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Beech (Fagus sylvatica l.) is one
of the economically most im-
portant tree species in europe. Extractives
The use of beech wood is limit-
ed however, due to the colour
change in the central part of of mechanically
the stem. Such discolouration, wounded wood
known as red heart, is formed
as a consequence of mechanical and knots in Beech
wounding of a standing tree (a).

wounded wood represents an important source
of variability of extractives in a living tree. the
results of this investigation represent an im-
portant contribution to the understanding of
discoloration processes that occur in beech
The formation of discoloured wood tained relatively low amounts of wood and reveal wood as a relevant source
is a consequence of physiological lipophilic extractives, among which of compounds with high added value.
and biochemical changes where free fatty acids and sterols were
non-structural components, i.e. ex- dominant. The content of fatty acids and flavanol polymers are charac-
tractives, play an important role. in is largest in the knots and reaction teristic for knots and wound-wood,
this context, extractives of wound- zones, moreover, the latter con- whereas, discoloured tissues con-
ed wood and knots of a beech tree tained larger amounts of free ster- tained the lowest amounts of these
were colorimetrically and chroma- ols as well. Beech wood contains compounds (c).
tographically investigated. extract- significantly more hydrophilic ex-
able compounds were obtained by tractives, mainly soluble sugars and
means of speed extraction by suc- phenolic substances, flavanol cat-
cessively applying non-polar and echin being the dominant one (b).
polar solvents. Beech wood con- The largest amounts of phenols

Source: VEK, Viljem, OVEN, PrimoĹľ, TERS, Thomas, POLJANĹ EK, Ida, HINTERSTOISSER, Barbara.
Extractives of mechanically wounded wood and knots in beech. Holzforschung. 2014, 68, 5:
529-539. [COBISS.SI-ID 2166153].