Deshojado precoz en Viura y Malvasía riojana

En este trabajo se ha estudiado la aplicación de deshojado precoz en las variedades blancas Viura y Malvasía riojana como herramienta para el control del rendimiento y la mejora de la sanidad de la uva, con el objetivo de incrementar la calidad de sus vinos. Estas variedades presentan una producción elevada y racimos de gran tamaño, muy compactos, por lo que son bastante sensibles a Botrytis cinerea. Los resultados obtenidos indican que esta práctica puede plantearse como un método eficaz para el control del rendimiento y la mejora del estado sanitario de la uva; asimismo, favorece una correcta evolución del proceso de maduración, mejorando la composición de la uva debido al incremento del contenido de sólidos solubles y de compuestos fenólicos. La disminución de la acidez total y el aumento de pH que se producen en la uva, debido a la modificación del microclima de los racimos y al control del rendimiento, podría considerarse un inconveniente a tener en cuenta, sobre todo en el caso de variedades blancas que se caracterizan por un déficit de acidez total.Peer Reviewe

Vineyard water status assessment by non-destructive, proximal, NIR spectroscopy

Trabajo presentado en el 20th GIESCO International Meeting (Group of International Experts for Cooperation on Vitivinicultural Systems), celebrado en Mendoza (Argentina) del 5 al 9 de noviembre de 2017Peer reviewe

Taste and mouthfeel properties of red wines proanthocyanidins and their relation to the chemical composition

The aim of this work is to assess the relationship between the in-mouth sensory properties of proanthocyanidins (PAs) and its chemical composition. To achieve such a goal, the proanthocyanidin fraction from six different young commercial red wines was obtained by gel permeation chromatography. A sensory panel, selected on the basis of their PROP status and trained in taste and mouthfeel sensations, described both the wines and fractions. MALDI-TOF-MS and UPLC-MS were used to identify thoroughly the polyphenolic composition of each proanthocyanidin fraction. The results showed that the PAs fractions were exclusively described as astringent and persistent. The astringent subqualities studied (velvety and puckering/drying) were mainly related to the quantity of proanthocyanidins and the proportion of the extension flavanol units linked to proanthocyanidins. A significant negative correlation was found between both of the astringencies (velvety and puckering/drying). Furthermore, both subqualities appeared to contribute to the persistence. A significant correlation was observed between the astringency and the persistence data of the wines and fractions. Significant multiple linear regressions were found between the sensory astringency data and the chemical compounds analyzed. The concentration of proanthocyanidins present in young red wines is the major determinant of the differences perceived in the astringency. Additionally, the extension flavanol units linked to the proanthocyanidins seem to have a different impact on the astringent subqualities. © 2013 American Chemical Society.Peer Reviewe

Study of the Effect of Low Molecular Weight Phenols in the In-Mouth Sensory Perception of High Molecular Weight Phenols in wines. An approach to taste-taste and taste-astringency interactions

Póster presentado en el 8th In Vino Analytica Scientia Symposium (IVAS 2013), celebrado en Reims del 2 al 5 de julio de 2013.Astringency has be en mainly attributed to the content of proanthocyanidins although monomeric phenols have been also described as astringen! and bitter [1]. In this work, the real contribution of monomeric phenols to the astringency perception and the interactions >taste~taste> and >taste-astringency> have been shtdied by means of wines fractions reconstih1tion experiments. For it, six wines were selected, separated into two fractions by gel penneation chromatography (GPC) and freeze-drying, respectively. Fraction >L> contents the low molecular weight phenols, sugars and acids. Fraction >H> presents the high molecular weight phenols. Thirty >reconstihtted wines> were prepared, combining six different >L> with five different >H> fractions, adjusting ethanol content to 13,5 % (v/v) and adding the same aroma for all of them. Aroma was extracted by so lid phase extraction from a sol e young red wine. >Reconstituted wines> and >original wines> (freeze-dried wines, added the same aroma than reconstihlted ones but without canying out GPC on them) \Vere described in-mouth by a trained sensory panel. The sensory properties of the >original wines> were retained by their corresponding >reconstihtted wines>. The results suggest that the low molecular compounds are clearly responsible for wines acidity, while these monomers phenols only play a relevant role in the astringency and the persistence in wines with low ash·ingency. Sweetness-astringency interaction has been observed among the samples together with bitterness-astringency and bittemess-persistence interaction. The high molecular weight phenols are mainly responsible for the perception of astringency being bittemess only attributed to the low molecular weight phenols although lots of interactions in the presence of proanthocyanidins and acids seem to happen, modifying the perception of this attiibute.Peer Reviewe

Study of perceptions implicated in masking wines bitterness and selection of phenolic compounds with ability to predict bitterness

