Aroma compounds involved in the fruity notes of red wines potentially adapted to climate change.

Wine polysaccharides (PS) play an important role in balancing mouthfeel and stability of wine and even influence aroma volatility. Despite this, there is limited research into the effect of winemaking additives on the polysaccharide profile and other macromolecules of New Zealand (NZ) Pinot noir wine. In this study the influence of a selection of commercial S. cerevisiae strains on the chemical profile, including polysaccharides, of New Zealand Pinot noir (PN) wine was investigated. Research scale PN fermentations using five strains of commercially available S. cerevisiae (Lalvin EC1118 and RC212, Levuline BRG YSEO, Viallate Ferm R71 and R82) were undertaken. PS were qualified and quantified using HPLC-RID.

The use of bentonite in oenology rounds around the limpidity and the stability that determine consumer acceptability. As a matter of fact, the haze formation in wine reduces its commercial value and makes it unacceptable for sale. Stabilization treatments are, therefore, essential to ensure a long-time limpidity and to forecast the formation of deposits in the bottle. Bentonite that is normally used in oenology for clarifying-fining purpose, shows a natural clay-based mineral structure allowing it to swell and to jelly in water and hence in must and wine.

Grapes (Vitis sp.) are considered a major source of phenolic compounds such as flavonols, anthocyanins and stilbenes. Studies related to the beneficial effects of these compounds on health have encouraged research aimed at increasing their concentration in fruits. On this behalf, several plant growth regulators such as jasmonic acid and its volatile ester, methyl-jasmonate (MeJa), have demonstrated promising results in many fruits. However, Brazilian subtropical climate might interfere on treatment response. The present study aims to evaluate the application of MeJa in the pre-harvest period in Concord and Isabel Precoce grapes (Vitis labrusca L.).

Alcoholic fermentation is the main step for winemaking, mainly performed by the yeast Saccharomyces cerevisiae. But other wine yeasts called non-Saccharomyces may contribute to alcoholic fermentation and modulate the wine aroma complexity. The recurrent problem with the use of these non-Saccharomyces yeasts is their trend to die off prematurely during alcoholic fermentation, leading to a lack of their interesting aromatic properties searched in the desired wine. This phenomenon appears to be mainly due to interactions with S. cerevisiae. These interactions are often negatives but remain unclear because of the species and strain specific response. Among the non-Saccharomyces yeasts, Lachancea thermotolerans is a wine yeast naturally found in grape must and well known as a great L-lactic acid producer and an aromatic molecules enhancer, but its behavior during alcoholic fermentation can be completely different in co-fermentation with S. cerevisiae in function of strain used.

Climate change is having an unprecedented impact on the wine industry, which is one of the major agricultural sectors around the world. Global warming, combined with the variation in rainfall patterns and the increase in frequency of extreme weather events, is significantly influencing vine physiology and exposing, more frequently, plants to severe biotic and abiotic stresses. This represents a challenge for viticulturists who need to take complex decisions to adjust vineyard management and achieve oenological goals.