminant analysis (PLS-DA)) and nonlinear (back propagation neural network (BPNN) and support vector machine (SVM)) multivariate classification methods were used to develop discrimination models. The results revealed that SVM model achieved the best result, with the identification rate of 100 % in the calibration set and 87.81 % in the prediction set. BPNN had a discrimination rate of 100 % for the training set and 85.37 % for prediction set, while PSL-DA and SIMCA model had a discrimination rate of 78.05 % and 60.98 % for prediction sets, respectively. The nonlinear classification methods used were superior to the linear ones. The overall results showed that HSI system with SVM classification tool could be used in identification of lychee varieties.     

Chemometric studies of bottled wines with denomination of origin from the Canary Islands (Spain)

Seventeen physicochemical parameters including conventional enological parameters, polyphenolic parameters and volatile compounds were determined in 153 wines from the main wine producers belonging to the Canarian zones with Denomination of Origin (DO). Numerous significant correlations were found between the physicochemical parameters analysed. Applying the principal component analysis, the wines tend to separate on the basis of the type of wine. Besides, the dimension space was reduced to six principal components that explain 76.1% of the total variance. The principal component analysis of the red wines separated them as a function of vintage. Linear discriminant analysis (LDA) applied to all the wines, allowed a reasonable differentiation according to vintage, type of wine and island of production.     

Comparative studies on the antioxidant properties and polyphenolic content of wine from different growing regions and vintages,a pilot study to investigate chemical markers for climate change

Many health benefits of wine result from specific polyphenolic compounds. Factors such as climate, CO₂ levels and region are known to affect polyphenolic compounds in wine; therefore a pilot study was conducted to focus on the Australian climate which has shifted from El Niño to La Niña. This research paper presents the influence of climate conditions and growing regions on the in vitro and ex vivo antioxidant capacity of red and white wine and the profile and concentration of polyphenols in these wines from the 2008 and 2009 vintages. The ORAC and polyphenolic data show that warmer climate wines had lower in vitro antioxidant capacity values but retained good bioavailability based on data from the RBC ex vivo assay compared to cool climate wines. Based on this pilot study, further research is being conducted at the National Measurement Institute, Australia (NMIA) with the goal of determining more polyphenolic compounds which appear to be affected by climate conditions.     

Nutraceutical value and toxicological profile of selected red wines from Morocco

The polyphenolic composition, antioxidant properties and multielement profile of selected red wines from Morocco were evaluated. The polyphenolic contents resulted higher than those reported elsewhere for the same variety of wines; the highest quantity was found in Cabernet Sauvignon, followed by Merlot, and last by Syrah wine. All of the wines tested showed very similar anthocyanin and flavonol patterns: individual compound contents resulted generally higher in comparison to conventional wines. The content of trans-resveratrol was significantly higher than that of cis-resveratrol in all of the wine samples. Particularly, Merlot showed the highest concentration of trans-resveratrol while Syrah exhibited the highest levels of cis-resveratrol. Reducing capacity resulted higher than antiradical property for all of the wines. The metal concentrations were below the official limits. The elemental pattern of wines were very similar, excepted V, Mn, Fe, Cu, As and Mo, for which Syrah markedly differed from the other wine samples.     

Ecology of Saccharomyces cerevisiae in Spontaneous Fermentations at a Rías Baixas Appelation Controlé Winery

PCR techniques and pulse field electrophoresis karyotyping showed wide genetic diversity in Saccharomyces cerevisiae strains isolated from spontaneous fermentations in progress at a wine cellar in the Rías Baixas appelation controlé region (Spain). The karyotyping method showed greater discriminating power than PCR profiling, making it better suited for the detection of genetic diversity in wine strains, and for the monitoring of selected strains in controlled fermentations.     

Influence of co-winemaking technique in sensory characteristics of new Spanish red wines

The influence of co-winemaking technique on the sensory profile of wines made from minority red grape varieties cultivated in La Mancha region (Spain) was researched by sensory characterization. Sensory analysis was carried out by a panel of 15 experienced wine-testers, all with a previous training. The sensory profiles of monovarietal red wines—Cencibel, Bobal and Moravia Agria—were studied and also the effects of co-winemaking technique on sensory characteristics were evaluated. Co-winemaking red wines were obtained by blending (a) Cencibel (50%) + Bobal (50%); (b) Cencibel (50%) + Moravía Agria (50%) and (c) the three grape varieties Cencibel (33%) + Bobal (33%) + Moravía Agria (33%). The co-winemaking technique intensified the principal sensory properties of monovarietal wines and the wines proved to be more complex than the monovarietal wines.     

