- Written by Anna Strom
Bio4Energy would like to acknowledge its researchers who contributed a presentation to the Lignin 2014 conference, held 24-28 August at Umeå, Sweden.
'Smart' packaging designed to prolong the shelf-life of food
Sandra Winestrand and colleagues at Umeå and Karlstad Universities
Edited abstract: Extending the shelf-life of packaged food is a potential way of reducing food waste. One possible way to do this is by using a system that scavenges the oxygen inside a package equipped with an oxygen barrier. A common way to scavenge oxygen inside a package is to insert a small sachet containing iron powder. An alternative to this is to use oxygen-scavenging enzymes that can be incorporated directly in the coating layer of the package.
The phenol-oxidising enzyme laccase uses molecular oxygen as its oxidising substrate, and could therefore be used for the latter type of application. Laccase can use derivatives of lignin as its reducing substrate, which would be interesting from a biorefinery perspective since lignin derivatives are underused co-products in biorefinery based on lignocellulosic feedstock. The aims of the investigation were to understand how the properties of lignin derivatives affected the enzymatic reaction and the quality of the coating layer.
The study involved the use of lignin derivatives and preparations of size-fractionated lignin derivatives from industrial processing of lignocellulose. The molecular properties of the lignin derivatives before and after oxidation by laccase were investigated, as well as the capability of films and coatings to scavenge oxygen. The results indicate that laccase-catalysed cross-linking decreases oxygen levels and improves the water stability of the packaging material.