title: Combined steam pretreatment and enzymatic hydrolysis of starch-free wheat fibers.
abstract: Steam treatment of an industrial process stream, denoted starch-free wheat fiber, was investigated to improve the formation of monomeric sugars in subsequent enzymatic hydrolysis for further bioconversion into ethanol. The solid fraction in the process stream, derived from a combined starch and ethanol factory, was rich in arabinose (21.1%), xylose (30.1%), and glucose (18.6%), in the form of polysaccharides. Various conditions of steam pretreatment (170-220 degrees C for 5-30 min) were evaluated, and their effect was assessed by enzymatic hydrolysis with 2 g of Celluclast + Ultraflo mixture/100 g of starch-free fiber (SFF) slurry at 5% dry matter (DM). The highest overall sugar yield for the combined steam pretreatment and enzymatic hydrolysis, 52 g/100 g of DM of SFF, corresponding to 74% of the theoretical, was achieved with pretreatment at 190 degrees C for 10 min followed by enzymatic hydrolysis.
authors.affiliation: Department of Chemical Engineering 1, Lund University, PO Box 124, SE-221 00, Lund, Sweden.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Palmarola-Adrados
authors.forename: Mats
authors.initials: M
authors.lastname: Galbe
authors.forename: Guido
authors.initials: G
authors.lastname: Zacchi
mesh_terms: D001089:Arabinose / Q000737:chemistry; D001709:Biotechnology / Q000379:methods*; D004798:Enzymes / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry*; D006868:Hydrolysis; D008872:Microwaves; D011134:Polysaccharides / Q000737:chemistry; D013227:Steam; D013696:Temperature; D013997:Time Factors; D014908:Triticum / Q000737:chemistry*; D014994:Xylose / Q000737:chemistry
chemical_list: D004798:Enzymes; D011134:Polysaccharides; D013227:Steam; D000431:Ethanol; D014994:Xylose; D001089:Arabinose