Multifunctional chitosan-lignin-containing nanocellulose composite films for food packing.

Maximizing the valorization of renewable resources to develop bio-composite materials is crucial for advancing environmental sustainability and ensuring food chain security. In this study, lignin-containing nanocelluloses (LCNs), derived from passion fruit husk using a combination of deep eutectic solvent (DES) and ultra-high-pressure homogenization (UHPH), were incorporated as nanocellulose into a chitosan matrix to produce innovative bioactive packaging films. The results indicated that the inclusion of LCNs improved the water resistance performance and the antioxidant and antimicrobial properties of the films. The tensile strength of the composite films significantly increased, while the elongation at break decreased. Moreover, the presence of LCNs notably enhanced UV shielding properties of the composite films, particularly in the short-wavelength UVC (200-280 nm) and medium-wavelength UVB (280-315 nm) regions. The banana preservation test further demonstrated that the chitosan-LCN composite films effectively inhibited bacterial growth and extended the shelf life of bananas at room temperature. Thus, these composite films offer a promising and sustainable solution for the high-value commercial use of agricultural by-products and chitosan in food packaging applications.