title: Glyoxal/glycolaldehyde: a redox system involved in malolactic fermentation of wine.
abstract: To verify the presence of glycolaldehyde in wine resulting from reduction of glyoxal after malolactic fermentation, sterilized solutions of synthetic cultures were inoculated with a lactic bacterium of the type Oenococcus oeni. Fermentation was also carried out on solutions with glyoxal added. The resulting glycolaldehyde concentrations turned out to be associated with the amounts of glyoxal present, and glyoxal was seen to decrease as glycolaldehyde increased. In addition, it was observed that glyoxal principally forms from breakdown of sugars and that reduction to glycolaldehyde is mainly promoted by bacterial activity. Finally, the ability of glycolaldehyde to induce browning of (+)-catechin in a model wine system was verified and turned out to be about 10 times higher than that of ascorbic acid.
authors.affiliation: Istituto Sperimentale per la Viticoltura, Viale XXVIII Aprile 26, I-31015 Conegliano (TV), Italy. flamini@mail.emmenet.it
authors.forename: Riccardo
authors.initials: R
authors.lastname: Flamini
authors.forename: Antonio
authors.initials: A
authors.lastname: Dalla Vedova
mesh_terms: D002392:Catechin / Q000737:chemistry; D005285:Fermentation; D006037:Glyoxal / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry*; D015416:Maillard Reaction; D008293:Malates / Q000737:chemistry*; D010084:Oxidation-Reduction; D012996:Solutions; D013242:Sterilization; D014920:Wine / Q000032:analysis*
chemical_list: D008293:Malates; D012996:Solutions; D019344:Lactic Acid; D006037:Glyoxal; C030298:malic acid; D002392:Catechin