OENOCOCCUS OENI RELEASE OF GLYCOSIDICALLY BOUND FLAVOUR COMPOUNDS IN CHARDONNAY DURING MALOLACTIC FERMENTATION

The work was undertaken to establish whether O. oeni is able to release aglycons from authentic wine glycosides during MLF. In order to study wine glycosides which had not already been subjected to bacterial glycosidases, wine was prepared from undamaged grapes fermented with pure yeast culture (AWRI 838 starter culture for alcoholic fermentation). Glycosides were isolated from a Chardonnay wine that had not been subjected to any bacterial activity during its preparation and glycosides were then used in a chemically defined wine (CDW) medium. O. oeni strain Lalvin EQ54 was inoculated and various glycosidic enzymes were added to the medium creating eight combinations, in two duplicates, to reveal the specificity of the bacterial glycosidases and to establish the successive release of sugar moieties. At MLF ending, routine analysis of wine were performed and glycosidases activity was assessed. Results obtained pointed out that O. oeni has the necessary glycosidases for the sequential liberation of the disaccharide sugars from wine glycosides. Glycosidases, produced by Oenococcus oeni strain contributed to the release of volatile aglycons from their glycosylated precursors. Release of aglycons was increased when purified glycosidase were added to O. oeni strain. We advise you to read the entire aticle. Original Title: Release of glycosidically bound flavour compounds of Chardonnay by Oenococcus oeni during malolactic fermentation