Alimentary film to reduce cork taint and improve wine organoleptic quality

Planted between 2018 and 2019, the ‘New Vine’ system is a vineplot, comprising 169 individuals genotypes (5 vines/individual), located on a gravelous soil, in the INRAE Grande-Ferrade site (Villenave d’Ornon, France).

The marketability of the table grapes is highly influenced by the consumer demand; therefore the market value of the table grapes is mainly characterized by its berry size, colour, taste and texture. Girdling could cause accumulation of several components in plants above the ringing of the phloem including clusters and resulting improved maturity. The aim of the experiments was to examine the effect of girdling on berry texture characteristics and aroma concentration.

Initiatives have been ongoing in recent years to safeguard biodiversity in the oenological sector via a process of enhancement of ancient varieties, under a pressure of a market strongly oriented towards production deriving from native vines of specific geographical zones. In that sense, Aosta Valley
(Italy) has raised the need to preserve and characterize its minority vine varieties which have the potentiality to give varietal wines. Fumin represents the 7% of the production of the region with 16 hectares of vineyards and 753 hectolitres of derived wine. Due to its large phenolic potential, strong astringency and deep colour, it has long been, and is still today, assembled or blended with other varieties as occurs, for example, for the Torrette.

A crucial issue associated with the long-term impact of climate change in viticulture concerns the capacity of resilience of the typical varieties currently cultivated in traditional areas. Indeed, regions that are currently characterized by optimal climatic conditions can cease to be so in the future. At the same time, new premium wine production regions may arise north of 50oN. Both these threats and opportunities are based on the assessment of a very likely gradual temperature increase along the 21st century, resulting from the ensemble mean of the state-of-the-art climate projections. Such an assessment is orienting decision-makers and stakeholders to rethink the grapevine cultivation zoning, prefiguring, for each variety, a shift at higher latitudes and/or at higher altitudes areas.

Despite the extensive research performed during the last decades, the multifactorial mechanism responsible for the white wine protein haze formation is not fully characterized. Herein, a new model is proposed, which is based on the experimental identification of sulfur dioxide as a major modulating factor inducing wine protein haze upon heating. As opposed to other reducing agents, such as 2-mercaptoethanol, dithiothreitol and tris(2-carboxyethyl)phosphine hydrochloride (TCEP), the addition of SO2 to must/wine upon heating cleaves intraprotein disulfide bonds, hinders thiol-disulfide exchange during protein interactions and can lead to the formation of novel inter/intraprotein disulfide bonds. Those are eventually responsible for wine protein aggregation which follows a nucleation-growth kinetic model as shown by dynamic light scattering [1].