Competitive adsorption-triggered release of cinnamaldehyde from ZSM-5/ZIF-8 nanocarriers in sodium alginate films for early-stage fish preservation

An adsorption-triggered mechanism was proposed for on-demand release. • Acidic sites on ZSM-5/ZIF-8 possess stronger adsorption energy for biogenic amines than CA. • The mechanical and gas barrier of film were improved after introducing ZSM-5/ZIF-8. • The developed packaging effectively prolonged fish preservation at 4 °C. Active packaging with on-demand release capability has attracted increasing interest in food preservation; however, the delayed response of active agents often compromises protection during the early stage of spoilage. In this work, an adsorption-triggered release strategy was proposed by incorporating cinnamaldehyde (CA)-loaded ZSM-5/ZIF-8 nanoparticles (CA@ZSM-5/ZIF-8) into a sodium alginate (SA) matrix. Owing to the strong affinity of biogenic amines toward the adsorption sites of ZSM-5/ZIF-8, low concentrations of histamine could competitively displace the preloaded CA, thereby enabling an early and responsive release behavior. In the absence of histamine, the cumulative release of CA from the composite film remained below 10% within 12 h, whereas it increased to approximately 60% in the presence of 5.0 mM histamine. Meanwhile, the optimized film exhibited improved tensile strength (54.6 MPa), water vapor barrier performance (0.86 × 10 −10  g·m·m −2 ·s −1 ·atm −1 ), UV-shielding capability, and water resistance. The film also showed pronounced antioxidant activity (91.4%), sustained antibacterial effects against E. coli and S. aureus , and favorable biodegradability. When applied to fish preservation, the optimized film effectively extended the refrigerated shelf life to 6 days at 4 °C. This study provides a novel paradigm for on-demand release in intelligent food packaging.