Oxygen-scavenging packaging with lignin derivatives and laccase

Approximately one-third of the human food products of the world are wasted, which is highly problematic from a sustainability perspective[1]. The purpose of an active package is to extend the shelf-life, maintain the quality, and improve the safety of the packaged food. This can be achieved by the scavenging of oxygen inside sealed food packages. A new approach in this area is to produce an active package by the inclusion of oxygen-scavenging enzymes in the coating layer of the package. The phenol-oxidizing enzyme laccase is possible to utilize for this application, since molecular oxygen serves as one of its substrates. From a biorefinery perspective it would be interesting to utilize lignin derivatives as the other substrate, as lignin derivatives are co-products of biorefining of lignocellulosic feedstocks. Laccase is known to catalyze crosslinking of lignosulfonates, which improves the properties of the coating layer[2], but little is known about how the properties of the lignin derivative used affect the biocatalytic reaction and the quality of the coating layer. In this study we have evaluated different lignin derivatives and preparations of size-fractionated lignin derivatives with regard to utilization as substrates for laccase in oxygen-scavenging systems. The properties of the lignin derivatives before and after the reaction were characterized, and the mechanical properties as well as the water stability of the coating layers were investigated. The results indicate that laccase-catalyzed crosslinking increases the water stability and the stiffness of the coating layer.

[1] http://www.fao.org/save-food/key-findings/en/

[2] Johansson K et al. (2012) J. Biotechnol. 161, 14-18.