Evaluation of new active packaging materials and analytical approaches

Abstract

This PhD thesis deals with the study of different aspects of food contact materials, including active packaging and food safety controls. In the first part of the present work the development and optimization of a simple and reproducible procedure for the realization of new antimicrobial active packaging materials is presented. The sol-gel technique was employed in order to obtain hybrid organic-inorganic films aimed at incorporating lysozyme and natamycin as active agents. The sols were properly formulated to be deposited on different substrates, and showed good adhesion and stability. In all cases the incorporation efficiency and release properties can be modulated through the modification of simple chemical and physical parameters, indicating this methodology as a good route for the realization of active packaging also on the industrial scale. In the attempt to individuate high efficiency natural antioxidants to be employed in active packaging, the second part study of the work was focused on different steeping methods allowed to determine the best infusion conditions for extraction of antioxidants from tea leaves allowing to maximise the amount of extracted substances. Antioxidant assay and evaluation of total phenolic content were performed on the extract indicating the tea-derived catechins as a potential active agent. The last part of this thesis is devoted to the development of a new analytical method for the determination of potentially toxic substances released from commercial polycarbonate. The coupling of GC-FID and FTIR techniques allowed individuating some additives and most of the dissolution products of PC, as well as their degraded components, information to be used in upcoming migration analyses. Despite its low sensitivity, the technique joins the quantitative analysis features typical of gas chromatography to the identification potentialities and chemical information of IR spectroscopy; as a result the whole technique is particularly fitting to qualitative analyses also of unknown compounds.