Tannat Grapes Research Articles

Climatological variables and their influence on the quality of Vitis vinifera grapes in Dom Pedrito, region of Campanha, Brazil

The climatic aspects influence the physicochemical characteristics of the grapes, interfering in the quality of the grapes, mainly in the period of cluster maturation. The objective of this study was to analyze the influence of climatic conditions and climatological variables, correlating with the physicochemical quality of viniferas Chardonnay and Tannat, from the 2019, 2020, 2021 and 2022 harvests, to evaluate a possible interference in the composition of these grapes, and consequently, in the wines to be produced, in the municipality of Dom Pedrito, Region of the Campanha. The Chardonnay and Tannat grapes were harvested at the stage of full maturation, and then physicochemical analysis were carried out to assess the quality of the must: SS (°Babo, °Brix), pH, Total acidity, Sugar and Probable alcohol. Climate data were collected 90 days before the date of harvest, for each cultivar, these being maximum, average and minimum temperatures and precipitation for each day. All DeltaT correlated positively with °Babo, °Brix and sugar for Chardonnay. As a negative correlation, P30 and minimum temperatures influenced the sugar contents. Delta6030 was negatively correlated with total acidity. For Tannat, all the variables linked to the sugar content in the grapes were positively correlated with the pH and the Tmed30. P9060 correlated positively with all sugar-related variables. Tmin9060 was negatively correlated with sugar content. Total acidity correlated positively with Tmax6030 and Tmax9060. The weather conditions when related to the cultivation of viniferas grapes directly influence the quality of the grapes.

Antioxidant Capacity and NF-kB-Mediated Anti-Inflammatory Activity of Six Red Uruguayan Grape Pomaces.

Grape pomaces have a wide and diverse antioxidant phenolics composition. Six Uruguayan red grape pomaces were evaluated in their phenolics composition, antioxidant capacity, and anti-inflammatory properties. Not only radical scavenging methods as DPPH· and ABTS·+ were employed but also ORAC and FRAP analyses were applied to assess the antioxidant potency of the extracts. The antioxidant reactivity of all extracts against hydroxyl radicals was assessed with ESR. The phenol profile of the most bioactive extract was analyzed by HPLC-MS, and a set of 57 structures were determined. To investigate the potential anti-inflammatory activity of the extracts, Nuclear Factor kappa-B (NF-κB) modulation was evaluated in the human colon cancer reporter cell line (HT-29-NF-κB-hrGFP). Our results suggest that Tannat grapes pomaces have higher phenolic content and antioxidant capacity compared to Cabernet Franc. These extracts inhibited TNF-alpha mediated NF-κB activation and IL-8 production when added to reporter cells. A molecular docking study was carried out to rationalize the experimental results allowing us to propose the proactive interaction between the NF-κB, the grape extracts phenols, and their putative anti-inflammatory bioactivity. The present findings show that red grape pomace constitutes a sustainable source of phenolic compounds, which may be valuable for pharmaceutical, cosmetic, and food industry applications.

Genome sequencing and oenologically relevant traits of the Uruguayan native yeast <i>Issatchenkia terricola</i>

Issatchenkia terricola 0621 is a non-Saccharomyces yeast strain isolated from Tannat grapes from Uruguayan vineyards; it stands out for its ability to produce high levels of β-glucosidase activity, which contributes to the aromatic complexity of wines. To delve into the potential oenological applications of this strain, its high-quality genome was obtained and explored, allowing the main central carbon and nitrogen metabolic pathways to be reconstructed. I. terricola is able to utilise glycerol as the sole carbon source in a way that has not previously been described for yeasts. The genes of the fermentome and those involved in stress resistance during winemaking were also identified, and differences were found when compared to S. cerevisiae, which may explain why I. terricola is unable to complete fermentation. The pathways responsible for natural aroma synthesis were also reconstructed, and the production of aromatic acids, alcohols, esters, acetates and lactones was verified experimentally. Finally, sequences encoding for β-glucosidases, in addition to the previously characterised one, were identified in the genome. The work presented here lays the groundwork for experimental research focused on the dissection of the metabolism of a native non-Saccharomyces strain and its application for oenological and biotechnological purposes.

Application of near-infrared spectroscopy/artificial neural network to quantify glycosylated norisoprenoids in Tannat grapes

Grape variety, vinification, and ageing are factors conditioning the aroma of a wine, with volatile secondary metabolites responsible for the so-called grape varietal character. Particularly, grape glycosylated norisoprenoids are mostly responsible for the sensory profile of Tannat wines, making relevant the use of fast instrumental tools to evaluate their concentration, allow classifying grapes and defining the optimum maturity for harvest. NIR spectroscopy is a fast, non-destructive technique, which requires minimal sample preparation. However, its quantitative applications need chemometric models for interpretation. In this work, a NIR-ANN calibration was developed to quantify norisoprenoids in Vitis vinifera cv. Tannat grapes during maturation and harvesting. Glycosidated norisoprenoids were determined by GC–MS. The ANN adjustments showed better performance than linear models such as PLS, while the best calibration was obtained by homogenising grape samples when comparing to grape juice; making possible to fit a model with an error of 146 μg/kg.

Caracterização físico-química de silagens de bagaço de uvas tintas e brancas

The use of grape marc, a co-product of the viticulture industry, presents itself as an alternative to reduce costs with ruminant feed, also helping the environment, besides giving a destination to this material that is discarded by the industry, still helps reduction of methane production by ruminants. The objective of this work was to present physico-chemical results of grape marc silage, with different varieties of red and white grapes. The silage was distributed in two treatments (white and red grapes) with three grape varieties, containing three replicates, totaling 18 silos. The silage process was carried out in pvc microsilows, in a completely randomized subdivision. The bromatological composition of the white and red grape silages was evaluated separately. In the varieties of white grapes studied, the Chardonnay grape presented higher levels of DM (23.23%), OM (92.10%), CP (12.60%), ADF (43.47%) and EE (7,2 %) in relation to the Gewurztramine and Sauvignon Blanc varieties. There were no differences (P <0.05) in the CP, but the pH values ​​were higher (4.10) in the Cabernet Sauvignon variety. The Merlot and Tannat grapes had similar contents (P <0.05) for DM, OM, MM and pH. The white grape marc silages and paints of this study present low DM values ​​resulting in nutritional losses, with medium BP levels when compared to other studies. Although pH values are adequate for good fermentation of the ensiled material, the lignin and fat contents are very high, making this ensiled material with low nutritional value for use in ruminant feed, where further studies should be performed with this co-product.

Impact on Tannat wines aroma produced by different yeast using three vinification systems

Vinifications were conducted using pure cultures of Saccharomyces cerevisiae, and mixed cultures by sequential inoculation of a Hanseniaspora vineae (T02/05F) and Hanseniaspora clermontiae (A10/82F), with a Saccharomyces cerevisiae conventional strain. The vinification systems applied to Tannat grapes were defined: semipilot, pilot and industrial scale. Fifty-one volatile compounds were identified in all the vinifications, sixteen of them were above the aroma threshold values and potentially contributed to the final sensory profiles. A sensory characterization of aroma was carried out using the projective mapping technique, with forty-eight consumers who made evaluation of the three vinifications. Multiple factorial analysis was used to compare the chemical and sensory data to find correlations. The results obtained from both methodologies were coincident, confirming the aromatic tendencies found in the different vinifications. Both studies demonstrated that wines obtained by semipilot scale was characterized by descriptors associated with “chemical” and “floral”; those from pilot vinification by the “spicy” descriptor; while industrial vinification produced wines described as “fruit” and “wood”.

Effects of Non-Saccharomyces Yeasts on Color, Anthocyanin, and Anthocyanin-Derived Pigments of Tannat Grapes during Fermentation

