Physical properties and antibacterial activity of the composited films based on carboxymethyl cellulose and gelatin functionalized with ε-polylysine

Antibacterial composite films were produced from carboxymethyl cellulose-gelatin (CMC-Gel) blend with different concentration of ε-polylysine (ε-PL) and their physical and chemical properties were characterized. Compared with the control CMC-Gel film, the functionalized films had almost indistinguishable crystalline type, thickness, tensile strength, and elongation at break, however, poor water vapor barrier properties. The results showed that the ε-PL was well incorporated into CMC-Gel matrix by electrostatic interaction, as the changes of absorption peaks in the Fourier transform infrared spectrometer and the increase of glass transition temperature in differential scanning calorimeter. The films containing ε-PL showed excellent antibacterial activity against S. aureus, B. subtilis, E. coli and P. aeruginosa. In the composting experiment, the films become degraded on the seventh day, and further degraded with the growth of molds over time. The present results showed that the active films could be a potential material for food packaging.