Naslov
Colour changes of Walnutwood (Juglans regia L.) during steaming process

Autori
Pervan, Stjepan ; Gorišek, Željko ; Straže, Aleš ; Prekrat, Silvana ; Humar, Miha

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Improvement of Wood Drying Quality by Conventional and Advanced Drying Techniques / Gorišek, Željko - Ljubljana : University of Ljubljana, Biotechnical Faculty, Department of Wood Science and Technology, 2009, 15-24

ISBN
978-961-6144-26-1

Skup
COST E53 “ Quality Control for Wood and Wood Products” Meeting

Mjesto i datum
Bled, Slovenija, 21.04.2009. - 23.04.2009

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
walnut; wood colour chemistry; wood colour anatomy; steaming

Sažetak
In this paper the results are presented of research on colour changes of walnutwood (Juglans regia L.) steaming process. The influence of steaming on chemical, anatomical and colour changes of wood tissue was researched. Randomly selected walnutwood boards, 43 mm thick, were indirectly steamed in period of 60 to 72 hours, between 45 to 70°C. Light microscopy analysis of parenchyma cells in samples was performed for first 16 hours of steaming. Intensive redistribution of cellular deposits during steaming treatment both in sapwood and heartwood was confirmed. Chemical analysis showed that all FT-IR spectra of the steamed Juglans regia L. sapwood samples looks similar to each other. The spectra of condensate from sapwood and hardwood were very similar. In both cases the same peaks appeared. Time of steaming, did not influence on chemical composition of condenses. In all cases, regardless how long steaming of sapwood or heartwood took place, very similar spectra of condenses were measured. Some peaks indicated that there were two groups of components leached from wood. Firstly, aromatic extractives and non-polymerised lignin fragments, and secondly fragments of hemicellulose and cellulose. It was presumed that hemicelluloses changes were the most important ones, as this change reflects from FT-IR spectra of wood it self, as well of condense. Comparison of peak surfaces does not reveal any significant change as a result of steaming, so it was concluded that the main chemical structure of wood does not change after steaming. There are some changes in the intensity of the spectra, but those changes mainly originate in the fact that the wood is not homogeneous material.

Izvorni jezik
Engleski

Znanstvena područja
Drvna tehnologija

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