Phenolic compounds can affect the sensory characteristics of quality wines, yet the chemical modifications induced by yeasts on phenolic compounds have been studied only to a limited extent. Forty-nine non-<i>Saccharomyces</i> yeast strains belonging to different genera were screened for their effects on color and fermentation capability in a synthetic must supplemented with anthocyanins from Tannat grapes. Total anthocyanins, color intensity, hue, and total polyphenol index were significantly affected (<i>p</i> &lt; 0.001) by the different yeasts studied, and the effects on these parameters were highly diverse in the yeasts’ capacity for improving color indexes of the red grape model wines. Six strains belonging to the species <i>Metschnikowia pulcherrima</i>, <i>Hanseniaspora guilliermondii</i>, <i>H. opuntiae</i>, <i>H. vineae</i>, and <i>H. clermontiae</i> were selected to evaluate the production of anthocyanin-derived pigments; significant variations in the production of four compounds were found between them and compared with <i>Saccharomyces cerevisiae</i>. The formation of vitisin A, vitisin B, malvidin-3-glucoside-4-vinylphenol, and malvidin-3-glucoside-4-vinylguaiacol are reported for the first time for species of genera <i>Hanseniaspora</i> and <i>Metschnikowia</i>.

Innovation and entrepreneurial orientation: the case of a global family wine firm

While academic research emphasises the importance of innovation for many firms' long-term sustainability, some authors indicate that the literature primarily focuses on large companies, overlooking small and medium-sized enterprises (SMEs). This study contributes to narrowing the knowledge gap on innovation in this domain, examining the case of Uruguay's Carrau Wines, a global family business. Data were collected since 2011 through interviews and email communication with the firm's owners, and the director of Wines of Uruguay. Content analysis identified that, fundamentally owners' leadership in diversifying and in investing on equipment and technology are driving innovation processes. These findings align with key variables and dimensions of the theory of innovation, particularly benefit-cost and resources. Entrepreneurial orientation emerged through the firm's strong focus on the Tannat grapes, as well as on product quality improvements, and on internationalisation efforts. The findings have important implications for family businesses, particularly those operating in emerging economies.

Non-Saccharomyces and Saccharomyces strains co-fermentation increases acetaldehyde accumulation: effect on anthocyanin-derived pigments in Tannat red wines.

During fermentation, Saccharomyces cerevisiae releases into the medium secondary metabolic products, such as acetaldehyde, able to react with anthocyanins, producing more stable derived pigments. However, very limited reports are found about non-Saccharomyces effects on grape fermentation. In this study, six non-Saccharomyces yeast strains, belonging to the genera Metschnikowia and Hanseniaspora, were screened for their effect on red wine colour and wine-making capacity under pure culture conditions and mixed with Saccharomyces. An artificial red grape must was prepared, containing a phenolic extract of Tannat grapes that allows monitoring changes of key phenol parameters during fermentation, but without skin solids in the medium. When fermented in pure cultures, S. cerevisiae produced higher concentrations of acetaldehyde and vitisin B (acetaldehyde reaction-dependent) compared to M. pulcherrima M00/09G, Hanseniaspora guillermondii T06/09G, H. opuntiae T06/01G, H. vineae T02/05F and H. clermontiae (A10/82Fand C10/54F). However, co-fermentation of H. vineae and H. clermontiae with S. cerevisiae resulted in a significantly higher concentration of acetaldehyde compared with the pure S. cerevisiae control. HPLC-DAD-MS analysis confirmed an increased formation of vitisin B in co-fermentation treatments when compared to pure Saccharomyces fermentation, suggesting the key role of acetaldehyde. Copyright © 2016 John Wiley & Sons, Ltd.

Occurrence and biodiversity of Aspergillus section Nigri on ‘Tannat’ grapes in Uruguay

Ochratoxin A (OTA) is a nephrotoxic mycotoxin which has been found worldwide as a contaminant in wines. It is produced on grapes mainly by molds from Aspergillus section Nigri. This study has demonstrated for the first time the occurrence of black aspergilli on Tannat grapes from Uruguay, in a two year survey. Aspergillus uvarum (uniseriate) and Aspergillus welwitschiae (from Aspergillusniger aggregate) were the prevalent species whereas Aspergillus carbonarius which is considered the main OTA producing species was not detected. OTA production in culture medium was evaluated for native isolates from A. niger aggregate and compared to levels produced by a type strain of A. carbonarius. This work also includes the development of quick and easy molecular methods to identify black aspergilli to species level, avoiding sequencing.

