The effect of bacterial strain and aging on the secondary volatile metabolites produced during malolactic fermentation of tannat red wine.

During malolactic fermentation (MLF), lactic acid bacteria influence aroma and flavor of wines by the production of volatile metabolites and the modification of aroma compounds derived from grapes and yeasts. In an effort to isolate these bacteria properties as advantages for winemaking, this study aimed to assess the relative contribution of two aspects: the effects of lactic acid bacteria activity on the volatiles compounds in Tannat wines and the consequences of aging in bottle on aroma compounds produced during MLF. To our knowledge, this is the first report related to the effect of wine aging in bottle on the aroma chemical compounds produced by MLF. Solid phase extraction complemented with chromatographic techniques was used to study the wine aroma compounds. A sensory evaluation of the wines was also performed through descriptive methods. We demonstrated modifications in the concentration of acetates, ethyl esters, and other secondary metabolites during MLF. Major sensorial differences between wines that had undergone MLF were also noted. In addition, some modifications detected in the composition of Tannat wines as a consequence of the aging in bottle contributed to the change in differences between wines with and without MLF and furthermore between strains. These changes probably influence its fruity character.