Post vinfication micro-ecology of wines; the role of phenolic composition and the effects on quality

The combination of high acidity and ethanol content makes the post fermentation, wine environment highly selective with only very few species of yeast and (mainly) lactic acid bacteria (LAB) able to interact with the medium. However post vinification microbial processes (malo-lactic fermentation and, where it occurs, spoilage) can profoundly effect the chemical composition of wine that can impact on the quality of the final product. Grape- and wood-derived, phenolic compounds compounds are known to influence the behavior of wine microbes but this is as yet still poorly defined. We will employ a combination of analytical chemistry (from GC, GC-O, GC-MS and LC, LC-MS) and microbial community -directed methods – including those optimized within ESR5, to study the impact of different, predominantly post-vinification, microbial communities on the phenolic composition of wines (including volatile phenols and their precursors) during the winemaking process. A metabolomic approach will also enable us to view from the opposite direction, i.e. how the phenolic profile influences the development of the microbial community and consequently the composition of the medium (wine).

Further information

• Center for Biotechnology and Fine Chemistry, Catholic University of Portugal