title: Twin-screw extrusion for hemicellulose recovery: influence on extract purity and purification performance.
abstract: A twin-screw extruder was used for the extraction of wheat bran hemicelluloses by the co-extrusion of wheat straw and bran. As compared with a stirred reactor extraction, a twin-screw extruder resulted in a lower extraction rate (only about 24% of hemicelluloses in the wheat bran), but it has the advantages of a shorter residence time for the vegetable matter and a lower chemical and water consumption. Hemicellulose powder production is usually effected via an expensive alcoholic precipitation step after concentration. Ultrafiltration was investigated as a means to reduce the alcohol consumption. Trials were made with hollow fiber polyethersulfone membranes with a molecular weight cut-off of 30 kDa. Ultrafiltration mainly concentrated the extract and removed small molecules such as monosaccharides and minerals. The combination of the anion-exchange chromatography and ultrafiltration allowed for the removal of colored compounds.
authors.affiliation: INRA, UMR 1010, F-31432 Toulouse, France. rawan.zeitoun@ensiacet.fr
authors.forename: Rawan
authors.initials: R
authors.lastname: Zeitoun
authors.forename: Pierre Yves
authors.initials: PY
authors.lastname: Pontalier
authors.forename: Philippe
authors.initials: P
authors.lastname: Marechal
authors.forename: Luc
authors.initials: L
authors.lastname: Rigal
mesh_terms: D001089:Arabinose / Q000032:analysis; D001709:Biotechnology / Q000379:methods*; D002845:Chromatography; D003116:Color; D004043:Dietary Fiber / Q000378:metabolism; D011134:Polysaccharides / Q000302:isolation & purification*; D011208:Powders; D059027:Recycling; D012117:Resins, Synthetic / Q000737:chemistry; D012972:Sodium Hydroxide / Q000737:chemistry; D013997:Time Factors; D014462:Ultrafiltration; D014994:Xylose / Q000032:analysis
chemical_list: D004043:Dietary Fiber; D011134:Polysaccharides; D011208:Powders; D012117:Resins, Synthetic; D012972:Sodium Hydroxide; C007916:hemicellulose; D014994:Xylose; D001089:Arabinose