Oak, cork

Kork-asbest, m. mountain cork, rock cork, -baum, m. cork tree, -bohrer, m. cork borer, -bohrerscharfcr, m. cork borer sharpener, -dichtung, /. cork packing, -eiche, /. cork oak, cork tree, korken, v.t. cork. 

Cork, a natural material - the bark of the Mediterranean cork oak tree. It is largely air cells and the fibrous cell walls have a high resin content. When baked, the resin softens and welds the pieces of bark into a comparatively homogeneous mass, which is sliced into blocks, commonly 50, 75 and 100 mm thick. 

Cork (or Suber). The outer tissues of the stems of the cork oak or the exterior layers of the bark beneath the epidermis. In young stems it consists of epidermis, cortical tissues periderm and in older stems of secondary phloem periderm. Cork is used in some expls mixts described below... 

Suberins. The cork cells in the outer bark contain polyestolides or su-berins. The suberin content in the outer layer of the cork oak bark (cork) is especially high and amounts to 20-40% in the periderm of birch bark. Polyestolides are complicated polymers composed of co-hydroxy monobasic acids which are linked together by ester bonds. In addition, they contain a,/3-dibasic acids esterified with bifunctional alcohols (diols) as well as ferulic and sinapic acid moieties. The chain lengths vary but suberins are enriched with molecules having 16 and 18 carbon atoms. There are also double bonds and hydroxyl groups through which ester and ether cross-links are possible. The outer layer of the epidermis contains so-called cutin, which is heavily branched and has a structure similar to suberin. 

Cork from the cork-oak (Quercus suber L.) differs chemically from wood, mostly by the presence of suberin as a major structural component (ca. 60% of extractive free cork) in addition to lignin and polysaccharides (6).The structure of suberin is not fully elucidated yet. It is a cross-linked polymer with a polyester linked aliphatic domain containing fatty acids, alcohols, hydroxyacids and diacids and a phenolic, probably lignin-like domain. 

Cork from cork-oak (Quercus suber L.) was collected in a mill as residue obtained from the production of stoppers and a 40-60 mesh fraction was separated. This fraction was exhaustively extracted with dichloromethane, ethanol and water in a Soxhlet apparatus. High-pressure extractions were performed upon extractive -free anhydrous cork samples. 

Cork taint is a musty/moldy off-odor in wine. It is related to the cork stopper, a wine botde closure made from the bark of the cork oak (Quercus suher). In a correlation between sensory evaluation and chemical analysis, 2,4,6-trichloroanisole (TCA) has b n identified as a major impact component. In sensitivity tests of a group of trained wine judges, a geometric mean of the minimum detectable concentrations of TCA has been determined at 4.6 ng/L. 

Cork stoppers are manufactured from the outer bark (suberose parenchyma) of the cork oak, Quercus suber L. 16). The cork oak is grown in several Mediterranean countries, with Portugal accounting for more than half of the world-wide production of cork (ca. 170,000 t on average) and about 78% of bark wine bottle stoppers (18 billion/year). Starting out with a planted acorn, it takes, even under ideal conditions. 

The cork oak (Q. suber) is another commercially valuable species found throughout the Mediterranean region. The thick bark composed mostly of cork cells can be harvested every 10 years in early summer to provide sheets of soft, smooth cork useful in many ways. The cork cells capture air inside as they dry, making the material extremely resilient and buoyant. Cork has been used to manufacture floats, handles, stoppers, and as insulation, since it is a poor conductor of heat and sound. 

Cork, oak wood, and sand are common materiah that have been included to provide familiar reference points. They are not pure elements or compounds as are the other substances listed. 

Cork flooring is sourced from the bark of cork oak trees. Mediterranean cork oak forests are harvested sustainably. These forests need all the help they can get—they are less profitable now that many wines are sold with plastic corks. 

Products and Uses The outer bark of the cork oak tree. A renewable natural resource as the bark can be harvested every eight to ten years without harming the tree. Used as insulation for heat as well as noise resistant to rot and mold. Also used for wall tiles. A component in linoleum floor tiles. 

C9H,g02, Mr 156.22, liquid with a flower-like odor, bp. 77 °C (6.53 kPa). Isolated from the sting apparatus of wasps (Paravespula and Dolichovespula) identified as a spiroacetal. C. is also produced by bark beetles of the genera Conophthoms, Cryphalus, and Leperisinus and used by them as pheromone to deter members of the same species (Alarm pheromone) in order to prevent local overpopulations. In Conophthoms species C. has the (55,7S)-configuration, [a] -78.3° (pentane). C. has also been detected in the bark of pine trees, cork oak, and the odor of orchids see also chtdcograne, oleane. 

C30H30O, Mr 426.73, needles, mp. 267-269 °C, [aJu -27.8 (CHCI3). A pentacyclic " triterpene widely distributed in many higher plants and lichens it can be obtained as the main component from the cork of the cork oak (Quercus suber, Fagaceae) by extraction with hot ethanol. F. has diuretic activity. 

Coriandrum sativum. See Coriander (Coriandrum sativum) extract Coriander (Coriandrum sativum) oil Coriandrum sativum extract. See Coriander (Coriandrum sativum) extract Coriandrum sativum oil. See Coriander (Coriandrum sativum) oil Cork, oak CAS 977038-68-8... 

Oak chips extract. See Oak bark extract Oak cork. See Cork, oak Oak, English, extract. See English oak, (Quercus robur) extract Oakmoss (Evernia prunastri) extract CAS 90028-68-5 EINECS/ELINCS 289-861-3 Synonyms Evernia prunastri Evernia prunastri extract Evernia prunastri lichen extract Oakmoss extract... 

Quercetin-3-(6-o-(6-deoxy-a-1-mannopyranosyl)-P-d-glucopyranoside). See Rutin Quercetine. See Quercetin Quercetin rhamnoglucoside Quercetin-3-rhamnoglucosine Quercetin-3-(6-o-a-1 -rhamnopyranosyl-P-d-glucopyranoside Quercetin-3-rutinoside. See Rutin Quercetol Quercitin. See Quercetin Quercus occidentalis. See Cork, oak Quercus robur. See English oak (Quercus robur) wood... 

Cinchona succirubra extract 977038-62-2 Citrus extract 977038-68-8 Cork, oak 977038-71-3... 

Puigderrajols, R, Mir, G. Molinas, M. (2001). Ultrastructure of early secondary embryogenesis by multicellular and unicellular pathways in cork oak Quercus... 

Toribo, M. Celestino, C. Molinas, M. (2005). Cork oak, Quercus suber L. In Jain, SM Gupta, P. (Ed(s).). Protocol for somatic embryogenesis in woody plants. Forestry Sciences 77, Vol. 35 445-458. Springer-Verlag. 

Accrustation materials of the C.w. of boundary tissues (epidermis, periderm) are cutin and suberin. Cu-tin forms a cuticle of varying thickness and strength. Suberin is the material of cork, e. g. in the cork oak, Quercus suber. Some plant C. w. secrete wax, e. g. the Andean wax palm, Copemica cerifera. TTie walls of pollen grains and cryptogam (e. g. fern) spores consist of Sporopollenin (see). 

Cork is produced by peeling the bark from the branches of cork oak trees in the Mediterranean basin at about ten-year intervals, when the tree is between thirty and two hundred years old. It is traditionally used for flooring, bottle stoppers, and buoyancy devices. As the trees are not felled, cork oak forests are an unusual wildlife habitat. 

Jensen W 1972 A study of the outer bark of birch Betula verrucosa) and cork oak Quercus suber) by scanning electron microscopy. Ann Rev Soc Esp Fis Quim 68 871-878... 

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