The quantitative determination of volatile compounds of Chardonnay wines using HS-SPME-GC × GC/TOFMS along with the determination of odor activity value (OAV) and relative odor contribution (ROC) of volatiles are reported for the first time. The use of GC × GC/TOFMS for the analysis of Chardonnay wine of Serra Gaucha resulted in the tentative identification of 243 compounds, showing the superior performance of this analytical technique for this specific varietal wine, considering that the number of compounds usually separated by 1D-GC for this type of wine is lower. Furthermore, 42 compounds co-eluted in the first dimension and 34 of them were separated in the second dimension, while the others were resolved by spectral deconvolution (8), which indicates that the conventional 1D-GC/MS may result in misleading results. The calculation of OAV and ROC allowed the determination of the volatile compounds that presented the greater contribution to wine aroma. Ethyl octanoate, ethyl hexanoate, ethyl butanoate, and beta-damascenone showed the highest OAV and ROC values, although other 43 compounds showed also potential to contribute to wine aroma. Figures of merit of the developed method were: accuracies from 92.4 to 102.6%, repeatability from 1.2% to 13.4%, LOD from 0.001 μg L −1 (ethyl isovalerate and hexanoic acid) to 2.554 μg L −1 (ethyl 3-hydroxybutanoate), LOQ from 0.003 μg L −1 (ethyl isovalerate and hexanoic acid) to 7.582 μg L −1 (ethyl 3-hydroxybutanoate).

This report has investigated the seasonal temperatures influences (winter and summer) of five vineyards at different altitudes on the concentrations of 2-methoxy-3-isobutylpyrazine (MIBP), alpha- and beta-ionone, and beta-damascenone in 2004 or 2005 vintages of Cabernet Sauvignon wines from Santa Catarina State, Brazil. Sensorial analyses were also carried out on the wine samples and compared to altitude and climate. Significant regression was observed between MIBP concentrations and the vineyard's altitude. No significant relation was observed between alpha- and beta-ionone and beta-damascenone with the vineyard's altitude. Principal component analysis positively correlated wines from higher altitudes with a "bell pepper" aroma. Conversely, the wines made with grapes from lower altitudes were correlated with "red fruits" and "jam" aromas. An important relation between the bell pepper aroma and the lower winter temperature was observed. A strong negative correlation was also observed between seasonal temperatures and vineyard altitude as well as between MIBP content and seasonal temperature of growing grapevines.

Wine aroma is an important characteristic and may be related to certain specific parameters, such as raw material and production process. The complexity of Merlot wine aroma was considered suitable for comprehensive two-dimensional gas chromatography (GC×GC), as this technique offers superior performance when compared to one-dimensional gas chromatography (1D-GC). The profile of volatile compounds of Merlot wine was, for the first time, qualitatively analyzed by HS-SPME-GC×GC with a time-of-flight mass spectrometric detector (TOFMS), resulting in 179 compounds tentatively identified by comparison of experimental GC×GC retention indices and mass spectra with literature 1D-GC data and 155 compounds tentatively identified only by mass spectra comparison. A set of GC×GC experimental retention indices was also, for the first time, presented for a specific inverse set of columns. Esters were present in higher number (94), followed by alcohols (80), ketones (29), acids (29), aldehydes (23), terpenes (23), lactones (16), furans (14), sulfur compounds (9), phenols (7), pyrroles (5), C13-norisoprenoids (3), and pyrans (2). GC×GC/TOFMS parameters were improved and optimal conditions were: a polar (polyethylene glycol)/medium polar (50% phenyl 50% dimethyl arylene siloxane) column set, oven temperature offset of 10 °C, 7s as modulation period and 1.4s of hot pulse duration. Co-elutions came up to 138 compounds in 1D and some of them were resolved in 2D. Among the co-eluted compounds, thirty-three volatiles co-eluted in both 1D and 2D and their tentative identification was possible only due to spectral deconvolution. Some compounds that might have important contribution to aroma notes were included in these superimposed peaks. Structurally organized distribution of compounds in the 2D space was observed for esters, aldehydes and ketones, alcohols, thiols, lactones, acids and also inside subgroups, as occurred with esters and alcohols. The Fischer Ratio was useful for establishing the analytes responsible for the main differences between Merlot and non-Merlot wines. Differentiation among Merlot wines and wines of other grape varieties were mainly perceived through the following components: ethyl dodecanoate, 1-hexanol, ethyl nonanoate, ethyl hexanoate, ethyl decanoate, dehydro-2-methyl-3(2H)thiophenone, 3-methyl butanoic acid, ethyl tetradecanoate, methyl octanoate, 1,4 butanediol, and 6-methyloctan-1-ol.

Headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry detection (GC×GC/TOFMS) was used to analyse the volatiles in five types of wines elaborated with grapes of Cabernet Sauvignon, Merlot, Chardonnay, Sauvignon Blanc and Pinot Noir varieties. Fisher ratio, principal component analysis (PCA) and stepwise linear discriminant analysis (SLDA) were used to develop a discriminant model and, as a result, 12 volatile compounds enabled differentiation and classification of wines according to grape cultivars. A detailed examination of GC×GC/TOFMS data showed that the use of one-dimensional gas chromatography with a mass spectrometric detector (1D-GC/MS) would probably result in misidentification of some of these 12 compounds, as they showed partial coelution with other components in the first chromatographic dimension.

Phenolic composition and antioxidant activity of agroindustrial residuesRecebido para publicação 08.07. BV (20,94±0,46; 8,03±0,43)> BI (16,57±0,19; 4,41±0,01)> BG (3,41±0,09;1,88±0,06 PV (20.94±0.46; 8.03±0.43) >PI (16.57±0.19; 4.41±0.01)>PG (3.41±0.09; 1.88±0.06

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Pouco é conhecido sobre o aroma dos vinhos produzidos na região sul do Brasil, que é responsável por 90% da produção brasileira de vinho. Um método baseado na microextração em fase sólida no modo "headspace" (HS-SPME) foi desenvolvido para a extração de compostos voláteis e semivoláteis relacionados ao aroma de vinhos base, de cinco diferentes vinícolas do estado do Rio Grande do Sul (Brasil). A relação entre a composição volátil, qualidade aromática e avaliação sensorial dos vinhos Chardonnay foi investigada neste estudo. As condições otimizadas do método de HS-SPME foram: utilização da fibra DVB-CAR-PDMS, 1 mL de amostra, 30% de NaCl, 45 min de extração a 55 ºC, sem o uso de diluição e agitação da amostra. Dezoito compostos foram identificados e catorze foram tentativamente identificados. Os ésteres foram os compostos majoritários (56%) e os outros compostos minoritários pertencem à classe dos álcoois e ácidos. Os vinhos do Vale dos Vinhedos e de Pinto Bandeira apresentaram a mais alta pontuação em relação aos parâmetros sensorais avaliados. Estes vinhos foram caracterizados por altas concentrações de ésteres etílicos, o que contribui para o aroma frutado dos vinhos.Very little is known about the aroma of wines produced in the South part of Brazil, a region that is responsible for 90% of the Brazilian wine production. A headspace solid phase micro extraction (HS-SPME) method was developed for the extraction of volatile and semivolatile compounds related to the aroma of base wines of five different wineries of the state of Rio Grande do Sul (Brazil). The relationships among volatile composition, aroma quality and sensory evaluation of Chardonnay base wines were performed in this study. Optimum conditions for HS-SPME included use of DVB-CAR-PDMS coating, wine samples without further dilution, no stirring, sample volume of 1 mL, 30% of NaCl, extraction time and temperature of 45 min and 55 ºC, respectively. Eighteen compounds were identified and fourteen were tentatively identified in the samples. The majority (56%) of them was esters and other minor components were alcohols and acids. The sensory analysis of Vale dos Vinhedos and Pinto Bandeira samples showed the highest quality scores, characterized by higher concentrations of ethyl esters, which contributes to the fruity aroma of these wines.Keywords: flavour, sparkling wine, SPME, base wine, volatiles IntroductionAroma is one of the most important factors in determining wine character and quality. The compounds that define wine aroma are related to acceptance or rejection of wines by the consumers. Sparkling wines produced by traditional or Champenoise method entails double fermentation Welke et al. 679 Vol. 23, No. 4, 2012 followed by aging of the wine in contact with the yeast in the bottle. The base wine is obtained from the first fermentation. After this step, a solution containing sugar and yeast is added to the base wine to provide proper conditions for the second fermentation. Therefore, the base wine can be considered as a decisive point for ob...