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EN
In view of the recent emphasis on non-conventional chemistry, application of ultrasound in isolation of plant polysaccharides represents a viable alternative to traditional extraction processes. This review presents an extensive literature survey of ultrasound-assisted extraction of polysaccharides from different plant materials, particularly herbal plants and secondary agricultural plant sources. Targeted, multistep methods were applied with respect to differences in the types of polysaccharides and their location in plant cell walls. The effectiveness of the methods was evaluated according to yield and properties of the isolated polysaccharides in comparison to classical extraction methods. Substantial shortening of extraction time, reduction of reagent consumption and/or extraction temperature are the most important advantages of the ultrasonic treatment. In combination with sequential extraction steps using different solvents, sonication was shown to be effective in separation and/or purification of polysaccharides. The disadvantages of the sonication treatment, such as degradation and compositional changes of the polysaccharide preparations are discussed as well.
EN
Chemical properties of any lignocellulose species are one of the major properties that used to select the material for any purpose either chemical or biological. Since bamboo is one of the woody grass species used for various applications worldwide; therefore knowing the chemical composition plays greater a role. Based on the above assumption, this research was conducted to study the major chemical composition of Yushania alpina (K. Schum.) W.C.Lin (1974) (Highland Bamboo) grown around Enjibara in Ethiopia. In the work, Yushania alpina (Highland Bamboo) sample was harvested, dried, milled using a Wiley Mill, sieved and all chemical composition were determined based on the National Renewable Energy Laboratory (ASTM) approaches, except that the Kurschner-Hoffer method (1931) was applied for cellulose determination. Based on the study, the chemical composition characterization shows that Yushania alpina has 46.76% cellulose content, 25.27% lignin content, 12.18% hemicellulose, 3.77% ash, 12.23% hot-water extractive and 3.93% ethanol-toluene extractives.
EN
The dissolution of corn stover in alkaline solvent system composed of NaOH-H2O2 was reported and the separation of its ingredients combined with acid precipitation, ethanol extraction was proposed. It is proven that the residual after alkali solvent was cellulose, the filtrate by the acid precipitation of the liquor was lignin, the solid by the ethanol extraction of the liquor was hemicellulose. The optimum dissolution conditions were determined by single-factor experiment as follows: the concentration of H2O2 5.0%, pH 11.5, dissolution temperature 60°C, dissolution time 3.0 h, the ratio of liquid to solid 30 mL/g. And chemical analysis were employed to determine the purity of the components separated. The structure of the components separated were identifi ed by FT-IR, SEM, XRD and NMR. The cellulose recovery yield can achieve to 84.2% and lignin recovery yield is 86.6%, the hemicellulose recovery yield is 96.7%. After recycling the solvent 3 times, the recovery yield of cellulose, lignin and hemicellulose were 82.7, 87.6 and 97.4%, and the purity of cellulose, lignin and hemicellulose were 98.0, 96.5 and 98.7%, respectively.
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