title: Fractionation of corn fiber treated by soaking in aqueous ammonia (SAA) for isolation of hemicellulose B and production of C5 sugars by enzyme hydrolysis.
abstract: A process was developed to fractionate and isolate the hemicellulose B component of corn fiber generated by corn wet milling. The process consisted of pretreatment by soaking in aqueous ammonia followed by enzymatic cellulose hydrolysis, during which the hemicellulose B was solubilized by cleavage into xylo-oligosaccharides and subsequently recovered by precipitation with ethanol. The pretreatment step resulted in high retention of major sugars and improvement of subsequent enzymatic hydrolysis. The recovered hemicellulose B was hydrolyzed by a cocktail of enzymes that consisted of β-glucosidase, pectinase, xylanase, and ferulic acid esterase (FAE). Xylanase alone was ineffective, demonstrating yields of less than 2% of xylose and arabinose. The greatest xylose and arabinose yields, 44% and 53%, respectively, were obtained by the combination of pectinase and FAE. A mass balance accounted for 87% of the initially present glucan, 91% of the xylan, and 90% of the arabinan. The developed process offered a means for production of corn fiber gum as a value-added co-product and C5 sugars, which could be converted to other valuable co-products through fermentation in a corn wet-milling biorefinery.
authors.affiliation: Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA. John.Nghiem@ars.usda.gov
authors.forename: Nhuan P
authors.initials: NP
authors.lastname: Nghiem
authors.forename: Justin
authors.initials: J
authors.lastname: Montanti
authors.forename: David B
authors.initials: DB
authors.lastname: Johnston
authors.forename: Caye
authors.initials: C
authors.lastname: Drapcho
mesh_terms: D000641:Ammonia / Q000737:chemistry; D001089:Arabinose / Q000737:chemistry / Q000378:metabolism; D002241:Carbohydrates / Q000737:chemistry*; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D044602:Cellulases / Q000737:chemistry / Q000378:metabolism; D002482:Cellulose / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D000431:Ethanol / Q000737:chemistry; D005936:Glucans / Q000737:chemistry; D006868:Hydrolysis; D009844:Oligosaccharides / Q000737:chemistry; D011096:Polygalacturonase / Q000378:metabolism; D011134:Polysaccharides / Q000737:chemistry; D014990:Xylans / Q000737:chemistry; D014994:Xylose / Q000737:chemistry / Q000378:metabolism; D003313:Zea mays / Q000737:chemistry*; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D002241:Carbohydrates; D005936:Glucans; D009844:Oligosaccharides; D011134:Polysaccharides; D014990:Xylans; C438402:hemicellulose B; C030080:araban; D000431:Ethanol; D000641:Ammonia; D002482:Cellulose; D014994:Xylose; D001089:Arabinose; D002265:Carboxylic Ester Hydrolases; C070196:feruloyl esterase; D044602:Cellulases; D011096:Polygalacturonase; D001617:beta-Glucosidase