<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Aliphatic bio-oils from corks: A Py–GC/MS study</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Analytical and Applied Pyrolysis</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2014</style></year></dates><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Cork samples from Betula pendula, Quercus suber and Quercus cerris were submitted to Py–GC–MS/FID at temperatures between 550°C and 900°C and the pyrolysis-derived compounds (py-products) were identified and quantified. Corks were compared with wood samples. Py-products include suberin, lignin and carbohydrates derivatives. Suberin py-products are dominated by unsaturated aliphatics. Corks pyrolysis yield and composition were dramatically influenced by temperature in contrast to wood that showed stable results across temperatures. At 850–900°C the peaks area of cork pyrograms were approximately two times higher than at 550°C, for which yield was about half of the woods, and cork py-products were dominated by suberin-derived short chain aliphatics, namely 1-alkenes, while at 550°C composition was dominated by lignin derivatives. Lignin and carbohydrate derived products decreased dramatically over 750°C while the opposite was observed for unsaturated aliphatics. Cork materials show a high potential as feedstock for production of aliphatic-rich pyrolytic biofuels or as a source of olefins.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Şen, Ali</style></author><author><style face="normal" font="default" size="100%">Van den Bulcke, Jan</style></author><author><style face="normal" font="default" size="100%">Defoirdt, Nele</style></author><author><style face="normal" font="default" size="100%">Van Acker, Joris</style></author><author><style face="normal" font="default" size="100%">Pereira, Helena</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Thermal behaviour of cork and cork components</style></title><secondary-title><style face="normal" font="default" size="100%">Thermochimica Acta</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cork</style></keyword><keyword><style  face="normal" font="default" size="100%">DSC</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus cerris</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">suberin</style></keyword><keyword><style  face="normal" font="default" size="100%">TGA</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2014///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencedirect.com/science/article/pii/S0040603114000902</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">582</style></volume><pages><style face="normal" font="default" size="100%">94 - 100</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Thermal behaviour of cork and cork chemical components was studied with coupled differential scanning calorimetry-thermogravimetrical analysis (DSC-TGA) in order to gain insight into the role of the chemical components on the thermal degradation of cork. Cork samples of Turkey oak (Quercus cerris) and cork oak (Quercus suber) were chemically treated to selectively remove inorganic material, extractives and suberin, to allow characterization of klason lignin and methanolysis-depolymerized suberin. Since Q. cerris cork granulates contain phloemic impurities, phloem from Q. cerris bark was also subjected to the same treatments as cork. The thermal decomposition of both cork species is similar, starting above 200°C and increasing with increasing temperature until ashing at approximately 485°C. TGA curves of both corks are almost identical but a detailed view on the differential thermogravimetry (DTG) and DSC curves shows that the two materials differ from each other. Two exothermal devolatilization and char combustion reactions occur, peaking at approximately 313°C and 445°C. These peak temperatures shift to lower temperatures in suberin-free and extractive-free corks giving evidence of the heat retarding effect of suberin and extractives and possible catalytic effect of inorganics in desuberinised cork. Phloem thermal degradation is similar to that of cork although exothermal peak temperatures are higher. Phloem-containing Q. cerris cork granulates thus show clear potential for high temperature applications.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Variability of the Chemical Composition of Cork</style></title><secondary-title><style face="normal" font="default" size="100%">BioResources</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2013</style></year></dates><volume><style face="normal" font="default" size="100%">8</style></volume><pages><style face="normal" font="default" size="100%">2246-2256</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The chemical composition of cork was determined, following a sampling that covered the whole production area in Portugal (29 provenances from six regions) with samples taken at cork stripping. To analyse between population variations, a more intensive sampling was made in two locations. The overall mean chemical composition of cork was: extractives 16.2% (dichloromethane 5.8%, ethanol 5.9%, water 4.5%), suberin 42.8% (long-chain lipids 41.0%, glycerol 3.8%), and lignin 22.0% (Klason 21.1%, acid soluble 