Properties of Wine Polysaccharides

Polysaccharides are the main macromolecules of colloidal nature in wines, and play a fundamental role in the technological properties and organoleptic characteristics of the wines. The role of the different wine polysaccharides will depend on their quantity but also on their chemical composition, molecular structure and origin. Wine polysaccharides originate from grapes and yeast acting during the winemaking. The main polysaccharides present in wines can be grouped into three major families: (i) polysaccharides rich in arabinose and galactose (PRAG), (ii) polysaccharides rich in rhamnogalacturonans (RG-I and RG-II), which both come from the pectocellulosic cell walls of grape berries, and (iii) mannoproteins (MP) released by yeasts. This paper describes the origin, structure and role of the different wine polysaccharide families through a bibliographic revision of their origin and extraction into the wines, as well as their technological and sensory properties

Influence of Wine Chemical Compounds on the Foaming Properties of Sparkling Wines

The foam of a sparkling wine is a key parameter of its quality, and the main characteristic differentiating sparkling wines from the so-called still wines. Both foam formation and duration are directly related to the chemical composition of sparkling wines. This chapter reviews the most recent studies made to determine the influence of chemical compounds on the foamability and foam stability of sparkling wines. Foam properties of sparkling wines are ruled by a large number of molecules, but some compounds seem to be more relevant than others to explain their behavior. The content of total amino acids, polysaccharides, anthocyanins, coumaric acid, and isorhamnetin showed high correlation values with foam quality parameters. The alcohol content and the concentration of acid polysaccharides, proanthocyanidins and free SO2 are the factors which most negatively affect foam quality. A recent study, by means of prediction models, has concluded that the different forms of malvidin show the highest influence on the foamability parameters in rosé sparkling wines, followed by amino acid compounds, while foam stability model was only predicted by polysaccharides rich in arabinose and galactose. These research findings provide industry with a better understanding of the compositional factors influencing the foam quality of sparkling wines

Relationship between foaming properties and polysaccharide composition of sparkling wines

Póster presentado en las XI Carbohydrate Symposium (XI Jornadas de Carbohidratos), celebradas en Logroño del 28 al 30 de mayo de 2014.Peer Reviewe

Appraisal of wine color and phenols from a non-invasive grape berry fluorescence method

[Aims] To investigate the relationships between the anthocyanin content of Vitis vinifera L. cvs. Tempranillo and Graciano grapes, determined in the vineyard and in the winery by a non-invasive fluorescence sensor, and the final wine color and phenolic traits.[Methods and results] Grape anthocyanin and phenol measurements were conducted with a hand-held, non-destructive fluorescence-based proximal sensor, in the vineyard (on clusters hanging on the vine) and at the winery (on harvested clusters in boxes) in two seasons. The anthocyanin fluorescence indices, ANTHRG and FERARI, were found to significantly correlate with the wine color density (R2 ranged from 0.51 to 0.82) and total phenol index (R2 ranged from 0.44 to 0.87), regardless that the measurements were made in the vineyard or in the winery. Similarly, the CIELAB parameters defining lightness (L*), hue angle (h*) and coordinate b* (yellow-blue component of the wine tonality) also showed significant relationships (R2 ranged from 0.55 to 0.74) with ANTHRG and FERARI indices in very young wines.[Conclusion] This preliminary study showed that satisfactory estimation of the final wine color and phenolic characteristics can be obtained from fast, non-destructive measurements in grapes, using a fluorescence-based sensor, either in the vineyard or in the winery.[Significance and impact of the study] This is the first work showing the capabilities of the chlorophyll fluorescence of grapes to estimate the final wine color and phenolic traits. This information could help the wine industry make more informed decisions regarding selective harvest and winemaking in a fast and cost-effective way. © Vigne et Vin Publications Internationales (Bordeaux, France).The authors want to thank Force-A and its team for their help and financial support.Peer Reviewe

Influence of polysaccharide commercial product addition on volatile composition of white sparkling wines

Póster presentado en las XI Carbohydrate Symposium (XI Jornadas de Carbohidratos), celebradas en Logroño del 28 al 30 de mayo de 2014.Peer Reviewe

