Critical evaluation of migration studies of silver nanoparticles present in food packaging: a systematic review

The large use of silver nanoparticles (AgNPs) has provided safety concerns due to the risks of exposure to this nanomaterial caused by the possibility of transfer of the AgNP from the polymer to the food. The gap in scientific knowledge regarding AgNP's migration capacity has been high in the number of publications. This article critically analyzes AgNP migration studies in food packaging, showing which parameters should be followed to ensure reliability in the results found. A systematic review (SR) of the literature was performed in the electronic databases PubMed, SCOPUS, SciELO, LILACS/BVS, and Embase and in the gray literature, without date restrictions, until August 21, 2017, to identify studies who evaluated the migration of AgNP in food packaging. Among the 26 articles that have been part of this SR, only 2 (M3 and M5) showed no migration evidence; however, these results are questionable, because all studies present conflicting, contradictory, or questionable results. From this RS, it was not possible to assure that the AgNPs present in food packages tend to migrate to the food matrix, since some methodological inconsistences were identified in all studies evaluated, demonstrating the need for standardization of methodological guidelines for the new migration studies.