Wood properties modification by an enzymatic assisted treatment with phenolic extractives
D Filgueira, C Fernández-Costas, D E García, D Moldes
Extractives of sawdust and bark from P. pinaster and, condensed tannins (CTs) from P. radiata bark were used to treat beech and pine veneers in combination with an oxidative enzyme, in order to stably graft such extractives onto the veneers. First, the antifungal activity of P. pinaster phenolic extractives against wood decay fungi was studied. These extractives were also used to hydrophobize pine and beech wood by means of the treatment with laccase enzyme. The same treatment was performed with CTs from P. radiata and chemically derivatized CTs (HPTs) to modify the physiochemical properties of beech wood.
Sawdust extractives of P. pinaster showed a high growth inhibition of P. ostreatus and C. puteana. Besides the biological activity, the treatment with laccase and the mentioned phenolic extractives provided stable hydrophobic properties to pine and beech wood. The chemical derivatization of CTs enhanced the hydrophobic properties of native CTs. After the inclusion of such HPTs in the enzymatic treatment of wood veneers, a higher resistance to water absorption was obtained.
Thus, the stable graft of P.pinaster phenolic extractives onto wood provided biological and hydrophobic properties. The chemical derivatization of natural phenolic extractives improved their chemical and biological properties which opens a new perspective for future applications of these compounds.