Pigment profile of red wines cv. Tannat made with alternative winemaking techniques

Applying Different Vinification Techniques in Teran Red Wine Production: Impact on Bioactive Compounds and Sensory Attributes

Six different vinification treatments, including a control treatment (7-day standard maceration) (K7), were performed to study the effects of non-standard techniques on bioactive compounds and sensory attributes of Teran red wine. Pre-fermentative mash cooling (8 °C; 48 h) and heating (50 °C; 48 h) followed by prolonged post-fermentative maceration of 13 days (C15;H15) or 28 days (C30;H30) were applied. In another treatment, after cooling, saignée was performed followed by 13-day prolonged maceration (CS15). Wine phenols and vitamins were analyzed by HPLC-DAD-FLD, minerals by ICP-OES, and sensory analysis was performed using the QDA and 100-point O.I.V./U.I.O.E. methods. Obtained results showed total phenolic concentration was the highest in the H30 treatment. The concentration of anthocyanins, flavan-3-ols and phenolic acids was significantly higher in wines of all vinification techniques compared to the control. Stilbene content was highly affected by pre-fermentative heating. Treatments CS15, H15, C30 and H30 resulted in the highest scores by both the QDA and 100-point sensory methods. The obtained results suggest that advanced non-standard vinification techniques have a significant impact on Teran wine by enhancing its composition of bioactive compounds and improving its sensory profile, which gives it an additional market value. Furthermore, a comprehensive comparison of such techniques applied simultaneously in one study is of substantial importance for additional research in wine production.

Wine Polyphenol Content and Its Influence on Wine Quality and Properties: A Review

Wine is one of the most consumed beverages around the world. It is composed of alcohols, sugars, acids, minerals, proteins and other compounds, such as organic acids and volatile and phenolic compounds (also called polyphenols). Polyphenols have been shown to be highly related to both (i) wine quality (color, flavor, and taste) and (ii) health-promoting properties (antioxidant and cardioprotective among others). Polyphenols can be grouped into two big families: (i) Flavonoids, including anthocyanidins, flavonols, flavanols, hydrolysable and condensed tannins, flavanones, flavones and chalcones; and (ii) Non-flavonoids, including hydroxycinnamic acids, hydroxybenzoic acids, stilbenes, tyrosol and hydroxytyrosol. Each group affects in some way the different properties of wine to a greater or a lesser extent. For that reason, the phenolic composition can be managed to obtain singular wines with specific, desirable characteristics. The current review presents a summary of the ways in which the phenolic composition of wine can be modulated, including (a) invariable factors such as variety, field management or climatic conditions; (b) pre-fermentative strategies such as maceration, thermovinification and pulsed electric field; (c) fermentative strategies such as the use of different yeasts and bacteria; and (d) post-fermentative strategies such as maceration, fining agents and aging. Finally, the different extraction methods and analytical techniques used for polyphenol detection and quantification have been also reviewed.

Chemical consequences of extended maceration and post-fermentation additions of grape pomace in Pinot noir and Zinfandel wines from the Central Coast of California (USA)

Pinot noir and Zinfandel wines were produced with traditional maceration (Control), and extended maceration for one (1 month-EM), and six months (6 months-EM). Addition of an extra amount of pomace during EM was also evaluated through a treatment referred to as Double pomace. The application of EM and Double pomace decreased the chromatic as well as the anthocyanin and anthocyanin-derived pigment composition of the wines. Large polymeric pigments were favored in EM and Double pomace wines, but the total polymeric pigment content was not improved by any of the winemaking treatments. The 6 months-EM wines showed a 13-fold (Pinot noir) and a 1.6-fold increase (Zinfandel) in tannins, respectively, relative to Control wines. However, the 1 month-EM and Double pomace treatments did not affect tannin levels, suggesting that in these wines, the extraction of tannins during EM may depend upon desorption of previously extracted tannins during extended contact time.

Impact of cold soak duration on Cabernet Sauvignon fermentation and phenolic composition

BACKGROUND

Cold soak is a prefermentative maceration technique believed to enhance grape skin extraction. Studies show variable results depending on cold soak and winemaking conditions. To investigate the effect of cold soak more fully, systematic and highly reproducible Cabernet Sauvignon fermentations with increasing cold-soak durations were performed.

RESULTS

Phenolic extraction during cold soak and fermentation showed significant differences among all treatments for monitored phenolics at the end of the cold soak. At the end of alcoholic fermentation only gallic acid, (-)-epicatechin, and the flavonols were significant, and only (-)-epicatechin was significant after bottle ageing. Descriptive analysis of the bottled wines showed that the 4- and 7-day treatments were significantly higher in caramelized/vanilla/browned flavor compared to the 1-day treatment and lower levels of bitterness were observed up to 2 days of cold soak. While oligosaccharide content increased with increasing cold-soak duration, differences were not large enough to result in sensory differences.

