CONSUMER PERCEPTION OF INTERSPECIFIC HYBRID RED WINE COLOR IN RELATION TO ANTHOCYANIN PROFILE AND CHEMICAL COLOR PARAMETERS

Pre-fermentative skin maceration is a technique used in white wine production to enhance varietal aroma, but it can increase protein concentration, leading to protein instability and haze formation [1]. To prevent protein instability, wine producers typically use fining agents such as bentonite, before wine bottling, which can negatively impact sensory characteristics and produce waste [2,3]. The aim of this study was to understand the impact of alternative techniques such as the application of polysaccharides (k-carrageenan and chitosan) on protein stability and on the wine macromolecular composition.

The importance of the non-Saccharomyces yeasts (NSY) in winemaking has been extensively reviewed in the past for their aromatic or bioprotective capacity while, recently their antioxidant/antiradical potential has emerged under winemaking conditions. In the literature the antioxidant potential of NSY was solely explored through their capacity to improve glutathione (GSH) content during alcoholic fermen- tation [1], while more and more studies pointed out the activity of the non-glutathione soluble fraction released by yeasts [2].

In recent years, consumer demand for products without chemical additives increased, becoming a priority for the wine sector. SO₂ is widely used for its multiple properties including antiseptics, antioxidants and antioxidasics and the strategy of bioprotection in winemaking represents now an alternative to this chemical additive. In oenology, results have highlighted the interest of bioprotection to limit the development of microorganisms like Hanseniaspora uvarum and thus reduce the doses of sulphite. Indeed, this species is considered because of its acetic acid and methyl butyl acetate production, the latter can cover the varietal character of wines.

Red wine ageing is an important step in the red wine evolution and impacts its chemical and sensory characteristics through many chemicals and physico-chemical reactions. The kinetics of these evolutions depend on the wine studied and influence the wine ageing potential. Generally, high quality red wines require a longer period of bottle ageing before consumption¹. The ageing potential is an impor-tant parameter for wine quality and is related to the capacity of a wine to undergo oxidation over time². Phenolic compounds which are ones of the main substrates for oxidation can then potentially modulate ageing potential³.

Polyphenols are secondary metabolite widely distributed in plant kingdom such as in fruits, in grapes and in wine. During the winemaking process, polyphenols are extract from the skin and seed of the berries. Fining is an important winemaking step just before bottling which has an impact on wine stabilization and clarification. Most the time, fining agent are animal or vegetal protein while some of them can be synthetic polymer like PVPP or natural origin like bentonite.