Brilliant fabrication of multifunctional collagen-based packaging films with rigid-flexible coupling structure bio-inspired by pangolins.

Deformable collagen-based films with superior stability, flexibility and intelligent packaging capabilities remains a substantial challenge. Adopt inspiration from the pangolin's barrier, a biomimetic "rigid-flexible coupling" strategy was employed to develop multifunctional film (Col/DA/ZnO/BW) incorporating collagen (rigid matrix), dibenzaldehyde-terminated polyethylene glycol (DA-PEG, flexible cross-linker), ZnO nanoparticles (reinforcer) and black wolfberry anthocyanins (BW, pH indicator). Structural analyses revealed the uniform film matrix stabilized through covalent and hydrogen bonding. Notable improvements in packaging performances included low water vapor permeability (4.76 × 10-11 g s-1 m-1 Pa-1), favorable UV-light screening capacity (68.71 %), enhanced thermal stability (71.17 °C), superior tensile strength (78.64 MPa), strong antioxidant activity (72.09 % DPPH scavenging) and notable antibacterial efficacy. Moreover, profiting from the pH-responsive nature and excellent biodegradability, the intelligent film enables real-time monitoring of pork freshness and provides an eco-friendly alternative to conventional plastics. This multifunctional film holds great promise for sustainable food packaging, boosting food safety and minimizing environmental pollution.