Evolution of volatile compounds treated with selected non-Saccharomyces extracellular extract during Pinot noir winemaking in monsoon climate

摘要

The dynamic pattern of volatiles during Pinot Noir winemaking in monsoon climate with yeast extracellular extract (EE) treatment was analyzed. EE from selected Pichia fermentans and Rhodotorula mucilaginosa strains, and almond beta-glucosidase were added after 12-h alcohol fermentation, and the volatiles were determined every 24 h by GC-MS. After 6-month storage, wine aroma was evaluated instrumentally as well as by well-trained panelists. Results showed that enzyme treatments improved the contents of both varietal and fermentative volatiles. The levels of C-6 compounds, terpenes, and higher alcohols increased constantly during alcohol fermentation, whereas acetates, short and medium chain fatty acid ethyl esters, phenylethyls, and fatty acids increased first, followed by gradual decrease. EE treatment retarded the decrease of fruity ester content in wine. Mathematical regression between wine aroma and volatiles showed that the relatively higher contents of acetates, ethyl esters, and C-13-norisoprenoids in 6-month EE-treated wine were responsible for the improvement in floral aroma intensity.