Study of the Volatile and Glycosidically Bound Compounds of Minority Vitis vinifera Red Cultivars from NW Spain

Aroma composition was analyzed in grape musts from five Vitis vinifera red cultivars (Pedral, Sousón, Caíño Redondo, Espadeiro and Mencía) grown in Galicia (NW Spain) with the aim to know the potential profile of these varieties. All cultivars were collected from Coto Redondo Winery vineyard (A.O.C. Rías Baixas) and grown under the same conditions. All cultivars (with a total of 96 aroma compounds, 35 free volatile and 61 glycosidically bound compounds) were identified and quantified by GC‐MS. The results showed that Caíño Redondo and Pedral had the highest concentrations of volatile compounds. The free fraction showed the highest concentration for all cultivars studied with the exception of Pedral. High concentrations of free C₆‐compounds and free alcohols were found for all red cultivars studied, especially for Caíño Redondo. Sousón and Mencía presented similar characteristics in the free fraction. Pedral showed an important contribution of glycosidically bound compounds. This cultivar showed the highest concentration of bound alcohols, terpenoids, volatile phenols, and C₁₃‐norisoprenoids. With terpenoids, higher levels were found in the bound fraction than in the free fraction. Regarding C₁₃‐norisoprenoids, Pedral also showed an important contribution of these varietal compounds. The principal component analysis (PCA) showed a good separation of the different grape cultivars, so they could be discriminated based on their potential volatile composition. The oenological potential of ancient and minority grape varieties from NW Spain, with the aim to provide genetic diversity, is illustrated with this work.     

Can spectroscopy geographically classify Sauvignon Blanc wines from Australia and New Zealand?

The combination of UV, visible (Vis), near-infrared (NIR) and mid-infrared (MIR) spectroscopy with multivariate data analysis was explored as a tool to classify commercial Sauvignon Blanc (Vitis vinifera L., var. Sauvignon Blanc) wines from Australia and New Zealand. Wines (n = 64) were analysed in transmission using UV, Vis, NIR and MIR regions of the electromagnetic spectrum. Principal component analysis (PCA), soft independent modelling of class analogy (SIMCA) and partial least squares discriminant analysis (PLS-DA) were used to classify Sauvignon Blanc wines according to their geographical origin using full cross validation (leave-one-out) as a validation method. Overall PLS-DA models correctly classified 86% of the wines from New Zealand and 73%, 86% and 93% of the Australian wines using NIR, MIR and the concatenation of NIR and MIR, respectively. Misclassified Australian wines were those sourced from the Adelaide Hills of South Australia. These results demonstrate the potential of combining spectroscopy with chemometrics data analysis techniques as a rapid method to classify Sauvignon Blanc wines according to their geographical origin.     

Effect of the winemaking technique on phenolic composition and chromatic characteristics in young red wines

The effect of six winemaking techniques (traditional, prefermentative maceration, delestage, Ganimede fermentation system, enzymes and tannins addition, or oak chip addition during alcoholic fermentation) on phenolic composition and chromatic characteristics of young red wines, elaborated from Mencía grapes grown in Galicia (northwestern Spain), was studied. The evolution of phenolic compounds from grapes to bottling and its influence on CIELab parameters were investigated. After bottling, 26 phenolic compounds were determined by high-performance liquid chromatography (HPLC), and their influence on colour stability for ageing was evaluated. Principal component analysis allowed the differentiation of the winemaking techniques studied on the base of phenolic composition, which is correlated with polymerization grade of anthocyanins. This paper can contribute to improve the knowledge about the importance of selecting the winemaking technique to elaborate high-quality young red wines and to evaluate their ability for ageing. So, the addition of enzymes and tannins seems to be the most adequate winemaking technique to elaborate red wines for ageing as it results in the formation of major number of pigmented polymers that are stable over time. Nevertheless, the prefermentative maceration, Ganimede autowinemaker and the addition of oak chips can be used for the elaboration of young red wines.     

