A Kinetic Study of the Reaction of (+)-catechin and Malvidin-3-glucoside with Aldehydes Derived from Toasted Oak

The reactions between (+)-catechin and malvidin-3-glucoside were investigated in the presence of furfuraldehyde and vanillin in model solution using LC/DAD and LC/MS analysis. New oligomeric colored pigments involving both (+)-catechin and anthocyanin moieties were detected, showing thus that the two polyphenols competed in the condensation process. Among the obtained colored pigment adducts, dimeric compounds in which the flavanol and aldehyde were bridged to the anthocyanin were observed. The kinetic study of the formation of these new compounds was also presented. Their UV-Visible spectra were similar to the spectrum of malvidin-3-glucoside, but the maximum in the visible region was bathochromically shifted. The formation of these condensed products can play an important role in the taste evolution and in the colour of wines ageing in oak wood barrels.