title: Strecker Aldehyde Formation in Wine: New Insights into the Role of Gallic Acid, Glucose, and Metals in Phenylacetaldehyde Formation.
abstract: Strecker degradation (SD) leading to the formation of phenylacetaldehyde (PA) was studied in wine systems. New insights were gained by using two full factorial designs focusing on the effects of (1) pH and (2) temperature. In each design of experiments (DoE) three factors, glucose, gallic acid, and metals at two levels (present or absence), were varied while phenylalanine was kept constant. The obtained results gave a clear indication, with statistical significance, that in wine conditions, the SD occurs in the presence of metals preferentially via the phenolic oxidation independent of the temperature (40 or 80 °C). The reaction of the amino acid with the o-quinone formed by the oxidation of the gallic acid seems to be favored when compared with the SD promoted by the reaction with α-dicarbonyls formed by MR between glucose and phenylalanine. In fact, kinetics results showed that the presence of glucose had an inhibitory effect on PA rate of formation. PA formation was 4 times higher in the control wine when compared to the same wine with 10 g/L glucose added. By gallic acid quinone quantitation it is shown that glucose affects directly the concentration of the quinone. decreasing the rate of quinone formation. This highlights the role of sugar in o-quinone concentration and consequently in the impact on Strecker aldehyde formation, a promising new perspective regarding wine shelf-life understanding.
authors.affiliation: Universidade Católica Portuguesa, CBQF-Centro de Biotecnologia e Química Fina-Laboratório Associado, Escola Superior de Biotecnologia , Rua Arquiteto Lobão Vital , Apartado 2511, 4202-401 Porto , Portugal.
authors.forename: Ana Rita
authors.identifier: http://orcid.org/0000-0003-2627-2656
authors.initials: AR
authors.lastname: Monforte
authors.affiliation: Food Quality & Design Group , Wageningen University , 6700 AA Wageningen , The Netherlands.|Unilever R&D Vlaardingen , 3130 AC Vlaardingen , The Netherlands.
authors.forename: Sara I F S
authors.initials: SIFS
authors.lastname: Martins
authors.affiliation: Universidade Católica Portuguesa, CBQF-Centro de Biotecnologia e Química Fina-Laboratório Associado, Escola Superior de Biotecnologia , Rua Arquiteto Lobão Vital , Apartado 2511, 4202-401 Porto , Portugal.|IWBT-DVO University of Stellenbosch , Private Bag XI, Matieland 7602 , South Africa.|Cork Supply Portugal, S.A. , Rua Nova do Fial , 4535 Santa Maria Da Feira , Portugal.
authors.forename: Antonio C
authors.initials: AC
authors.lastname: Silva Ferreira
mesh_terms: D000079:Acetaldehyde / Q000031:analogs & derivatives* / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry*; D005707:Gallic Acid / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008670:Metals / Q000737:chemistry*; D010084:Oxidation-Reduction; D011809:Quinones / Q000737:chemistry; D013696:Temperature; D014920:Wine / Q000032:analysis*
chemical_list: D000447:Aldehydes; D008670:Metals; D011809:Quinones; D005707:Gallic Acid; D000079:Acetaldehyde; D005947:Glucose; C013192:phenylacetaldehyde
keywords: Strecker degradation; o-quinone; phenolic; phenolic oxidation; phenylacetaldehyde; sugar