0.9%). The suberin compositional ratio of long chain lipids to glycerol, LCLip:Gly, was 11.3. The proportion of neutral sugars in the polysaccharides was: glucose 46.1%, xylose 25.1%, arabinose 18.0%, mannose 3.0%, galactose 7.3%, and rhamnose 0.5%. The range of values was large and the variation between individual trees seemed to be the major factor of the differences. Geographical location of cork production was statistically significant only in a few cases when considering site and not when considering regions. The population variation in two sites was important and the absolute difference between the site mean values was small. This research covers the natural variability of cork’s chemical composition and discusses the contribution of the structural compounds to the variation of cork properties.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Aguado, Pedro L.</style></author><author><style face="normal" font="default" size="100%">Curt, M. Dolores</style></author><author><style face="normal" font="default" size="100%">Pereira, Helena</style></author><author><style face="normal" font="default" size="100%">Fernández, Jesús</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Allocation of 14C assimilated in late spring to tissue and biochemical stem components of cork oak (Quercus suber L.) over the seasons</style></title><secondary-title><style face="normal" font="default" size="100%">Tree Physiology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">C-14 labeled compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">carbon assimilation</style></keyword><keyword><style  face="normal" font="default" size="100%">microautoradiography</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">suberin</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012///</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://treephys.oxfordjournals.org/content/32/3/313.abstract</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">32</style></volume><pages><style face="normal" font="default" size="100%">313 - 325</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Carbon distribution in the stem of 2-year-old cork oak plants was studied by 14CO2 pulse labeling in late spring in order to trace the allocation of photoassimilates to tissue and biochemical stem components of cork oak. The fate of 14C photoassimilated carbon was followed during two periods: the first 72 h (short-term study) and the first 52 weeks (long-term study) after the 14CO2 photosynthetic assimilation. The results showed that 14C allocation to stem tissues was dependent on the time passed since photoassimilation and on the season of the year. In the first 3 h all 14C was found in the polar extractives. After 3 h, it started to be allocated to other stem fractions. In 1 day, 14C was allocated mostly to vascular cambium and, to a lesser extent, to primary phloem; no presence of 14C was recorded for the periderm. However, translocation of 14C to phellem was observed from 1 week after 14CO2 pulse labeling. The phellogen was not completely active in its entire circumference at labeling, unlike the vascular cambium; this was the tissue that accumulated most photoassimilated 14C at the earliest sampling. The fraction of leaf-assimilated 14C that was used by the stem peaked at 57% 1 week after 14CO2 plant exposure. The time lag between C photoassimilation and suberin accumulation was ∼8 h, but the most active period for suberin accumulation was between 3 and 7 days. Suberin, which represented only 1.77% of the stem weight, acted as a highly effective sink for the carbon photoassimilated in late spring since suberin specific radioactivity was much higher than for any other stem component as early as only 1 week after 14C plant labeling. This trend was maintained throughout the whole experiment. The examination of microautoradiographs taken over 1 year provided a new method for quantifying xylem growth. Using this approach it was found that there was more secondary xylem growth in late spring than in other times of the year, because the calculated average cell division time was much shorter.</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue><notes><style face="normal" font="default" size="100%">10.1093/treephys/tps01210.1093/treephys/tps012</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Cellular structure and chemical composition of cork from the Chinese cork oak (Quercus variabilis)</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Wood Science</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Quercus variabilis Blume, the Chinese cork oak, is an oak species with a thick cork outer bark. The cork is exploited at a limited scale in China and considered of lower quality than the commercial cork from Quercus suber. We studied an industrial cork granulate feedstock of Q. variabilis in relation to cellular structure and chemical composition and compared it to Q. suber cork under a material’s perspective. The cork of Q.variabilis has 1.1 % ash, 9.6 % extractives, 34.8 % suberin and 19.1 % lignin. The monosaccharide composition with shows a predominance of hemicelluloses: glucose 42.8 % of total neutral sugars, xylose 27.5 %, arabinose 15.4 %, galactose 9.0 %, mannose 4.0 %, rhamnose 