Tuning of Chitosan with Lignin derived Bioactive Properties to develop a Lignin Reinforced and Sustainable Food Packaging Biomaterial

The crucial component of food storage, preservation, and transportation is food packaging. Biodegradable biopolymers are a major area of focus for the future development of food packaging materials due to their ability to mitigate adverse environmental impact by reducing plastic pollution and promoting sustainable waste management practices. Exploring renewable resources is crucial for facilitating the transition from non-renewable practices to sustainability. Chitosan is known for its superior film-forming abilities but has limited antibacterial activity. The inherent properties of lignin, including its high tensile strength, antioxidant, antimicrobial, and UV barrier ability, can contribute to enhance chitosan film performance when added as a co-polymer, making it an active material for food packaging applications. The present work explores the acid-alkali treatment to extract lignin from sugarcane tops, an abundant agricultural waste, and the application of extracted lignin in biopolymer-based hydrogel synthesis for food packaging. The goal is to enhance the hydrogel formulation by incorporation and optimisation of lignin that holds high antioxidant, antimicrobial, UV barrier, and mechanical properties along with significantly low water transmissibility. This study introduces a novel approach by utilizing lignin extracted from sugarcane tops (SCT) rather than commercially derived lignin, thereby expanding the raw material scope of lignin applications. The incorporation of higher proportions of lignin in the hydrogel formulations represents an advancement over reported studies, aimed at improving the bioactivity of the hydrogel by leveraging its advantageous characteristics emanating from lignin. This approach can also reduce the dependency on chitosan which is relatively expensive. Further, the modified synthesis of hydrogels expedited through heating method contributes to shorten the time duration needed for hydrogel film casting and drying. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=139 SRC="FIGDIR/small/592363v1_ufig1.gif" ALT="Figure 1"> View larger version (48K): org.highwire.dtl.DTLVardef@c88b2forg.highwire.dtl.DTLVardef@29c658org.highwire.dtl.DTLVardef@9ce06borg.highwire.dtl.DTLVardef@151a8b5_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIEnhanced lignin extraction from sugarcane tops using Plackett Burman Design C_LIO_LIFormulating green packaging hydrogels through valorisation of sugarcane tops C_LIO_LIHeating-based short time casting method for Lignin/Chitosan hydrogel synthesis C_LIO_LIOptimization of lignin content in the hydrogels for balanced mechanical and bioactive properties C_LI