Aroma development from non-floral grape precursors by wine lactic acid bacteria

A fraction of glycosidic precursors extracted from different non-floral grapes was reconstituted with a synthetic wine and was fermented by lactic acid bacteria belonging to different genera previously selected for their glycosidase activity (Oenococcus oeni, Lactobacillus brevis, Lactobacillus casei). Malolactic fermentation was allowed to take place for 45 days, but was only complete for O. oeni. Wines were analyzed by sensory analysis and gas chromatography–mass spectrometry in order to determine sensory descriptors and volatile composition. Both O. oeni and Lactobacillus strains were able to release, in the conditions tested (model wine), terpenes, norisoprenoids, phenols and vanillins. Although only small increments in the concentrations were observed, the presence of bacteria caused a broad change on the odour profile of the samples.