Ti-BEA and Ti-FAU, obtained by post-synthesis treatment, and TS-1, obtained by direct hydrothermal synthesis, have been tested as catalysts for the Ruff oxidative degradation of calcium d-gluconate to d-arabinose using diluted hydrogen peroxide as oxidant. Only large-pore zeolites Ti-BEA and Ti-FAU were found to be active. It was shown, in particular, that a very rapid leaching of titanium occurred and that the titanium species present in the solution were responsible for the catalytic activity observed.