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Chemical characterization and extractives composition of heartwood and sapwood from Quercus faginea
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Orientador(es)
Resumo(s)
Heartwood and sapwood of Quercus faginea were evaluated in relation to summative chemical
composition and non-polar and polar extracts composition, including an assessment of
antioxidant properties (DPPH and FRAP). Twenty trees from two sites in Portugal were analysed.
Heartwood had approximately two times more solvent extractible compounds than
sapwood (on average 19.0% and 9.5%). The lipophilic extractible compounds were below
1%, and most of them were polar e.g. ethanol-soluble compounds corresponded to 65% of
total extractives in heartwood and 43% in sapwood. Lignin content was similar in sapwood
and heartwood (28.1% and 28.6% of extractive-free wood respectively) as well as the sugar
composition. Site did not influence the chemical composition. The lipophilic extractible compounds
from both sapwood and heartwood included mainly saturated fatty acids (23.0%
and 36.9% respectively) and aromatic compounds were also abundant in sapwood (22.9%).
The ethanol-water extractibles had a high content of phenolic substances (558.0 and 319.4
mg GAE/g extract, respectively of heartwood and sapwood). The polyphenolic composition
was similar in heartwood and sapwood with higher content of ellagitannins (168.9 and
153.5 mg tannic acid/g of extract in sapwood and heartwood respectively) and very low content
of condensed tannins. The antioxidant activity was very high with IC50 of 2.6 μg/ml and
3.3 μg/ml for sapwood and heartwood respectively, as compared to standard antioxidants
(IC50 of 3.8 μg/ml for Trolox). The ferric reducing ability was 2.8 and 2.0 mMol Trolox equivalents/
g extract of heartwood and sapwood respectively. The variability between trees was
low and no differences between the two sites were found. Q. faginea showed a very good
potential for cooperage and other applications for which a source of compounds with antioxidant
properties is desirable
Descrição
Research Article
Palavras-chave
Quercus faginea heartwood sapwood
Contexto Educativo
Citação
Miranda I, Sousa V, Ferreira J, Pereira H (2017) Chemical characterization and extractives composition of heartwood and sapwood from Quercus faginea. PLoS ONE 12(6): e0179268.
Editora
Horacio Bach (ed.)