Characterization of exopolysaccharide / starch composite film incorporated with TiO 2 nanoparticles and its application in chilled meat preservation

Multifunctional food packaging composite films were prepared using Pediococcus acidilactici J1 exopolysaccharide (EPS), potato starch (PS) and TiO nanoparticles by casting method. The microstructure, physicochemical properties and antibacterial activity of EPS/PS composite films with different weight ratio of TiO nanoparticles were characterized. Transmission electron microscope (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed the uniform distribution of TiO nanoparticles in the EPS/PS matrix. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) results indicated that the interaction between polymers and nanoparticles through non-covalent bonds. When TiO nanoparticles were added at 1 % (wt), the composite film had higher barrier properties against water vapor and UV-vis light, and better mechanical properties then EPS/PS film. Notably, EPS/PS/1%TiO composite film exhibited good antioxidant and antibacterial activity against Escherichia coli and Staphylococcus aureus. Through the analysis of the quality indexes and microbial community structure during the storage of chilled meat, the composite film slowed the oxidation rate of chilled meat and inhibited the growth of dominant spoilage bacteria, effectively extending its shelf life. All results suggested that EPS/PS/1%TiO composite film could serve as an effective packaging material for chilled meat, providing a novel approach to solve its limited shelf-life problem.