• color;
  • malvidin 3-glucoside;
  • (+)-catechin;
  • acetaldehyde;
  • model solution

ABSTRACT: The contribution of the aldehyde composition of wine spirit to the color changes in Port red wine was studied in model solutions. Malvidin 3-glucoside was shown to be very reactive towards catechin in the presence of different aldehydes: acetaldehyde, isovaleraldehyde, benzaldehyde, propionaldehyde, isobutyraldehyde, formaldehyde, and 2-methylbutyraldehyde. LC/MS data confirmed the formation of oligomeric pigments resulting from the reaction between the anthocyanin and the flavanol (colored products) and between 2 flavanol units (colorless products) mediated by each aldehyde assayed. The UV-visible spectra of the colored pigments showed a λmax bathochromically shifted relatively to the λmax of original anthocyanins. All samples revealed a “blueing” and “darkening” color effects using the CIELAB system.