Where nanoparticles found in food come from?

Nanoparticles (NPs) are added to processed food on purpose by the producers or they derive from contamination from food processing or/and from food contact materials. NPs can also be present in food due to their presence in the environment (soil, air, water), from where they translocate to plants or animals, as remains of use of protective measures (fungicides, pesticides, inorganic antibiotics) or they are formed inside living organisms during their growth.