Isolation of hemicelluloses from barley husks

In this work, arabinoxylan, the primary hemicellulose in barley husks, was isolated from barley husks by steam explosion and ultrafiltration. Ultrafiltration and diafiltration were used to concentrate and to increase the purity of the product which was intended for use as an oxygen barrier film in food packaging. A composite fluoropolymer membrane with a nominal molecular mass cut-off of 10,000 g/mol was used during ultrafiltration and diafiltration. The average flux during ultrafiltration to a volume reduction of 0.85 was 90 L/m(2) h. The flux was approximately constant (50 L/m(2) h) during diafiltration. Polysaccharides constituted about 40% of the solids fraction before ultrafiltration and nearly 70% after diafiltration. Arabinoxylan made up 45% of the polysaccharide fraction after diafiltration. (C) 2007 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.