Fabrication and Characterization of HOBA‐Intercalated LDH Fillers for Multifunctional PE Composite Films in Food Packaging

In this study, 2‐hydroxy‐5‐octanoylbenzoic acid (HOBA) was successfully intercalated into Zn–Al layered double hydroxide (LDH) via ion‐exchange to form HOBA‐LDH with simultaneously enhanced thermal stability, enhanced UV absorption, hydrophobicity, antioxidant activity, and antimicrobial performance. HOBA‐LDH exhibited remarkable antibacterial activity against Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ) with both inhibition rates exceeding 99.9%. Multifunctional composite films were fabricated by melt‐casting HOBA‐LDH with polyethylene (PE). Compared with pure PE, the composite films showed enhanced tensile strength, higher elongation at break, reduced oxygen and water vapour transmission rates, superior UV‐barrier properties, and effective antimicrobial activity against E. coli and S. aureus with inhibition rates of 94.0% and 78.9%, respectively. Application tests demonstrated that composite films effectively preserved Red Globe grapes, reducing weight loss, suppressing respiration intensity, preventing microbial spoilage, while maintaining fruit firmness, sweetness and prolonging sensory quality for up to 30 days. The results clearly show that HOBA‐intercalated LDH fillers enhance the overall performance of the composite films. Composite films exhibit strengthened mechanical properties, reduced water and oxygen permeability, and improved antibacterial activity. In conclusion, these improvements indicate the strong promise of active food packaging materials.