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

Libros

RESEÑA 1 de : Echevarría Arsuaga, Ana. Caballeros en la frontera. La guardia morisca de los reyes de Castilla (1410-1467). Madrid : UNED, 2006. RESEÑA 2 de : Bueno, María Luisa. Miradas Medievales : más allá del hombre y de la mujer. Ed. Dilex, S.L., 2006. RESEÑA 3 de : Fuente, María Jesús. Velos y desvelos. Cristianas, musulmanas y judías en la España medieval. Madrid : La Esfera de los Libros, 2006. RESEÑA 4 de : Quintanilla Raso, Mª Concepción. Titulos, grandes del reino y grandeza en la sociedad política. Fundamentos en la Castilla medieval. Madrid : Sílex, 2006. RESEÑA 5 de : Cateura Bennásser, Pau. Comprar, Vendre i Pagar al Rei. Els impostos indirectes al Regne de Mallorca (segles XIV-XV). Palma de Mallorca : El Tall Editorial, 2006

Chemo-sensory approach for the identification of chemical compounds driving green character in red wines

The present work seeks to define the “green character” of red wines and characterise the groups of molecules potentially involved in that perception. Fifty-four wines were screened by wine experts for different levels of green character. Six different phenolic fractions were obtained by liquid chromatography (LC) and further submitted to sensory and chemical characterisation. The volatile fraction was screened by semipreparative LC, Gas Chromatography-Olfactometry (GC-O) and quantitative analysis. The green character was linked to vegetal aroma, astringency, green and dry tannins according to experts of the Somontano region. Non-volatile fractions containing tannins with mean degree of polymerisation of ten and smaller anthocyanin-derivative pigments (<tetramers) imparted astringency-related sensations such as dryness and stickiness, respectively. No specific aroma compounds were identified in the GC-O study of green wines, however the wines contained significantly higher levels of fusel alcohols. The interaction between isoamyl alcohol and the anthocyanin-derivative fraction and/or tannins is suggested to be involved in the formation of green character in red wines

Effect of enological tannin addition on astringency subqualities and phenolic content of red wines

Four Italian red wine varieties (Sangiovese, Montepulciano, Barbera, Nero d'Avola) were used to investigate the effect of enological tannins on astringency characteristics and phenolic content of red wines. Wines were treated with three tannins of different origins (G = grape, E= oak, and P = exotic wood) at two concentrations (10, 20 g/hl) and aged for 1 year. Wines were evaluated for astringency and for 16 subqualities using check-all-that-apply questions. In addition, polymeric pigments, tannins, flavans, total anthocyanins, and color parameters were analyzed. Enological tannin promoted color stability by pigmented polymers formation. Astringency intensity was not enhanced, even better an improvement of mouthfeel sensations was achieved with wood-derived tannins. Multivariate analysis revealed a great influence of the variety on astringency and phenolic characteristics of wines. Therefore, the initial phenolic composition of wine seems to be the main driver of the evolution of wine during aging. Practical applications: Tannin addition is an enological practice widely widespread because of many economical benefits. The use of enological tannins during aging can contribute to color stabilization and to an improvement of astringency subqualities of wines. Training on astringency subqualities with touch standards coupled with the check-all-that-apply questions can provide an interesting way to reveal the different aspects of red wine astringency. Despite high astringency and high phenolic content, a wine may present desirable subqualities which can improve wine experience. Finally, a tailored use of enological tannins depends on wine variety

Em busca de marcadores sensoriais por entre a composição do vinho tinto: um estudo nacional inovador

The objective of this work was to verify the signaling/profiling potential of wine compounds and the physicochemical and bioclimatic winerelated measurements on a nationwide sensory scale of red wine typicality. Color tonality evolved from violet-purple in cooler northern regions to ruby-garnet in hotter southern regions. Acidity and astringency were enhanced from south to north. Conversely, alcohol and viscosity progressed southward. Bitterness was primarily affected by inland-coastal influence. The regional differentiation of astringency and bitterness introduced an orthogonal reading (N north- S south vs. E inland-W coastal, respectively), rather than a linear one, these findings adding novelty to sensory research. Additionally, several Portuguese-related studies were reviewed, and their findings were correlated with six sensory measures. Bioclimatic indexes, pH and the total phenol index were considered the strongest profilers in a nationwide assessment on red wine typicality. The ratio of the oligomeric/polymeric composition of tannins, as well as total anthocyanins, was also to be considered to be a valid sensory profiler. Several nationwide tendencies and correlations between sensory evaluations and wine chemistry may represent interesting findings and challenge unexplored ways for new researc

Estudio químico-sensorial de la composición no volátil de los vinos. Influencia de técnicas de aclareo en el perfil fenólico y organoléptico de los vinos

Los compuestos fenólicos, junto con los compuestos volátiles, son los parámetros de calidad más importantes en los vinos, ya que son responsables de su perfil organoléptico por contribuir al color, a la astringencia, al amargor y a la percepción aromática. La relación existente entre la evaluación sensorial y la composición no volátil de los vinos, junto con el estudio de las interacciones sabor-sabor y sabor-astringencia, son puntos clave a investigar en la enología actual. En esta Tesis Doctoral se ha llevado a cabo el aislamiento de diferentes fracciones no volátiles del vino, con el fin de conocer los compuestos sensorialmente activos responsables de propiedades sensoriales, tales como el amargor y la astringencia. Además, se ha realizado la reconstitución de vinos con el fin de evaluar el rol de los compuestos de bajo y alto peso molecular en sus propiedades sensoriales. Por otra parte, se ha estudiado un método alternativo para controlar la producción del viñedo mediante la aplicación de un regulador de crecimiento vegetal denominado prohexadiona de calcio, con especial hincapié en su impacto en la composición fenólica de los vinos. Los resultados obtenidos pusieron de manifiesto el importante papel desempeñado por la concentración de proantocianidinas en la astringencia del vino. Además, se ha propuesto un modelo matemático capaz de explicar el amargor. Este modelo se aplicó a los datos químicos y sensoriales obtenidos en la evaluación de una fracción vínica desaromatizada, desalcoholizada y en la cual se habían eliminado los compuestos ácidos y astringentes. Asimismo, se observó que tanto el amargor como la astringencia aportados por los compuestos fenólicos de bajo peso molecular fueron ¿vino dependientes¿, mientras que la concentración de proantocianidinas resultó determinante por su capacidad para modular la percepción de otros sabores y por la influencia que ejerció en el equilibrio final de los vinos. Respecto al estudio del regulador de crecimiento, se observó que se comportó de forma similar a la realización de un aclareo manual de racimos. La aplicación de este regulador proporcionó uvas y vinos con mayor contenido polifenólico y organolépticamente más apreciados

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

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

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