Titanium dioxide is a white metal oxide used in many food categories as food additives to provide a whitening effect. If its use complies with the five specifications including synthesis pathway, crystallographic phase, purity, amount and innocuousness, all other parameters are not defined and were hardly documented. However, in the last 3 years, two studies have deeply characterized food-grade TiO2 and converged to the fact that the size distribution of food-grade TiO2 spans over the nanoparticle range (<100 nm) and the surface is not pure TiO2 but covered by phosphate and eventually silicon species or aluminium species, which modify the surface chemistry of these particles. Until now, this material was considered as safe. However, the toxicological studies later to the last re-evaluation by the European Food Safety Agency reveal some concerns due to the ability of TiO2 particles to alter the intestinal barrier. This reinforces the idea to go on reinforcing the risk assessment about food-grade TiO2.
Part of the book: Application of Titanium Dioxide