Evaluating the reinforcing potential of steam-exploded chitin nanocrystals in chitosan-based biodegradable nanocomposite films for food packaging applications

Chitosan-based films, despite being biodegradable and edible, often lack the necessary requisite properties such as mechanical strength, water resistance, and thermal stability, which are critical for effective food packaging. To address these limitations, incorporating reinforcing nanofiller materials offers a promising solution. This study utilizes steam-exploded chitin nanocrystals (ChNCs) to reinforce chitosan nanocomposite films through a solution-casting technique. The resulting nanocomposite films were evaluated for their physical, mechanical, optical, and thermal properties. Our findings indicate that ChNC incorporation significantly enhanced the mechanical and thermal properties, with tensile strength improving by 88.83 %, Young's modulus by 52.82 %, and elongation at break by 126.15 %, while reducing water uptake by 61.09 % and solubility by 43.03 %. The nanocomposite films also exhibited improved UV-Vis light barrier properties and maintained reasonable transparency. Additionally, color analysis revealed increased lightness and decreased yellowness compared to pure chitosan films. FTIR confirmed the successful integration of ChNCs into the chitosan matrix, while XRD indicated higher crystallinity for composite films. SEM analysis showed a homogeneous dispersion of ChNCs in the chitosan matrix. These results underscore the potential of steam-exploded ChNC-reinforced chitosan nanocomposite films for food packaging applications, positioning them as promising candidates for sustainable and functional packaging solutions in the food industry.