Targeted functionalization of spruce galactoglucomannans with aid of galactose oxidase (FunMan)

Funding: Academy of Finland, KETJU-research programme
Collaboration: Prof. Stefan Willför, Åbo Akademi University, Finland
Project description:
Hemicelluloses (xylans, mannans) are after cellulose the second most abundant polysaccharides produced by plants. Galactoglucomannans are the most common softwood hemicelluloses (15-20%). Parts of these galactoglucomannans (5-10%) are dissolved in mechanical pulping of spruce. The Process Chemistry Centre at Åbo Akademi University has developed a method for recovering dissolved galactoglucomannans from these process waters. Recently the method has also been tested at mill scale. The usefulness of spruce galactoglucomannans as hydrocolloids in various applications are evaluated in the project. The galactoglucomannans will be enzymatically modified using galactose oxidase, which selectively oxidises the primary hydroxyl group on the galactose to aldehyde form. The generated aldehyde groups enable a novel type of interactions between galactoglucomannan chains through so-called hemiacetal bonds. These bonds can then influence the rheological properties of the galactoglucomannan solutions and also influence their interaction with other polymers and cellulose fibres. The aldehyde groups can further be chemically oxidised to carboxyl groups. Different functional groups can also be chemically bonded to the aldehyde groups to increase, for example, the hydrophobicity or the antioxidant properties. In the project, we concentrate on the nationally interesting galactoglucomannans that are dissolved during mechanical pulping of spruce. The goal is to develop novel innovative applications for a side-product from the processing of spruce.