title: Roles of grape thaumatin-like protein and chitinase in white wine haze formation.
abstract: Grape chitinase was found to be the primary cause of heat-induced haze formation in white wines. Chitinase was the dominant protein in a haze induced by treating Sauvignon blanc wine at 30 °C for 22 h. In artificial wines and real wines, chitinase concentration was directly correlated to the turbidity of heat-induced haze formation (50 °C for 3 h). Sulfate was confirmed to have a role in haze formation, likely by converting soluble aggregates into larger visible haze particles. Thaumatin-like protein was detected in the insoluble fraction by SDS-PAGE analysis but had no measurable impact on turbidity. Differential scanning calorimetry demonstrated that the complex mixture of molecules in wine plays a role in thermal instability of wine proteins and contributes additional complexity to the wine haze phenomenon.
authors.affiliation: The Australian Wine Research Institute, PO Box 197, Glen Osmond, SA 5064, Australia.
authors.forename: Matteo
authors.initials: M
authors.lastname: Marangon
authors.forename: Steven C
authors.initials: SC
authors.lastname: Van Sluyter
authors.forename: Karlie A
authors.initials: KA
authors.lastname: Neilson
authors.forename: Cherrine
authors.initials: C
authors.lastname: Chan
authors.forename: Paul A
authors.initials: PA
authors.lastname: Haynes
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Waters
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Falconer
mesh_terms: D002688:Chitinases / Q000737:chemistry* / Q000378:metabolism; D006358:Hot Temperature; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D055550:Protein Stability; D027843:Vitis / Q000737:chemistry / Q000201:enzymology*; D014920:Wine / Q000032:analysis*
chemical_list: D010940:Plant Proteins; C003427:thaumatin protein, plant; D002688:Chitinases