Enhancing barrier properties of biopolymer films for food packaging

 
Innovations in packaging and protective films for food products aim to reach improved aesthetics, design, and technical properties for better food preservation. The use of biopolymers and bio-based materials as alternatives has been highlighted. Therefore, the incorporation of gum rosin resins which are derived from a natural renewable resource presents a promising opportunity. Biopolymers, prized for biodegradability and sustainability, are being used for this purpose, but require enhancements to match current packaging standards and prevent food waste. Gum rosin resin derivatives offer several advantages, such as availability and chemical properties, enhancing competitiveness against fossil-derived alternatives, and yielding environmental, economic, and social benefits. The application of functional coatings on biopolymeric films for food packaging has garnered significant attention due to its potential to enhance barrier properties against water vapor and oxygen. The primary goal of this work was to improve these barrier properties, which are crucial for extending the shelf life of food products and maintaining their quality. Water-based formulations and methods of coating application, such as spray, Mayer bar, layer-by-layer, and, additionally, physical vapor depositions under vacuum pressure (PVD), were assessed for their impact on the structural and performance properties of the films. The results show that the incorporation of gum rosin resin derivatives into biopolymers increased the barrier performance to the water vapor and oxygen transmission, being improved with the application of functional coatings. In one of the approaches studied it was possible to decrease by 67% the water vapor transmission rate (WVTR) and 98% the oxygen transmission rate (OTR). This work highlights the potential of biopolymer films with functional coatings as a sustainable alternative in the food packaging industry, aligning with the growing demand for eco-friendly and biodegradable packaging solutions. The authors acknowledge to RN21 project, funded by the Environmental Fund through Component 12 - Promotion of Sustainable Bioeconomy (Investment TC-C12-i01 - Sustainable Bioeconomy No. 02/C12-i01/2022), of European funds allocated to Portugal by the Recovery and Resilience Plan (PRR), within the scope of the European Union (EU) Recovery and Resilience Mechanism, framed within the Next Generation EU, for the period 2021 - 2026.