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Polysaccharides are the main group of macromolecules in wines. Climate change is a major problem for viticulturists as it leads to the production of unbalanced grapes. This is attributed to a mismatch between the technological maturity and phenolic maturity of grapes, which can negatively impact the production of high quality wines. To mitigate this effect, biostimulants can be applied to grapevines. For the first time in the literature, this work studied the foliar application of methyl jasmonate plus urea (MeJ + Ur) on the vineyard and its effect on the monosaccharide and polysaccharide composition of Tempranillo grapes and wines over two consecutive seasons. To achieve this, the extraction and precipitation of polysaccharides was conducted, and the identification and quantitation of monosaccharides was performed via GC–MS. The effect of MeJ + Ur foliar treatment in both the grapes and wines was season-dependent. The MeJ + Ur treatment had a slight impact on the monosaccharide composition of the grapes and also demonstrated a small effect on the wines. Multifactor and discriminant analysis revealed that the season had a greater influence on the monosaccharide and polysaccharide composition of grapes and wines compared to the influence of MeJ + Ur treatment. Interestingly, the MeJ + Ur-treated wines exhibited a higher sensory evaluation than the control wines in the second vintage. To gain further insights into the effect of MeJ + Ur foliar application on the monosaccharide and polysaccharide composition of grapes and wines, further investigations should be conducted.

The disruptive effect exerted by high-power ultrasound (US) on grape cell walls is established as the reason behind the chromatic, aromatic and mouthfeel improvement that this treatment causes in red wines. Given the biochemical differences that exist between the cell walls of different grape varieties, this paper investigates whether the effect of the application of US in a winery may vary according to the grape variety treated. Wines were elaborated with Monastrell, Syrah and Cabernet Sauvignon grapes, applying a sonication treatment to the crushed grapes using industrial-scale equipment. The results showed a clear varietal effect. The wines made with sonicated Syrah and Cabernet Sauvignon grapes showed an important increase in the values of color intensity and concentration of phenolic compounds, and these increases were higher than those observed when sonication was applied to Monastrell crushed grapes, whereas Monastrell wines presented the highest concentration in different families of polysaccharides. These findings correlate with the differences in the composition and structure of their cell walls since those of Monastrell grapes presented biochemical characteristics associated with a greater rigidity and firmness of the structures.

The effects of the carbonic maceration and conventional winemaking on the volatile composition and aromatic sensory characteristics of Tempranillo Blanco wines were studied for the first time, during three consecutive vintages. Relationships between instrumental (volatiles) and sensory variables were analyzed applying partial least squares regression (PLS). Carbonic macerated wines had higher contents of alcohols and carbonyl compounds, yet lower concentrations of C6 alcohols and volatile acids than wines conventionally produced. The Odor Activity Values (OAV) exhibited an increase in wines when carbonic maceration was applied. According to the geometric mean (% GM) obtained from aroma descriptors the effect of the winemaking process was significant for seed fruit, ripe fruit and floral notes. When subjected to PLS the data from the instrumental analysis yielded a satisfactory model for the prediction of aroma descriptors in this set of wines.

The aim of this work was to study oenological techniques to obtain adequate base wine for red sparkling wine elaboration. Four winemaking techniques were carried out: pre-fermentative cold maceration with dry ice and delestage with premature grapes; and sugar reduction in must and partial dealcoholisation of wine with mature grapes. Their effect on oenological parameters, volatile composition, foam and sensory characteristics was valuated. Reduction of sugar content and partial dealcoholisation allow obtaining base wines with more adequate alcohol content. No differences were found between the oenological parameters during the ageing time. Pre-fermentative cold maceration and partial dealcoholisation had a greater influence on the volatile composition of the base and red sparkling wines. Oenological technique did not affect the foam instrumental parameters. Red sparkling wines from premature grapes showed higher vegetal aromas, and pre-fermentative cold maceration the best foam sensory descriptors., The authors would like to thank the ‘Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria’ (INIA) for the funding provided for this study through the project RTA2012-092-C02-01 (with FEDER funds). M. G-L. thanks the Comunidad Autónoma de La Rioja and Universidad de La Rioja for her FPI-UR-CAR grant.

