Preparation and characterization of highly stable melleolides @ chitosan nanoemulsion and its effect on Salmo salar preservation

Active packaging is a novel food packaging concept where natural active ingredients enhance the packaging's performance. This study aimed to develop a chitosan (CS)-based nanoemulsion combined with melleolides (CS-M) as a novel edible active coating for preserving fresh salmon. Additionally, the study evaluated the physical stability, microstructure, rheology, and antibacterial properties of CS-M, as well as the preservation effects on salmon when combined with atmospheric cold plasma (ACP). Results showed that CS-M maintained uniform particle size and stable dispersity over 7 days, demonstrating long-term stability, particularly at 4 °C. Compared to CS and melleolides alone, CS-M exhibited superior antibacterial activity against S. aureus and E. coli , effectively inhibiting microbial growth during salmon preservation. Furthermore, CS-M alone demonstrated a good preservation effect, which was significantly enhanced when combined with ACP. In conclusion, the CS-based nanoemulsion containing melleolides shows strong potential for salmon preservation, with its effectiveness further enhanced by ACP.