Characterisation of an edible active film prepared from bacterial nanocellulose/forsythia essential oil Pickering emulsions with funoran and its application in fresh meat

This study sought to develop an edible active film by integrating Pickering emulsions of forsythia essential oil and bacterial nanofibers at various concentrations into a film-forming matrix composed of funoran (F). The stability of the emulsions was evaluated through examination of the micro-morphology, particle size and distribution, 7-day emulsification index, and embedding rate of the Pickering emulsions. Subsequently, selected Pickering emulsions were incorporated into F to generate the edible active film. Scanning electron microscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy revealed that the Pickering emulsion was uniformly distributed throughout the F film, interconnected by hydrogen bonds. X-ray Diffraction spectra exhibited changes in peak intensity and shifts in position attributable to the edible active film. Pickering emulsion had a minimal impact on thermal stability. The film's tensile strength significantly increased, while elongation at break decreased. The heightened concentration of hydroxyl groups in the film led to increased thickness, reduced moisture content, and enhanced hygroscopicity. The edible active film exhibited superior antioxidant and antibacterial properties, thereby more efficiently shielding against oxygen and water vapour. In preservation tests involving chicken and lamb, the Pickering emulsion led to elevations in pH, total volatile basic nitrogen, and thiobarbituric acid reactive substance levels in the meat.