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Development of an integrated process for continuous winemaking

Tese de Doutoramento em Engenharia Química e Biológica ; Microorganisms play an important role in the food industry, particularly in the processing of foods and beverages. In wine production, two consecutive fermentation processes occurs, involving yeasts (alcoholic fermentation) and lactic acid bacteria (malolactic fermentation), its control is being crucial to obtain high quality products. Considering that t...

Utilização da extração em fase sólida seguida de análise por GC-MS na caracteri...

Uma das características mais significativas dos vinhos é o aroma[1]. De acordo com a sequência biotecnológica empregue na elaboração do vinho, o aroma está geralmente dividido em três grupos: aroma primário, que engloba o varietal e o préfermentativo, aroma secundário ou fermentativo e aroma terciário ou pós-fermentativo[1]. Embora seja elevado o número de constituintes voláteis de um vinho passíveis de contrib...

Changes in free and bound fractions of aroma compounds of four Vitis vinifera c...

The volatile composition of white Agudelo, Blanco lexitimo, Godello and red Serradelo cultivars (NW Spain) harvested at two different stages of ripening have been evaluated. C6-compounds, alcohols, volatile fatty acids, monoterpenes, C13-norisoprenoids, volatile phenols and carbonyl compounds were identified and quantified in free and glycosidically bound forms by gas chromatography–mass spectrometry (GC–MS). T...

Early leaf removal impact on volatile composition of Tempranillo wines

Early defoliation is a very innovative technique in viticulture used for yield management. The effects of early leaf removal performed manually and mechanically at two different phenological stages, pre-bloom and fruit set, on the volatile composition of Tempranillo (Vitis vinifera L.) wines were studied. Volatiles were identified and quantified by gas chromatography Early leaf removal only modified the total c...

Evaluating the potential of wine-making residues and corn cobs as support mater...

Three wine-making residues(grape seeds, skins and stems), and corn cobs were evaluated as support material for immobilization of Saccharomyces cerevisiae and the ethanol production by the immobilized cells was assessed. The main objective of this study was to find an abundant and low cost material suitable for the cells immobilization and able to be used in a next step of wine production by immobilized yeast ce...

Correlation between volatile composition and sensory properties in Spanish Alba...

To characterize the flavour of Albariño wines, a total of 35 samples representing five geographic areas from Denomination of Origin Rías Baixas were analyzed by sensory descriptive analysis and instrumental analysis (GC-FID). The objective of this work was to study the correlation between instrumental analysis and sensory perception of wine constituents. The results of the investigation were presented by means ...

Volatile composition of wines from cvs. Blanco lexítimo, Agudelo and Serradelo ...

Wine aroma is formed by volatile compounds of different chemical natures and origins. Betanzos is the most northern viticole geographic area from Galicia (NW Spain). The aromatic profiles of wines produced from two white varieties (Blanco lexítimo and Agudelo) and one red variety (Serradelo) from Betanzos, harvested in 2006 and 2007, have been established by gas chromatography (GC/FID). A total of 35 varietal a...

Monoterpenic characterization of white cultivars from Vinhos Verdes appellation...

The monoterpenic composition of Alvarinho, Arinto, Avesso, Azal, Batoca, Loureiro and Trajadura Vitis vinifera cultivars from the Vinhos Verdes region (Portugal), in respect to free volatile compounds as well as glycosidically bound aroma precursors, was determined by GC-MS after adsorption on XAD-2 resin. Eighteen monoterpenic compounds were identified and quantified in the free form and twenty-two compounds i...

Selection of natural materials for use on yeast immobilization

Characterization and differentiation of seven vinhos verdes grape varieties on ...

The aromatic profiles of the 7 recommended cultivars for Vinho Verde wine production have been established with respect to monoterpenic and C13-norisoprenoids compounds, present either in free or in glycosidically bound fractions. Eighteen monoterpenic compounds have been identified and quantified in the free form and 22 in the glycosidically bound form. Fifteen C13-norisoprenoids compounds have been identified...