EXPLORING RED WINE TYPICITY OF CORBIÈRES: EVALUATION OF THE DEGREE OF IMPACT OF VINIFICATION PROCESS ON THE CHEMICAL COMPOSITION AND ORGANOLEPTIC PROPERTIES OF WINES FROM DIFFERENT TERROIR

Malolactic fermentation (MLF)¹, the decarboxylation of L-malic acid into L-lactic acid, is performed by lactic acid bacteria (LAB). MLF has a deacidifying effect that may compromise freshness or microbiological stability in wines² and can be inhibited by fumaric acid [E297] (FA). In wine, can be added at a maximum allowable dose of 0.6 g/L³. Its inhibition with FA is being studied as an alternative strategy to minimize added doses of SO₂⁴. In addition, wine yeasts are capable of metabolizing and storing small amounts of FA and during alcoholic fermentation (AF).

The light exposure of wine can be detrimental as a relevant loss of aromas takes place [1] and light-induced reactions can occur. The latter involves riboflavin (RF), a photosensitive compound, that is fully reduced by acquiring two electrons. When the electron-donor is methionine, the light-struck taste (LST) can appear leading to cooked cabbage, onion and garlic odours-like [2]. The use of oenological tannins can limit the appearance of LST in both model wine [3] and white wine [4]. This research aimed to evaluate the impact of certain oenological tannins, selected in a previous study as the most effective against LST [5], in both white and rosé wines.

Usually the winemaker consider polyphenols from the grape berry as an actor of the wine quality. There are frequently consider as a marker of grape maturity. It is commonly known that winemaker consider tannins and anthocyanins as main polyphenol actors for winemaking practices and wine quality. Here we will focus on the characterisation of lignins in grape seeds. Previous studies suggest that the seed is lignified [1], which could explain the change in colour of the seed when it reaches maturity and thus provide a reliable indicator for describing the maturity stage in the seed.

Microbial ecosystems are primary drivers of viticultural, oenological and other cellar-related processes
such as wastewater treatment. Metagenomic datasets have broadly mapped the vast microbial species
diversity of many of the relevant ecological niches within the broader wine environment, from vineyard
soils to plants and grapes to fermentation. The data highlight that species identities and diversity
significantly impact agronomic performance of vineyards as well as wine quality, but the complexity
of these systems and of microbial growth dynamics has defeated attempts to offer actionable
tools to guide or predict specific outcomes of ecosystem-based interventions.

Volatile compounds play a significant role on the organoleptic properties defining wines quality. This particular role was exploited in several studies with the aim to differentiate wines from a more or less extensive production area, according to their sensory profile [1], as well as their chemical composition [2,3] (Di Paola-Naranjo et al., 2011; Kustos et al., 2020). Indeed, since aroma compounds development in grapes depends primarily on the environmental conditions of the vines and grapes (soil and climate), it is conceivable that these parameters craft the aromatic signature of the wine produced, in relation to its origin (Van Leeuwen et al., 2020). In this work, a general study on the aromatic and sensorial profile of wines produced in five sub-regions of the Corbières denomination, a renowned red grape varieties viticultural region in South France, was reported.