Vitis vinífera L. cv. Maturana Blanca is an autochthonous minor variety recently recovered in the Rioja Qualified Denomination of Origin (D.O.Ca Rioja, Spain) for the production of monovarietal white wines with singular and differentiated characteristics. In this paper, Maturana Blanca wines made with different technologies were analyzed by sensory analysis and aromatic profile by gas chromatography-mass detector. Maturana Blanca wines were characterized by low pH, high acidity, and yellowish tonalities. The compounds that most influenced the aroma of Maturana Blanca wines were those related to fruity (acetates and ethyl esters), floral aromas (2-phenylethanol), and spicy notes (γ-decalactone). These wines were mainly characterized by volatile compounds of fruity aromas of banana and apple. The use of pre-fermentative maceration increased the concentration of ethyl esters and acetates and produced wines with higher odor activity values, indicating a greater aromatic intensity. The aromatic profile of Maturana Blanca wines fermented in oak barrels showed a greater complexity as they were also characterized by the presence of important amounts of furfural, whiskey lactone, and eugenol. The sensory analysis confirmed the results obtained in the aromatic analysis, and described the wines as fresh and balanced in mouth, with notes of acidity and medium to high persistence. These results will contribute to a better knowledge of this white variety.

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.

The aim of this paper is to optimize a method to recover polysaccharides from white grape pomace (non-fermented), the main waste by-product of the food industry. Different conditions are tested and the polysaccharides extracted are analyzed by high performance size exclusion chromatography with refractive index detector (HPSEC-RID) and gas chromatography with mass detector (GC-MS). The extraction solvent did not show a significant effect on the polysaccharide extraction, acid pH yielded to higher efficiencies, and longer extraction times extracted more smaller polysaccharides (≤5.4 kg mol). The highest efficiencies were obtained with both solvents at pH 1 and 1:4 solid to liquid ratio. The optimum conditions selected (TA as solvent of extraction, 2.5 g L solvent concentration, pH = 1, 1:4 solid to liquid ratio, and 18 h of extraction time) allow the extraction of polysaccharides rich in arabinose and galactose, rhamnogalacturonans, homogalacturonans and glucosyl polysaccharides, under efficient and food-safe conditions., The authors would like to thank the Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) and the Ministerio de Ciencia e Innovación for the funding provided for this study through the project RTA2017-00005-C02-02.

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.

BACKGROUND: Verdejo and Tempranillo are traditional varieties for producing still wines; however, they could provide an alternative for the manufacturing of sparkling wines. Sparkling wines were elaborated by the traditional method, followed by ageing on lees for 9 months. A study on the changes that take place in polysaccharides, oligosaccharides and nitrogenous compounds during the ageing on lees of Tempranillo and Verdejo sparkling wines has been undertaken. RESULTS: Mannoproteins and the glucose residue of oligosaccharides were the major carbohydrates detected in all vinification stages. Yeast polysaccharides and glucan-like structures of the oligosaccharides increased after 3 months of ageing. The evolution of yeast polysaccharides and the composition of PRAG-like structure were different among grape varieties. A decrease in amino acids and biogenic amines was observed during the ageing. The contents of polysaccharides, oligosaccharides and nitrogenous compound were significantly higher in Tempranillo than in Verdejo sparkling wines at the end of the ageing period. CONCLUSION: Polysaccharides and oligosaccharides from yeast were more significant autolysis markers of sparkling wines than the nitrogenous compounds. Our data suggest a potential cultivar effect on the evolution of yeast polysaccharides and on the composition of PRAG, which may influence the physico-chemical and sensory properties of sparkling wines.

