9A Anthocyanins and Anthocyanin-Derived Compounds 453
Similarly, the entire series of anthocyanidin-3-glucosides and most of theirp-
coumaroyl and acetyl esters have also been reported (Atanasova et al. 2002a; Heier
et al. 2002; Mateus et al. 2003a; Alcalde-Eon et al. 2004, 2006; Wang et al. 2003a;
Boido et al. 2006).
Pyranoanthocyanins arising from the condensation between anthocyanins and
acetaldehyde have also been identified in wines. The corresponding derivatives
of malvidin-3-glucoside and its acetyl ester, also known as vitisin B (Fig. 9A.3i)
and acetylvitisin B, respectively, firstlyisolated from Port wines (Bakker and Tim-
berlake 1997), were later identified in a synthetic medium fermented by yeasts
(Benabdeljalil et al. 2000), as well as in red wines and in red wine fractions
(Revilla et al. 1999; Vivar-Quintana et al. 1999, 2002; Atanasova et al. 2002a;
Hayasaka and Asenstorfer 2002; Heier et al. 2002; Mateus et al. 2002b; Monagas
et al. 2003; Wang et al. 2003a; Alcalde-Eon et al. 2006; Boido et al. 2006). The
corresponding B-type vitisins of numerous glucosides (delphinidin, petunidin and
peonidin-3-glucosides) and acylated-glucosides (peonidin-3-(6-acetyl)-glucosides
and malvidin-3-(6-p-coumaroyl)-glucosides) of anthocyanidins have been
identified in wine (Heier et al. 2002; Alcalde-Eon et al. 2006; Boido et al.
2006).
Other pyranoanthocyanins bearing a methyl moiety, resulting from the reaction
between anthocyanins and acetone (Benabdeljalil et al. 2000; Lu and Foo 2001;
Hayasaka and Asenstorfer 2002; Alcalde-Eon et al. 2006) or with acetoacetic acid
(He et al. 2006a) have also been reported in wine. Recently, complete character-
ization by UV-visible spectroscopy, NMR and mass spectrometry has been pro-
vided for the methyl-linked pyranomalvidin-3-glucoside and itsp-coumaroyl ester
(He et al. 2006b). Finally, pyranoanthocyanins resulting from the reaction of antho-
cyanins and vinylalcohol have also been described in red wines (Hayasaka and
Asenstorfer 2002).
Factors affecting the reaction. The extent of the reactions between anthocyanins
and pyruvic acid in model solutions follows a first order kinetic with respect to
the anthocyanin disappearance. This reaction is affected by several factors, such
as: anthocyanin composition, pH, pyruvic acid concentration, temperature and
acetaldehyde concentration. The maximum formation took place at pH 2.7–3.0 due
to requirement of the anthocyanin flavylium form, at high pyruvic acid concentra-
tion, at low storage temperature (10–15◦C) and in the absence of acetaldehyde
(Romero and Bakker 1999a,b, 2000a,b).
Recent studies indicated that fermentation was the most important stage for the
production of malvidin-3-glucoside-pyruvate (Asenstorfer et al. 2003). Maximum
production of this compound inVitis viniferacv Shiraz musts, occurred in the period
corresponding to 20–85% of glucose utilization, coinciding with the maximum
concentration of both precursors, malvidin-3-glucoside and pyruvic acid. Morata
et al. (2003a) have reported that the yeast strain used in the alcoholic fermentation
also affected the production of malvidin-3-glucoside-pyruvate, and that the concen-
tration of the pigment was in direct relation with the production of pyruvic acid
by the yeast. Moreover, the content of SO 2 in must was also shown to influence
the production of malvidin-3-glucoside-pyruvate since SO 2 regulates the concentra-
tion of pyruvic acid through the formation of a weak bisulfite addition compound