Curdlan-based films and coatings for sustainable food packaging: structure, biosynthesis, functional properties, and...

Curdlan has attracted increasing attention as a sustainable biopolymer for food packaging because of its strong film-forming ability, thermogelation behavior, and structural robustness. This review analyzes recent advances in the development and functional enhancement of curdlan-based films and edible coatings. The structural properties of curdlan films are discussed in relation to thermal treatment and plasticizer incorporation. Particular attention is given to how these factors affect mechanical strength, water resistance, and barrier performance. Blending curdlan with natural polysaccharides and proteins has been shown to improve miscibility and versatility, enabling the development of robust binary and ternary systems tailored for diverse food applications. In addition, curdlan demonstrates strong potential as a matrix for incorporating antimicrobial and antioxidant agents, including essential oils, polyphenols, and silver nanoparticles, thereby enhancing its functionality in active packaging. Its application in edible coatings for fresh produce has also proven effective in reducing weight loss, delaying spoilage, and preserving quality attributes. Advanced analytical techniques, including FTIR, SEM, DSC, and low-field NMR, are useful for characterizing film morphology, thermal stability, water distribution, and functional performance. The review concludes with a discussion of regulatory and environmental considerations, emphasizing the importance of scalable and eco-friendly design approaches for future curdlan-based packaging innovations.