Chlorogenic acid crosslinked cellulose nanocomposite film embedded with chitosan for improved mechanical and barrier...

The need to develop sustainable and active food packaging materials has increased the pace of concern towards bio-based nanocomposite films that have superior mechanical and barrier properties. The paper explains the preparation of a chlorogenic (CG) acid crosslinked cellulose nanocomposite film containing chitosan to enhance strength of structure and functionality. Urtica dioica cellulose (UDC) was transformed into cellulose nanocrystals (CNC) by acid hydrolytic (AH) treatment which were integrated into a chitosan (CS) matrix. Chlorogenic acid was a bioactive compound and cross-linked to citric acid along with ascorbic acid in the composite. Addition of 10% cellulose nanocrystals gave rise to an enhancement of the overall film performance by almost 60%. The optimized CNC-CS-CG film obtained a water solubility of 16.30%, moisture content of 11.03% and a low water vapor permeability of 0.7 × 10^-1 g/m³ s Pa which was better than that of neat cellulose films though increased CNC contents lowered tensile strength. Chlorogenic acid was also shown to have 95-97% UV-blocking and antimicrobial activity in the film, which means that it has high potential as an active and sustainable food packaging. The synergic effect of polysaccharides (CNC and CS) and bioactive compound (CG acid) protected the strawberries until the 8th day of storage. Hence, it proved to be a promising coating material for extending shelf life.