Caracterização físico-química de vinhos de uvas viníferas e uvas americanas e avaliação do processo oxidativo por ozonização

• Autor(a) principal: Souza, Michelle Izolina Lopes de
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2942
• topic: Vinho; Ozonização; Caracterização físico-química; Wine; Ozonation; Physico-chemical characterization; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS

Brazilian wine industry has always been characterized by the production of common wine from american grapes, more adaptable to climatic conditions in Brazil. However, the fine wines produced from the varieties of the specie Vitis vinifera are considered of better quality and their production and consumption has increased significantly in Brazil and worldwide. Their wines are clearly distinct in sensory terms, although its composition, in terms of legislation, is the same. The first part of this study had the objective of physicochemical characterization of wines from american grapes and wines from vinifera grapes and the comparison of the composition of these wines. The wines from vinifera species showed, in general, higher alcohol content, pH, total soluble solids, reducing sugars, dry extract, dry extract lowered, total and combined sulfite, and lower acidity. These characteristics can show the best fit of the vinifera grapes to the winemaking process. The other parameters, regarding the color and the volatiles compounds, did not show similar characteristics to wines of the same group, indicating a non-dependency on the grape species, but on its variety. In order to improve the characteristics of color, flavor and aroma of this drink, techniques have been developed to promote its oxidation, improving its quality, which is a decisive factor when choosing a wine. Therefore, the second part of this study evaluated the oxidation process by ozone, aiming the acceleration of its maturation process, and its implications on the chemical characteristics and color of wines. A significant increase in the concentration of acetaldehyde, the oxidation product of ethanol, and reduction of the concentrations of total sulfite, sulfite free, anthocyanins, monomeric anthocyanins, polymeric anthocyanins and phenolic compounds was observed. Overall, these reductions were proportional to the concentration of ozone applied and reflected in the characteristics of color and antioxidant capacity of wines, in a way that the effect of ozonation on these properties was higher than expected.