Water soluble pentosans (WSP) from doughs and breads made with different enzyme preparations are characterized according to extraction yield, sugar composition, xylose/arabinose ratio and molecular weight (MW) distribution. Extraction yield was greater for dough than for bread samples, ranging from 0.94 to 1.64%, but bread extracts had a higher purity. Percent of pentoses in purified WSP was greater in pentosanase supplemented samples (28-55%) than in control and amylase containing samples (23-32%). Major sugars were xylose and arabinose, but glucose and mannose also appeared in the extracts. The xylose/arabinose (Xyl/Ara) ratio was 1.3-1.6 and underwent small changes during processing. Enzyme addition caused an increase in Xyl/Ara ratio, attributable to a debranching of arabinoxylans (AX) with higher degree of Ara substitution by arabinofuranosidase. Addition of pentosanases had a significant effect in increasing WSP with MW over 39 000, whereas those of low MW changed only slightly. MW distribution depended on enzyme source, and whereas some enzymes showed activity during fermentation others increased their activity during baking. No synergistic effects were observed in studied variables due to the combination of amylases with pentosanases. Protein in WSP extracts eluted together with ferulic acid suggesting they were linked, but not associated with a determined carbohydrate fraction.
The expression and purification of human steroid hormone processing enzyme CYP7B1 and the characterization of its interactive network
