Effetto antimicrobico su Listeria monocytogenes di nanoparticelle caricate con rame come precursori per la produzione di un imballaggio alimentare attivo

This work deals with the development, characterization and microbiological testing of copper-loaded carbon nanoparticle synthetized by a green methodology. Such particles have been purposely developed to enhance the shelf life of meat and its derivatives. In order to achieve the objectives of the thesis, the study of the State of the Art has included: a general description of nanomaterials and their related synthesis techniques; the main methodologies used for their physical-chemical characterization; an overview on the main nanomaterials properties and their main functioning principles; a review on the nanomaterial legislation in force; a literature study of the main pathogens microorganisms in food products. The study has been focused on the antimicrobial effect of copper-loaded carbon nanoparticles (Cu-CNPs) tested on Listeria monocytogenes ATCC 19117 (serotype 4d) strain which is a pathogen foodborne gram-positive bacteria able to cause listeriosis disease. The technique applied is the hydrothermal carbonization (HTC) that has been used to synthetize Cu-CNPs which have been characterized by DLS and ELS techniques. Moreover, the copper quantification has been carried out by ICP-OES optical emission spectrometer. While, the MIC (minimum inhibitory concentration) testing have been carried out following ISO/IEC 17025 and others guidelines. The results obtained clearly shows an antimicrobial activity Cu-CNPs against Listeria monocytogenes compared to CuSO4 * 5 H2O activity. It can be concluded that Cu-CNPs can be used as antimicrobial nanomaterial for an active food packaging though, more detailed studies are needed to identify the effective concentration able to inhibit or stabilize the bacteria growth with the aim to produce an innovative active food packaging against specific foodborne microorganism and/or other microbial populations. This project has been carried out in a collaboration between the University of Turin and the Experimental Zooprophylactic Institute of Lazio and Toscana (IZSLT) in Rome. In particular, at the University, Cu-CNPs have been synthetized and characterized while, at the IZSL microbiological testing have been carried out.