Recently, there has been an increased interest in the develop-
ment of food colorants from natural sources as alternatives
to synthetic dyes because of both legislative action and consumer
concern (Giusti and Wrolstad, 1996).
Anthocyanins are the more important plant pigments visible
to the human eye. They belong to the widespread class of
phenolic compounds collectively named flavonoids. They are
glycosides of polyhydroxy and polymethoxy derivatives of
2-phenylbenzopyrylium or flavylium salts (MingKong et al.,
2003); furthermore, they are characterized by a wide spectrum
of color tones, ranging from orange through red, to purple