title: HPLC-DAD-ESI-MS/MS characterization of pyranoanthocyanins pigments formed in model wine.
abstract: Formation of wine pyranoanthocyanins in model wine was monitored by HPLC-DAD-ESI-MS/MS, using red grape skin extracts and wine fermentation metabolites (acetaldehyde, pyruvic and acetoacetic acids, and diacetyl) and also hydroxycinnamic acids (p-coumaric, caffeic, ferulic, and sinapic acids). Pyruvic acid and acetaldehyde reacted fast, the first reaching high product yield and the second inducing mainly pigment polymerization. In contrast, acetoacetic acid and diacetyl reacted slowly with poor product yields. Hydroxycinnamic acids progressively reacted without apparent formation of polymeric pigments, the reaction rate and yield increasing as the number of hydroxy/methoxy groups did. Substituent at C-10 strongly affected the visible maximum absorbance wavelength, whereas B-ring substitution pattern or sugar acylation exerted little effect. The 10-methylpyranoanthocyanins formed from acetoacetic acid were also found as side products in the formation of 10-carboxypyranoanthocyanins. Finally, we report for the first time on UV-vis and MS spectral data of 10-acetylpyranoanthocyanins formed from diacetyl, and their occurrence in commercial red wines is suggested.
authors.affiliation: Escuela Universitaria de Ingeniería Técnica Agrícola, Universidad de Castilla-La Mancha, Ronda de Calatrava 7, 13071 Ciudad Real, Spain.
authors.forename: Dora
authors.initials: D
authors.lastname: Blanco-Vega
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: López-Bellido
authors.forename: José María
authors.initials: JM
authors.lastname: Alía-Robledo
authors.forename: Isidro
authors.initials: I
authors.lastname: Hermosín-Gutiérrez
mesh_terms: D000079:Acetaldehyde / Q000737:chemistry; D000872:Anthocyanins / Q000032:analysis* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D003373:Coumaric Acids / Q000737:chemistry; D005285:Fermentation; D011714:Pyrans / Q000032:analysis* / Q000737:chemistry; D019289:Pyruvic Acid / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D014920:Wine / Q000032:analysis*
chemical_list: D000872:Anthocyanins; D003373:Coumaric Acids; D011714:Pyrans; D019289:Pyruvic Acid; D000079:Acetaldehyde