The effect of egg albumin fining, progressive clarification and cross-flow microfiltration on the polysaccharide and proanthocyanidin composition of four red varietal wines was studied in this work. Discriminant analyses were applied to achieve a possible differentiation of the wines according to treatment or grape variety. Egg albumin fining did no produce a significant decrease in the content of wine polysaccharides. Progressive clarification caused a significant reduction of mannoproteins, homogalacturonans and polysaccharides rich in arabinose and galactose in Graciano wines. However, both treatments reduced the total content of proanthocyanidins in all varietal wines. Cross-flow microfiltration produced the highest retention of polysaccharides and proanthocyanidins in all the wines, mainly polysaccharides rich in arabinose and galactose, yeast mannoproteins and highly polymerized phenols. Polysaccharides rich in arabinose and mannoproteins were more retained on the ceramic membrane than polysaccharides rich in galactose and proanthocyanidins. Discriminant analyses allowed a clear differentiation of cross-flow microfiltrated wines from the rest of the 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.

Amino acids, polysaccharides and oligosaccharides changes during the aging of white and rosé sparkling wines. . 10. Symposium In Vino Analytica Scientia

[EN] The relationship between cell wall composition and extractability of anthocyanins from red grape skins was assessed in Tempranillo grape samples harvested at three stages of ripening (pre-harvest, harvest and over-ripening) and three different contents of soluble solids (22, 24 and 26 !Brix) within each stage. Cell wall material was isolated and analysed in order to determine cellulose, lignin, non-cellulosic poly- saccharides, protein, total polyphenols index and the degree of esterification of pectins. Results showed the influence of ripeness degree and contents of soluble solids on cell wall composition. Furthermore, principal components analysis was applied to the obtained data set in order to establish relationships between cell wall composition and extractability of anthocyanins. Total insoluble material exhibits the biggest opposition to anthocyanin extraction, while the highest amounts of cellulose, rhamnogalacturonans-II and polyphenols were positively correlated with anthocyanin extraction. Moreover, multiple linear regression was performed to assess the influence of the cell wall composition on the extraction of anthocyanin compounds. A model connecting cell wall composition and anthocyanin extractabilities was built, explaining 96.2% of the observed variability.

BACKGROUND The aim of this work was to study for the first time the volatile compounds and olfactory profile of La Rioja red wines made with the local varieties Vitis vinifera cv. Monastel and Maturana Tinta de Navarrete, using Tempranillo as a reference variety. The impact of vintage on these compounds was also evaluated, and chemometric techniques were applied to achieve a possible differentiation of the wines. RESULTS A clear classification of wines according to grape variety and vintage was obtained. Volatile compounds that differentiated wines by grape variety were varietal aromas whereas vintage was mainly differentiated by compounds formed during the alcoholic fermentation and extracted from wood during the elaboration process in wooden barrels. Sensory analysis also allowed differentiation of wines by grape variety. Tempranillo wines were characterized by liquorice notes, whereas Maturana Tinta de Navarrete wines were the least fruity and showed herbaceous and pepper notes. The sensory profile of Monastel varied between vintages. CONCLUSION These minor grape varieties could provide a good alternative to the most widespread variety in La Rioja: Tempranillo. The use of these varieties produced wines with their own personality and different aromatic profile from other wines on the market. © 2013 Society of Chemical Industry

The aim of this work was to focus on the study of the volatile composition of white and rosé base wines elaborated from different autochthonous grape varieties in Spain (Verdejo,Viura, Malvasía, Albarín, Godello,PrietoPicudo and Garnacha) and the evolution of the sparkling wines elaborated from them following the “champenoise” method. The amino acids and biogenic amines were also studied. Multivariate analyses (factorial and stepwise discriminant) were carried out to study the influence of these compounds all together. Base and sparkling wines from Albarín, Verdejo, Godello and PrietoPicudo were the richest in most of the volatile compounds analyzed, especially of ethyl esters and alcohol acetates, compounds that contribute to the fruity aroma of wines. During the aging on lees in the bottle of sparkling wines, an increase in branched ethyl esters, ethyl lactate and γ-butyrolactone, and a decrease in terpenes (mainly citronellol and geraniol) were observed. In general, the levels of biogenic amines in all the sparkling wines studied were very low, which does not represent a negative effect on their quality and safety., The authors would like to thank the “Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria” (INIA) for the funding provided for this study through the project RTA2009-029-C02 (with FEDER funds). L. Martínez also thanks to La Rioja Government for the financing of her pre-doctoral fellowship.

