Study of the acetaldehyde induced polymerisation of flavan-3-ols by liquid chromatography-ion spray mass spectrometry

Formation of Flavanol-aldehyde Adducts in Barrel-aged White Wine – Possible Contribution of These Products to Colour

“…These reactions are particularly well known in the case of red wines. During the ageing process we observed a polymerisation reaction with acetaldehyde in particular (Haslam, 1980;Fulcrand et al, 1996;Es-Safi et al, 1999). The resulting products have an effect on the colour of the solution, with varying impact depending on the polymeric degree and pH (Es-Safi et al, 2000).…”

“…Colour provides the first contact with a wine in a tasting session and has a strong influence on the remainder of the tasting (Morrot et al, 2001). In red wines, colour characteristics and evolution are often studied, especially by direct linkage with the polymerisation of anthocyanin-tannin complexes (Salas et al, 2004) or with the addition of aldehydes such as acetaldehyde (Fulcrand et al, 1996), glyoxylic acid, pyruvic acid, furfuraldehyde and hydroxymethylfurfuraldehyde (Fulcrand et al, 1998;Es-Safi et al, 2002), vinyl phenols (Hakansson et al, 2003) or various aldehydes from spirits (Pissara et al, 2004). Some of the products formed display different colours than the originals.…”

Phytochemical Bioactives in Berries

“…After a few days of fermentation, anthocyanins reach a maximum level followed by a decrease of their concentration as a result of precipitation with tartaric salts in a form of colloidal material, adsorption on yeast cell walls, or elimination during ltration and ning. Anthocyanin pigments extracted from the grapes give the color of the young wines, but during the winemaking and aging of wine, anthocyanins may be modied to create stable, C4-substituted pigments through reactions involving pyruvic acid (Bakker et al 1997;Fulcrand et al 1998) and vinyl phenol derivatives (Fulcrand et al 1996). A number of oligomeric pigments resulting from a condensation reaction involving acetaldehyde and from direct reactions of anthocyanins with avanols have also been described (Somers 1971;Fulcrand et al 1996;Berg and Akiyoshi 1975;Bakker and Timberlake 1986).…”

“…Anthocyanin pigments extracted from the grapes give the color of the young wines, but during the winemaking and aging of wine, anthocyanins may be modied to create stable, C4-substituted pigments through reactions involving pyruvic acid (Bakker et al 1997;Fulcrand et al 1998) and vinyl phenol derivatives (Fulcrand et al 1996). A number of oligomeric pigments resulting from a condensation reaction involving acetaldehyde and from direct reactions of anthocyanins with avanols have also been described (Somers 1971;Fulcrand et al 1996;Berg and Akiyoshi 1975;Bakker and Timberlake 1986). Recently, the existence of anthocyanins acylated with lactic acid, formed in wine, has been reported (Alcalde-Eon et al 2006).…”

“…Those changes are mostly due to the conversion of grape anthocyanins to derived pigments (Somers 1971) through reactions of anthocyanins with pyruvic acid (carboxy-pyrano-anthocyanins) and acetaldehyde (pyrano-anthocyanins) leading to pyranoanthocyanin formation (Timberlake and Bridle 1976;Glories 1984;Bakker and Timberlake 1986;Fulcrand et al 1996;Remy et al 2000). Another possible mechanism of the evolution of phenolics during wine aging that takes place spontaneously is the formation of direct condensation adducts between anthocyanins and avonols (Timberlake and Bridle 1976), as well as, formation of ethyl linked pigments formed by acetaldehyde-mediated condensation between anthocyanins and avan-3-ols.…”