caa a22 4500 463216539 CHVBK 20180405153158.0 cr unu---uuuuu 170326e20070801xx s 000 0 eng 10.1007/s00226-007-0144-7 doi (NATIONALLICENCE)springer-10.1007/s00226-007-0144-7 Element content and pH value in American black cherry ( Prunus serotina ) with regard to colour changes during heartwood formation and hot water treatment [Elektronische Daten] [Ingo Mayer, Gerald Koch] Element content and pH value in wood tissues of veneer grade logs of P. serotina Ehrh. were investigated with regard to wood colour variations, measured in the CIEL*a*b* system. The average pH value of heartwood tissue was about pH 4.0 and medium colour parameters of veneer sheets were determined at L*=73, a*=9.8, and b*=23.5. Optical emission spectroscopy (ICP-OES) analyses showed differences in the element contents between two regional forest sites coming from Pennsylvania and West Virginia, USA, respectively. The latter is mainly characterised by higher variations of micro-element content in the transition zone (influencing heartwood formation) and also pH value of wood tissue, which contributes to higher variations in colour response of industrially produced veneer sheets. Investigations under industrial conditions underline the correlation between length and intensity of heat treatment in veneer production and colour development: with increasing duration and temperature of hot water treatment, veneer surfaces become darker and wood colour is intensified (ΔL=3.6, Δa=2.1, comparing 12 and 72h of hot water treatment at 60°C). However, no equalisation of wood colour was achieved by modifying the treatment conditions. Artificial radiation by UV-visible light, quickly and extensively darkens and intensifies wood colour (ΔL=16, Δa=3.5, and Δb=4.0 after 15h of artificial radiation), but variations in wood colour deriving from different treatment conditions during veneer production, were not reduced. Springer-Verlag, 2007 Mayer Ingo Department of Wood Science, Division Wood Biology, University of Hamburg, Leuschnerstr. 91, 21031, Hamburg, Germany aut Koch Gerald Institute for Wood Biology and Wood Protection, Federal Research Centre for Forestry and Forest Products, Hamburg, Germany aut Wood Science and Technology Springer-Verlag 41/6(2007-08-01), 537-547 0043-7719 41:6<537 2007 41 226 https://doi.org/10.1007/s00226-007-0144-7 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00226-007-0144-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Mayer Ingo Department of Wood Science, Division Wood Biology, University of Hamburg, Leuschnerstr. 91, 21031, Hamburg, Germany aut NATIONALLICENCE 700 1- Koch Gerald Institute for Wood Biology and Wood Protection, Federal Research Centre for Forestry and Forest Products, Hamburg, Germany aut NATIONALLICENCE 773 0- Wood Science and Technology Springer-Verlag 41/6(2007-08-01), 537-547 0043-7719 41:6<537 2007 41 226 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer