The food packaging industry is a major source of global plastic waste due to the short lifespan of these materials, creating a significant environmental challenge. Bio-based polymers from renewable sources have emerged as sustainable alternatives to fossil-based plastics. Among them, tannins are particularly promising due to their abundance, low cost, and antioxidant, antibacterial, and photoprotective properties. However, tannin-based biofilms alone lack the mechanical strength required for food packaging, necessitating their combination with film-forming biopolymers such as chitosan.
This study explores the enzymatic graft polymerization of tannins onto chitosan using laccase enzymes, a process that offers environmental benefits by operating under mild conditions, eliminating the need for organic solvents, and reducing energy consumption. This environmentally friendly method provides an effective strategy for developing advanced materials suitable for food packaging applications.
The aim was to synthesize chitosan-tannin biofilms by enzymatic polymerization to obtain materials with improved mechanical, thermal, antioxidant and photoprotective properties. The copolymerization of chitosan and tannins, catalyzed by laccase enzymes, resulted in biofilms with significant improvements in mechanical and thermal properties compared to the base polymers, along with strong antioxidant capacity.
The results indicate that the synthesized biofilms are promising for creating sustainable and functional food packaging, capable of extending product shelf life while reducing dependence on conventional plastics. This study highlights enzymatic polymerization as a green and efficient approach to develop innovative biopolymer-based packaging materials.