Investigation of VvDXS function and its effects on muscat flavor levels
In the present study the connection between the positional candidate gene VvDXS and muscat flavor was evaluated by investigating the expression profiles in the berries from a Muscat-type cultivar and a neutral cultivar and its nucleotide diversity of full ORF on grapevine accessions.
Aroma accumulation trends during berry development and selection of grape aroma candidate genes suitable for functional characterization
Grape flavour management in the vineyard requires knowledge of the derivation of individual flavour and aroma characteristics and the effects that different concentrations and interactions between these compounds have on flavour potential.
Chitosan elicits mono-glucosylated stilbene production and release in fed-batch fermentation of grape cells
In the present study, the optimal conditions of grape (Vitis vinifera cv ‘Barbera’) cell cultures in batch and fed-batch bioreactor processes were studied to specifically improve the production of mono-glucosylated stilbenes.
Seed phenolics oxidation: development of a new ripening index
During ripening seed tannins evolve, as demonstrated by the taste and color changes. In this work we tried to develop an objective, easy and fast index, useful for winemakers. In this direction we propose two different spectrophotometric indexes, one related to the molecular structure and tannin subunits linkages, and the other related to the antioxidant properties. Especially the second one gave very interesting and unexpected results.
Anthocyanins, flavonols and hydroxycinnamates of eight vitis vinifera cultivars from the balearic islands
In 2008 the anthocyanin, flavonol and hydroxycinnamate (HCT) contents of the skins of five coloured berry cultivars (‘Escursac’, ‘Esperó de Gall’, ‘Galmeter’, ‘Valent negre’ and ‘Vinater negre’), of two white cultivars (‘Argamussa’ and ‘Prensal blanc’) and of one weakly rose cultivar (‘Giró ros’), native from Balearic Islands, were characterized.
Modification on grape phenolic and aromatic composition due to different leafroll virus infections
Viral diseases are reported to cause several detrimental effects on grapevine. Among them, leafroll, due to single or mixed infection of GLRaV1 and GLRaV3, and rugose wood, associated to GVA, are considered the most widespread and dangerous.
Influence of light exclusion on anthocyanin composition in ‘Cabernet sauvignon’
The aim of this study was to determine how artificial shading influenced berry development and anthocyanin accumulation in ‘Cabernet sauvignon’. Opaque polypropylene boxes were applied to grape bunches over three different developmental stages.
Recent observations in wine oxidation
The chemistry of wine oxidation is captured in the reactions between the oxidation products, mostly reactive electrophiles, with other wine constituents. An understanding of both components and their reactions can lead to ideas and techniques to control and mitigate or enhance these reactions to allow for the desired development of the wine. Current investigations are yielding much useful information about oxidation reactions in wine.
Terroir aspects of harvest timing in a cool climate wine region: physiology, berry skin phenolic composition and wine quality
Preliminary experiment of harvest timing was carried out in Eger wine district, Hungary in 2009. In situ physiological responses, berry quality parameters and wine quality of the Kékfrankos grapevine were studied at two growing sites (Eger-K6lyuktet6 – non-stressed, flat vineyard, and Eger-Nagyeged hill – water stressed, steep slope vineyard).
Relevance of an immunoassay test for rapid detection of Botrytis cinerea in ‘Ugni blanc’ musts and wines
A new immunoassay kit, called Botrytis Lateral Flow Device has been tested to detect Botrytis cinerea on musts and wines. The comparison of the immunoassay result with the quantitative analysis of usual markers (gluconic acid, sugars and polyols) showed the relevance of this innovative tool.
Valorisation of nutraceutical and health-related properties of wine-grapes of Emilia-Romagna Italian region
In this work, results about the composition in polyphenols and polyamines in important wine-grape cultivars from the Emilia-Romagna region are presented. Spectrophotometric and HPLC analyses suggest that especially coloured berries are particularly rich of antioxidant species (stilbenes and catechins). Potential allergenic capability of biogenic amines was also characterized.
Toward a model of grape proanthocyanidin extraction during vinification
PAs are compartmentalised within the grape berry, and differ in their composition and degree of extractability. Within each compartment, the CWM limits PA extraction firstly by its degree of permeability and secondly its ability to complex with PA molecules.
Effectiveness of carboxymethyl cellulose (CMC) on tartaric stabilization of cava base wine
Recent EU regulations allow the use of carboxymethylcellulose (CMC) as a stabilization agent in wine. We tested CMC in bases for sparkling wines, which must be stabilized before the second fermentation that raises alcohol concentration by 1,5%.
Phenolic compounds present in natural haze protein of Sauvignon white wine
The aim of this work was the identification and quantification of polyphenols present in natural precipitate of a Sauvignon wine. Phenol analysis in wine precipitate was based on acid hydrolysis, CG- MS after derivatization, and LC-MS.
Protein stabilization of white wines by stabilizing filtration: pilot studies
Protein stabilization is an important part of the winemaking process of white wines, and in this work we present the results of protein stabilization of different monovarietal wines (Xarel.lo, Chardonnay, and Muscat) by a continuous stabilizing filtration process using a column packed with zirconium oxide operating in a continuous regime in a closed loop at pilot scale.
The use of zirconia dioxide enclosed in a metallic cage for the stabilisation of Chardonnay white wine
White wines are commonly stabilised by removing the heat unstable proteins through adsorption by bentonite, an effective but inefficient wine processing step. Alternative absorbents are thus sought and zirconium dioxide (zirconia) is recognised as a promising candidate.
Enological potential of autochtonous grape cultivars from Castilla y León (Spain) to elaborate sparkling wines: polyphenolic and biogenic amines and amino acid composition of base wines
In white wines, Verdejo wine stands out because of its high content in total amino acids. The total content in biogenic amines was low in all wines analyzed and putrescine was the predominant biogenic amine.
Polysaccharides and glycerol production by non-Saccharomyces wine yeasts in mixed fermentation
A great variability in the amount of polysaccharides recovered at the end of fermentations carried out by pure cultures of 89 non-Saccharomyces yeasts was observed. The utilization of the best polysaccharides producers in mixed cultures with S. cerevisiae resulted in considerable increases in the final concentration of polysaccharides and showed a strain dependent effect on glycerol production as compared to pure culture of S. cerevisiae.
Influence of dipping pretreatments in drying of ‘Pedro Ximenez’ grapes in chamber at controlled temperature
The influence of dipping pretreatments on drying of ‘Pedro Ximenez’ grapes, destined to the elaboration of sweet wines, in chamber at controlled temperature, has been studied. Changes in color and phenolic composition of raisins produced were observed during the process of raisining.
Chemical systems behind wine aroma perception: overview, genesis and evolution
This talk presents a revision of our knowledge and understanding of the role played by the different aroma chemicals in the positive aroma attributes of wine. A systematic approach to classifying the different aroma chemicals of wine is presented .