Kimchi cabbage-derived sustainable composite cellulose films for food packaging: Contributions of components to physical properties and functionalities.

Given the sustainable nature of cellulose, the corresponding films are ecofriendly alternatives to conventional packaging; however, their limited physical properties hinder broader application. To address this problem, we herein prepared twelve composite films by incorporating reagent-grade hemicellulose, pectin, and lignin into a cellulose film matrix at varying ratios and evaluated the contribution of each component to film performance. Hemicellulose improved the thermal stability of the films, while pectin facilitated film formation and enhanced the tensile strength (from 0.82 MPa at low pectin contents to 4.86 MPa at high pectin contents). Lignin provided excellent ultraviolet (UV)-blocking properties, reducing the UV-region transmittance to nearly zero while enhancing the antioxidant capacity, with the maximum scavenging efficiencies of 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radicals reaching 77.97 % and 100.0 %, respectively. A representative formulation was used to prepare a film from kimchi cabbage-derived components, and the film was compared with its reagent-based counterpart. Compared with the reagent-based film, the kimchi cabbage extract-based film exhibited a lower mechanical strength and higher permeability while showing similar UV-blocking and antioxidant properties. This study highlights the potential of composite cellulose films as sustainable packaging materials and demonstrates the feasibility of valorizing agricultural waste through material upcycling.