Microoxygenation (MO) allows the addition of small, continuous, and controlled amounts of pure oxygen or air to wines. This technique was developed to enhance quality of red wines. However, its positive effects are only achieved with adjusted supplies of oxygen, adequate for each kind of wine. The aim of this study was the evaluation of MO treatment effects on the sensory properties of different young single-variety red wines from two consecutive vintages. Wines from four diverse varieties were made to semi-industrial scale (5000 kg of grapes for each one). MO treatment was applied between alcoholic and malolactic fermentation to 2000 L of each wine, and it was adjusted to the characteristics of each wines. Descriptive sensorial analysis was carried out to evaluate the effects of MO treatment. The results obtained showed that, independently of the sort of wine, MO allowed to stabilize the wine color, intensifying the color intensity as well as the blue or violet tones; it also reduced notes such as herbaceous, vegetal, reduction, dirty, or sulphidric ones; however increased fruity note and had a structuring effect modifying the global astringency as well as its particular components. The intensity of oxygen effects varied among wines, being detected variety and vintage factors of variability.
Study of changes organic acids in red wines during malolactic fermentation
