Composite films of sodium alginate and konjac glucomannan incorporated with tea polyphenols for food preservation

At present, food waste has become a serious issue and the use of petroleum-based food packaging films has resulted in a series of potential hazards. Therefore, more attention has been focused on the development of new food packaging materials. The polysaccharide-based composite film loaded with active substances considered to be an excellent preservative material. A novel packaging film based on sodium alginate and konjac glucomannan (SA-KGM) blended with tea polyphenols (TP) was prepared in the present study. The excellent microstructure of films was shown by atomic force microscopy (AFM). It was indicated by FTIR spectra that the components could interact with each other through hydrogen bonds, which was also confirmed by molecular docking simulation. Meanwhile, the mechanical properties, barrier property, oxidation property, antibacterial activity, and stability of the structure of the TP-SA-KGM film were significantly improved. The AFM images and results of molecular docking simulation indicated that TP could affect the cell wall of bacteria by acting with peptidoglycan. Finally, the film showed excellent preservation effects in both beef and apples, which suggested that TP-SA-KGM film could be a novel bioactive packaging material with wide application potential in food preservation.