Cereal Chem 58:421 - 423.  |  VIEW ARTICLE
A Mechanism for the Oxidative Gelation of Wheat Flour Water-Soluble Pentosans.

R. C. Hoseney and J. M. Faubion. Copyright 1981 by the American Association of Cereal Chemists, Inc. 

The oxidative gelation of wheat flour water-soluble pentosans was studied with viscometry. Such common oxidants as potassium bromate, potassium iodate, and ascorbic acid did not increase the viscosity of wheat flour water solubles, but hydrogen peroxide, ammonium persulfate, and formamidine disulfide did. Hydrogen peroxide was effective only in the presence of the enzyme peroxidase, which flour contains. The enzyme tyrosinase was also effective in increasing viscosity. Ferulic acid, fumaric acid, and cysteine stopped formation of the gel when hydrogen peroxide was added. Vanillic acid had no effect on gel formation. These results suggest a mechanism involving the addition of a protein radical to the activated double bond of ferulic acid. The ferulic acid is esterified to the arabinoxylan fraction of pentosan. The resultant cross-linking is responsible for the oxidative gelation of wheat flour water solubles. The gelation appears to be responsible for some, but not all, oxidative changes in bread doughs.