Extraction of water-soluble hemicelluloses from barley husks

Roos, Alexandra A.; Persson, Thomas; Krawczyk, Holger; Zacchi, Guido; Stålbrand, Henrik

doi:10.1016/j.biortech.2008.07.022

Cited by 72 publications

(46 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In general, lower extraction yields and shorter polymer chains are obtained when low pHs are used (Benkő et al 2007;Roos et al 2009). Xylan extraction yields increased with time of extraction, whereas changes in the molecular structure were observed (high-molecular-weight fraction decreased (from 36 % to 25 %) and low-molecular-weight fraction increased (from 21 % to 30 %)) (Panthapulakkal et al 2013).…”

Section: Xylansmentioning

confidence: 97%

Microwave-Assisted Extraction of Polysaccharides

et al. 2015

View full text Add to dashboard Cite

Section: Xylansmentioning

confidence: 97%

Microwave-Assisted Extraction of Polysaccharides

et al. 2015

View full text Add to dashboard Cite

“…An example of such a potential residue is barley husks (cf. Glasser et al 2000;Höije et al 2005;Krawczyk et al 2008;Pitkänen et al 2008;Roos et al 2009), a side-stream waste material from the manufacture of starch and ethanol. The main structural features of barley husk xylan were early identified (Aspinall and Ferrier 1957) and further knowledge of the structure was recently obtained by means of NMR (Höije et al 2006).…”

Section: Introductionmentioning

confidence: 97%

Adsorption of cationized barley husk xylan on kraft pulp fibres: influence of degree of cationization on adsorption characteristics

2009

View full text Add to dashboard Cite

A water-soluble (glucurono)arabinoxylan (GAX) was isolated from barley husk using chlorite delignification followed by alkaline extraction and enzymatic purification of the extract. The isolated xylan was shown to adsorb on bleached softwood kraft fibres, but the degree of adsorption was rather low under the applied conditions. This can be explained by the inhibited adsorption of GAX molecules with a relatively high degree of arabinofuranosyl substitution, as indicated by iodine complexation and neutral carbohydrate analysis of the non-adsorbing xylans. In order to increase the driving force for adsorption of the more highly substituted GAX, the xylan was cationized through a reaction in an aqueous alkaline medium with 2,3-epoxypropyltrimethylammonium chloride (EPTMAC). The chemical modification of xylan was confirmed by using 1 H-13 C HSQC (Heteronuclear Single Quantum Coherence) NMR, and was quantified by using elemental analysis. The GAX cationization, which introduced cationic charge densities ranging from 110 to 740 leq/g, was shown to increase the rate and magnitude of adsorption extensively, due to the induced electrostatic interaction between the anionic fibres and the cationic xylan. Similar to non-modified xylan, cationic xylan possessed a non-electrostatic cellulose surface affinity, as shown by adsorption at high ionic-strength and on esterified (carboxyl-free) pulp fibres.

show abstract

“…Heat pretreatment or autohydrolysis can also be used and has an advantage over other chemical extraction methods, such as alkaline extraction, because it does not require neutralization. Heat pretreatment is performed in a pressure vessel using water or steam and has been applied in many cases to isolate AX or make (A)XOS from different lignocellulose materials, such as barley husks (Roos et al, 2009). Wheat bran materials (Immerzeel et al, 2014;SchooneveldBergmans and Hopman, 1998) have also been used.…”

Section: Introductionmentioning

confidence: 99%