Cereal Chem 43:156 - 168.  |  VIEW ARTICLE

Nonstarchy Polysaccharides and Proteins of Soft Wheat Flour Tailings.

E. M. Upton and E. E. Hester. Copyright 1966 by the American Association of Cereal Chemists, Inc. 

The composition of nonstarchy polysaccharides and proteins of subfractions of soft wheat tailings was determined. The subfractions were: (a) the supernatant solids (5.5% pentosans, 52% protein); (b) mucilaginous material (18% pentosans, 16% protein); and (c) a polysaccharide-protein complex (95% pentosans, 5% protein) purified by enzyme digestion of the mucilage. The polysaccharides of the starch-free supernatant solids contained 1.5% L-arabinose, 0.8% D-xylose, and 6.6% D-glucose; the glucose was believed to be derived from a nonstarchy polysaccharide. The mucilage contained 4.5% L-arabinose, 5.8% D-xylose, and 17.2% D-glucose; glucose was largely the result of starch degradation. The purified polysaccharide-protein complex was an arabinoxylan consisting of 27.4% L-arabinose and 43.5% D-xylose. Starch-gel electrophoresis and amino acid analyses showed similarities between the proteins of the tailings supernatant solids and gluten and between the proteins of the tailings mucilage and the water-solubles of the same flour. The resistance of the polysaccharide-protein complex to complete hydrolysis prevented total analyses of amino acids associated with the arabinoxylan. Undigested material, suggestive of cell-wall debris, appeared to remain structurally intact in the hydrolysate, attesting to the strength of bonding of the glycoproteins of the tailings of soft wheat flour.