Characterization of phenolic composition of Vitis vinifera L. 'Tempranillo' and 'Graciano' subjected to deficit irrigation during berry development

The response of phenolic composition of skins from Vitis vinifera L. 'Tempranillo' and 'Graciano' grapes to water-deficit irrigation during berry growth and ripening was evaluated. The study was carried out using container-grown grapevines grown under controlled conditions in a greenhouse. Two irrigation treatments were imposed: control (well-watered) and sustained deficit irrigation (SDI). Twenty-eight phenolic compounds, including anthocyanins, flavonols and monomeric flavan-3-ols (catechins) as well as phenolic acids derivatives have been identified in the extracts prepared from the berry skins at physiological maturity. For both varieties, water deficit reduced leaf area and leaf area to crop mass ratio, and decreased berry size. However, there were no changes in juice total soluble solids, pH or total polyphenolic content. Water deficit resulted in decreased must titratable acidity in 'Graciano' berries. In 'Tempranillo', water limitation reduced total anthocyanins and flavonols, and increased hydroxycinnamic acids. In 'Graciano', water deficit resulted in increased flavonols and reduced catechins. Altogether, we concluded that under water-deficit irrigation, 'Graciano' grapes presented a differential composition of phenolic compounds that could result in improved fruit quality.This project was supported by Fundación Universitaria de Navarra (2011) and the Ministerio de Ciencia e Innovación (MCINN BFU2011-26989) of Spain. M. NICULCEA was the recipient of a grant from Asociación de Amigos de la Universidad de Navarra.Peer Reviewe

Effect of grape maturity on the carbohydrate composition of red sparkling wines

Póster presentado en el 10th International Symposium of Enology (OENO 2015), celebrado en Burdeos del 19 de junio al 1 de julio de 2015.The authors thank the INIA for financing this study through the projects RTA2012-00092-C02-01 (with FEDER funds). Leticia Martínez thanks the Consejería de Educación del Gobierno de La Rioja for the FPI-CAR grant.Peer Reviewe

Polysaccharide content of extracts obtained from unfermented skins from red varieties

Grape pomace is one of the main by-products generated by wine industry and contains several bioactive compounds such as polysaccharides. They are contained in the cell walls of the grape skins. The variety can be an important factor influencing the polysaccharide content of grapes. Actually, there is great interest in the revaluation of by-products and their incorporation into the production process. Therefore, the aim of this work was to evaluate the polysaccharide content of different extracts obtained from unfermented pomaces of different red grape varieties from Castilla y León. Eight different grape varieties were studied. The polysaccharides from grape pomace was obtained following a flash extraction process and the total polysaccharide content and the molecular weight distribution were estimated by High-Performance Size-Exclusion Chromatography with a Refractive Index Detector. Statistically significant differences were found in the content of total polysaccharides by grape variety varying between 112 and 200 mg/g. Only high and low molecular weight polysaccharide fractions were detected. All varietal extracts presented higher percentage of low molecular weight polysaccharides (50.8-64.3%) than of high molecular weight (35.7-49.2%)

Ultrasound treatment of crushed grapes: Effect on the must and red wine polysaccharide composition

This paper studied the effect on the molecular weight and polysaccharide composition of musts and wines of the application of high-power ultrasound (US) at 20 and 28 kHz on crushed grapes. Two different pomace maceration times (short and mid) were tested for sonicated and control vinifications. A long pomace maceration time was also tested for non-treated wines. In must samples, US significantly increased the content of monosaccharides and polysaccharides rich in arabinose and galactose (PRAG), and the average molecular weight of smaller PRAG, mannoproteins (MP) or mannans. The 28 kHz had a major effect on most wine monosaccharides and grape polysaccharides. The wine obtained from sonicated grapes at 28 kHz and with mid maceration had higher rhamnogalacturonans type II and PRAG content than its control, and closer polysaccharide and monosaccharide content to long maceration control wines. No significant differences were obtained in the MP content between sonicated and control wines.This research was funded by the Ministerio de Ciencia, Innovación y Universidades from the Spanish Government and Feder Funds, grant number RTI2018-093869-B-C21