Controlled release of chlorine dioxide from α-cyclodextrin complexes embedded in poly(lactic acid)/poly(butylene...

In this study, chlorine dioxide (ClO₂) was encapsulated within α-cyclodextrin (α-CD) via two approaches: in situ ClO₂ generation (EC) and effervescent tablets (ET). FTIR, XRD, TG-DTG, SEM, and water contact angle (WCA) analyses verified the successful formation of ClO₂/α-CD inclusion complexes and revealed distinct structural, thermal, and morphological differences between EC and ET. EC exhibited superior encapsulation efficiency (2.3% vs. 0.9% in ET), and slower ClO₂ release rates across varying storage temperatures, indicating stronger host - guest interactions and more robust structural integration. Kinetic analysis confirmed that ClO₂ release followed the first-order model for 1% and 5% groups and the zero-order model for the 3% group, with a non-Fickian anomalous diffusion mechanism controlled by both gas diffusion and polymer chain relaxation. The EC complex was incorporated into biodegradable PLA/PBAT composite films at varying concentrations (1-5%) to develop functional packaging materials. The incorporation of EC enhanced surface hydrophilicity but reduced tensile strength and light transmittance due to particle aggregation. At low loadings (1-3%), well-dispersed EC particles created a tortuous diffusion path and improved oxygen barrier properties. At 5% EC, excessive agglomeration induced microstructural defects and increased gas permeability, which was supported by microstructural observations. Grape preservation tests at 25 °C showed that PLA/PBAT/EC films effectively inhibited microbial spoilage and extended shelf life, despite a slight increase in mass loss related to higher water vapor permeability. In vitro antimicrobial evaluation against Rhizopus stolonifer further validated the concentration-dependent antibacterial activity of the films. These results highlight the potential of ClO₂/α-CD inclusion complexes for active food packaging applications. These results support the potential of EC-based ClO₂ complexes in active packaging systems for enhanced food preservation.