Multi-layer Active Biopolymer System as a Perspective for Improving the Quality and Scope of Applying Semi-rigid Biodegradable Packaging

In this study, the possibility of modifying a multi-layer biopolymer active system to reduce permeability to gases of a biodegradable material with potential application in food technology was analysed. A four-layer biopolymer film was used, wherein the initial two layers comprised furcellaran, whilst the subsequent two layers were a mixture of chitosan and gelatin. The film was modified with active ingredients, including silver nanoparticles (AgNPs), montmorillonite, a curcumin-capsaicin mixture and gelatin hydrolysate. The film formed an integrated, semi-rigid packaging system together with the tray, which was developed from tea brewing waste and biopolymers. Application properties were assessed by analysing mechanical parameters, key to the assessment of their quality, proving that the active ingredients significantly improved the strength properties. There was an almost twofold increase in modulus of elasticity values compared to the control film. The permeability against oxygen was also assessed as the main performance characteristic of the packaging and was only 13.64 ± 3.92 [cm³/m² × 24 h]. The impact of the applied material innovation in packaging on the freshness of food products was also evaluated by analysing the microbiological purity of stored Salmo Salar fillet. The active, biodegradable packaging extended the shelf-life of salmon by 6 days compared to the low-density polyethylene (LDPE) film. Toxicity analysis has shown that the used active ingredients are safe for the environment and consumers.