title: Roles of proteins, polysaccharides, and phenolics in haze formation in white wine via reconstitution experiments.
abstract: Residual proteins in finished wines can aggregate to form haze. To obtain insights into the mechanism of protein haze formation, a reconstitution approach was used to study the heat-induced aggregation behavior of purified wine proteins. A chitinase, four thaumatin-like protein (TLP) isoforms, phenolics, and polysaccharides were isolated from a Chardonnay wine. The same wine was stripped of these compounds and used as a base to reconstitute each of the proteins alone or in combination with the isolated phenolics and/or polysaccharides. After a heating and cooling cycle (70 °C for 1 h and 25 °C for 15 h), the size and concentration of the aggregates formed were measured by scanning ion occlusion sensing (SIOS), a technique to detect and quantify nanoparticles. The chitinase was the protein most prone to aggregate and the one that formed the largest particles; phenolics and polysaccharides did not have a significant impact on its aggregation behavior. TLP isoforms varied in susceptibility to haze formation and in interactions with polysaccharides and phenolics. The work establishes SIOS as a useful method for studying wine haze.
authors.affiliation: Department of Agronomy Food Natural Resources Animals and Environment, Centro Interdipartimentale per la Ricerca in Viticoltura ed Enologia (CIRVE), University of Padua, via dell'Università 16, 35020 Legnaro (PD), Italy.
authors.forename: Diana
authors.initials: D
authors.lastname: Gazzola
authors.forename: Steven C
authors.initials: SC
authors.lastname: Van Sluyter
authors.forename: Andrea
authors.initials: A
authors.lastname: Curioni
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Waters
authors.forename: Matteo
authors.initials: M
authors.lastname: Marangon
mesh_terms: D002851:Chromatography, High Pressure Liquid; D010636:Phenols / Q000032:analysis*; D011134:Polysaccharides / Q000032:analysis*; D011506:Proteins / Q000032:analysis*; D013696:Temperature; D014920:Wine / Q000032:analysis*
chemical_list: D010636:Phenols; D011134:Polysaccharides; D011506:Proteins