In situ modification of foaming bacterial cellulose with chitosan and its application to active food packaging

Owing to a lack of specific biological functions, bacterial cellulose (BC) has been restricted in its application to the field of active packaging. In this study, we developed antimicrobial packaging materials using foaming BC (FBC) with chitosan (CS) and applied it to the preservation of chilled sea bass. The material property analysis demonstrated that 1.5 % CS/FBC maintained a high water content of 91 %, a swelling ratio of 75.6 %, great stress of 1.61 MPa, and great strain of 1.87 %. CS incorporation into FBC also decreased its crystallinity from 73.39 % to 69.3 %. Meanwhile, 1.5 % CS/FBC also provided great antimicrobial ability against Escherichia coli and Staphylococcus aureus by approximately 2 log colony-forming units/mL inhibition utilizing contact-killing. Results of the preservation assessment indicated that 1.5 % CS/FBC efficiently inhibited Shewanella putrefaciens growth, reduced total volatile basic nitrogen release, and slightly inhibited lipid oxidation. Based on the above results, CS/FBC is an ecofriendly biomaterial produced from a microorganism that possesses high absorbency and strong antibacterial properties, making it suitable for development as antibacterial active packaging.