1.2 %. The FT-IR spectrum shows the indicative peaks of suberin. The composition is overall similar to that of Q. suber cork. Q. variabilis cork has the typical cellular characteristics of bark cork tissues with a regular and radially aligned structure of cells without intercellular voids. Solid volume fraction was estimated at approximately 16 %. Compared with Q. suber, the Q. variabilis cork cells are smaller, the cell wall undulation and the overall row alignment less homogeneous, the cell surface is irregular and the solid volume proportion higher. The characteristics of Q. variabilis cork support its use as a cellular material for sealing, insulation and energy absorption, but the overall quality is lower than that of Q. suber cork. The negative impact of the higher density and structural lower uniformity at tissue and cell level should be evaluated for processing and product performance.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Temperature-induced structural and chemical changes in cork from Quercus cerris</style></title><secondary-title><style face="normal" font="default" size="100%">Industrial Crops and Products</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2012</style></year></dates><volume><style face="normal" font="default" size="100%">37</style></volume><pages><style face="normal" font="default" size="100%">508-513</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The effects of temperature on anatomical and chemical characteristics of Quercus cerris cork were examined. Cork samples were subjected to isothermal air heating between 150 ◦ C and 400 ◦ C and analyzed for mass loss, cellular structure and chemical composition. The thermal decomposition of Q. cerris cork is similar to that of Q. suber cork. Cork is thermally stable below 200 ◦ C and after that degradation depended on temperature and heating time with increasing mass loss, i.e. 3% at 200 ◦ C 10min and 46% at 350 ◦ C 60min.With temperature and starting at 200 ◦ C, cells expanded, cell wall thickness was reduced and corrugations were lost. Extractives degraded at lower temperatures, although aliphatic extractives were found to be more stable. Suberin from Q. cerris was more heat resistant than Q. suber suberin, while lignin showed similar resistance. These results provide a basis for studies on the production of Q. cerris bark expanded cork agglomerates for insulation purposes.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Teixeira, Rita Teresa</style></author><author><style face="normal" font="default" size="100%">Pereira, Helena</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Suberized Cell Walls of Cork from Cork Oak Differ from Other Species</style></title><secondary-title><style face="normal" font="default" size="100%">Microscopy and Microanalysis</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">cell wall</style></keyword><keyword><style  face="normal" font="default" size="100%">Cork</style></keyword><keyword><style  face="normal" font="default" size="100%">lamellae</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">suberin</style></keyword><keyword><style  face="normal" font="default" size="100%">ultrastructure</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010///</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">16</style></volume><pages><style face="normal" font="default" size="100%">569 - 575</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Plants have suberized cells that act as protective interfaces with the environment or between different plant tissues. A lamellar structure of alternating dark and light bands has been found upon transmission electron microscopy (TEM) observation of cork cells and considered a typical feature of the suberized secondary wall. We observed cork cells from periderms of Quercus suber, Quercus cerris, Solanum tuberosum, and Calotropis procera by TEM after uranyl acetate and lead citrate staining. A lamellated structure was observed in S. tuberosum and C. procera but not in Q. suber and Q. cerris where the suberized cell wall showed a predominantly hyaline aspect with only a dark dotted staining. Removal of suberin from Q. suber cells left a thinner secondary wall that lost the translucent aspect. We hypothesize that the species' specific chemical composition of suberin will result in different three-dimensional macromolecular development and in a different spatial location of lignin and other aromatics. A lamellated ultrastructure is therefore not a general feature of suberized cells.