Póster presentado en el 8th In Vino Analytica Scientia Symposium (IVAS 2013), celebrado en Reims del 2 al 5 de julio de 2013.Severa! compounds have been conelated to the perception of wines bittemess being the monomeric phenols the main responsible for eliciting this attribute. Otherwise, it has been reported in a wine reconstihltion experiment that the omission of the high molecular weight phenols bring about a decrease in the astringency perception but not in bittemess, being these compounds excluded to elicit this taste. Fmthennore, until now, any predictive model has been proposed around wine bittemess. For achieving this purpose, a wine fraction free of proanthocyanidins by means of gel penneation chromatography was obtained. An important sensory interaction was observed by means of sensory descriptive analyses between acidity and bittemess once omitted the astringent fraction. Salid phase extraction was can-ied out with the aim of eliminating the high acidity perceived that could be modifying the bittemess perception. This fraction, fi·ee of acids, was sensory and chemically analysed and was mainly described as bittemess and persistence and also slightly astlingent. For the first time a predictive model explaining the bittemess perceived was built. This model included twelve significant compounds, among them, two procyanidins, B 1 and B2, two t1avanol monomers, catechin and catechin~gallate, one flavonol, quercetin mtinoside, two phenolic acids as coutaric acid and kaempherol, four di fferent anthocyanins and the protocatechuic a cid ethyl es ter. Al! the compounds were positively correlated to bittemess except the protocatechuic acid ethyl ester. It is the first time that some of these compounds as the anthocyanins are revealed as contributors of bittemess in wines.Peer Reviewe

Contribution of low molecular weight phenols to bitter taste and mouthfeel properties in red wines

The aim of this study was to explore the relationship between low molecular weight compounds present in wines and their sensory contribution. Six young red wines were fractionated by gel permeation chromatography and subsequently each fraction obtained was separated from sugars and acids by solid phase extraction. Wines and both fractions were in-mouth evaluated by a trained sensory panel and UPLC-MS analyses were performed. The lack of ethanol and proanthocyanidins greatly increased the acidity perceived. The elimination of organic acids enabled the description of the samples, which were evaluated as bitter, persistent and slightly astringent. Coutaric acid and quercetin-3-O-rutinoside appear to be relevant astringent compounds in the absence of proanthocyanidins. Bitter taste was highly correlated with the in-mouth persistence. A significant predictive model for bitter taste was built by means of PLSR. Further research must be carried out to validate the sensory contribution of the compounds involved in bitterness and astringency and to verify the sensory interactions observed. © 2014 Elsevier Ltd. All rights reserved.This research was supported by funds from the Ministry of Education and Science under the National Scientific R&D&I Plan (Project:AGL2010-22355-C02-02). The author A.G.D. receives support from the University of La Rioja’s FPI Research Fellowship Programme.Peer Reviewe

Vinos reconstituidos: Efecto de los compuestos de bajo peso molecular en la percepción gustativa de los compuestos fenólicos de alto peso molecular y viceversa

Póster presentado en el XII Congreso de los Grupos de Investigación Enológica (GIENOL 2013, Nuevas perspectivas en investigación vitivinícola), celebrado en Madrid del 18 al 21 de junio de 2013.Peer Reviewe

Wines reconstitution strategy: a thorough study of the effect of low molecular weight phenols in the in-mouth sensory perception of high molecular weight phenols and vice versa

Póster presentado en el EUROFOODCHEM XVII, celebrado en Estambul del 7 al 10 de mayo de 2013.Peer Reviewe

Caracterización del perfil de aminoácidos en variedades blancas de vid. Implicaciones enológicas

Trabajo presentado en la 32ª Reunión del Grupo de Trabajo de Experimentación en Viticultura y Enología (GTVE), celebrada en Valladolid (España), del 19 al 20 de marzo de 2017Peer reviewe

Understanding the relationship between wine phenolic compounds and sensory properties: Bitterness and astringency

Phenolic compounds are a large family of metabolites that result from the secondary metabolism of plants. Novel insights about phenolic chemical structure, analytical methods, therapeutic effects, sensory properties, viticultural practices to modify their content and the use of these compounds found in agro-industrial wastes have been gathered in this book. A comprehensive overview on phenolic compounds and neurodegenerative disorders, highlighting their antioxidant, anti-inflammatory properties and their effects on Parkinson’s disease have been compiled. In relation to antioxidant properties, the metabolism and bioavailability of several hydroxycinnamic acids present in coffee have been studied in detail, and also the methods to determine antioxidant capacity have been included. Different strategies in order to improve the extraction and determination of phenolic compounds in a complex matrix by analytical techniques are provided, reporting problems and new analytical solutions. The role of these compounds in color stabilization and also in bitterness and astringency perception has been reported. Moreover, the interactions that take place among no volatile and volatile compounds present in wine affecting sensory perception have been briefly introduced. Furthermore, the use of cover crops in vineyards and their effects on agronomical and enological behavior – particularly, their impact on phenolic compounds – have been highlighted. Finally, the biological properties of phenolic compounds from industrial wastes have been tackled, since they are a promising alternative to transform agro-industrial wastes into a source of natural and healthy compounds.Peer reviewe