José-Luis Santiago

Classification and characterization of different white grape juices by using a hybrid electronic tongue

A multisensor system combined with multivariate analysis is applied for the characterization and classification of white grape juices. The proposed system, known as hybrid electronic tongue, consists of an array of electrochemical microsensors and a colorimetric optofluidic system. A total of 25 white grape juices representing the large variability of vines grown in the Northwest Iberian Peninsula were studied. The data obtained were treated with Principal Component Analysis (PCA) and Soft Independent Modeling Class Analogy (SIMCA). The first tool was used to train the system with the reference genotypes -Albariño, Muscat à Petit Grains Blanc and Palomino- and the second to study the feasibility of the hybrid electronic tongue to distinguish between different grape juice varieties. The results show that the three reference genotypes are well differentiated in the PCA model and this can be used to interpolate the rest of varieties and predict their basic characteristics. Besides, using the SIMCA, the system demonstrates high potential for classifying and discriminating grape varieties.

Contribution of some grape-derived aromatic compounds to the primary aroma in red wines from cv. Caiño Tinto, cv. Caiño Bravo and cv. Caiño Longo grapes

The free volatile compounds of two successive vintages of cv. Caino Tinto, Caino Bravo and Caino Longo red wines, together with the volatile compounds released after the enzymatic hydrolysis of their glycosidically bound forms, were identified and quantified by gas chromatography using a flame ionization detector (GC/FID). All these wines possessed the same free volatile compounds; Caino Longo wines showed the highest concentrations and Caino Tinto wines the lowest. In all cases, the release of the bound forms of these compounds may contribute to the final aroma, from both a qualitative standpoint (with the appearance of free 4-terpineol, nerol and geraniol) and quantitative standpoint (notable increases were recorded for most of the compounds detected). The principal component analysis (PCA) showed a good separation of the different wine cultivars and vintages. Caino Tinto wines were more homogeneous between vintages than the others.

Grapevine (Vitis vinifera L.): Old Varieties are Reflected in Works of Art

Grapevine (Vitis viniferaL.): Old Varieties Are Reflected in Works of Art. The northwest of the Iberian Peninsula is home to a number of ancient grapevine varieties now in danger of extinction, regarding which the literature contains only a few references, dating from the 19th century. In this region, baroque religious art, which is commonly ornamented with grapevine motifs, achieved great importance. This work reports the ampelographic comparison of the leaves of 19 old grapevine varieties from this region with those represented on 42 baroque altarpieces. Many of the latter were found to be ampelographically correct representations of grapevine leaves; in some cases they showed such similarity to these old varieties that their cultivation at the time when the corresponding sculptures were made can be confirmed. A larger study may therefore help determine when other varieties were cultivated in the past.

Works of Art and Crop History: Grapevine Varieties and the Baroque Altarpieces

Works of Art and Crop History: Grapevine Varieties and the Baroque AltarpiecesThis study compares the ampelographic characterization of adult leaves and clusters from real grapevine varieties with those present in Solomonic columns of Baroque altarpieces. In a previous preliminary work, the authors concluded that sculpted grapevine leaves in Baroque altarpieces were represented with botanical accuracy and may represent real varieties. Grapevines are a very important decorative feature of these art works, in particular as ornamentation on Solomonic columns. The present work examines more of these carved leaves and includes also the clusters. Six real grapevine varieties were identified on as many altarpieces, enriching their cultural value and pointing to their existence in the wine-growing zone by the 17th century. Further varieties may be identifiable on Baroque altarpieces in other winemaking areas using the same methods. These results encourage other researchers to use unconventional sources for the study of the evolution of agriculture and crop history.Obras de arte e historia de las especies cultivadas: El caso de las variedades de vid y los retablos BarrocosEl presente trabajo compara a nivel ampelográfico las hojas adultas y los racimos de variedades de vid reales con aquellos que aparecen representados en las columnas salomónicas de ciertos retablos barrocos. En un trabajo preliminar publicado anteriormente los autores habían concluido que las hojas esculpidas en estos retablos barrocos están representadas con una gran precisión botánica y por lo tanto podrían estar representando a variedades reales. La vid es un elemento decorativo muy importante en este tipo de obras de arte, en particular como decoración de las columnas de estilo salomónico. El presente trabajo examina un mayor número de retablos e incluye el estudio de los racimos. Seis variedades reales de vid han sido identificadas en otros tantos retablos lo que les aporta nuevos valores culturales y permite demostrar su existencia en la zona vitícola en el siglo XVII. Otras variedades podrían ser también identificadas en retablos barrocos localizados en otras zonas vitícolas diferentes siguiendo la misma metodología. Estos resultados podrían abrir las puertas para que otros investigadores utilicen fuentes de información menos convencionales en el estudio de la evolución de la agricultura y la historia de los diferentes cultivos.

