The environmental impact of plastic waste has become a critical global issue, with traditional food packaging contributing significantly to the accumulation of nonbiodegradable materials in landfills and oceans. This has spurred extensive research on sustainable alternatives that can replace conventional plastics without compromising the functionality essential for food preservation. The ideal substitute must not only be eco-friendly but also maintain or extend the shelf life of food products to reduce food waste. This study aimed to establish the effectiveness of an active biopolymer based on chitosan, olive leaf extract, and rosemary essential oil on the shelf life of tench (Tinca tinca) fillets and their combination with high hydrostatic pressures.

The shelf life of the tench fillets packed in biopolymers after 10 days of refrigerated storage was determined by plate counts of mesophilic aerobic microorganisms, enterobacteria, and psychrophilic microorganisms. The results showed that packaging of the fillets increased the shelf life of the product by more than 10 days compared to that of the controls (traditional packaging). The subsequent combination of biopolymers with high hydrostatic pressure treatments was carried out by optimizing the time and intensity of the treatment by response surface analysis inoculated with Salmonella enterica into the tench. Response surface analysis showed that for effective reduction of S. enterica in fillets, treatments above 420 MPa or 108 s (reductions of 3 log CFU·g-1) are necessary, with an optimum treatment of 600 MPa for 27.85 s a maximum reduction.

Our findings indicate that the combination of high hydrostatic pressure with packaging in active biopolymers decreases the initial microbiology and ensures that good conditions for consumption are maintained over time. The development and application of these sustainable packaging solutions are essential to achieve a circular economy in the food industry, ultimately contributing to environmental conservation and food safety.