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Cereal Chem 45:183 - 191.  |  VIEW ARTICLE
Action of Chlorine on Wheat Flour Polysaccharides.

R. L. Whistler and R. E. Pyler. Copyright 1968 by the American Association of Cereal Chemists, Inc. 

As a result of the present and earlier work from this laboratory, it is now possible to explain the reactions which occur between polysaccharides and chlorine during flour bleaching. Chlorinolysis of wheat-straw hemicellulose proceeds in the same manner as earlier established for starch and cellulose. The principal difference is the lack of 1,6-anhydro ring formation in hemicelluloses. Hence under dry and semidry conditions they develop higher numbers of aldehydic end units and possibly more intermolecular grafting than observed with hexose polymers. Work with isolated polysaccharides such as cellulose, starch, and hemicellulose leads to the belief that direct oxidation of these occurs, at most, to only a minor degreen when flour is bleached with chlorine. Instead, a chlorinolysis proceeds with depolymerization through breakage of glycosidic bonds. In dry or semidry reactions, cellulose and starch cleave with development of levoglucosan units at the potentially reducing chain end. Xylans, whose units cannot form stable anhydro rings involving carbon C1, yield either reducing chain ends through acceptance of hydroxyl groups from water or, to a minor degree, produce grafts through union of the active chain ends of hydroxyls of neighboring chains.

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