Food grade titanium dioxide is really common and not so nano. The titanium dioxide used by Dunkin' Brands and many other food producers is not a new material, and it's not really a nanomaterial either. Nanoparticles are typically smaller than 100 nanometers in diameter.Yet most of the particles in food grade titanium dioxide are larger than this.itanium dioxide (which isn't the same thing as the metal titanium) is an inert, insoluble material that's used as a whitener in everything from paper and paint to plastics.