Colour stabilization of red wines by microoxygenation treatment before malolactic fermentation

Microoxygenation allows the addition of small, continuous and controlled amounts of oxygen, in order to improve wine quality. Then, the effect of this treatment on colour stabilization and phenolic composition was studied. Four single varietal red wines were elaborated during three consecutive vintages. One part of them was microoxygenated before malolactic fermentation, the other part being maintained in stainless steel tanks without microoxygenation.The results showed that the microoxygenation treatment slightly decreased the global phenolic composition of wines but allowed the stabilization of wine colour, without showing an appreciable increase in tonality values. Thus, the slow and controlled addition of small amounts of oxygen could partially avoid the colour drop habitually occurring in red wines after malolactic fermentation.