WOOD RESEARCH Volume 69, Number 1, 2024
RIZKI ARISANDI, AQMAL NUR JIHAD, ALMAAS HUKMA SHABIYYA PALEVA, FAJAR ARIEF KURNIAWAN, GANIS LUKMANDARU, NOOR KHOMSAH KARTIKAWATI, ANTO RIMBAWANTO, SRI SUNARTI, TONI HERAWAN, LILIEK HARYJANTO, ASRI INSIANA PUTRI, FAJAR LESTARI, and ARIF NIRSATMANTO

CHARACTERIZATION OF EXTRACTIVE COMPOSITION IN THE WOOD AND BARK OF CAJUPUTI (MELALEUCA CAJUPUTI SUBSP. CAJUPUTI POWELL.) GROWN IN GUNUNGKIDUL, INDONESIA

The aim of this study was to analyze the extractive composition of the wood and bark of cajuput (M. cajuputi subsp. cajuputi) to consider the end use material according to the characteristics of the its extractives. Results showed that the extractives properties of M. cajuputi, i.e. the contents of n-hexane, methanol, hot water extractives and total phenolic content (TPC), flavonoid content (TFC) and total polysaccharides (TSP) were 0.84 to 1.05%, 1.00 to 1.03% and 1.43 to 1.46%, and 19.2 to 38.7 and 23.2 to 27.3 mg GAE/g dried extract, 11.8 to 16.0 and 7.55 to 14.0 mg QE/g dried extract and 79.3 to 102.8 and 148.8 to 165.9 mg Glu/g dried extract, respectively. Bark had higher extractive levels than wood. In addition, TPC and TSP in the bark were greater than in the wood parts, whereas the reverse trend was found in TFC. The relatively high contents of TPC and TFC in the wood and bark suggest that their potential antioxidant properties. Based on the GC-MS analysis, the high content of sterols-steroids (31.4%) and triterpenoids (21.9%) in the bark part will have potential in the field of pharmacology

WOOD RESEARCH Volume 67, Number 1, 2022
Murzabyek Sarkhad, Futoshi Ishiguri, Ikumi Nezu, Bayasaa Tumenjargal, Bayartsetseg Baasan, Ganbaatar Chultem, Jyunichi Ohshima, Naoto Habu, and Shinso Yokota

Wood chemical components and decay resistance of four common mongolian softwoods

To utilize wood resources in Mongolia, amounts of wood chemical components (hot-water extracts, 1% NaOH extracts, ethanol-toluene extracts, holocellulose, -, -, and -cellulose, Klason lignin, and ash) were determined in four common Mongolian softwoods, Pinus sylvestris, Pinus sibirica, Picea obovata, and Larix sibirica. In addition, decay resistance of heartwood was evaluated against a white-rot fungus Trametes versicolor, and a brown-rot fungus Formitopsis palustris. Among the four species, heartwood of Larix sibirica was chemically characterized by higher amounts of hot-water and 1% NaOH extracts, and lower amounts of holocellulose and Klason lignin. These characteristics may be related to the presence of arabinogalactan which is easily extracted with cold water. Mean mass loss in each softwood ranged from 6.9% to 28.1% in white-rot fungus, and from 24.8% to 48.3% in brown-rot fungus. Among four species, Pinus sibirica showed the highest decay resistance against both fungi. By the linear mixed-effects model analysis, negative relationships were found between mass loss and amounts of extracts in heartwood, suggesting that heartwood having larger amounts of extracts showed higher natural decay durability.

WOOD RESEARCH Volume 62, Number 3, 2017
Martin Zachar, Andrea Majlingová, Iveta Mitterová, and IVETA ČABALOVÁ

Influence of an age and damage of the oak wood on its fire risk

The aim of this work is to study the effects of different ages and damage of the oak wood (Quercus petraea Mattusch) in relation to its flash point temperature and ignition temperature, as well as on determination of the ratio of changes in extractives, cellulose and lignin, in the heat loaded samples of 5 – years old oak wood, 160 – years old oak wood, and also 160 – years old oak wood degraded by wood-destroying insects and fungi. The results of the analyses showed that the flash point temperatures were in the range of 357.52°C – 360.63°C.The ignition temperatures were at interval of 398.93°C – 414.92°C. The time to reach the ignition point was at the interval between 344 and 365 seconds. Under the thermal loading of oak wood, there comes to the significant changes, especially in the surface layers. These are, in addition to colour changes, demonstrated the chemical changes of the main components of wood and extractives. Increasing the temperature, there increases also the content of the substances extractable with ethanol and toluene. Increase in their amount is mainly due to the lignin, but partially also due to the polysaccharides decomposition products.

WOOD RESEARCH Volume 63, Number 5, 2018
Vladimir Ilyich Fedyukov, Mikhail Vladimirovich Boyarsky, Ekaterina Yuryevna Saldaeva, Maria Sergeyevna Chernova, and Vasiliy Yuryevich Chernov

Dependence of spruce wood resonance properties on its chemical composition

Nowadays there are no reasoned scientific data on inter relation of resonant properties of spruce-tree wood and its chemical composition. Thus the purpose of the study was to reveal the features of sonorous spruce in view of the content of basic organic substances in their timber. 20 model trees at the age of 180-190 years were selected as material for studies in taiga woods in the north of Kirov region of Russia. Special 0.5 m long blocks were made from each model tree at height of 1.3 m. Standard 20×20×300 mm samples were made from those blocks. Test samples were kept at room dry conditions for 2 years. After that dendro acoustic studies were carried out on them to define acoustic constant in different directions with respect to timber fibers. Further the percentage of cellulose, lignin, extractives and ashes in them was defined applying standard techniques. As a whole the chemical composition of spruce tree resonant wood lies approximately within the same limits as in common wood of the breed given. However significant influence of cellulose on a longitudinal acoustic constant and lignin on a radial constant is revealed. Joint influence of lignin and cellulose on a tangential constant is found out, the influence of lignin in the latter case being dominant. Continuation of fundamental research in this field has great cognitive value for revealing the nature of unique acoustic properties formation in sonorous spruce wood. Such studies acquire special topicality when dealing with outstanding violins as well as the wood kept for many decades in old buildings subject to demolition.

WOOD RESEARCH Volume 63, Number 2, 2018
GANIS LUKMANDARU

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.

WOOD RESEARCH Volume 66, Number 4, 2021
Denes Varga, Laszlo Tolvaj, and Edina Preklet

Colour stability of steamed black locust, beech and spruce timbers during short-term photodegradation

Black locust (Robinia pseudoacacia L.), beech red heartwood (Fagus sylvatica L.) and spruce (Picea abies Karst.) wood samples were treated in saturated steam at 100, 110 and 120°C then irradiated using a UV emitter mercury lamp in order to test their colour stability. Colour change was evaluated and presented in the CIE Lab colour coordinate system. Untreated black locust, beech and spruce specimens as control samples were irradiated using the same mercury lamp. Results revealed that beech produced the greatest colour stability during both steam treatment and the following UV treatment while spruce was the most sensitive species to photodegradation. Steaming reduced the colour change intensity only for black locust during photodegradation. Both redness and yellowness change demonstrate this colour stability increase. Steaming at 120°C resulted in the greatest protection against the colour alteration of black locust caused by photodegradation. The investigated thermal treatments did not change the photodegradation properties of beech and spruce specimens. A considerable increase in colour saturation of the specimens was generated by steaming, and the saturation value further increased during the UV treatment.