18-06: Lignin derivatives and laccase for active-packaging applications

Lignin-rich residues and lignin derivatives are quantitatively and economically important co-products of forest biorefineries. Lignin is useful as a solid fuel, but utilization of lignin or derivatives of lignin for advanced applications in other areas would be advantageous from a biorefinery perspective. We have explored a novel coating based on lignin derivatives and laccase and its potential as an oxygen-scavenging system for active packages. Oxygen-scavenging active packaging can be used to extend the shelf-life of food by protecting the food against deteriorative oxidation processes. The lignin derivatives that were included in the study were alkali lignin, hydrolytic lignin, organosolv lignin, and lignosulfonates. After initial studies of lignin derivatives in aqueous solutions and in coatings on paperboard, two of the lignin derivatives were selected for further investigation. Paperboard coatings and free films containing selected lignin derivatives and laccase were evaluated with respect to oxygen-scavening capability, water stability, and mechanical properties.  Laccase-catalyzed cross-linking of lignin derivatives resulted in increased stiffness and improved water stability.