Effects of the pre-fermentative addition of chitosan on the nitrogenous fraction and the secondary fermentation products of SO -free red wines.

Background: Different red winemaking were carried out to evaluate the effects of the prefermentative addition of chitosan, as an alternative to the use of SO , on the secondary products of alcoholic fermentation, yeast available nitrogen (YAN), biogenic amines and ethyl carbamate.

Results: The wines made with chitosan presented higher total acidity and higher content of tartaric and succinic acids than those made only with SO . The use of chitosan in winemaking resulted in wines with higher glycerol and diacetyl content without increasing the concentration of ethanol, acetic acid, acetaldehyde or butanediol.