Regulation of vascular endothelial function by red wine procyanidins: implications for cardiovascular health

The effects of oligomeric procyanidins (OPC) on vascular endothelial function provide a plausible explanation for the reduced incidence of coronary heart disease in red wine drinkers. Grape variety is an important influence on the amounts of OPC in wines. Red wines made from Aglianico, Sagrantino or Tannat grapes typically have higher OPC levels. The endothelial response to OPC induces atheroprotective changes in vascular function, which are likely mediated via oxidant signalling mechanisms originating from the mitochondrial electron transport chain.

Role of Canopy Management in Controlling High pH in Tannat Grapes and Wines

Elevated wine pH is one of the main problems affecting the quality of <i>Vitis vinifera</i> L. Tannat wines in Uruguay. High soil fertility, promoting vigorous vines, and high potassium availability result in high pH grapes and wine. The main objective of this work was to determine the effects of partial leaf and lateral shoot removal practices on the reduction of juice and wine pH over three growing seasons. Partial defoliation in shaded canopies significantly reduced grape potassium accumulation, malic to tartaric acid ratio, and wine pH without negatively affecting other quality parameters of soluble solids, organic acids, anthocyanins, and phenolics.

Characterization of Glycosylated Aroma Compounds in Tannat Grapes and Feasibility of the Near Infrared Spectroscopy Application for Their Prediction

The objective measure of grape quality is an important requirement to enhance wine quality. Particularly, the quantitation of glycosylated aroma compounds could be a useful index for winemakers. In the present work, we evaluated the bound compounds profile on Tannat grapes, and the potential of near infrared (NIR) spectroscopy coupled to chemometric techniques to determine the concentration of the different glycosylated aroma compounds present in this grape variety. The results showed phenols and norisoprenoids as the quantitative most important group of compounds, representing almost 80 % of the total glycosidic components present in Tannat grapes. The glycosidic form of ethyl-β-(4-hydroxy-3-methoxy-phenyl)-propionate was identified for the first time in grapes. The results suggested NIR technique as a screening tool for a fast analysis of the grape aroma potential. The application of such methodology would be ideal for fast grape screening purposes, contributing to the winemaking decisions, classification of the fruit, and perhaps maturity monitoring.

Characterisation and evolution of grape polyphenol profiles of Vitis vinifera L. cv. Tannat during ripening and vinification

Background and Aims: Changes in different polyphenol families during grape ripening and vinification were determined in Tannat grapes. This was done to establish a polyphenol profile for Tannat grapes during ripening and for young wines. Methods and Results: We demonstrated, by high-performance liquid chromatography with diode array detection and mass spectrometry (HPLC-DAD-MS) analysis, that the content of flavan-3-ols in Tannat seeds was higher than that reported for a large number of other grape varieties analysed. Forty per cent of the total flavan-3-ols in seeds were galloylated compounds, whereas the flavan-3-ol profile in skins was characterised by the absence of galloylated forms. Prodelphinidins in skins ranged between 30 and 35% with very low values for epigallocatechin. Epicatechin gallate was not detected in Tannat wine and galloylated forms represented a low percentage of total flavan-3-ols. Tannat grapes had very high concentrations of anthocyanins in skins with levels increasing during ripening. Eleven phenolic acids were identified in Tannat grape skins and wines, but only gallic and protocatechuic acids were found in the seeds. Conclusions: Tannat wines were shown to have one of the highest levels of phenolic compounds reported for vinifera grape varieties. The profiles for different polyphenol families present in Tannat grapes (skins and seeds) and wines were determined. Significance of the Study: The results presented will help to better understand the phenolic winemaking potential of this variety and its functional properties within food chemistry.

Estudio plurianual del potencial polifenólico de uvas Tannat en el sur de Uruguay

