Chiara Bufalini

The recovery of antioxidant compounds from agri-food by-products represents a sustainable strategy for active packaging production. However, the compatibility between natural extracts and film-forming techniques plays a key role in determining film formation and properties. In this work, antioxidant extracts obtained from spent coffee grounds and tomato waste were incorporated into zein-based films produced using two different techniques. The objective was to investigate how extract type and processing technique influence film morphology, wettability, thickness, and mechanical properties. The results demonstrated a strong processing-dependent compatibility between extract composition and production techniques. Spent coffee ground extract was successfully incorporated into compact cast films, while tomato waste extract did not allow the formation of homogeneous cast films and required electrospinning to obtain uniform fibrous structures. The incorporation of spent coffee ground extract significantly increased surface wettability and film stiffness, with Young’s modulus reaching 695 MPa. In contrast, electrospun films containing tomato waste extract exhibited lower tensile strength due to their porous fibrous structure, although uniform fibers were obtained. These findings demonstrate that extract chemistry critically affects the suitability of the processing technique and provide useful guidelines for the design of sustainable zein-based active packaging systems derived from agri-food waste valorization.

Encapsulation is defined as the entrapment of active agents within another substance, which can be either solid or liquid. These substances need to be protected in order to preserve their functional and physicochemical properties, to enhance their stability, and to extend their shelf-life. Among all the existing methodologies, emulsion-based techniques are selected to be investigated in this review. Emulsion-based techniques are versatile and adaptable to different applications and different substances. In fact, these methods use the emulsion structure to protect the compounds of interest. Emulsions can be used as standalone systems or as a template for the production of polymeric particles. This review provides a comprehensive overview of emulsion-based techniques, with a particular focus on production processes. The emulsions have been described in terms of classification, composition, and characterization. The main production processes are examined in detail, with the main advantages and disadvantages of each methodology highlighted to provide a comprehensive overview of the topic.

Encapsulation of antibodies represents a significant advance to protect and deliver these therapeutics in a controlled manner, increasing the stability requested to cover the temporal gap between particle production and their administration. Furthermore, using encapsulation, extracellular, cell surface, and intracellular targets can be reached. This work examines the feasibility of encapsulating mouse IgG isotype control antibodies within phosphatidylcholine-based liposomes using a supercritical fluid-based process called SuperLip (Supercritical-assisted Liposome formation). This process allows a continuous production of both nano- and micrometric liposomes with high encapsulation efficiency working under mild operative conditions. The effect of some operative parameters has been studied on liposome mean diameter, particle size distribution, and antibody entrapment efficiency, comparing these data with those collected working with liposomes obtained by the thin-layer hydration technique. In particular, the effect of water flow rate and of the antibody loading were studied. Antibody-loaded liposomes with mean diameters in the range between 205 and 501 nm have been obtained by using a supercritical fluid-assisted process. High entrapment efficiencies up to 94% have been calculated.