Cereal Chem 40:515 - 530.  |  VIEW ARTICLE

The Oxidation of Wheat Flour. IV. Labile and Nonlabile Sulfhydryl Groups.

B. Sullivan, L. K. Dahle, and J. H. Schipke. Copyright 1963 by the American Association of Cereal Chemists, Inc. 

The measurement of sulfhydryl groups in flour and in dough is discussed. A fraction of the -SH groups appears to be reacted in a water slurry in the absence of oxygen. When a dough is mixed, there is a rapid initial loss of -SH groups, but about half the measurable amount remains unreacted after prolonged mixing in air, varying with the flour used. Maximum improvement in the rheological properties of a dough and the resultant bread occurs upon addition of iodate reagents equivalent to approximately half the measurable -SH groups and somewhat less with specific-SH reagents such as N-ethylmaleimide. An explanation is offered which rationalizes the improver action of a blocking or oxidizing agent, based on the current hypothesis of sulfhydryl-disulfide interchange.