Study of quinones reactions with wine nucleophiles by cyclic voltammetry.
Quinones are electrophilic species which can react with various nucleophiles, like wine antioxidants, such as sulfur dioxide or ascorbic acid, thiols, amino acids, and numerous polyphenols. These reactions are very important in wine aging because they mediate oxygen reactions during both production and bottle aging phases. In this work, the major challenge was to determine the interaction between ortho-quinones and wine nucleophiles (amino acids, thiols, and the antioxidants SO2 and ascorbic acid), by cyclic voltammetry. Wine-model solutions with gallic acid, caffeic acid, or (+)-catechin and nucleophilic compounds were used. To understand the effect of nucleophilic addition in wine, a white wine with the same added nucleophiles was also analysed. Cyclic voltammograms were taken with glassy carbon electrode or screen-printed carbon electrodes, respectively, for wine-model and white wines solutions, in the absence and in the presence of nucleophiles. A nucleophilic order profile related to the cathodic current intensity decrease was observed.
Departamento de Química & QOPNA, Universidade de Aveiro, 3810-193 Aveiro, Portugal; Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto, Portugal.
Carla M
CM
Oliveira
Departamento de Química & QOPNA, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
António S
AS
Barros
Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto, Portugal; Stellenbosch University, Private Bag X1, Matieland, 7602 Stellenbosch, South Africa.
António C S
AC
Ferreira
Departamento de Química & QOPNA, Universidade de Aveiro, 3810-193 Aveiro, Portugal. Electronic address: artur.silva@ua.pt.
Artur M S
AM
Silva
D000975:Antioxidants / Q000032:analysis; D059808:Polyphenols / Q000737:chemistry*; D011809:Quinones / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D014920:Wine / Q000032:analysis*
D000975:Antioxidants; D059808:Polyphenols; D011809:Quinones; D013438:Sulfhydryl Compounds
(+)-Catechin (PubChem CID: 9064); 3-Sulfanylhexan-1-ol (PubChem CID: 521348); 4-Methyl-4-sulfanylpentan-2-one (PubChem CID: 88290); Amino acids; Antioxidants; Ascorbic acid (PubChem CID: 54670067); Caffeic acid (PubChem CID: 689043); Cyclic voltammetry; Furan-2-ylmethanethiol (PubChem CID: 7363); Gallic acid (PubChem CID: 370); Oxidation; Phenolics; Quinones; Sodium metabisulfite (PubChem CID: 656671); Thiols; Wine; l-Methionine (PubChem CID: 6137); l-Phenylalanine (PubChem CID: 6140)