Effect of a yeast industrial lysate on the evolution of red wines after bottling [Effet d'un lysat industriel de levure sur l'évolution des vins rouges en bouteille]

The use of yeast polysaccharides in the stabilization of the phenolic fraction of red wines, is a recent application. Increasing amounts of an industrial product made by thermal lysis of yeast cell walls were added to two red wines: the effects on phenolic and coloring fraction were studied, in relation to bottle storage. The effects on wine color and astringency, showed strongly dependence to the characteristics of the wine and to the dosage; they were limited to short times of conservation. In fact, a loss in the positive effects on color intensity was observed during the bottle storage, probably as a result of the modifications in the colloidal equilibrium during conservation. The complexity of the conditioning factors makes other studies necessaries, in order to optimize this kind of technology.