Humidity-Responsive Antibacterial Film for Prawn Preservation: Characterization, Release Behavior, and Shelf-Life Evaluation

High relative humidity (RH) in prawn storage environments accelerates microbial proliferation, resulting in a shelf life within 3 days at 4 °C. Based on this preservation environment, this study developed an antimicrobial smart film composed of cinnamon essential oil (CEO)-liposome-mussel adhesion proteins (MAP)-polyvinyl alcohol (PVA), evaluated prawn preservation effects, and explored the RH trigger mechanism. The results showed that the film containing CEO-loaded liposomes and 75 mg of MAP (F-CLP 75 ) could reduce the premature loss of CEO under relatively dry conditions. Under high-RH conditions, the film swelled and promoted CEO release while maintaining structural integrity, thereby delaying prawn quality deterioration associated with free water accumulation, microbial proliferation, and protein degradation, and extending the acceptable storage period of prawns to approximately 5–6 days at 4 °C. Additionally, compared with the blank liposome film (F-LP 0 ), F-CLP 75 exhibited significantly improved water resistance, thermal stability, mechanical properties, and barrier properties. This study provides useful guidance for the development of RH-responsive antimicrobial packaging films and the upgrading refrigerated preservation technologies for aquatic products. Graphical