Bacterial nanocellulose films functionalized with Janus nanoparticles: Preparation and application in chicken meat preservation and safety

Janus nanoparticles (JPs) were prepared from hydrophobic carbon dots and carboxymethylcellulose via an ex-situ method, and incorporated into bacterial nanocellulose (BNC) films at concentrations of 0.01%, 0.02%, and 0.03%. Cytotoxicity test revealed a toxic effect of JPs on human gastric cancer cells only at concentrations above 5 mg/mL. Fourier transform infrared spectroscopy confirmed the successful incorporation of JPs without interfering with BNC network. JPs incorporation reduced the tensile strength and elongation at break of the films but improved the radical scavenging activity of BNC in a concentration-dependent manner. The diameters of inhibition zones for BNC films containing 0.01%, 0.02%, and 0.03% JPs against Salmonella Typhimurium were 17.1 mm, 20.7 mm, and 27.5 mm, respectively. Upon application to chicken breast meat, all treated samples exhibited an inhibitory effect on S. Typhimurium, as indicated by the absence of detectable levels on day 16. For BNC-JPs samples, a notable decrease in mesophilic bacterial counts was observed, representing reductions of 3.2, 4.6, and 5.6 log₁₀ CFU/g at JP 0.01%, 0.02%, and 0.03%, respectively. The BNC-JPs-treated samples also had lower volatile nitrogenous compounds and lipid oxidation levels. These findings highlight the potential of BNC-JPs films as green, active food packaging materials with commercial potential.