This paper studied how grape maturity affected complex carbohydrate composition during red sparkling wine making and wine aging. Grape ripening stage (premature and mature grapes) showed a significant impact on the content, composition, and evolution of polysaccharides and oligosaccharides of sparkling wines. Polysaccharides rich in arabinose and galactose, mannoproteins, rhamnogalacturonans II, and oligosaccharides in base wines increased with maturity. For both maturity stages, polysaccharides rich in arabinose and galactose, and the glucuronic acid glycosyl residue of the oligosaccharides were the major carbohydrates detected in all vinification stages. The total glycosyl content of oligosaccharides decreased during the whole period of aging on yeast lees. The reduction of polysaccharides rich in arabinose and galactose and rhamnogalacturonans type II during the aging was more pronounced in mature samples. To our knowledge, this is the first report of the polysaccharide and oligosaccharide composition of red sparkling wines., The authors would like to thank the Spanish Ministry of Economy and Competitiveness and the “Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria” (INIA) for the funding provided for this study through project RTA2012-00092-C02-02 (with FEDER funds). L. Martínez-Lapuente also thanks the La Rioja Government for the financing of her predoctoral fellowship.

Spanish grape varieties that have been traditionally used to produce still wines were examined for their potential to make white and rose sparkling wines. Sparkling wines manufactured from Vitis vinifera cv. Verdejo, Viura, Malvasia, Albarin, Godello, Garnacha, and Prieto varieties were examined for sensory attributes and for the evolution of monomeric and polymeric phenolics during different stages of winemaking and aging. Stabilization and clarification of the base wines significantly decreased the concentrations of anthocyanins and proanthocyanidins. During the initial months of aging on yeast lees, all types of polyphenols decreased, although some were released back into the wine during the final months. Garnacha rose and Albarin white wines had high phenolic potential. Garnacha rose sparkling wines had particularly high hydroxycinnamic acid concentrations, while Prieto Picudo rose sparkling wines had the highest color intensity and anthocyanin concentrations. Among white sparkling wines, Albarin had the most catechin, proanthocyanidins, and, together with Viura, hydroxycinnamates. In sensory profiling, Prieto Picudo had more visual color intensity, red tones, olfactory intensity, freshness sensations, and foam quality than Garnacha wines. Albarin and Verdejo had more visual color and olfactory intensity than the other white wines, and Verdejo had better foam quality. Prieto Picudo, Albarin, and Verdejo were the most promising varieties for the production of high-quality sparkling wines.

Oscar Fernández...et al., A practice in wineries is to age wine in the presence of lysated lees instead of fresh lees, in order to reduce the time wine is conserved on lees and avoid possible microbiological and organoleptic risks caused by lees. Two treatments were used to induce lees lysis: acidification and acidification in combination with a mixture of β-glucanases and pectinases. Acidification treatment in combination with enzymes induced significantly greater mannoprotein and glucan release. The presence of lysated lees during wine storage in barrels produced wines with significantly different tannin contents. The ageing technique on lysated lees by acidification in combination with enzymes produced wines with more intense colors, lower luminosity and saturation, and a slight tendency towards red tones, and an increase in sweetness, fullness and mouth length. On the contrary, ageing technique on lysated lees by acidification increased wine acid and fresh sensations., This work was supported by the Gobierno de La Rioja (Project FOMENTA 2007/01) and the Universidad de la Rioja (Projects API). The authors wish to thank Antonio Palacios for conducting the sensory analysis

