During the last year we have been able to synthesize and purify labeled malvidin 3-glucoside (the major pigment in red wine). Our report on the novel procedure to prepare this radiolabeled substance has been accepted for publication. The amount of material produced was enough to start a series of experiments that study the fate of malvidin-3-glucoside during wine aging. The variables that are being varied are pH, temperature, tannin concentration, co-pigmentation and oxygen. In order to analyze the new products we have developed an analytical technique that combines the fractionation of polymeric compounds with tritium quantification.
We have also taken advantage of labeled malvidin-3-glucoside to study the fate of malvidin-3-glucoside during wine fermentation. In this case we have conducted small-scale fermentation where the labeled material has been added when the maximum concentration of anthocyanins occurred.