hemicellulose


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Related to hemicellulose: pectin

hemicellulose

[¦he·mē′sel·yə‚lōs]
(biochemistry)
(C6H10O5)n A type of polysaccharide found in plant cell walls in association with cellulose and lignin; it is soluble in and extractable by dilute alkaline solutions. Also known as hexosan.
References in periodicals archive ?
Lignin in pulp is chemically and physically bonded to cellulose and hemicellulose forming a three-dimensional polymer complex that contains acetal, [alpha] phenyl-[beta]-ether, phenyl-[beta]-glucosidic and hydrogen bonds [9, 25-27].
Figure 3 shows the relative intensity RI of the absorption of the chromophore C=O stretching vibration at 1730 [cm.sup.-1] ([RI.sub.1730]), the absorption of the lignin C=C stretching vibration at 1510 [cm.sup.-1] ([RI.sub.1510]), and the absorption of the cellulose and hemicellulose OH in-plane deformation/CH bending vibration at 1330 [cm.sup.-1] ([RI.sub.1330]) during Xe-WOM CAM 0 exposure.
Treatment with heat, pressure, or acids first removes hemicellulose and lignin from the long cellulose fibers.
The recycled material had much higher levels of nitrogen and lower levels of cellulose and hemicellulose indicating lower levels of carbon compounds.
There is a slight increase in cellulose content, while the content of the cementing vegetable substances is reduced: hemicellulose by 24%, pectin by 86%, and lignin by 20%.
Cellulose and hemicellulose can be broken down into sugars to produce alcohol and biofuels, making trees an important potential energy source.
The topics covered include biomass derivatives; carbon dioxide as a renewable C1 feedstock; hemicellulose from biodelignified wood; optimization of the process conditions for the extraction of heteropolysaccharides from birch; and protein-based plastics and composites as smart green materials.
"The opportunity to recover energy value from waste hemicellulose as part of the emerging forest biorefinery concept will generate new applications for performance chemicals to further benefit paper-maker profitability," he added.
Notice that the hemicellulose and lignin fractions are split between crude fiber and nitrogen-free extract.
The report defines biomass as all plant-derived molecules, including grain, starch, sugar, oil, and waste products, as well as the plant structural components cellulose, hemicellulose, and lignin.