Characterization of Bacteriostatic Sausage Casing: A Composite of Bacterial Cellulose Embedded with ε-Polylysine

The feasibility of a novel bacteriostatic sausage casing made of bacterial cellulose (BC) embedded with epsilon-polylysine (epsilon-PL) was evaluated. The epsilon-PL/BC composite was prepared by immersing BC tubes in epsilon-PL solution and its characteristics were analyzed with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and atomic force microscopy (AFM) techniques, respectively. The results suggested that epsilon-PL molecules were incorporated into the cellulose fiber networks and the epsilon-PL/BC composite might have a novel unique structure. No significant loss of antimicrobial activity was observed even after autoclaving at 121 degrees C for 30 min and the oxygen permeability was far below than that of polyethylene (PE) and polyvinyl alcohol (PVA) membrane. Its tensile strength was 51.8 MPa. The epsilon-PL/BC composite exhibits bacteriostatic and/or bacteriocidal activities against a broad spectrum of Gram-positive and Gram-negative bacteria; as a result, an extended shelf life than controls was observed for sausage packaged with the epsilon-PL/BC composite.