Changes in phenolics and color components during vinification and aging of Tempranillo wines were studied. Different phenolics display different diffusion into the must, and with the exception of proanthocyanidins and acetyl-glucoside anthocyanins, with maximum concentration at the end of postmaceration, the rest of the unacylated and coumarated anthocyanins, monomeric flavanols, and hydroxycinnamic acids reached their maximum at the end of alcoholic fermentation. This resulted in a significant increase in both wine color and stable color, mainly due to the formation of copigmentation complexes, although polymeric pigment formation was also important. Malolactic fermentation produced a significant decrease in flavonoid content while nonflavonoid concentrations were maintained, prompting a considerable loss in wine color, despite the dramatic increase in bisulfite-stable color. Wine oak aging did not produce any significant change in the studied parameters, while bottle aging reduced the level of monomeric anthocyanins and flavanols, and hydroxycinnamic acids. However, wine color remained stable due to a significant increase in stable color. Polymerization reactions of anthocyanins prevailed over pigment degradation reactions, and copigmentation was still relevant after 2 years of bottle aging.

Passing from must to wine produced a loss of low-molecular-weight grape structural glucosyl polysaccharides, and an important gain in yeast mannoproteins (MP) and grape-derived arabinogalactan proteins (AGP), and rhamnogalacturonans-II (RG-II). AGP were more easily extracted than RG-II, and small quantities of RG-II monomers and galacturonans were detected. Postmaceration produced a reduction in all grape polysaccharide families, particularly acute in AGP. The reduction of polysaccharides during malolactic fermentation only affected grape AGP, and MP were continuously liberated during the entire vinification process. Wine oak and bottle aging was associated with a relative stability of the polysaccharide families. AGP were thus the majority polysaccharides in young wines but, contrary to what may be thought, structural glucosyl oligosaccharides dominated in musts and MP in aged wines. Precipitation of polysaccharides was noticeable during vinification, and it mainly affected high-molecular-weight AGP and MP. Hydrolytic phenomena affected the balance of wine polysaccharides during late maceration-fermentation.

Póster presentado en el 9th In Vino Analytica Scientia Symposium (IVAS 2015), celebrado en Trento del 14 al 17 de julio de 2015.

© 2015 American Chemical Society. In sparkling wines, mannoproteins released during yeast autolysis largely affect their final quality. This process is very slow and may take several months. The aim of this work was to study the effect of several commercial dry yeast autolysates on the chemical composition, foam, and sensory properties of white and rosé sparkling wines aged on lees for 9 months during two consecutive vintages. The addition of these products in the tirage phase did not affect either the content of phenolic compounds, amino acids, and biogenic amines or the foam properties. The commercial product with the highest mannoprotein content and the highest purity caused significant changes in the volatile composition of the wines and enhanced the fruity aromas in both Verdejo and Godello sparkling wines., We thank the Instituto Nacional de Investigación y Tecnologı́a Agraria y Alimentaria (INIA) for the funding provided for this study through Project RTA2009-029-C02 (with FEDER funds). L.M.-L. also thanks La Rioja Government for the financing of her predoctoral fellowship.

The aim of this work was focused on the study of the influence of grape variety and aging time in contact with lees and without lees, on volatile composition and foamability of white and rosé sparkling wines. Seven different grape varieties were used and the sparkling wines were studied until 30 months of aging on lees and after 12 months of aging in bottle after disgorging. Sparkling wines from Albarín, Verdejo, Godello and Prieto Picudo grape varieties were the richest in most of the volatile compounds analyzed, especially those that contribute to the fruity aroma of wines, and maintained their varietal characteristics even after long aging time (30 months). Verdejo and Prieto Picudo sparkling wines presented the best foam characteristics, followed by Albarín and Godello wines. Considering all the results, Albarín, Verdejo, Godello and Prieto Picudo were the most interesting grape varieties to elaborate sparkling wines, following the traditional or “champenoise” method., The authors would like to thank the Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria for the funding provided for this study through the project RTA2009-029-C02 (with FEDER funds). L. Martínez also thanks to La Rioja Government for the financing of her pre-doctoral fellowship.

Editors: Kishan Gopal Ramawat; Jean-Michel Mérillon, Polysaccharides are one of the major classes of macromolecules found in wines. They play a critical role in stabilizing other molecules in solution and thus are able to modify both the wine processing and organoleptic properties. Detailed analyses of these polysaccharides are essential to know their physicochemical properties and biological functions. We present analytical techniques not only to define the fine chemical structures of individual wine polysaccharides but also to estimate the overall polysaccharide composition of must and wines. The procedure covers the preparation of the sample, together with gas chromatography-mass spectrometry-based methods, for both the analysis of monosaccharides as their volatile trimethylsilyl methyl glycoside derivatives and methylation analysis to determine linkage positions between monosaccharide residues as their volatile partially methylated alditol acetate derivatives. We also provide a protocol for estimating the global content of wine polysaccharides by using size-exclusion chromatography with refractive index detector (SEC-RID). This is a rapid and simple method that can be used routinely in a reasonably equipped laboratory. Analysis complexity and time will vary depending on the method used, and the duration ranges from 2 days for a global polysaccharide estimation to 2 weeks for a carboxyl reduction/methylation linkage analysis.

© 2014 Elsevier Ltd. All rights reserved. The chemical composition of sparkling wines is directly related to their foam quality, but the compounds responsible are not yet completely established. This work aims at identifying the contribution of the different wine compounds to the foaming properties of white and rosé sparkling wines. Our results demonstrated the positive contribution of anthocyanins and amino acids to the foamability parameters HM (maximum height reached by foam after CO2 injection) and HS (foam stability height during CO2 injection), and the negative contribution of proanthocyanidins. Mannoproteins and polysaccharides rich in arabinose and galactose (PRAG) were poor foam formers but good foam stabilizers. The different forms of malvidin showed the highest influence on the HM and HS parameters, followed by amino acid compounds, mainly β-alanine. The model to explain foam stability was only predicted by polysaccharides from grapes, concretely PRAG. To our knowledge, this is the first time these correlations in sparkling wines have been described., The authors would like to thank the ‘Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria’ (INIA) for the funding provided for this study through the project RTA2009-029-C02 (with FEDER funds). Leticia Martínez-Lapuente also thanks La Rioja Government for the financing of her pre-doctoral fellowship.

The influence of commercial enzymes on wine polysaccharide content was studied. Tempranillo wines were made using commercial maceration enzyme preparations along with controls. The analytical method for the quantification of wine polysaccharides was carried out by a multistep procedure. Wine-soluble polysaccharides were isolated by wine concentration polysaccharides precipitation with an acid-alcohol medium and separation of each polysaccharide family by high resolution size-exclusion chromatography on a Superdex-75 HR column. The glycosyl-residue compositions of the fractions obtained were determined by gas chromatography with flame ionisation and mass spectrometry of their trimethylsilyl-ester O-methyl glycosides after acidic methanolysis and derivatization. The content of each fraction was estimated from the concentration of individual glycosyl residues that are characteristic of well-defined wine polysaccharides. The analytical method proposed had good sensitivity, repeatability, reproducibility and accuracy. Soluble polysaccharides in wine were essentially composed of grape cell wall polysaccharides: arabinogalactans and arabinogalactan-proteins (38-41%), and rhamnogalacturonans-II (38-46%). Yeast mannans and mannoproteins were also present but in smaller proportions (14-19%). Wines treated with commercial enzymes had larger concentrations of arabinogalactans, arabinogalactan-proteins and rhamnogalacturonans-II than control wines, but the content of mannans and mannoproteins was similar in both wines. This indicated that the commercial enzymes hydrolysed grape pectic polysaccharides during the maceration- fermentation stage but had no influence on yeast parietal polysaccharides. © 2003 Elsevier B.V. All rights reserved.

