Roles of Grape Thaumatin-like Protein and Chitinase in White Wine Haze Formation
journal contributionposted on 26.01.2011, 00:00 by Matteo Marangon, Steven C. Van Sluyter, Karlie A. Neilson, Cherrine Chan, Paul A. Haynes, Elizabeth J. Waters, Robert J. Falconer
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.