Natural barite and anthracite containing more than 95% barium sulfate are mixed and fed at a ratio of 3:1 (mass). After being crushed to a diameter of less than 2cm, it enters the reduction furnace. The furnace temperature is controlled to be 1000-1200°C in the front section and 500-500 in the back section. 600°C, the reduction furnace rotates at a speed of 80 seconds per revolution, and the reaction conversion rate is 80% to 90%.

In order to contribute with experimental evidence that could help to achieve a better understanding of the field for future regulation, in the present work, the biocompatibility of commercial P25TiO₂NPs (one type of TiO₂NPs used in sunscreen formulations) and two novel functionalized P25TiO₂NPs were evaluated under solar simulated irradiation. White light, generated by red, blue, and yellow LEDs, together with UV ones, was chosen to simulate the solar spectra. Functionalization of TiO₂NPs was made with antioxidant vitamins in order to prevent the expected photo-initiated ROS production when nanoparticles are exposed to the simulated solar spectra. Vitamin B2 (riboflavin) and vitamin C were chosen to carry out the functionalization because they are water-soluble, low-cost, and are a constitutive part of biological processes. In addition, it is known that both have the potential to prevent macromolecular oxidation by ROS [23], [24], [25], [26].

Titanium dioxide in food is used in a variety of products as a color enhancer. The most common foods containing titanium dioxide include: