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Helena Pereira - One of the best experts on this subject based on the ideXlab platform.
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chemical characterization and extractives composition of Heartwood and sapwood from quercus faginea
PLOS ONE, 2017Co-Authors: Isabel Miranda, Vicelina B Sousa, Joana Ferreira, Helena PereiraAbstract: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.
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Circumferential variation of Heartwood and stem quality in maritime pine stems
European Journal of Forest Research, 2014Co-Authors: Sofia Knapic, Vanda Oliveira, Marika Makkonen, Isabel Pinto-seppä, Helena PereiraAbstract:Maritime pine (Pinus pinaster Ait.) is an important timber and pulpwood species covering about 4 million ha in Portugal, Spain and France. This work studied the cross-sectional distribution of Heartwood and sapwood along the stem using 3D modelling on 20 trees. The target was to assess the potential of this species for the industrial production of Heartwood sawn products. The maritime pine stems were characterized by wide sapwood of 10 cm, in average, and the presence of Heartwood at all height levels with constant diameter up to 35 % tree height, decreasing afterwards. In the radial section, the Heartwood follows a circumferential-like shape which changes along the stem. Pith eccentricity index values were low and homogeneous regarding to stem and higher for Heartwood. Heartwood cross-sectional shape was constant up to 45 % of total height of the tree and more elongated upwards. The constant Heartwood diameter, low taper and pith eccentricity index, and an approximate circular shape up to 10 m height indicated these species’ potential to produce solid wood products made out of Heartwood.
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comparison between heat treated sapwood and Heartwood from pinus pinaster
European Journal of Wood and Wood Products, 2014Co-Authors: Bruno Esteves, Lina Nunes, Idalina Domingos, Helena PereiraAbstract:Sapwood and Heartwood samples of Pinus pinaster were treated in an oven at 190 and 200 °C for 2–6 h. Dimensional stability, measured as Anti Shrinking Efficiency (ASE) between 0 and 65 % relative humidity, durability against fungi, mechanical resistance (MOE and MOR), hardness and chemical composition were determined for treated and untreated sapwood and Heartwood. Radial ASE reached 52 % for sapwood and 50 % for Heartwood, while tangential ASE reached 50 and 40 %, respectively. MOE increased slightly at the beginning of the treatment, decreasing afterwards. No significant differences were found between sapwood and Heartwood. MOR decreased by 50 and 30 % for sapwood and Heartwood, respectively. A significant increase in durability against Rhodonia placenta was found for both Heartwood and sapwood at the higher temperature (200 °C), but at the lower temperature (190 °C) only Heartwood showed good results.
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Ring Width Variation and Heartwood Development in Quercus Faginea
Wood and Fiber Science, 2013Co-Authors: Vicelina B Sousa, Sofia Cardoso, Helena PereiraAbstract:High-value exploitation of endogenous forest species may help in fighting the threat to their sustainability, as is the case for Quercus faginea Lam. (Portuguese oak) for which research is underway to determine the wood potential for high-quality products. Ring widths were measured in 20 trees in two sites in Portugal and within-tree Heartwood and sapwood development was determined. The wood shows distinct ring porosity. The mean annual radial growth at dbh was 2.3 and 1.0 mm for the two sites, respectively. Ring width decreased with cambial age, ie 3.1 ± 1.2 mm in the first 10 rings to 1.3 ± 0.8 mm at around 40 yr (site 1). Ring width decreased axially from the tree base upward but the variation was small. The trees showed a relatively high proportion of Heartwood, ie 60-70% Heartwood for 20-25 cm wood diameters that decreased with height, and followed the stem profile. Heartwood diameter was modeled as a function of stem diameter, to be used for Heartwood estimation in standing trees. Sapwood width was relatively constant. Overall the stem quality was found to be good for production of solid wood products regarding ring and Heartwood features.
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Family effects in Heartwood content of Eucalyptus globulus L.
European Journal of Forest Research, 2013Co-Authors: Isabel Miranda, Jorge Gominho, Clara Araújo, Helena PereiraAbstract:Thirty families of Eucalyptus globulus L., established in a first-generation open-pollinated progeny test, were evaluated for the production of Heartwood. Five trees of each family were harvested at 9 years of age, total tree height was measured and a cross-sectional disc was removed at 25 % stem height to estimate the amount of Heartwood. The Heartwood proportion of the stemwood cross-sectional area averaged 41 % with significant between-family variation (P = 0.016) ranging from 27 to 53 %. There were also important within-family differences with coefficients of variation of the mean between 4 and 48 %. Moderate heritability values were obtained for Heartwood diameter and proportion (h 2 = 0.31 and 0.23, respectively) but low estimates were found for sapwood width (h 2 = 0.17). Strong positive genetic and phenotypic correlations of Heartwood diameter were found with stem DBH and with Heartwood proportion. Both correlation estimates indicated that larger trees tended to have more Heartwood. The results indicate that there is an opportunity to reduce Heartwood content in E. globulus through selection and breeding.
Rick G. Kelsey - One of the best experts on this subject based on the ideXlab platform.
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Volatile terpenoids and tropolones in Heartwood extracts of yellow-cedar, Monterey cypress, and their hybrid Leyland cypress
Annals of Forest Science, 2015Co-Authors: Rick G. Kelsey, M. P. González-hernández, Joe Karchesy, Sheeba VeluthoorAbstract:Key message Leyland cypress, an intergeneric hybrid, produces the same volatile Heartwood compounds as its parental taxa, yellow-cedar and Monterrey cypress. However, the proportion of total sesquiterpenes and some of the individual components appear unique to their respective Heartwoods. Context Leyland cypress, x Hesperotropsis leylandii is an intergeneric hybrid between yellow-cedar, Callitropsis nootkatensis, and Monterey cypress, Hesperocyparis macrocarpa. Their Heartwoods are protected by bioactive compounds and rated very durable to durable for products used above ground. Several compounds in yellow-cedar and Monterrey cypress Heartwoods are also active against various fungi, bacteria, human insect pests, and plant pathogens, whereas Leyland cypress Heartwood has never been thoroughly investigated. Aims The first aim for this study was to examine the volatile compounds in ethyl acetate extracts from the Heartwood of all three tree species in Oregon. The second aim was to determine the extent Leyland cypress differs from its parental species, and further investigate any of its novel compounds for biological activity. Methods Ethyl acetate extracts of fresh Heartwood were prepared for three trees of each species and analyzed by gas chromatography. Results Thirty-three compounds were detected at 0.5 % or greater abundance across all species, and 23 were identified. Carvacrol was the major monoterpene and nootkatin the most abundant tropolone in all three species. Valencene 11, 12-diol and nootkatone topped the list of sesquiterpenes in yellow-cedar and Leyland cypress, respectively, whereas no sesquiterpenes were detected in Monterrey cypress. This appears to be the first report of tropolones hinokitiol, procerin, and nootkatin in Leyland cypress, α-thujaplicinol, pygmaein, and procerin in Monterrey cypress, and hinokitiol in yellow-cedar. Conclusions Leyland cypress Heartwood does not biosynthesize structurally unique compounds from those produced by its parental species, and is an unlikely source of novel biocides. However, the proportion of total sesquiterpenes and some of the individual components in Leyland cypress Heartwood may distinguish it from the Heartwood of its parental species.
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Changes in Heartwood Chemistry of Dead Yellow-Cedar Trees that Remain Standing for 80 Years or More in Southeast Alaska
Journal of Chemical Ecology, 2005Co-Authors: Rick G. Kelsey, Paul E. Hennon, Manuela Huso, Joseph J. KarchesyAbstract:We measured the concentrations of extractable bioactive compounds in Heartwood of live yellow-cedar ( Chamaecyparis nootkatensis ) trees and five classes of standing snags (1–5, averaging 4, 14, 26, 51, and 81 years-since-death, respectively) to determine how the concentrations changed in the slowly deteriorating snags. Three individuals from each of these six condition classes were sampled at four sites spanning a 260-km distance across southeast Alaska, and the influence of geographic location on Heartwood chemistry was evaluated. Cores of Heartwood were collected at breast height and cut into consecutive 5-cm segments starting at the pith. Each segment was extracted with ethyl acetate and analyzed by gas chromatography. Concentrations of carvacrol, nootkatene, nootkatol, nootkatone, nootkatin, and total extractives (a sum of 16 compounds) for the inner (0–5 cm from pith), middle (5–10 cm from pith), and surface (outer 1.1–6.0 cm of Heartwood) segments from each core were compared within each tree condition class and within segments across condition classes. Heartwood of class 1 and 2 snags had the same chemical composition as live trees. The first concentration changes begin to appear in class 3 snags, which coincides with greater Heartwood exposure to the external environment as decaying sapwood sloughs away, after losing the protective outer bark. Within core segments, the concentrations of all compounds, except nootkatene, decrease between snag classes 2 and 5, resulting in the Heartwood of class 5 snags having the lowest quantities of bioactive compounds, although not different from the amounts in class 4 snags. This decline in chemical defense is consistent with Heartwood of class 5 snags being less decay-resistant than Heartwood of live trees, as observed by others. The unique Heartwood chemistry of yellow cedar and the slow way it is altered after death allow dead trees to remain standing for up to a century with a profound impact on the ecology of forests in southeast Alaska where these trees are in decline.
Sheeba Veluthoor - One of the best experts on this subject based on the ideXlab platform.
