Comprehensive characterization of cold plasma/nanoparticles-functionalized gelatin active film and its application in tilapia fillets.

With the increasing demand of consumers for food preservation materials, the development of high-performance active packaging films has become a research hotspot. This study constructed a novel chondroitin sulfate-zein nanoparticles system co-encapsulating curcumin and resveratrol (ZCRC NPs) for gelatin-based active packaging, modified by atmospheric cold plasma (ACP) to achieve multifunctional enhancement. The ACP-treated composite film exhibited significantly improved in physical properties, with opacity increasing to 1.15 ± 0.16, while mechanical strength and elongation at break improved by 168 % (from 0.025 ± 0.001 MPa to 0.067 ± 0.003 MPa, P < 0.05) and 105 % (from 25.76 ± 2.46 % to 52.81 ± 3.54 %), respectively. Barrier properties were simultaneously enhanced, with oxygen permeability reduced by 50 % (from 3.61 ± 0.05 to 1.82 ± 0.03 g/m·d) and water vapor permeability decreasing from (7.45 ± 0.76) × 10 to (2.63 ± 0.86) × 10 g/m·d·Pa. The scanning electron microscopy (SEM) exhibited that ZCRC NPs were uniformly dispersed in the gelatin-based film and exhibited good compatibility with the matrix. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analyses confirmed that ACP treatment enhanced NPs cross-linking in gelatin-based films by driving hydrogen bonding, hydrophobic interactions, and electrostatic forces, while also enhancing crystallinity. Moreover, differential scanning calorimetry (DSC) and thermogravimetry (TG) analysis demonstrated that the thermal stability of the composite film was significantly improved (P < 0.05). Antioxidant capacity significantly increased (P < 0.05), with DPPH inhibition (29.11 ± 1.34 % to 60.63 ± 1.05 %) and ABTS scavenging (45.25 ± 1.67 % to 76.80 ± 1.94 %), effectively delaying fish fillet deterioration. In summary, this study provides new insights into the application and preservation potential of ACP-modified NPs in active food packaging films.