HE Hui, FAN Jiaxun, LIU Zijun, MA Haoxiang, ZHA Fengchao
To develop a bio-based active packaging material with mechanical support, antibacterial and antioxidant activities, biocompatibility, and fruit preservation capacity, a double-network hydrogel was prepared using polyvinyl alcohol (PVA) and hydroxypropyltrimethyl ammonium chloride chitosan (HACC) as the matrix through a citric acid-freeze-thaw synergistic crosslinking strategy.Curcumin/anthocyanin-loaded β-cyclodextrin metal-organic framework (C/A@β-CD-MOF) and titanium dioxide (TiO2) were incorporated to fabricate a multicomponent composite hydrogel.The structure, physicochemical properties, mechanical performance, antibacterial and antioxidant activities, biocompatibility, and non-contact preservation effect of the hydrogel were systematically evaluated.The results showed that the incorporation of C/A@β-CD-MOF and TiO2 enhanced hydrogen bonding and interfacial interactions within the hydrogel matrix, resulting in a more compact network structure.Combined with the release behavior, the confinement effect of β-CD-MOF channels and β-CD hydrophobic cavities, together with the diffusion resistance of the PVA/HACC network, contributed to the stable loading and sustained release of the active compounds.Compared with the PVA/HACC hydrogel, the dual-filler composite hydrogel showed a decrease in water contact angle from (56.10±0.50)° to (27.30±0.19)°.Its water vapor permeability decreased to (1 211.00±45.00) g/(m2·d), and its equilibrium swelling ratio decreased to (531.60±31.04)%.The hardness, springiness, initial modulus, and rupture force increased to (3.18±0.08) N, (2.42±0.19) mm, (2.29±0.31) N/mm, and (2.41±0.08) N, respectively.The inhibition rates against Escherichia coli and Staphylococcus aureus reached (84.27±3.18)% and (91.36±2.69)%, respectively.The ABTS cation radical and DPPH radical scavenging activities were (79.47±5.89)% and (73.87±5.41)%, respectively, and the Caco-2 cell viability remained at (82.70±4.31)%.The non-contact preservation experiment showed that the composite hydrogel significantly reduced weight loss, decay, softening, and surface microbial proliferation in mini bananas during storage.After 9 d, the weight loss rate, decay index, and firmness change rate were controlled at (3.55±0.08)%, (18.20±1.00)%, and (-14.10±1.20)%, respectively.In summary, the PVA/HACC/C/A@β-CD-MOF/TiO2 composite hydrogel achieves synergistic preservation through compact network barrier effects, sustained release of active compounds, free radical scavenging, photocatalysis-assisted antibacterial activity, and packaging microenvironment regulation.It shows good application potential in the field of bio-based active packaging.