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Volatile terpenoids and tropolones in Heartwood extracts of yellow-cedar, Monterey cypress, and their hybrid Leyland cypress
Annals of Forest Science, 2015Co-Authors: Rick G. Kelsey, M. P. González-hernández, Joe Karchesy, Sheeba VeluthoorAbstract:Key message Leyland cypress, an intergeneric hybrid, produces the same volatile Heartwood compounds as its parental taxa, yellow-cedar and Monterrey cypress. However, the proportion of total sesquiterpenes and some of the individual components appear unique to their respective Heartwoods. Context Leyland cypress, x Hesperotropsis leylandii is an intergeneric hybrid between yellow-cedar, Callitropsis nootkatensis, and Monterey cypress, Hesperocyparis macrocarpa. Their Heartwoods are protected by bioactive compounds and rated very durable to durable for products used above ground. Several compounds in yellow-cedar and Monterrey cypress Heartwoods are also active against various fungi, bacteria, human insect pests, and plant pathogens, whereas Leyland cypress Heartwood has never been thoroughly investigated. Aims The first aim for this study was to examine the volatile compounds in ethyl acetate extracts from the Heartwood of all three tree species in Oregon. The second aim was to determine the extent Leyland cypress differs from its parental species, and further investigate any of its novel compounds for biological activity. Methods Ethyl acetate extracts of fresh Heartwood were prepared for three trees of each species and analyzed by gas chromatography. Results Thirty-three compounds were detected at 0.5 % or greater abundance across all species, and 23 were identified. Carvacrol was the major monoterpene and nootkatin the most abundant tropolone in all three species. Valencene 11, 12-diol and nootkatone topped the list of sesquiterpenes in yellow-cedar and Leyland cypress, respectively, whereas no sesquiterpenes were detected in Monterrey cypress. This appears to be the first report of tropolones hinokitiol, procerin, and nootkatin in Leyland cypress, α-thujaplicinol, pygmaein, and procerin in Monterrey cypress, and hinokitiol in yellow-cedar. Conclusions Leyland cypress Heartwood does not biosynthesize structurally unique compounds from those produced by its parental species, and is an unlikely source of novel biocides. However, the proportion of total sesquiterpenes and some of the individual components in Leyland cypress Heartwood may distinguish it from the Heartwood of its parental species.
Stefan Willför - One of the best experts on this subject based on the ideXlab platform.
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Knotwood as a window to the indirect measurement of the decay resistance of Scots pine Heartwood
Holzforschung, 2007Co-Authors: Outi Karppanen, Martti Venäläinen, Stefan Willför, Anni Harju, Suvi Pietarinen, Tapio Laakso, Pirjo KainulainenAbstract:Abstract There is wide variation in the extractive content and decay resistance of Scots pine (Pinus sylvestris L.) Heartwood. The Heartwood is not visible in standing trees and only poorly visible in timber. Therefore, it is difficult to identify extractive-rich trees, and consequently the most decay-resistant Heartwood. On the other hand, knots are clearly visible in standing trees and timber. In the present paper we studied the possibility of measuring the decay resistance of Scots pine Heartwood indirectly on the basis of the extractive concentration of knotwood. The material investigated consisted of 40 felled trees with a wide between-tree variation for extractive content and decay resistance of their Heartwood. The extractive content of knotwood was found to be four- to five-fold higher than that of Heartwood. Statistically significant correlations were found between the mass loss of Heartwood and the concentrations of total phenolics and stilbenes in knotwood (r=-0.54, P<0.001 and r=-0.40, P=0.011, respectively), and for the concentration of total phenolics (r=0.42, P=0.008) and stilbenes (r=0.39, P=0.012) between Heartwood and knotwood. We suggest further development of this technique in the context of rapid industrial screening of durable pine Heartwood.
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Polysaccharides in some industrially important softwood species
Wood Science and Technology, 2005Co-Authors: Stefan Willför, A. Sundberg, J. Hemming, Bjarne HolmbomAbstract:The content and composition of carbohydrates comprising polysaccharides in sapwood and Heartwood of 12 industrially important pulpwood species were analysed. The polysaccharide content was between 60% and 80% (w/w) for all species, with cellulose as the predominant polysaccharide type. The carbohydrate composition suggested that the main non-cellulose polysaccharides were galactoglucomannans, except in Larix Heartwood, where arabinogalactans were predominant, while the content of xylans were in the same range as the mannans in Pinus resinosa Heartwood and Thuja occidentalis Heartwood and sapwood. Pectins, i.e. polygalacturonic acids, were the main acidic polysaccharides in all species. The amount and composition of water-soluble carbohydrates from ground wood samples were also analysed, since these are important in mechanical pulping and as a possible source of bioactive polymers. The main polysaccharides released from the spruce species were mannans, together with starch from sapwood. Especially Abies balsamea stemwood, but also Abies sibirica Heartwood, released considerable amounts of pectins, suggesting that fir species may release more troublesome anionic polysaccharides than spruce species. Heartwood of Larix lariciana , Larix decidua , Pinus banksiana , and Pinus resinosa released considerable amounts of acidic arabinogalactans. Thuja occidentalis released mainly arabinogalactans and pectins. Pseudotsuga menziesii Heartwood released a large amount of arabinogalactans.
