Valorization of banana peel waste into a hybrid-crosslinked cellulose nanofiber/chitosan hydrogel with antibacterial properties

A composite hydrogel was developed by integrating chitosan with cellulose nanofibers (CNF) isolated from Musa acuminata Colla (ambon lumut) banana peel waste, a sustainable and underutilized agricultural byproduct. The fabrication employed a hybrid crosslinking approach, combining freeze–thaw cycles with citric acid as a non-toxic crosslinking agent to reinforce the hydrogel network. CNF isolation yielded 6.8% nanofibers with a crystallinity index of 54.98% and fiber diameters ranging from 15 to 55 nm. Citric acid incorporation enhanced mechanical stability and crosslinking density, while concurrently reducing the degradation degree, swelling ratio, and water retention. Increasing the number of freeze–thaw cycles incrementally influence the crosslinking degree and swelling behavior. The resulting hydrogels exhibited a stable, interconnected porous morphology with approximately 48% porosity, forming a poroelastic network capable of retaining substantial amounts of water. Antibacterial evaluation demonstrated effectiveness against Staphylococcus aureus , with an inhibition zone of 7.0 mm and a 3.85-log bacterial reduction (>99.9%). Collectively, these findings underscore the potential of valorizing banana peel waste as a sustainable source for a hybrid crosslinked CNF/chitosan hydrogel with promising antibacterial properties.