Journal of cereal science vol:39 issue:2 pages:181-186
Destarched, deproteinised wheat bran contains ca 40% of water-unextractable arabinoxylan (WU-AX) which is solubilised more effectively by Bacillus subtilis endoxylanase (EC 188.8.131.52, XBS, ca. 41 % of WU-AX) than by Aspergillus aculeatus endoxylanase (XAA, ca. 18%). While XBS preferentially converts WU-AX into enzymically solubilised arabinoxylan (ES-AX), XAA preferentially degrades water-extractable arabinoxylan and ES-AX Arabinose to xylose ratios of ES-AX, released by XBS, decreased with increasing enzyme levels indicating an unexpected difference in their enzymic solubilisation which may be due to close packing of AX with low degree of substitution and/or limited solubility of the hydrolysed fragments. Wheat bran ES-AX released at low XBS concentrations had a higher relative peak molecular mass than those released at higher XBS concentrations. ES-AX invariably was of low relative molecular mass for all XAA concentrations tested. The results indicate that XBS is useful for the conversion of insoluble fibre to soluble fibre. (C) 2003 Elsevier Ltd. All rights reserved.