title: Oxygen Consumption by Red Wines. Part II: Differential Effects on Color and Chemical Composition Caused by Oxygen Taken in Different Sulfur Dioxide-Related Oxidation Contexts.
abstract: Chemical changes caused by oxidation of red wines during 5 consecutive air-saturation cycles have been assessed. In order to investigate the existing relationship between the effects caused by O2 and the levels and consumption rates of wine SO2, the total oxygen consumed by the wines (16-25 mg/L) was subdivided into different nonmutually exclusive categories. The ones found most influential on chemical changes were the O2 consumed in the first saturation without equivalent SO2 consumption (O2preSO2) and the O2 consumed when levels of free SO2 were below 5 mg/L (radical forming O2). Chromatic changes were strongly related to both O2 categories, even though anthocyanidin degradation was not related to any O2 category. Radical forming O2 prevented both formation of red pigments and reduction of epigallocatechin and other proanthocyanidins, induced accumulation of phenolic acids, and caused losses of β-damascenone and whiskylactone without evidence of acetaldehyde formation. O2preSO2 seemed to play a key role in the formation of blue pigments and in the decrease of Folin index and of many important aroma compounds.
authors.affiliation: Laboratory for Flavor Analysis and Enology, Instituto Agroalimentario de Aragón (IA2), Department of Analytical Chemistry, Faculty of Sciences, Universidad de Zaragoza , E-50009 Zaragoza, Spain.
authors.forename: Vanesa
authors.initials: V
authors.lastname: Carrascon
authors.affiliation: Instituto de Ciencias de la Vid y el Vino, Universidad de La Rioja-CSIC-Gobierno de la Rioja , Finca La Grajera, Ctra. De Burgos Km. 6, 26007 Logroño, Spain.
authors.forename: Purificación
authors.initials: P
authors.lastname: Fernandez-Zurbano
authors.affiliation: Laboratory for Flavor Analysis and Enology, Instituto Agroalimentario de Aragón (IA2), Department of Analytical Chemistry, Faculty of Sciences, Universidad de Zaragoza , E-50009 Zaragoza, Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Bueno
authors.affiliation: Laboratory for Flavor Analysis and Enology, Instituto Agroalimentario de Aragón (IA2), Department of Analytical Chemistry, Faculty of Sciences, Universidad de Zaragoza , E-50009 Zaragoza, Spain.
authors.forename: Vicente
authors.initials: V
authors.lastname: Ferreira
mesh_terms: D000872:Anthocyanins / Q000737:chemistry; D003116:Color; D007783:Lactones / Q000032:analysis; D045792:Norisoprenoids / Q000032:analysis; D009812:Odorants / Q000032:analysis; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D059808:Polyphenols / Q000032:analysis; D044945:Proanthocyanidins / Q000032:analysis; D017382:Reactive Oxygen Species / Q000737:chemistry; D013458:Sulfur Dioxide / Q000737:chemistry*; D014920:Wine / Q000032:analysis*
chemical_list: D000872:Anthocyanins; D007783:Lactones; D045792:Norisoprenoids; D059808:Polyphenols; D044945:Proanthocyanidins; D017382:Reactive Oxygen Species; D013458:Sulfur Dioxide; D010100:Oxygen; C075388:beta-damascenone
keywords: aroma; color; mechanisms; oxidation; polyphenols; radicals; red wine; sulfur dioxide