Effect of Geothermal Drying Treatment on Extract Composition of Sugi (Cryptomeria japonica) Board

Geothermal drying treatment is one of the wood drying methods. To investigate the quantitative change of terpenes in sugi (Cryptomeria japonica) board caused by four drying treatments, extracts of sugi board dried by moderate-temperature, high-temperature, geothermal energy and air were analyzed by gas-chromatograph mass-spectrometer (GC/MS). Samples were prepared using a planer to plane dried boards (1-2 mm from the surface), and to extract the shavings with ethyl acetate. As a result, total extractive content detected by GC/MS did not differ among the drying treatments. However, content of β-Caryophllene and Thujopsene was higher in air-dried boards than in those dried by the other methods (p<0.05). Sandaracopimarinal and Ferruginol content was highest in geothermaldried board as compared to all drying methods. From the principal component analysis, a portion of terpenes in sugi board exposed to geothermal-drying treatment was similar to that of air-dried boards.