title: Protein/polysaccharide interactions and their impact on haze formation in white wines.
abstract: Proteins in white wines may aggregate and form hazes at room temperature. This was previously shown to be related to pH-induced conformational changes and to occur for pH <3.5. The aim of the present work was to study the impact of wine polysaccharides on pH-induced haze formation by proteins but also the consequences of their interactions with these proteins on the colloidal stability of white wines. To this end, model systems and purified global pools of wine proteins and polysaccharides were used first. Kinetics of aggregation, proteins involved, and turbidities related to final hazes were monitored. To further identify the impact of each polysaccharide, fractions purified to homogeneity were used in a second phase. These included two neutral (mannoprotein and arabinogalactan) and two negatively charged (rhamnogalacturonan II dimer (RG-II) and arabinogalactan) polysaccharides. The impact of major wine polysaccharides on wine protein aggregation at room temperature was clearly less marked than those of the pH and the ionic strength. Polysaccharides modulated the aggregation kinetics and final haziness, indicating that they interfere with the aggregation process, but could not prevent it.
authors.affiliation: INRA, UMR1083 SPO , F-34060 Montpellier, France.|Montpellier SupAgro, UMR1083 SPO , F-34060 Montpellier, France.|Université Montpellier I, UMR1083 SPO , F-34060 Montpellier, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Dufrechou
authors.affiliation: INRA, UMR1083 SPO , F-34060 Montpellier, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Doco
authors.affiliation: INRA, UMR1083 SPO , F-34060 Montpellier, France.|Montpellier SupAgro, UMR1083 SPO , F-34060 Montpellier, France.|Université Montpellier I, UMR1083 SPO , F-34060 Montpellier, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Poncet-Legrand
authors.affiliation: INRA, UMR1083 SPO , F-34060 Montpellier, France.|Montpellier SupAgro, UMR1083 SPO , F-34060 Montpellier, France.|Université Montpellier I, UMR1083 SPO , F-34060 Montpellier, France.
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Sauvage
authors.affiliation: INRA, UMR1083 SPO , F-34060 Montpellier, France.|Montpellier SupAgro, UMR1083 SPO , F-34060 Montpellier, France.|Université Montpellier I, UMR1083 SPO , F-34060 Montpellier, France.
authors.forename: Aude
authors.initials: A
authors.lastname: Vernhet
mesh_terms: D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010940:Plant Proteins / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*; D013696:Temperature; D027843:Vitis / Q000737:chemistry*; D014920:Wine / Q000032:analysis*
chemical_list: D010940:Plant Proteins; D011134:Polysaccharides
keywords: arabinogalactan proteins; haze; mannoproteins; protein/polysaccharide interactions; rhamnogalacturonan II dimer; wine proteins