Synergistic antibacterial capabilities of berberine-docusate in polyvinyl acetate coatings for meat preservation: Boosting generation of reactive oxygen species

Hydrophobic berberine-docusate (BA) was successfully utilized as synergistic antibacterial agent in polyvinyl acetate (PVAc) coatings for decontamination of fresh meat. BA showed good antibacterial capabilities against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) under dark or light conditions. Reactive oxygen species (ROS) generation was significantly enhanced after aggregation in water. BA showed a high survival rate and minimal cytotoxicity of cell at a concentration less than 30 μg/mL. Good compatibility between PVAc and BA ensured the low release of BA in coatings during preservation relative to berberine-chloride (BBR). The coatings showed concentration-dependent and time-dependent photosensitive antibacterial activity against S. aureus and E. coli. After white light (60 mW/cm²) for 5 min, the antibacterial rate of PVAc coating containing 5 % BA (PVAc-BA₅) against S. aureus reached 99.47 ± 0.18 %. Fluorescence lifetime and quantum yield of BA in coatings were significantly enhanced, probably owing to aggregate-induced emission (AIE) and reduce in non-irradiation deactivation, which was conducive to boost the generation of ROS. Low total viable count (TVC) and total volatile base nitrogen (TVB-N) values of fresh meat packaged by PVAc-BA₅ coatings during storage at 4℃ demonstrated the practicability of the PVAc-BA₅ coating in decontaminating fresh meat. The results provided the possibility to utilize berberine-based antibacterial agents in coatings when packaging the food and fresh agricultural products rich in water.