Cereal Chem 42:201 - 208.  |  VIEW ARTICLE

Some Interrelationships of Ascorbic Acid and Dehydroascorbic Acid in the Presence of Flour Suspensions and in Dough.

J. E. Carter and J. Pace. Copyright 1965 by the American Association of Cereal Chemists, Inc. 

In suspensions of flour (65% extraction) at pH 6.0, ascorbic acid (AA) is oxidized only slowly, and the evidence does not suggest the presence of a very active AA oxidase in the endosperm of wheat. But AA is oxidized rapidly in dough when the dough is mixed in air. Under these conditions most of the AA is oxidized to dehydroascorbic acid (DHA). When DHA is added to flour suspensions or to dough, there is only a slight reduction to AA, in 90 min. at 27 C. But if glutathione (GSH) is also present, then DHA is reduced to AA in a few minutes. This does not occur with flour made from steamed wheat. The observations confirm the presence of an active DHA reductase in the wheat grain. The distribution of this enzyme in the wheat grain has been determined. Preliminary observations have been made on the potential usefulness of measurements of the activity of the enzyme as an index of heat-damage to the endosperm of the wheat grain.