C. Romero et J. Bakker, Anthocyanin and colour evolution during maturation of four port wines: effect of pyruvic acid addition, J SCI FOOD, 81(2), 2001, pp. 252-260
The formation of vitisin A-type compounds has been studied in four maturing
fortified red port wines stored for 29 weeks at 15 degreesC. The anthocyan
in concentrations were determined by high-pressure liquid chromatography (H
PLC), and colour changes were monitored by spectrometric measurements. The
losses of anthocyanins followed first-order reactions, and the concurrent f
ormation of polymeric pigments was demonstrated. Vitisin A-type compounds w
ere found to be in low concentration in these four naturally maturing forti
fied wines. The addition of pyruvic acid to the wines led to the formation
of large concentrations of vitisin A derivatives. Up to 23 mg litre(-1) vit
isin A derivatives (vitisin A and its acylated forms acetylvitisin A and p-
coumarylvitisin A) could be determined. Owing to their greater colour expre
ssion and greater stability than malvidin 3-glucoside, these new anthocyani
ns were shown to play an important role in the colour quality of the wines.
An analytical survey of 32 port wines matured for between 2 and 6 years sh
owed that vitisin A-type compounds were the main, and sometimes the only, a
nthocyanins present. (C) 2000 Society of Chemical Industry.