Preparation of a microfibrillated cellulose/chitosan/polypyrrole film for Active Food Packaging

Abstract

The objective of this research was to develop an effective and complete green approach for the production of composite films with enhanced antioxidant and antibacterial properties and oxygen barrier properties. This was accomplished by incorporating chitosan (CS) and polypyrrole (PPy) to microfibrillated by coasting method prepare MFC/CS/PPy film. The contact angle was used to evaluate poor water resistance, which increased from 94.1° to 122°. The contact angle of the composite film was further increased to 122° due to the chemical polymerization of pyrrole produces a layer of PPy nanoparticles on the surface of the MFC/CS composite film. The CS and PPy improved the uniformity of the surface and filled the pores, indicating that the channel has been blocked, resulting in significant reduction in oxygen transmission (32.38 cm3 (m−2·day−1). The MFC/CS/PPy film showed bactericidal activity against Escherichia coli (5.43 log CFU mL −1 reduction) The synergistic effect of proton amino (in acidic medium) in CS with the positively charged PPy chain improves the antimicrobial performance of MFC/CS/PPy. The positive charges Ions may attach to the negatively charged bacterial cell wall, thus destroying the cell wall and eventually killing the bacteria. The composite films have good thermal stability. The ability of MFC/CS/PPy composite membrane to inhibit 2,2-diphenyl-1-picrylhydrazyl assay (DPPH) activity increases to 54 %. This property depends on the increased activity of the hydrogen atoms. Considering a series of current properties, MFC/CS/PPy composite film was successfully used in the active packing of fresh cherry tomatoes (10 days), effectively extending shelf life. Therefore, MFC/CS/PPy composite film has the potential to be used as biodegradable packaging materials for fresh fruits.