Authors: F Ishiguri S Maruyama K Takahashi Z Abe S Yokota M Andoh N Yoshizawa
Publish Date: 2003/04
Volume: 49, Issue: 2, Pages: 135-
Abstract
Sugi green logs with red or black heartwood were smokeheated and the changes in the color of the heartwood after ultraviolet UV λ = 365 nm radiation exposure were then observed After UV radiation exposure the redness and yellowness increased in both the red and black heartwoods whereas the brightness decreased In the black heartwood the resulting color turned from yellowish white to reddish brown Reddening in black heartwood after exposure to a combination of smoke heating and UV radiation is thought to be due to a decrease in brightness and an increase in both redness and yellowness However the degree of change in heartwood color by UV radiation exposure was not greatly affected by smokeheating treatments of various lengths When methanol extracts were fractionated and exposed to UV radiation the yellowness increased in the nhexanesoluble portion and the redness increased in the acetonesoluble fractions from the nhexaneinsoluble portion These results suggest that the nhexanesoluble fraction contains the substances that allow heartwood color to change to yellow after UV radiation exposure and the acetonesolublefraction from the nhexaneinsoluble portion contains the substances that allow it to change to red
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