Les nanoparticules dans l'alimentation : quels risques pour le consommateur ?

Nanoparticles (NPs) are used in many consumer products for their specific properties combining their very small size, very low mass but also their proportionally considerable surface. In the food processing sector, they have already a lot of applications, for example, they are used to improve the transparency, resistance and self-cleaning and antimicrobial ability of packaging. The risk for the consumer here is a release of NPs into the products, following a physical contact with the packaging. Their use in food is more diversified and difficult to assess. Firstly, the nanoemulsions made from biological molecules such as lipids, sugars or proteins, are intended to encapsulate fragile molecules such as flavors or vitamins to protect them during gastro-intestinal transit. It is likely interesting, but the risk may be a modification in the intestinal absorption of the active ingredient transported. A second category, solid manufactured NPs, especially metallic nanoparticles, are more problematic. Their physicochemical properties and, in particular, their surface reactivity are the causes for their biological reactivity and their potential capacity to overcome barriers and penetrate into the organism. These metal NPs are able to generate oxidative stress and induce multiple cellular responses including inflammation and genotoxicity. The capability to pass through biological barriers including the intestinal barrier and their ability to accumulate in different organs are current fields of research and they have been demonstrated for some NPs (for example NanoAg, TiO2) in animals but not in humans.