Contribution to the knowledge of malolactic fermentation influence on winearoma

In this work, we study two aspects of malolactic fermentation: the use of i ndustrial lactic acid bacteria starter-cultures in a white Sauvignon wine a nd the effects of the bacterial activity on the composition of wines in ter ms of volatile substances from oakwood during partial malolactic fermentati on in barrels. A sensory evaluation was made by the use of discriminative a nd descriptive methods. The consequences of bacterial development are thus limited, but it is nevertheless possible to make characteristic observation s. The carbonyl substances were formed in connection with a more or less fa st bacterial growth and a degradation of the citric acid. However, the infl uence of the bacterial starter-culture is difficult to establish. The conce ntration of the compounds resulting from wood was higher in the wines after malolactic fermentation compared to a wine not having undergone bacterial development. Greater complexity was perceived during the sensory analysis, with buttered, spiced, roasted, vanilla, and smoked notes. On the other han d, the intensity of the descriptors characteristic of grape variety decreas ed.