</style></abstract><issue><style face="normal" font="default" size="100%">5</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Teixeira, Rita Teresa</style></author><author><style face="normal" font="default" size="100%">Pereira, Helena</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Ultrastructural Observations Reveal the Presence of Channels between Cork Cells</style></title><secondary-title><style face="normal" font="default" size="100%">MICROSCOPY AND MICROANALYSIS</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Calotropis procera</style></keyword><keyword><style  face="normal" font="default" size="100%">Cork</style></keyword><keyword><style  face="normal" font="default" size="100%">phellogen</style></keyword><keyword><style  face="normal" font="default" size="100%">plasmodesmata</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber</style></keyword><keyword><style  face="normal" font="default" size="100%">suberin</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2009///</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">15</style></volume><pages><style face="normal" font="default" size="100%">539 - 544</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The ultrastructure of phellem cells of Quercus Silber L. (cork oak) and Calotropis procera (Ait) R. Br. were analyzed using electron transmission microscopy to determine the presence or absence of plasmodesmata (PD). Different types of Q. Silber cork samples were studied: one year shoots; virgin cork (first periderm), reproduction cork (traumatic periderm), and wet cork. The channel structures of PD were found in all the samples crossing adjacent cell walls through the suberin layer of the secondary wait. Calotropis phellem also showed PD crossing the cell walls of adjacent cells but in fewer numbers compared to Q. suber. In one year stems of cork oak, it was possible to follow the physiologically active PD with ribosomic accumulation next to the aperture of the channel seen in the phellogen cells to the completely obstructed channels in the dead cells that characterize the phellem tissue.</style></abstract><issue><style face="normal" font="default" size="100%">6</style></issue><notes><style face="normal" font="default" size="100%">The following values have no corresponding Zotero field:&lt;br/&gt;pub-location: 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA&lt;br/&gt;publisher: CAMBRIDGE UNIV PRESS</style></notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Ultrastructural Observations Reveal the Presence of Channels between Cork Cells</style></title><secondary-title><style face="normal" font="default" size="100%">MICROSCOPY AND MICROANALYSIS</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><publisher><style face="normal" font="default" size="100%">CAMBRIDGE UNIV PRESS</style></publisher><pub-location><style face="normal" font="default" size="100%">32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA</style></pub-location><volume><style face="normal" font="default" size="100%">15</style></volume><pages><style face="normal" font="default" size="100%">539-544</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The ultrastructure of phellem cells of Quercus Silber L. (cork oak) and Calotropis procera (Ait) R. Br. were analyzed using electron transmission microscopy to determine the presence or absence of plasmodesmata (PD). Different types of Q. Silber cork samples were studied: one year shoots; virgin cork (first periderm), reproduction cork (traumatic periderm), and wet cork. The channel structures of PD were found in all the samples crossing adjacent cell walls through the suberin layer of the secondary wait. Calotropis phellem also showed PD crossing the cell walls of adjacent cells but in fewer numbers compared to Q. suber. In one year stems of cork oak, it was possible to follow the physiologically active PD with ribosomic accumulation next to the aperture of the channel seen in the phellogen cells to the completely obstructed channels in the dead cells that characterize the phellem tissue.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Methanolysis of bark suberins: analysis of glycerol and acid monomers</style></title><secondary-title><style face="normal" font="default" size="100%">Phytochemical Analysis</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2000</style></year></dates><volume><style face="normal" font="default" size="100%">11</style></volume><pages><style face="normal" font="default" size="100%">45-51</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The depolymerization and subsequent analysis of cork suberins from the outer barks of Pseudotsuga menziesii and Quercus suber was performed using a simpliﬁed methanolysis procedure. The amount of sodium methoxide catalyst was maintained at 20–30 mM and the methanolysis mixture was submitted to trimethylsilyl derivatisation and used directly for gas chromatographic analysis, allowing simultaneous quantiﬁcation of glycerol and long-chain monomers. Response factors for glycerol, ferulic acid and one saturated homologue representing each of the suberinic families (i.e. the 1-alkanols, 1-alkanoic acids, vhydroxyacids and a,v-diacids) were determined. Effective depolymerization of suberin was checked using the infrared specta of the residues after methanolysis. Glycerol is a major constituent of the suberins from P. menziesii (26% of total) and from Q. suber (14%). In both suberins, a,v-diacids are dominant, i.e. 54% of the long-chain monomers in P. menziesii (mostly saturated C16-C22 homologues and the C18 unsaturated diacid), and 53% in Q. suber (mostly the C18 unsaturated diacid and mid-chain oxygenated (epoxide and vic-diol) derivatives). In P. menziesii epoxyacids are absent. The importance of glycerol and a,v-diacids as suberin monomers supports a polymeric structure based on their successive esteriﬁcation.