Title : Characterization of nanoparticles in Silicon dioxide food additives
Food additives are substances intended to become a component or affect the characteristics of food (e.g., emulsifier, stabilizer, thickener, anticaking agent, antioxidant, etc.). Some food additives may have a particle size distribution that extends into the nanoscale range. For example, amorphous silicon dioxide, which is an approved direct food additive (21 CFR 172.480) for use as an anticaking agent may possibly contain nanosized silicon dioxide particles due to the nature of its manufacturing process. However, there are limited data concerning the particle size distribution of silicon dioxide used as a food additive. Therefore, we used multiple analytical techniques to characterize the particle size distribution of six commercially available silicon dioxide food additives. In this work, we used dynamic light scattering to measure particle size distribution, electron microscopy for imaging, and single-particle inductively coupled mass spectrometry (sp-ICP-MS) to measure the concentration of nano-sized materials present in silicon dioxide additives. These results allow the US FDA to gain a greater understanding of the potential for nano-sized particle occurrence in silicon dioxide intended for use as food additives.