Trabajo presentado en el 37th World Congress of Vine and Wine, celebrado en Mendoza (Argentina) del 9 al 14 de noviembre de 2014., [EN] Natural sparkling wines are obtained after a second fermentation in closed bottles, and they remain in contact with the yeast lees for at least 9 months. During sparkling wine aging, different compounds such as polysaccharides can be released due to yeast autolysis that can cause important changes in wine composition, affecting the quality of sparkling wines. Yeast autolysis is a slow natural process that takes long time, and the addition of some products could improve the quality characteristics of these wines. Therefore, the aim of this work was to study the effect of the addition of several commercial yeast autolysated on the volatile composition of white sparkling wines elaborated from two white grape varieties (Godello and Verdejo), and aged on lees for 9 months. The base wines were elaborated following the traditional white winemaking process. The studied varieties were: Verdejo from the Rueda Designation of Origin (DO), and Godello from the Bierzo DO. The sparkling wines were elaborated following the traditional or “champenoise” method, and after the tirage phase, the bottles were kept in a cellar at temperature and relative humidity controlled for 9 months. The volatile compounds were analysed by gas chromatography coupled to a mass detector, after a previous liquid-liquid extraction. The polysaccharide and monosaccharide composition of the commercial preparations was determined by GC-MS of their trimethylsil yl-ester O-methyl glycosyl residues. The percentage of mannoproteins of the different commercial products, estimated by the mannose concentrations, was between 53-83%. The percentage of glucans, estimated by the concentrations of glucose, was between 14-47%. Therefore these results indicate that these products presented in general higher amounts of mannoproteins than of glucans. The statistical analysis of the data was carried out by the discriminant analysis, which indicated that the sparkling wines treate d with PCP2 in the tirage phase showed the highest differences in the volatile composition of both sparkling wines studied, being the ethyl esters, alcohol acetates and terpenes the compounds that were affected in a greater extent. This fact could be due to the commercial product, PCP2, presented the highest percentage of mannoproteins that can interact with volatile compounds, modulating their volatility and perception., [ES] Los vinos espumosos naturales se obtienen tras una segunda fermentación en botella, y permanecen en contacto con las lías al menos 9 meses. Durante la crianza sobre lías, diferentes compuestos como los polisacáridos pueden liberarse durante la autolisis de las levaduras, y pueden producirse importantes cambios en la composición de los vinos, que afecten a su calidad. La autolisis de las levaduras es un proceso natural que lleva mucho tiempo, y la adición de algunos productos comerciales podría mejorar la calidad de estos vinos. Por ello, el objetivo de este trabajo ha sido estudiar el efecto de la adición de diferentes autolisados de levaduras comerciales en la composición volátil de vinos blancos espumosos elaborados con dos variedades de uva (Godello y Verdejo), y envejecidos sobre lías durante 9 meses. Los vinos base se elaboraron siguiendo el proceso de elaboración tradicional en blanco. Las variedades de uva estudiadas fueron: Verdejo de la D.O. Rueda, y Godello de la D.O. Bierzo. Los vinos espumosos se elaboraron siguiendo el método tradicional o “champenoise”, y tras el tiraje, las botellas se mantuvieron en la cava subterránea a temperatura y humedad relativa controlada durante 9 meses., Los compuestos volátiles se analizaron por cromatografía de gases-masas, previa extracción líquido-líquido. La composición de polisacáridos y monosacáridos de los productos comerciales se determinó por cromatografía de gases-masas de sus derivados trimetilsilil-ester O-metil glicósidos. El porcentaje de manoproteinas de los diferentes productos comerciales, estimado a partir del contenido en manosa, fue de 53-83%. El porcentaje de glucanos, estimado a partir del contenido en glucosa, fue de 14-47%. Estos resultados indican que estos productos presentan, en general, mayores concentraciones de manoproteinas que de glucanos. El análisis estadístico de los datos se llevó a cabo mediante un análisis discriminante, que indicó que los vinos espumosos tratados con el producto comercial PCP2 en la fase de tiraje mostraron las mayor es diferencias en el contenido de compuestos volátiles en ambos tipos de vinos, principalmente de ésteres etílicos, acetatos de alcoholes y terpenos. Esto puede ser debido a que este producto comercial, PCP2, presentó el mayor porcentaje de manoproteinas, las cuales pueden interaccionar con los compuestos volátiles modificando su volatilidad y percepción., The authors thank the INIA for financing this study through the project RTA2009-029-C02.

