title: Enzymatic saccharification of sugar beet pulp for the production of galacturonic acid and arabinose; a study on the impact of the formation of recalcitrant oligosaccharides.
abstract: Enzymatic saccharification of sugar beet pulp was optimized on kg-scale to release the maximum amounts of monomeric galacturonic acid and arabinose with limited concomitant degradation of cellulose, using conditions that are feasible for industrial upscaling. A selected mixture of pectinases released 79% of the galacturonic acid and 82% of the arabinose as monomers from sugar beet pulp while simultaneously degrading only 17% of the cellulose. The recalcitrant structures that were obtained after hydrolysis were characterized using mass spectrometry. The most abundant structures had an average degree of polymerization of 4-5. They were identified as partially acetylated rhamnogalacturonan-oligosaccharides, mostly containing a terminal galacturonosyl residue on both reducing and non-reducing end, partially methyl esterified/acetylated homogalacturonan-oligosaccharides, mostly containing methyl and acetyl esters at contiguous galacturonosyl residues and arabinan-oligosaccharides, hypothesized to be mainly branched. It could be concluded that especially rhamnogalacturonan-galacturonohydrolase, arabinofuranosidase and pectin acetylesterase are lacking for further degradation of recalcitrant oligosaccharides.
authors.affiliation: Wageningen University, Laboratory of Food Chemistry, PO Box 8129, 6700 EV Wageningen, The Netherlands.
authors.forename: A G M
authors.initials: AG
authors.lastname: Leijdekkers
authors.forename: J P M
authors.initials: JP
authors.lastname: Bink
authors.forename: S
authors.initials: S
authors.lastname: Geutjes
authors.forename: H A
authors.initials: HA
authors.lastname: Schols
authors.forename: H
authors.initials: H
authors.lastname: Gruppen
mesh_terms: D001089:Arabinose / Q000138:chemical synthesis*; D027461:Beta vulgaris / Q000737:chemistry*; D004789:Enzyme Activation; D004795:Enzyme Stability; D006603:Hexuronic Acids / Q000138:chemical synthesis*; D009005:Monosaccharides / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D011096:Polygalacturonase / Q000737:chemistry*
chemical_list: D006603:Hexuronic Acids; D009005:Monosaccharides; D010936:Plant Extracts; C007819:galacturonic acid; D001089:Arabinose; D011096:Polygalacturonase