CONCLUSION

While increased cold soak duration led to differences in phenolic extraction during early fermentation, these differences did not last through to the end product. Thus, under the conditions of this study, cold-soak duration had little overall impact on Cabernet Sauvignon wine composition and style. © 2018 Society of Chemical Industry.

Composición de vinos tintos elaborados por procedimientos alternativos de vinificación

Los procedimientos empleados en la vinificación pueden atenuar el impacto de eventos climáticos extremos, que afectan la calidad de los vinos. El objetivo de este trabajo fue comparar una vinificación por maceración tradicional (MT) con una vinificación con extracción diferida de antocianos y maceración extendida (EDA+ME), en seis variedades de Vitis vinifera L. (Tannat, Cabernet Sauvignon, Merlot, Cabernet Franc, Syrah y Marselan). Los vinos fueron analizados a los 6 meses de la vinificación. Los vinos de Marselan y Cabernet Sauvignon tuvieron pH muy elevados. Los vinos con mayores contenidos fenólicos totales fueron Tannat y Marselan, que también tuvieron los mayores contenidos de antocianos y proantocianidinas. La mayor intensidad colorante se obtuvo en los vinos Marselan y la menor en Syrah. Los vinos producidos con las dos técnicas presentaron diferencias en tonalidad y % de amarillo (mayores en EDA+ME) y rojo (mayores en MT). Los vinos MT tuvieron mayores contenidos de antocianos y taninos más polimerizados. Los vinos EDA+ME tuvieron contenidos significativamente mayores de polifenoles totales, catequinas y mayor reactividad de los taninos. Un Análisis Discriminante Canónico confirmó que la variedad de uva fue el factor que incidió en mayor medida en las características de los vinos.

Geographical Classification of Tannat Wines Based on Support Vector Machines and Feature Selection

Geographical product recognition has become an issue for researchers and food industries. One way to obtain useful information about the fingerprint of wines is by examining that fingerprint’s chemical components. In this paper, we present a data mining and predictive analysis to classify Brazilian and Uruguayan Tannat wines from the South region using the support vector machine (SVM) classification algorithm with the radial basis kernel function and the F-score feature selection method. A total of 37 Tannat wines differing in geographical origin (9 Brazilian samples and 28 Uruguayan samples) were analyzed. We concluded that given the use of at least one anthocyanin (peon-3-glu) and the radical scavenging activity (DPPH), the Tannat wines can be classified with 94.64% accuracy and 0.90 Matthew’s correlation coefficient (MCC). Furthermore, the combination of SVM and feature selection proved useful for determining the main chemical parameters that discriminate with regard to the origin of Tannat wines and classifying them with a high degree of accuracy. Additionally, to our knowledge, this is the first study to classify the Tannat wine variety in the context of two countries in South America.

Effect of cold pre-fermentative maceration on the color and composition of young red wines cv. Tannat

Cold Pre-fermentative Maceration (CPM) is an interesting winemaking technique to enhance the extraction of pigments, aroma and flavour compounds from grape skins to wine. This work aimed to evaluate the effect of Cold Pre-fermentative Maceration (CPM) on the composition of Tannat red wines produced in Uruguay in several vintages. For this purpose, wines elaborated by CPM were compared with control wines produced by Traditional Maceration (TM) in 4 years. Control wines (TM) were made with classical fermentation on skins. The CPM was carried out with additions of dry ice for 5 days to keep the must at 10 ºC. Wines were analysed at devatting. The impact of CPM on composition and color of wines was different in each year. Color intensity was significantly higher in CPM than control wines in 2007 and 2009 whereas the anthocyanins levels were higher in control wines every year. However, CPM wines had the highest polyphenols contents in 2007, 2009 and 2010 principally due to their catechins and proanthocyanidins contents. Anthocyanin profile was similar in the wines of each vintage, according to the varietal fingerprint. The highest contents of higher alcohols were verified in CPM wines. The Cold Pre-fermentative Maceration could have an important effect on the characteristics of Tannat red wines, although it depends strongly on the composition of the grapes of origin.

Impact of adding white pomace to red grapes on the phenolic composition and color stability of Syrah wines from a warm climate

The influence of the fermentative addition of Pedro Ximenez grape pomace (PXGP, white variety) on the phenolic composition and color of Syrah red wines from a warm climate was studied. Changes on phenolic composition (HPLC), copigmentation/polymerization (spectrophotometry), and color (tristimulus colorimetry) allowed differences among the maceration treatments to be established. PXGP additions at the rates studied increased the extraction of total phenolics, phenolic acids, and monomeric flavanols. However, the effect on the anthocyanins, copigmentation, and polymerization depended on the doses applied, with important consequences on the color. PXGP addition at 10% led to wines with higher polymerization, more stable colors, and bluish hues. in contrast, perceptibly lighter and less intense wines were obtained with PXGP addition at 20%. Thus, the use of white grape byproducts as wine additives at appropriate levels (10% w/w) could improve the phenolic potential of red young wines from a warm climate, contributing to preserve their color characteristic.