Detection of nano silicon dioxide in tomato soup using MALS-ICP-MS
In a joint project with researchers from the University of Vienna (Austria) and the Technical University of Denmark, JRC scientists developed a suitable analytical approach for the detection of silicon dioxide (silica) nanoparticles in tomato soup. This method not only has the potential to monitor the fate of nanoparticles during food production but could also be used by food authorities and laboratories for control purposes.
The use of nanotechnology in food production has already generated significant benefits to consumers in the area of food packaging. Potential future benefits include higher stability of vitamins by nano-encapsulation or an entirely novel application such as solubilisation of certain ingredients. However, the safety of nanoparticles in food products needs to be ensured. New EU legislation will require food producers to specify if foodstuffs contain materials in their nano-form (revision of Regulation (EC) No 258/97 on novel food).
Silicon dioxide particles derived from crushing or milling of its crystalline form i.e. quartz is found in the Earth crust. Amorphous silica can be used in food production as an anti-caking agent, particularly as it absorbs excess moisture and prevents ingredients from sticking together. This is not only important for instant soups but also in coffee cream powders. It can also serve as a carrier of flavours and fragrances. Since silicon dioxide may also contain nano silica, it is important to know the number of nanoparticles to comply with the labelling requirement.
Consequently, a lot of research is presently carried out on how to best detect and quantify nanoparticles in complex matrices such as food or other consumer products. In the scope of the FP7 Project NanoLyse (Grant agreement 245162), a group of researchers from the University of Vienna and the Technical University of Denmark, supported by scientists from the JRC-Institute for Reference Materials and Measurements (IRMM) developed a sample preparation procedure for the detection of silica nanoparticles in tomato soup. They succeeded in the nearly complete recovery of the silica contained in the sample, while minimising the change in the particle size distribution.
The method has shown its potential to be suitable for detecting silica-nanoparticles in complex matrices such as food and could, therefore, be used in future to monitor the presence of such nanoparticles during production and control of food sold in the EU.