Blue zinc oxide nanopowders functionalized with anthocyanins from red cabbage were obtained by using two synthesis routes, i.e. one-pot synthesis and sensitization of white ZnO nanopowder. The structure and properties (optical, photocatalytic) of functionalized zinc oxide nanopowders where determined by XRD, SEM, TEM, HRTEM, electron diffraction, specific surface area analysis, FTIR, UV-Vis and PL spectroscopy, and compared with those of pristine zinc oxide nanopowder, obtained in similar conditions. A detailed structural study of nanoparticles (cell parameters, lattice strain, and crystallite size) was performed on the basis of electron diffraction data. The functionalized zinc oxide nanoparticles obtained by one-pot method present smaller particles size and different morphology in comparison with the other zinc oxide samples, exhibiting also the highest specific surface area and best photocatalytic activity in the discoloration of a Congo red solution (88.1%, after 120 min).