Multispectral fluorescence sensitivity to acidic and polyphenolic changes in Chardonnay wines – The case study of malolactic fermentation

Chitosan is a natural polymeric saccharide admitted by EU since 2011 for must and wine clarification, the reduction of some contaminants (e.g. ochratoxin A) and to prevent the development of wine microbialspoilage due to lactic acid bacteria or Dekkera/Brettanomyces yeasts.

Levels of esters derived from substituted acids increase during the first years of aging and some of them are strongly involved in red wine fruity aromatic expression.

The postharvest dehydration of grapes is a traditional practice to obtain wines with unique traits (e.g., sweet, dry/reinforced).

Brettanomyces bruxellensis is found in various ecological niches, but particularly in fermentative processes: beer, kombucha, cider and wine. In the oenological sector, this yeast is undesirable, as it can produce ethyl phenols, thus altering wine quality. These compounds are characterized by stable or horse-sweat aromas, unpleasant for consumers.

Specific inactivated yeast derivatives (SYDs) from S. cerevisiae are obtained through thermal, mechanical, and enzymatic processes and are used to enhance wine quality.