Effect of cellulose and lignin on disintegration, antimicrobial and antioxidant properties of PLA active films

• Cellulose (CNC) and lignin (LNP) nanostructures were combined in PLA or graft-PLA.
• Inhibition of Gram negative bacterial growth was revealed in ternary systems.
• LNP and CNC generated a synergistic effect in the antioxidant response of films.
• All the formulations disintegrated up to 90% after 15 days of incubation in compost.
• Migration tests confirmed the possible use of films in food packaging field.

This study reports the effects on antimicrobial, antioxidant, migration and disintegrability activities of ternary nanocomposite films based on poly(lactic acid) incorporating two biobased nanofillers, (cellulose nanocrystals (CNC) and lignin nanoparticles (LNP)), in two different amounts (1 and 3% wt.). Results from antimicrobial tests revealed a capacity to inhibit the Gram negative bacterial growth of Xanthomonas axonopodis pv. vesicatoria and Xanthomonas arboricola pv. pruni along the time, offering innovative opportunities against dangerous bacterial plant pathogens. LNP proved to be highly efficient in antioxidation activity, based on the disappearance of the absorption band at 517 nm of the free radical, 2,2-diphenyl-1-picrylhydrazyl (DPPH) upon reduction by an antiradical compound; moreover the combination of LNP and CNC generates a synergistic positive effect in the antioxidation response of PLA ternary films. Furthermore, all the studied formulations showed a disintegrability value up to 90% after 15 days of incubation in composting conditions. Migration results showed that the films can be considered suitable for application in food packaging field.