Development and characterization of sustainable biopolymer films from sugarcane bagasse derived carboxymethyl cellulose and orange peel pectin

Agricultural waste is an abundant yet underutilized resource that can serve as an excellent raw material for developing biodegradable biofilms as sustainable alternatives to conventional synthetic food packaging materials used in food industries. Utilizing such waste not only helps reduce environmental pollution but also promotes a circular economy by converting low-value agricultural residues into high-value functional products. The present research focuses on waste utilization (orange peel and sugarcane bagasse) for the synthesis of pectin and Carboxymethyl cellulose (CMC), which were used for the formulation of CMC orange peel pectin film. Further, comparative characterization of the two sustainable composite films, sugarcane bagasse CMC with commercial pectin and sugarcane bagasse CMC with orange peel pectin was done. CMC-orange peel pectin film showed a slightly higher moisture content and significantly higher moisture uptake (6.97%) than CMC-commercial pectin film, whereas the latter one has higher TSM (27.86%), affecting the structural integrity. The FTIR spectroscopy revealed the change in hydrogen bonding in CMC- orange peel pectin film due to presence of ester carbonyl (C O) group whereas SEM analysis revealed voids and cavities with average diameters of 36–38 μm and pore areas ranging from 17% to 20% in CMC-commercial pectin film as compared to CMC-orange peel pectin film hence, impacting the barrier properties of the film. CMC-orange peel pectin films include fewer and smaller holes, resulting in a more compact film matrix. The orange peel pectin variant's reduced void formation improves gas and moisture transmission resistance. This study utilizes orange peel-derived pectin as a sustainable biopolymer for biodegradable film production, promoting citrus waste valorization and circular economy principles. Compared to films prepared with commercial pectin, the developed films exhibited improved structural compactness, better barrier properties, and a lower environmental footprint.