Este estudio fue realizado con el objetivo de caracterizar el potencial polifenólico de las uvas de la variedad Tannat y evaluar la utilidad de estos índices como indicadores de madurez, de calidad enológica, y como valores de referencia para optimizar la gestión de las vinificaciones. Los ensayos fueron realizados durante 4 años (2001 a 2004) en viñedos de la variedad Tannat situados en el sur de Uruguay. Los análisis se hicieron desde el envero hasta la cosecha de las uvas. Se determinaron el peso de la uva y su composición básica (azúcar, acidez total y pH), así como su potencial polifenólico por el método de Glories y Augustin (1993), con modificaciones según González-Neves (2005). Los potenciales en antocianos totales y extraíbles aumentaron durante la maduración, pero las concentraciones máximas de estos compuestos se obtuvieron unos días antes del máximo de azúcares en la mayor parte de las parcelas. La extractibilidad de los antocianos tuvo una evolución diversa, según los viñedos y las cosechas, con una tendencia decreciente durante la mayor parte del período evaluado. Los contenidos de taninos de semillas disminuyeron, pero en los hollejos aumentaron durante la maduración. En la cosecha se verificaron importantes diferencias en los contenidos de polifenoles en los hollejos y semillas entre las uvas de los distintos viñedos y años considerados. Los índices polifenólicos determinados no permiten definir un momento óptimo de cosecha, pero proporcionan datos relevantes para la valoración enológica de la uva y para la gestión de las vinificaciones.

Aging Effect on the Pigment Composition and Color ofVitis viniferaL. Cv. Tannat Wines. Contribution of the Main Pigment Families to Wine Color

Red wines made from Vitis vinifera L. cv. Tannat grapes are known to possess high contents of tannins and intense color, features that are responsible for the originality of these wines. This work aimed to study the evolution of the pigment composition and CIELAB color parameters as Tannat wines become older, as well as to establish the contribution to wine color of the main pigment families. Tannat wines produced in Uruguay from grapes of the same vineyard in six consecutive vintages (1998-2003) and Tannat grapes of the 2003 harvest were analyzed by means of HPLC-DAD-MS and UV-vis spectrometric techniques. The correlations between the different pigment families and the CIELAB parameters revealed the importance of the variations of the percentage, found in anthocyanins and flavanol-anthocyanin acetaldehyde-mediated condensation products (decrease) and pyranoanthocyanins and direct condensation products (increase), in the modification of the color from purple-red hues to more orange-red ones. The color suffered qualitative rather than quantitative changes, that is, the hue (h*ab) increased, whereas the chroma (C*ab) and lightness (L) did not show a defined trend with time.

Avaliação da cv. Tannat para elaboração de vinho tinto

A uva Tannat, originária do Sudoeste da França, foi introduzida no Rio Grande do Sul, pela Estação Experimental de Caxias do Sul. É uma cultivar difundida na Serra Gaúcha para elaboração de vinho tinto, utilizado para corte e para a produção de vinho varietal. O objetivo do presente trabalho foi avaliar o potencial enológico da cv. Tannat para a elaboração de vinho tinto fino nessa região vitícola. Para isso, realizaram-se estudos para caracterizar o cacho, o mosto e o vinho nas safras de 1987 a 1994, a partir de um vinhedo localizado em Bento Gonçalves, RS. Os resultados evidenciaram que a cv. Tannat tem cacho com peso médio de 216,1g e baga esférica pequena (1,54g). O mosto apresenta teor elevado de acidez titulável (155meq/L-1). O vinho se caracteriza por teores elevados em: polifenóis totais (I 280= 43,0), taninos (1,9g/L), antocianinas (539mg/L), potássio (1.856mg/L-1) e soma dos álcoois superiores (512mg/L-1). As características sensoriais do vinho Tannat na Serra Gaúcha evidenciam uma cor vermelha-violácea intensa, tânicos, nervosos, relativamente duros e aromas de frutas vermelhas. É recomendável para corte com outros vinhos tintos finos para intensificar sua cor e estrutura e também para a produção de vinho varietal podendo melhorar com o amadurecimento em barricas de carvalho.

