title: Impact of wine production on the fractionation of copper and iron in Chardonnay wine: Implications for oxygen consumption.
abstract: Copper and iron in wine can influence oxidative, reductive and colloidal stability. The current study utilises a solid phase extraction technique to fractionate these metals into hydrophobic, cationic and residual forms, with quantification by ICP-OES. The impact of aspects of wine production on the metal fractions was examined, along with the relationship between metal fractions and oxygen decay rates. Addition of copper and iron to juice, followed by fermentation, favoured an increase in all of their respective metal fractions in the wine, with the largest increase observed for the cationic form of iron. Bentonite fining of the protein-containing wines led to a significant reduction in the cationic fraction of copper and an increase in the cationic form of iron. Total copper correlated more closely with oxygen consumption in the wine compared to total iron, and the residual and cationic forms of copper provided the largest contribution to this impact.
authors.affiliation: Groupe École Supérieure d'Agriculture d'Angers, 55 rue Rabelais, Angers 49007, France; National Wine and Grape Industry Centre, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia.
authors.forename: Michaela
authors.initials: M
authors.lastname: Rousseva
authors.affiliation: National Wine and Grape Industry Centre, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Kontoudakis
authors.affiliation: National Wine and Grape Industry Centre, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia.
authors.forename: Leigh M
authors.initials: LM
authors.lastname: Schmidtke
authors.affiliation: National Wine and Grape Industry Centre, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia; School of Chemistry, The University of Melbourne, Vic. 3010, Australia.
authors.forename: Geoffrey R
authors.initials: GR
authors.lastname: Scollary
authors.affiliation: National Wine and Grape Industry Centre, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia. Electronic address: aclark@csu.edu.au.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Clark
mesh_terms: D001546:Bentonite / Q000737:chemistry; D005591:Chemical Fractionation; D003300:Copper / Q000032:analysis*; D005285:Fermentation; D000067030:Fruit and Vegetable Juices / Q000032:analysis; D007501:Iron / Q000032:analysis*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D010101:Oxygen Consumption; D052616:Solid Phase Extraction; D027843:Vitis / Q000737:chemistry; D014920:Wine / Q000032:analysis*
chemical_list: D001546:Bentonite; D003300:Copper; D007501:Iron; D010100:Oxygen
keywords: Bentonite; Copper; Fractionation; Iron; Oxidation; Oxygen consumption; Wine