Abstract

Discolouration of wood raw material during wet storage has a notable negative effect on the quality of the final product. In this study, fluorescence microscopy was used to investigate the spatial distribution of discolouring substances in water-sprinkled Norway spruce pulpwood. Water-sprinkled wood was characterised by the presence of discolouring substances on the pit membranes of wood cells. In vitro model studies on the interaction between a model bark substance ( tannic acid) and torus constituents support the hypothesis that pectic structures facilitate the allocation of bark substances on pit membranes. Applied pectinase or tannase could not remove the discolouring substances from pit membranes. Manganese peroxidase had a minor but documented effect. The effect of manganese peroxidase, as well as HCl/vanillin labelling, indicated that the discolouring substance may be condensed tannins

Published in

Holzforschung
2006, volume: 60, number: 1, pages: 93-98
Publisher: WALTER DE GRUYTER & CO

Authors' information