Covalent engineering of bacterial cellulose (BC) with multifunctional agents for active food packaging

Bacterial cellulose (BC) has emerged as a promising sustainable material for food packaging due to its biocompatibility, high mechanical strength, and versatile functionalization capability. However, its inherent lack of antimicrobial and antioxidant properties, together with its hydrophilic nature, limits its protective efficacy and broader practical application in food preservation. Covalent grafting offers a powerful approach to overcome these drawbacks by permanently anchoring functional agents onto BC, thereby boosting its food preservation capabilities. In this review, we discuss various covalent modification strategies for immobilizing active compounds - including biocidal agents, antioxidants, and hydrophobic agents - onto the BC structure. These modifications address key challenges of BC films in food packaging such as microbial and oxidative spoilage and moisture sensitivity. Representative examples are highlighted in which covalently modified BC has been successfully employed to extend the shelf-life of foods. Antimicrobial modifications can achieve >95% pathogen inactivation; hydrophobic agents such as silanes increase contact angles to 150°; antioxidant functionalization with dopamine enables 90% radical scavenging. Modified BC extends the shelf life of fruits and meat by 10-14 days with minimal impact on BC's biodegradability.