Synonymy of two ancient grapevine cultivars (Vitis vinifera L.) - Cascón and Corbillón - from the D.O. Rías Baixas Ribeira do Ulla Subzone (Galicia, Spain).

In 1986, the Spanish CSIC began a project to find, describe, and recover ancient grapevine cultivars in the regions of Galicia and Asturias. Almost 100 such cultivars have been found, all of which now form part of the grapevine collection at the Misión Biológica de Galicia (CSIC). Until now, the red cultivars “Cascón” and “Corbillón,” two of the most ancient cultivars of the Ribeira do Ulla subzone Protected Designation of Origen (P. D. O.) Rías Baixas, remained undescribed. An ampelographic and molecular analysis of these cultivars showed them to in fact be one and the same.

Variation in Sensitivity of Different Grapevine Genotypes to Erysiphe necator Growing under Unfavourable Climatic Conditions

This paper reports the susceptibility to powdery mildew of 41 grapevine genotypes growing in the north and northwest of Spain over a three-year period. Although the humid climate of these vine-growing areas is not particularly favourable to the development of this disease, serious damages appears in some years when dry weather alternates with times of some rain. All the examined genotypes belonged to the collection of the Mision Biologica de Galicia (CSIC) (Pontevedra, Galicia, Spain). The incidence and severity of powdery mildew were determined on leaves three weeks after the onset of flowering and on clusters at harvest. The values for both variables were smaller than those recorded for other fungal diseases, although great differences in susceptibility between the different genotypes were observed. The most susceptible was Castanal (recently included in the Spanish Registry of Commercial Varieties), a genotype native to the O Rosal subzone of the Rias Baixas denomination of origin area. The present results could help viticulturalists grow different grapevine genotypes more successfully in regions with climatic conditions similar to those where the study was undertaken.

Value of two Spanish live grapevine collections in the resolution of synonyms, homonyms and naming errors

Background and Aims Numerous descriptions have been made of the wines produced in the past, however, the grapevine genotypes have been poorly recorded. Naming errors are also common, a problem that could negatively impact scientific work and cause economic damage to wine markets. The aim of the present work was to compare the accessions from Galicia and Asturias held in the Mision Biologica de Galicia‐Consejo Superior de Investigaciones Cientificas and El Encin‐Instituto Madrileno de Investigacion y Desarrollo Rural, Agrario y Alimentario collections in Spain in order to resolve synonyms, homonyms and naming errors in both. Materials and Methods The accessions of these collections were compared in terms of their leaf and bunch ampelographic characteristics, via simple sequence repeat analysis and via the examination of old photographs and other historic documentation. Results The two collections were found to hold 59 distinct genotypes from the two regions. Ten were unique to the Mision Biologica de Galicia‐Consejo Superior de Investigaciones Cientificas collection and four to the El Encin‐Instituto Madrileno de Investigacion y Desarrollo Rural, Agrario y Alimentario collection – rather fewer than expected. Traces of intra‐genotype variation were seen for some genotypes. Conclusions The comparison of the accessions allowed some problems of genotype identity and origin to be identified and resolved. The possible intra‐genotype variation detected should be examined in greater depth. The results also highlight the value of well documented live collections, gathered at different times and curated in different places, for this type of work, as well as in the conservation of world viticultural heritage. Significance of this Study These findings open up paths for future research on the material conserved, and its commercial exploitation.

Ampelographic and agronomic variability of two Iberian grapevine cultivars grafted onto 110R and SO4 rootstocks.

This work compares the effects of two different rootstocks (110R and SO4) on a number of ampelographic and production variables in two grape cultivars (‘Albariño’ and ‘Caíño Tinto’) of great importance in north-western Spain and in northern Portugal. Plants growing under the same conditions were studied over a period of three years. The effect of the two rootstocks differed depending on the cultivar. No influence of rootstock was seen on production in ‘Albariño’, but significant differences were seen in terms of cluster weight and weight of pruning wood in ‘Caíño Tinto’. The rootstock type did not influence the ampelographic characteristics of either cultivar.