Chemical characteristics of Eucalyptus pellita with heart rot
Eucalyptus pellita has been posited as a primary raw material in Indonesia due to its fast growth. In some areas, however, trees with heart rot were found. Thus, the wood with heart rot was analysed chemically both in sound (sapwood, outer heartwood, inner heartwood) and degraded parts (heart rot-affected wood/HRAW). The results revealed that there was a different trend in the wood chemical composition between bottom and centre parts. In bottom parts, wood with bigger diameter of heart rot, the slight changes in polysaccharides and lignin amounts was observed in HRAW compared to sound wood parts. On the contrary, comparatively high lignin and low polysaccharide levels in HRAW were measured in centre parts. HRAW was also characterized with high content of inorganic materials and high pH values but low in extractive content, mostly ethanol soluble extractives or its polar fraction. Increasing of phenolic contents was more pronounced in HRAW of lower part than that of upper of the stem. The difference trend of chemical composition between bottom and centre parts suggesting the cause of heart rot could be several wood degraders.