Mechanical, barrier and antimicrobial properties of corn distarch phosphate/nanocrystalline cellulose films incorporated with Nisin and ε-polylysine.

Antimicrobial bio-nanocomposite films were prepared by incorporating nisin (0.25-0.5% W/W) and ε-polylysine (PL, 0.2% W/W) into corn distarch phosphate/nanocrystalline cellulose based films (CN) via casting method. Nisin and PL had significant effects on color parameters (L*, a*, b* and ∆E*) and improved the mechanical, barrier properties, thermal stability of the films. The CN bio-nanocomposite films incorporation the combination of nisin and PL had synergistic antimicrobial activity against Gram-positive bacteria (S. aureus) and Gram-negative bacteria (E. coli). Structural property assessment by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) revealed that a clear interaction between the hydroxyl groups of corn distarch phosphate and the amino groups of nisin and PL, leading to the microstructure of the CN bio-nanocomposite films with appropriate content of nisin and PL was more continuous and compact. These results indicate that the CN bio-nanocomposite films containing nisin and PL is a potential active packaging material with enhanced physicochemical properties in food industry.