Póster presentado en el 37th World Congress of Vine and Wine (OIV 2014), celebrado en Mendoza (Argentina) del 9 al 14 de noviembre de 2014., [EN] Sparkling wines elaborated following the champenoise method undergo a second fermentation in closed bottles of base wines, followed by aging of wines with lees for at least 9 months. The foam of sparkling wines is a key parameter of their quality but the compounds that are directly involved in foam quality are not yet completely established. Some authors have attempted to correlate the amount of proteins, polysaccharides, amino acids and peptides in sparkling wines with the quality of their foam properties . However, there are few studies about effect of polyphenols on foam quality , and most of them are carried out in model systems, musts or base wines and refer to global measurements of polyphenols ., [ES] Los vinos espumosos naturales elaborados con el método champenoise se obtienen después de dos fermentaciones seguidas de un periodo de envejecimiento sobre lías en botella de al menos 9 meses (Regulación CE Nº 606/2009). La espuma es un parámetro de calidad de los vinos espumosos. Las propiedades espumantes de un vino espumoso, espumabilidad o espuma producida y estabilidad de la espuma, se han correlacionado con su composición química, aunque todavía no se conocen bien los compuestos concretos que influyen en estos parámetros. Algunos autores han intentado correlacionar la cantidad de proteínas, polisacáridos, amino ácidos y péptidos en los vinos espumosos con sus características espumantes, pero hay pocos estudios sobre la influencia de los polifenoles y la mayoría se llevan a cabo en medios sintéticos, mostos o vinos base, y se refieren a medias globales del contenido de polifenoles. Por ello, el objetivo de este trabajo fue correlacionar las propiedades espumantes de vinos espumosos con su composición polifenólica para así poder conocer qué compuestos concretos son los que más influyen en la espuma, un factor importante para la elaboración de vinos espumosos rosados y tintos. Los vinos espumosos se realizaron a partir de uvas tintas durante diferentes añadas siguiendo el método champenoise. Las propiedades espumantes de los vinos se analizaron con el método Mosalux (Maujean et al. 1990). Los antocianos, ácidos hidroxicinámicos, flavanoles y flavan-3-oles se analizaron por HPLC-DAD como se describe en la bibliografía (Gómez-Alonso et al. 2007). Las muestras de vino se fraccionaron por cromatografía de permeación en gel (GPC) como describen Guadalupe et al. (2006), y los aductos de fluoroglucionol en las fracciones F2 se analizaron por HPLC-DAD como describen Kennedy y Jones (2001). Ninguno de los polifenoles se correlacionó con el tiempo de estabilidad de la espuma (TS). Sin embargo, la mayoría de los antocianos y proantocianidinas se relacionaron con la altura máxima de la espuma (HM) y la altura a la que se estabiliza la espuma (HS), indicando que afectan a la formación de la espuma en la elaboración de los vinos espumosos., The authors would like to thank the Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) for the funding provided for this study through the project RTA2009- 00029-C02-01 (with FEDER funds). Leticia Martínez thanks the Consejería de Educación del Gobierno de La Rioja for the FPI-CAR grant.