Wine growing regions global climate analysis

The main objective of this work is to study and model the impact of the polyphenolic profile on the stability and quality of wine aroma during oxidative aging.

The consequences of the global climate change in the vitiviniculture are revealed as a gap between phenolic and technological grape maturities, higher grape sugar concentration that leads to high wine alcohols levels, lower acidities and high pH values, among others. The unbalanced phenolic maturity caused in this scenario leads to harsh astringency and to instable colour of wines. Previous studies have reported that the addition of yeast mannoproteins (MPs) to wines may have positive effects on these two organoleptic properties due to their capability to interact with wine polyphenols [1]; however, studies about the effect of the pH on these interactions have not been carried out so far.

Chardonnay is the world’s most planted white grape variety and has met a great commercial success for decades.

Nowadays, the trend is to reduce the use of chemical inputs in the food sector, including in oenology. One of the inputs widely used in the wine making process are sulfites, for its several properties: antimicrobial and antioxidiant. This use isn’t without consequences on consumer’s health and environment, it can lead for example to allergic reactions and pollution. To limit the addition of chemical inputs, microbial alternatives are used. It consists to inoculate in grape must, a micro-organism able to inhibit the growth of the negative indigenous flora during the phase before the fermentation and to guarantee the sensory qualities of wines.

The plant surface typically comprises of various epidermal cell types which synthesise and deposit a protective waxy layer known as the cuticle. The cuticle is a significant contributor to important crop traits related to drought tolerance, biotic stress, postharvest fruit quality as well as providing structural support. In this work we have investigated grape berry cuticle formation in the context of the accumulation of anti-fungal specialised metabolites and the ability of the cuticle to structurally cope with the rapid expansion of ripening berries. Metabolic QTL analysis was performed in a grapevine cross population, using chemical profiling data collected via GC-MS analysis for cuticular waxes.