Determination of titanium dioxide nanoparticles used in various foods

Titanium dioxide (TiO₂) is commonly used in foods with code E171. There is information on the food packaging that it contains E171 in the ingredients section. However, there is no information on the amount of E171 used as ingredient. Therefore, determination of TiO₂ content of foods is extremely important for human health. In this study, confectionary foods, chewing gums, chocolates and white colored foods were investigated. TiO₂ levels of investigated foods were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The average titanium dioxide concentrations were found ranging from 3 to 2400 mg kg^-1. The size of TiO₂ particles in the foods samples was determined with transmission electron microscopy (TEM). Titanium dioxide nanoparticles in the studied foods were found to vary in size from 30 to 410 nm.