Linda Nisula

372 Pages·2017·11.45 MB·English

by  Linda Nisula

Linda Nisula
Wood Extractives in Conifers
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Johan Gadolin d
Process Chemistry Centre a
N A Study of Stemwood and Knots of Industrially Important Species
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9 789517 658911
ISBN 978-951-765-891-1
Åbo Akademi University Press
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WOOD EXTRACTIVES IN CONIFERS

Wood Extractives in Conifers
A Study of Stemwood and Knots of Industrially Important Species
Linda Nisula
Åbo Akademis förlag | Åbo Akademi University Press
Åbo, Finland, 2018
CIP Cataloguing in Publication
Nisula, Linda.
Wood extractives in conifers : a study
of stemwood and knots of industrially
important species / Linda Nisula. -
Åbo : Åbo Akademi University Press,
2018.
Diss.: Åbo Akademi University.
ISBN 978-951-765-891-1
ISBN 978-951-765-891-1
ISBN 978-951-765-892-8 (digital)
Painosalama Oy
Åbo 2018
Till Mormor
iii
Supervisor and custos
Professor Emeritus Bjarne Holmbom
Laboratory of Wood and Paper Chemistry
Åbo Akademi University
Åbo, Finland
Co-supervisor
Academy lecturer, Docent Anna Sundberg
Laboratory of Wood and Paper Chemistry
Åbo Akademi University
Åbo, Finland
Opponent and reviewer
Docent Rolf Gref
Sveriges lantbruksuniversitet
Umeå, Sweden
Reviewer
Professor Raimo Alén
Laboratory of Applied Chemistry
University of Jyväskylä
Jyväskylä, Finland
iv
Preface
The work presented in this thesis was carried out at the Laboratory of Wood
and Paper Chemistry during the years 2003–2018 under supervision of
Professor emeritus Bjarne Holmbom and at the final stage also of Docent
Anna Sundberg. The work was part of the activities of Johan Gadolin
Process Chemistry Centre (PCC) at Åbo Akademi University.
Some of the sampling and laboratory work was done within the industrial
projects Bioactive extractives from important pulpwoods “BioExtra I”
(2000–2002) and “BioExtra II” (2002–2004). Another part was done within
the EU-project “CERBERUS” QLK5-CT-2002-01027 (2003–2006) and the
industrial project “Siberian Larch” (2006–2008).
Financial support was received from the Rector at Åbo Akademi
University, Magnus Ehrnrooth foundation, Oscar Öflunds Stiftelse, the
Finnish Foundation for Technology Promotion (TES), Victoriastiftelsen and
Åbo Akademi University.
Contribution of the author
The author did part of the sampling, and most of the extractions and GC
analyses. The author did not do the actual GC-MS analyses, but did
contribute to the identification of the peaks in the chromatograms. The
author scrutinized all GC chromatograms, treated all data, interpreted the
results and wrote the entire thesis.
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Abstract
Throughout the years, extractives have been studied with various analytical
methods, and it has been found that different tree species contain different
types and amounts of extractive compounds. However, many studies have
been incomplete and the number of methods used has been almost as vast
as the number of publications, making it difficult or even impossible to
compare the results of different studies.
This thesis contains data on lipophilic and hydrophilic extractives in
heartwood, sapwood and knots of 39 industrially important conifer species:
14 pines (Pinus), 7 spruces (Picea), 9 firs (Abies), 5 larches (Larix), 3
hemlocks (Tsuga) and Douglas-fir (Pseudotsuga). The wood samples were
sequentially extracted, and the amount and composition of resin acids, fatty
acids, sterols, steryl esters, acylglycerols, juvabiones, lignans, oligolignans,
flavonoids and stilbenes were analysed by gas chromatography (GC) and
GC-mass spectrometry. The main conclusions were that:
• there are major differences in amount and composition of
extractives, not only between genera, but also between species,
especially regarding the hydrophilic extractives;
• lignans are present in heartwood and knots of all genera. The knots,
however, contain remarkably more, in some cases several hundred
times more, lignans than the adjacent heartwood. Some spruce, fir,
larch and hemlock species contain especially high concentrations of
lignans. Hydroxymatairesinol is the dominating lignan in spruce
and hemlock, while secoisolariciresinol dominates in fir and larch;
• considerable amounts of flavonoids are found in all larches, some
of the pines and in Douglas-fir;
• stilbenes are present in heartwood and knots of all pines;
• considerable amounts of juvabiones are found in all firs, some pines
and in Douglas-fir. The concentrations are significantly higher in
knots than in ordinary stemwood; and
• pine heartwood and pine knots in particular contain much more
resin acids than the sapwood.
Lipophilic extractives are known to cause problems in pulp and paper mills,
mainly in the form of deposits and specks. On the other hand, they can be
recovered and utilized as tall oil and sterol-based products. The hydrophilic
compounds are not detrimental in pulping and papermaking. They do,
however, exhibit strong bioactivity and play a significant role in the
protection of trees against insects, bacteria and fungi. Several of these
compounds are strong antioxidants, and some are already used as active
agents in dietary supplements and cosmetic products. The extraction,
purification and utilization of these bioactive polyphenols should be further
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