Gluconic acid, its lactones, and SO(2) binding phenomena in musts from botrytized grapes.
Intramolecular gluconic acid esterification reactions led to the formation of two lactones, gamma- and delta-gluconolactone (glucono-1,4-lactone and glucono-1,5-lactone). The presence of the first has not yet been reported in must or wine. These lactones are in equilibrium with gluconic acid, gamma- and delta-gluconolactone representing, respectively, 5.8 and 4.1% of the acid level. Correlations between must SO(2) binding power, gluconic acid, and consequently its lactones are shown. The SO(2) affinity of a mixture containing this acid and gamma- and delta-gluconolactone was determined, and gluconic acid appeared to be indirectly responsible for approximately 8% of the bindable SO(2) in musts from botrytized grapes.
Barbe
Jean-Christophe
JC
Unité Associée INRA/Université Victor Segalen Bordeaux II, Faculté d'OEnologie, 351 Cours de la Libération, F-33405 Talence Cedex, France. jc-barge@enitab.fr
De Revel
Gilles
G
Bertrand
Alain
A
D020171:Botrytis / Q000378:metabolism*; D005942:Gluconates / Q000032:analysis* / Q000737:chemistry; D007783:Lactones / Q000032:analysis* / Q000737:chemistry; D013458:Sulfur Dioxide / Q000737:chemistry*; D027843:Vitis / Q000737:chemistry / Q000382:microbiology*; D014920:Wine / Q000032:analysis* / Q000382:microbiology
D005942:Gluconates; D007783:Lactones; D013458:Sulfur Dioxide; C030691:gluconic acid