Anthocyanic composition of Tannat grapes from the south region of Uruguay

The anthocyanic composition of Tannat grapes produced in different vineyards in the south region of Uruguay was studied. Two training systems (vertical trellis and lyre) and two pruning methods (Guyot and Royat cordon) in the lyre were considered. A follow-up was carried out, considering 60 plants per treatment, and the vintage was determined according to the traditional indices of maturity. At the moment of the harvest, samples of grapes were taken in duplicate in each treatment and the soluble solids, total acidity, pH, phenolic richness, total potential in anthocyanins and extractable anthocyanin contents were determined. Grapes were frozen and later analysed; skin extractions over 24 h with a solution of 12% ethanol and pH 3.2 were carried out. The anthocyanic contents of the extracts obtained were determined by liquid chromatography. The total potential in anthocyanins of the grapes from the lyre with cordon pruning was significantly higher than the others, whereas the grapes from the cane pruning presented the highest extractable anthocyanins contents. The phenolic richness of the grapes from the lyre (with both pruning systems) was significantly higher than in the vertical trellis. Significant differences in the contents of the anthocyanins and in the anthocyanic profiles of the grapes of each treatment were found. Grapes from the vertical trellis system presented significantly higher proportions of malvidin, coumarylic and acetyl anthocyanins. Grapes from the lyre with cordon pruning presented significantly higher proportions of delphinidin, cyanidin, petunidin and peonidin, and non-acylated glucosides. It can be concluded that the yields and the environmental conditions given by the different vineyards determined important differences in the phenolic composition of Tannat grapes. The anthocyanic profiles of the grapes presented significant differences that might determine important variations in the colour and composition of the respective wines.

Phenolic potential of Tannat, Cabernet-Sauvignon and Merlot grapes and their correspondence with wine composition

The phenolic potential of Tannat, Cabernet-Sauvignon and Merlot grapes was evaluated in 2001 and 2002 and its correspondence with the colour and composition of the respective wines was established. Three vineyards of each variety, situated in the south of Uruguay were considered. Two samples of each vineyard were taken at the moment of the harvest. Phenolic richness, extractable anthocyanins contents and total potential in anthocyanins of the grapes were estimated. Two fermentations on skins were carried out for each vineyard using 50 kg of grape in each one. The anthocyanic and total polyphenols contents of the musts were analysed every 24 h, and skins extractions were carried out in parallel in the laboratory. The duration of the maceration for each variety was decided in function of the analytical results in the grapes, musts and skins extractions. Wines were analysed 2 months after the alcoholic fermentation, determining its phenolic composition and colour. Tannat grapes presented anthocyanic and total polyphenols contents significantly higher in both years. Therefore, wines from this variety presented colour intensity and phenolic contents statistically higher than Cabernet-Sauvignon and Merlot. The correlations between the phenolic contents of the grapes, skins, musts and wines were very significant. Colour intensity and phenolic contents of the wines were highly correlated with the total polyphenols of the grapes and with anthocyanins of the grapes, skins, musts and wines. The estimate of the phenolic potential of the grapes and the extractability of the pigments allows to manage more adequately the fermentation on skins and is an interesting tool to predict the colour and the composition of the wines.

Anthocyanic composition of Tannat grapes from the south region of Uruguay

The anthocyanic composition of Tannat grapes produced in different vineyards in the south region of Uruguay was studied. Two training systems (vertical trellis and lyre) and two pruning methods (Guyot and Royat cordon) in the lyre were considered. A follow-up was carried out, considering 60 plants per treatment, and the vintage was determined according to the traditional indices of maturity. At the moment of the harvest, samples of grapes were taken in duplicate in each treatment and the soluble solids, total acidity, pH, phenolic richness, total potential in anthocyanins and extractable anthocyanin contents were determined. Grapes were frozen and later analysed; skin extractions over 24 h with a solution of 12% ethanol and pH 3.2 were carried out. The anthocyanic contents of the extracts obtained were determined by liquid chromatography. The total potential in anthocyanins of the grapes from the lyre with cordon pruning was significantly higher than the others, whereas the grapes from the cane pruning presented the highest extractable anthocyanins contents. The phenolic richness of the grapes from the lyre (with both pruning systems) was significantly higher than in the vertical trellis. Significant differences in the contents of the anthocyanins and in the anthocyanic profiles of the grapes of each treatment were found. Grapes from the vertical trellis system presented significantly higher proportions of malvidin, coumarylic and acetyl anthocyanins. Grapes from the lyre with cordon pruning presented significantly higher proportions of delphinidin, cyanidin, petunidin and peonidin, and non-acylated glucosides. It can be concluded that the yields and the environmental conditions given by the different vineyards determined important differences in the phenolic composition of Tannat grapes. The anthocyanic profiles of the grapes presented significant differences that might determine important variations in the colour and composition of the respective wines.