Amino acids and biogenic amines in red varietal wines: the role of grape variety, malolactic fermentation and vintage

This work studies for the first time the amino acid and biogenic amine composition of Rioja red wines made with the red minority varieties Vitis vinífera cv. Monastel and Maturana Tinta de Navarrete, using Tempranillo as a reference variety. The role of malolactic fermentation and vintage on these compounds was also analysed, and discriminate analyses were applied to achieve a possible differentiation of the wines. Amino acid composition allowed a differentiation of wines according to grape variety. Monastel was characterised by the highest value in β-alanine and Maturana Tinta de Navarrete by its highest value in OH-proline. However, biogenic amines were no able to classify varietal wines. The malolactic fermentation had significant changes on the amino acid and biogenic amine content, and allowed distinguishing wines that underwent this process from wines without malolactic fermentation. No correlation was found between total amino acids and total biogenic amines after malolactic fermentation, suggesting that a higher initial concentration of amino acids in the medium did no affect the concentration of biogenic amines after malolactic fermentation. Vintage influenced the amino acid and biogenic amine pattern, obtaining a clear separation of wines by vintages. Monastel and Maturana Tinta de Navarrete wines showed a minor varietal character and were more influenced by the climatic conditions of each vintage than Tempranillo wines. All the wines showed histamine levels below the human physiological threshold and implemented regulations.     

Polyphenols and colour variability of red wines made from grapes harvested at different ripeness grade

Several red wines were elaborated in order to study the influence of the grape harvesting date (degree of maturity of the grape) on their chromatic characteristics and polyphenolic contents. Wines made from two grape varieties, at three different harvesting dates and from two consecutive vintages, were selected for this study. The results showed that the harvesting date of grapes (directly correlated with the degree of maturity of the grapes), influenced the chromatic characteristics of the wines, although their polyphenolic compositions were clearly different, especially in Cabernet Sauvignon wines. In general, higher intensities of blue or violet tones were detected in wines made from the grapes collected on the second harvesting date, in which the ratios anthocyanins/proanthocyanidins and anthocyanins/(proanthocyanidins + catechins) were the lowest. These ratios are proposed as probable indicators of the aptitude for wine ageing.     

Free radical scavenging and antibacterial activities of southern Serbian red wines

Free radical scavenging and antibacterial activities were determined for several red wines from different grape varieties from the southern Serbia wine region. The amount of polyphenols and anthocyanins in selected wines was investigated and the potential antibacterial activity of the wines against pathogenic strains of Staphylococcus aureus and Escherichia coli was also determined. The free radical scavenging and antibacterial activity of the wines was correlated with polyphenolic and anthocyanin content. The significant differences in the antioxidant and antibacterial activities between the wines from grape cultivars (Cabernet Sauvingon and Pinot Noir) and the indigenous varieties (Vranac and Prokupac) were not confirmed. The hypothesis of a protective effect of red wine is supported by our results that show that the red wines with higher amounts of polyphenols and anthocyanins had higher antioxidant and antibacterial properties.     

Phenolic characterisation of red wines from different grape varieties cultivated in Mendoza province (Argentina)

BACKGROUND: Knowledge of the chemical composition of wine and its association with the grape variety/cultivar is of paramount importance in oenology and a necessary tool for marketing. Phenolic compounds are very important quality parameters of wines because of their impact on colour, taste and health properties. The aim of the present work was to study and describe the non‐flavonoid and flavonoid composition of wines from the principal red grape varieties cultivated in Mendoza (Argentina). RESULTS: Sixty phenolic compounds, including phenolic acids/derivatives, stilbenes, anthocyanins, flavanols, flavonols and dihydroflavonols, were identified and quantified using high‐performance liquid chromatography with diode array detection coupled with electrospray ionisation mass spectrometry (HPLC‐DAD/ESI‐MS). Marked quantitative differences could be seen in the phenolic profile among varieties, especially in stilbenes, acylated anthocyanins and other flavonoids. CONCLUSION: The polyphenolic content of Malbec wines was higher compared with the other red varieties. Dihydroflavonols represent a significant finding from the chemotaxonomic point of view, especially for Malbec variety. This is the first report on the individual phenolic composition of red wines from Mendoza (Argentina) and suggests that anthocyanins, flavanols and phenolic acids exert a great influence on cultivar‐based differentiation. Copyright © 2011 Society of Chemical Industry     

Color and phenolic compounds of a young red wine as discriminanting variables of its ageing status

The purpose of this work is to characterize young red wines regarding their ageing status using objective color and phenolic compounds measurements as variables. Discriminant analysis was used to obtain functions that made it possible to classify wines. Using the above-mentioned variables, five classification functions were obtained that correctly classified 100% of the wine samples. To validate the model and to check its discriminanting potential we applied it to wines stored at different temperatures. The five functions correctly classified 81.6% of the wines regarding their ageing status.