Modulating the release properties of active compounds from packaging materials by a physicochemical/nanotechnology approach

Controlled release system (CRS) is a new generation of release systems that can release active molecules at different controlled rates for enhancing the quality and safety of foods during storage. One critical point is to maintain a concentration of the active molecule to a predetermined level over a required time span. The different controlled rates are influenced by the distribution of the active molecule across the polymer matrix and ‘active molecule-polymer matrix interactions’, besides the effect of external triggers (pH, temperature, humidity). This is why a deep knowledge of the active compound release is necessary. The research activity carried out during these three years focused on three main topics, namely:I. investigation of the release kinetics of a model drug-like compound (Coomassie brilliant blue) from polyvinyl alcohol (PVOH) films into a hydro-alcoholic solution as a function of the physicochemical properties of the polymer matrix;II. study of a cellulose-based matrix (MFC) for the release of lysozyme.The results obtained can be profitably used for the development of delivery systems for different applications (e.g. food packaging), where the controlled release over time of an active molecule is the target. Moreover, these studies have shown the possibility of using a green and nanotechnology approach (through the use of MFC) for the development of CRS.Finally, branches from the aforementioned two topics led to further research, grouped in three main sub-topics:III. development of a ‘wetting enhancer’ pullulan coating for antifog packaging applications;IV. development of pullulan films reinforced with MFC;V. study of a gelatin-based matrix for the release of a soluble compound (Lauric arginate ethyl ester LAE).Overall, these topics prompted an advancement in the field of bio-based materials, as they investigated new approaches for a suitable and feasible exploitation of biopolymers for applications that are beyond the development of controlled release systems.