Effect of growing site, sampling date, wood location in trunk and drying method on concentration of soluble proanthocyanidins in Betula pendula wood, with special reference to wood colour

Abstract

Proanthocyanidins (PAs), which are common phenolic compounds in plants, are considered to be mainly defensive compounds against different kinds of stress, e.g. herbivory. In addition to increasing after stress, they may condense and/or oxidize to form coloured compounds when cells die, which may affect both the resistance of xylem to rot and its colour. This is important in the mechanical wood industry. The effects of some biological factors (growing site, sampling date, wood location in the trunk) on the concentration of soluble PAs (sPAs) were studied in fresh and dried birch wood. Those factors that affected sPA concentration most were sampling date and radial location. Drying method also had a great effect on the sPA concentration, which in turn correlated with the colour of the wood.

Keywords:

• Proanthocyanidins
• silver birch
• wood discoloration
• wood drying

Acknowledgments

The authors thank Prof. Antti Asikainen, Ph.D. (For.), Leila Alvila, Ph.D., Kirsi Mononen, Phil.Lic., Sari Heikkinen, M.Sc., Juha Ikäheimo, M.Sc. (For.), and Jukka Eronen, M.Sc. (For.), for help with tree felling, sampling and sawing. Drying in lowered air pressure was carried out by Timo Lahtinen, B.Eng., birches were donated by Stora Enso Oyj and the project was funded by the Academy of Finland (project no. 43153).

Notes

Luostarinen, K. and Möttönen, V. (Faculty of Forestry, University of Joensuu, P.O. Box 111, FI-80101 Joensuu, Finland). Effect of growing site, sampling date, wood location in trunk and drying method on concentration of soluble proanthocyanidins in Betula pendula wood with special reference to wood colour.

Additional information

Notes on contributors

Katri Luostarinen

Luostarinen, K. and Möttönen, V. (Faculty of Forestry, University of Joensuu, P.O. Box 111, FI-80101 Joensuu, Finland). Effect of growing site, sampling date, wood location in trunk and drying method on concentration of soluble proanthocyanidins in Betula pendula wood with special reference to wood colour.