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isolation and characterisation of water soluble polysaccharides from norway spruce and scots pine
Wood Science and Technology, 2004Co-Authors: Stefan Willför, Bjarne HolmbomAbstract:Water soluble polysaccharides from Norway spruce, Scots pine, and Siberian larch were compared. For all species the total amount of polysaccharides isolated from the Heartwood was higher than that from the sapwood. The Heartwood polysaccharides had a high content of galactose and arabinose units, and some glucuronic acid units, suggesting the presence of acidic arabinogalactans. The total amounts of recovered water-soluble arabinogalactans were 1.9 mg/g for spruce Heartwood, 5.3 mg/g for pine Heartwood, and as much as 106 mg/g for larch Heartwood. The other water-soluble polysaccharides were mainly glucomannans. The average ratio of Gal:Ara:GlcA in the water-soluble arabinogalactans of spruce Heartwood was about 4.3:1:1, pine Heartwood about 4.5:1:0.2, and larch Heartwood about 6.7:1:0.1. The corresponding molar ratios then being about 3.6:1:0.8 for spruce, 3.8:1:0.2 for pine, and 5.6:1:0.08 for larch. Thus, the content of glucuronic acid units was especially high in the spruce Heartwood arabinogalactans. The content of arabinose was slightly higher in spruce and pine than in larch Heartwood arabinogalactans.
Bjarne Holmbom - One of the best experts on this subject based on the ideXlab platform.
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Polysaccharides in some industrially important softwood species
Wood Science and Technology, 2005Co-Authors: Stefan Willför, A. Sundberg, J. Hemming, Bjarne HolmbomAbstract:The content and composition of carbohydrates comprising polysaccharides in sapwood and Heartwood of 12 industrially important pulpwood species were analysed. The polysaccharide content was between 60% and 80% (w/w) for all species, with cellulose as the predominant polysaccharide type. The carbohydrate composition suggested that the main non-cellulose polysaccharides were galactoglucomannans, except in Larix Heartwood, where arabinogalactans were predominant, while the content of xylans were in the same range as the mannans in Pinus resinosa Heartwood and Thuja occidentalis Heartwood and sapwood. Pectins, i.e. polygalacturonic acids, were the main acidic polysaccharides in all species. The amount and composition of water-soluble carbohydrates from ground wood samples were also analysed, since these are important in mechanical pulping and as a possible source of bioactive polymers. The main polysaccharides released from the spruce species were mannans, together with starch from sapwood. Especially Abies balsamea stemwood, but also Abies sibirica Heartwood, released considerable amounts of pectins, suggesting that fir species may release more troublesome anionic polysaccharides than spruce species. Heartwood of Larix lariciana , Larix decidua , Pinus banksiana , and Pinus resinosa released considerable amounts of acidic arabinogalactans. Thuja occidentalis released mainly arabinogalactans and pectins. Pseudotsuga menziesii Heartwood released a large amount of arabinogalactans.
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isolation and characterisation of water soluble polysaccharides from norway spruce and scots pine
Wood Science and Technology, 2004Co-Authors: Stefan Willför, Bjarne HolmbomAbstract:Water soluble polysaccharides from Norway spruce, Scots pine, and Siberian larch were compared. For all species the total amount of polysaccharides isolated from the Heartwood was higher than that from the sapwood. The Heartwood polysaccharides had a high content of galactose and arabinose units, and some glucuronic acid units, suggesting the presence of acidic arabinogalactans. The total amounts of recovered water-soluble arabinogalactans were 1.9 mg/g for spruce Heartwood, 5.3 mg/g for pine Heartwood, and as much as 106 mg/g for larch Heartwood. The other water-soluble polysaccharides were mainly glucomannans. The average ratio of Gal:Ara:GlcA in the water-soluble arabinogalactans of spruce Heartwood was about 4.3:1:1, pine Heartwood about 4.5:1:0.2, and larch Heartwood about 6.7:1:0.1. The corresponding molar ratios then being about 3.6:1:0.8 for spruce, 3.8:1:0.2 for pine, and 5.6:1:0.08 for larch. Thus, the content of glucuronic acid units was especially high in the spruce Heartwood arabinogalactans. The content of arabinose was slightly higher in spruce and pine than in larch Heartwood arabinogalactans.
