Sustainable chitosan bio-resin composites reinforced with flax fibers for high-performance food packaging

This study proposes an innovative strategy for developing chitosan-based bio-resin composites as sustainable alternatives to address the environmental impacts of petroleum-derived plastics in food packaging. The chitosan matrix was enhanced using a synergistic formulation of sorbitol (50 % w/v) as a plasticizer and genipin (0.1 % w/v) as a cross-linking agent, which significantly improved its mechanical and functional performance. Further reinforcement with short flax fibers (5 wt%) resulted in a chitosan-flax fiber (CS/FF) composite with a remarkable 220 % increase in tensile strength, reaching 11.20 MPa, and an enhanced thermal stability with an onset degradation temperature of 350 °C. The composite demonstrated exceptional functional properties, including 98 % UV-blocking efficiency, superior antibacterial activity with a 90 % reduction in microbial growth, and complete biodegradability within 30 days. Additionally, preservation trials on bananas showed a broad extension in shelf life compared with conventional packaging materials. These findings highlight the potential of CS/FF composites as high-performance, biodegradable alternatives for smart food packaging applications, offering an environmentally sustainable solution that combines advanced mechanical and functional properties with effective food preservation capabilities.