This article reports for the first time on the capacity of a wine Lactobacillus plantarum strain to alter the oxidative coloration of (+)-catechin and (−)-epicatechin hydroethanolic wine model solutions in the presence of Fe2+ as catalyst. The time course of color development and pigment formation in the solutions was tracked over 42 days. The pigments formed were characterized as xanthylium structures regardless of the flavanol isomer present in the solution. The solutions supplied with Lactobacillus plantarum RM71 were oxidized at a slower rate, and consequently, its final color was less than that in the controls. The formation of both (+)-catechin and (−)-epicatechin-derived xanthylium pigments was also delayed over time in the presence of the bacterium compared to their respective cell-free controls. The delaying effects provided by L. plantarum on the oxidative coloration and the generation of xanthylium-derived pigments were more pronounced for the (−)-epicatechin than for the (+)-catechin model solutions. In view of these results and given that L. plantarum is naturally present in winemaking and generally recognized as a safe microorganism, the potential application of this bacterium as an antibrowning agent for wine is now opened (We recommend that you consult the full text of this article).