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For the first time, the influence of different vine management was evaluated in relation to volatile profile and sensory perception through GC×GC/TOFMS, QDA, GC-FID, GC/MS, and GC-O. GC×GC/TOFMS analyses and QDA have shown that a larger spacing between vine rows (2 rather than 1m), attachment of shoots upwards, and irrigation did not result in wine improvement. Conversely, wines elaborated with grapes from a vine with a lower bud load (20 per plant; sample M1) stood out among the other procedures, rendering the most promising wine aroma. GC×GC/TOFMS allowed identification of 220 compounds including 26 aroma active compounds also distinguished by GC-O. Among them, eight volatiles were important to differentiate M1 from other wines, and five out of those eight compounds could only be correctly identified and quantified after separation in second dimension. Higher levels of three volatiles may explain the relation of M1 wine with red and dry fruits.

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Parte da Tese de Mestrado do primeiro autor. Universidade Estadual de Ponta Grossa. Ponta Grossa PR. 2010. RESUMOOs vírus são capazes de induzir desordens metabólicas e estruturais nas células vegetais, as quais podem variar com a espécie viral e a suscetibilidade da planta. Neste enfoque, videiras (Vitis vinifera) com e sem sintomas de infecção viral, das cvs. Cabernet Franc e Cabernet Sauvignon, em dois vinhedos comerciais, foram avaliadas comparativamente quanto ao potencial fotossintético (fotossíntese de saturação luminosa, radiação de saturação, ponto de compensação de luz, taxa de respiração no escuro, rendimento quântico aparente, clorofilas total, a e b), quanto ao metabolismo de carbono foliar (açúcares solúveis totais e amido) e quanto a qualidade enológica da uva produzida (sólidos solúveis totais -°Brix, densidade, pH e acidez total titulável no mosto -ATT; intensidade total da cor e índice de polifenóis totais na casca). Nas plantas sintomáticas foram detectados o Grapevine leafroll-associated virus 2 (GLRaV-2) e o Rupestris stem pitting-associated virus (RSPaV) pelo teste ELISA para seis vírus, os quais provocaram reduções significativas na clorofila e no potencial fotossintético, em ambas as cultivares. As folhas de plantas infectadas também apresentaram acúmulos significativos de carboidratos, caracterizando um bloqueio no transporte de carbono desses órgãos. Quanto à qualidade enológica da uva, no momento da colheita as plantas infectadas apresentaram uvas com nível de maturação significativamente menor, considerando todos os parâmetros tecnológicos do mosto (°Brix, densidade, pH, ATT e polifenóis). De modo geral, destaca-se que estes vírus podem comprometer diretamente a capacidade produtiva e a qualidade da produção destas cultivares. Palavras-chave: Vitis, RSPaV, GLRaV-2, fotossíntese, açúcares, uva. ABSTRACT Leaf physiology and enologic grape quality of virus-infected plantsViruses may induce metabolic and structural disarray in plant cells to varying degrees depending on viral species and plant susceptibility. With this focus, grapevine plants (Vitis vinifera) cvs. Cabernet Franc and Cabernet Sauvignon, symptomless and showing symptoms of virus-infection, in two commercial vineyards were comparatively analyzed. The parameters were: 1. photosynthetic potential (light-saturated rate of photosynthesis, saturating light intensities, light compensation point, dark respiration rate, apparent quantum yield, chlorophyll a and b); 2. foliar carbon metabolism (total soluble sugars and starch), and 3. enologic quality of the produced grapes (total soluble solids -°Brix, density, pH and titerable total acidity in the must; total color intensity and total polyphenols in berry skins) were recorded. In symptomatic plants Grapevine leafroll-associated virus 2 (GLRaV-2) and Rupestris stem pitting-associated virus (RSPaV) have been detected by ELISA carried out for six viruses. The virus infections induced significant reductions in chlorophyll content and in photosynthetic potential of both cultivars. Leave...

Winemaking processes and volatile compounds perform an important role in contributing to the quality of wines. ‘Marselan’ is a red grape variety grown in several countries such as France, Brazil and China. This variety has gained international interest in recent years. The volatile profile of Brazilian ‘Marselan’ red wines during various winemaking processes was studied. Four processes were applied: thermovinification, integrale vinification, classic winemaking and classic winemaking pretreated with ultrasound. The wines were characterized with conventional physicochemical analyses, volatile composition and sensory analysis. Sixty-three volatile compounds were identified and semi-quantified. The wines presented different sensory characteristics. The thermovinification and classic winemaking with ultrasound application methods showed a large presence of esters contributing to a fruity and overmaturation aroma in the volatile profile and sensory analysis. An increased presence of vegetal and sulfurous aromas was observed in the wines from the classic winemaking and integrale vinification processes. This effect was most likely attributed to the lower influence of esters which generated a greater perception of other compounds and conferred these aromas. The differences can be directly linked to the various extraction rates in the vinification processes, which result in different interactions between the compounds.