Effect of nanofibrillated cellulose on alginate and chitosan film properties as potential barrier coatings for paper food packaging

This study aimed to test the utility of ammonium persulfate (APS) oxidised nanofibrillated cellulose (NFC) as an additive for chitosan- and alginate-based biopolymer films that could eventually be used as paper coatings for food packaging applications. Sodium alginate and chitosan were used as the base for the films. Various concentrations of APS oxidised NFC ranging from 0% to 10% were used as a reinforcing agent, resulting in six combinations of either alginate-NFC or chitosan-NFC composite films. Biofilms were tested for their mechanical properties (tensile strength and strain), grease barrier properties, air permeability, water vapour permeability, and degradation in the soil. Overall, when using the ammonium persulfate oxidation pretreatment method, the best performance of the films was estimated with the addition of 2.5% NFC.