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Feruloyl Esters of ω-Hydroxyacids in Cork Suberin</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Wood Chemistry and Technology</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><publisher><style face="normal" font="default" size="100%">Taylor &amp; Francis</style></publisher><volume><style face="normal" font="default" size="100%">18</style></volume><pages><style face="normal" font="default" size="100%">207-217</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Feruloyl esters of ?-hydroxyacids were found in the alcoholysis products of suberin from Quercus suber cork. Their identification was made from mass spectra and by comparison with synthetic model compounds. The co-hydroxyls of suberinic hydroxyacids are thought to be the ester-bonding points between suberin aliphatics and associated aromatics.</style></abstract><notes><style face="normal" font="default" size="100%">doi: 10.1080/02773819809349577</style></notes><research-notes><style face="normal" font="default" size="100%">doi: 10.1080/02773819809349577</style></research-notes></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Cork Suberin: A Glyceryl Based Polyester</style></title><secondary-title><style face="normal" font="default" size="100%">Holzforschung - International Journal of the Biology, Chemistry, Physics and Technology of Wood</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1997</style></year></dates><volume><style face="normal" font="default" size="100%">51</style></volume><pages><style face="normal" font="default" size="100%">225-234</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Total depolymerization of cork from the cork oak (Quercus suber L.) by using a sodium methoxide catalysed methanolysis solubilized 53.2 % of the material, including 5.2 % of glycerol, 48,0 % of suberinic fatty acids and alcohols and minor amounts of ferulic acid. A very mild depolymerization using calcium oxide treated methanol, which solubilized only 2.0% of the cork material was studied by GC-MS. In the solubilized material, the total amount of aliphatic acids was 43.8 % (including alkanoic acids 4.0%. ω-hydroxyacids 13.2% and α,ω-diacids 26.6%), of 1-alkanols 2.1 % and of monoacylglycenols 32.1%. It was possible to identify 1-monoacylglycerols and 2-monoacylglycerols of alkanoic acids (1,2%), ω-hydroxyacids (3.7 %) and α,ω-diacids (22.8 %). It is proposed that suberin is a glyceryl based polymer and that its insoluble character is given, at least in part, by the cross-linking of dicarboxylic fatty acids with glycerol. The term suberin should be used for this aliphatic polyester component of the cell wall.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>3</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">Suberina: o polímero responsá vel pelas propriedades da cortiça</style></title><secondary-title><style face="normal" font="default" size="100%">II Congreso Forestal Español</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1997</style></year></dates><pub-location><style face="normal" font="default" size="100%">Pamplona</style></pub-location><pages><style face="normal" font="default" size="100%">225-228</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The macromolecular structure of suberin, the biopolymer mainly responsable for cork properties, is dicussed. The link of the suberinic aliphatic acids to glycerol is presented, supporting the hypothesis that suberin is a glyceridic polyester. The linkage of this aliphatic part, through ferulic acid, to the aromatic part, and the similarities of the later to lignin, are discussed. K.W.:</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>7</ref-type><contributors></contributors><titles><title><style face="normal" font="default" size="100%">High - pressure extraction of cork with CO2 and 1,4-dioxane</style></title><secondary-title><style face="normal" font="default" size="100%">High Pressure Chemical Engineering Proceedings of the 3rd International Symposium on High Pressure Chemical Engineering</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1996</style></year></dates><publisher><style face="normal" font="default" size="100%">Elsevier</style></publisher><volume><style face="normal" font="default" size="100%">Volume 12</style></volume><pages><style face="normal" font="default" size="100%">417-422</style></pages><isbn><style face="normal" font="default" size="100%">0921-8610</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The extraction of cork from cork-oak (Quercus suber L.) by high-pressure dioxane and supercritical CO2 mixtures was studied at 170 bar and in the temperature range of 160°C - 180°C. Suberin is preferably extracted, but extraction percentages were lower than 46%. Lignin extraction percentages are lower than 11%. Extraction selectivity did not change significantly with extracting fluid composition. The results so far obtained support the idea of the existence of an extensive polymeric system across the cell wall and the concept of a close interaction of suberin and lignin, which hinders lignin depolymerization and solubilization in the high-pressure fluid. Fourier transform infrared spectra of cork, extraction residues and extracts are also presented.</style></abstract></record></records></xml>