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International audience; Microbial analyses of older and recently bottled wines demonstrated the ability of certain wine microbial species to survive and grow in the bottle. Among them, the spoilage yeast Brettanomyces bruxellensis was predominant, necessitating effective methods for removing these microorganisms before bottling. This work reports on various filtering assays. Each technique was evaluated over several years after bottling by microbial analysis and by volatile phenols measurements. The smaller the pore size, the more microbes were eliminated. Elimination of bacteria required a 0.3-mu m filter, but a 1.0-mu m filter was efficient for yeast elimination. In more tightly filtered wines, volatile phenol concentrations were lower than in less tightly filtered wines and in nonfiltered wines.

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), a- and ß-ionone, and ß-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 a- and ß-ionone and ß-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. Made available in DSpace on 2019-04-18T01:39:56Z (GMT). No. of bitstreams: 1 ASURVEY.pdf: 89286 bytes, checksum: c3ac75a59f3e1cebdc2a307b5817538f (MD5) Previous issue date: 2007