Cereal Chem 40:399 - 408.  |  VIEW ARTICLE

Changes in Sulfhydryl and Disulfide Contents of Doughs During Mixing under Various Conditions.

C. C. Tsen and W. Bushuk. Copyright 1963 by the American Association of Cereal Chemists, Inc. 

Changes in sulfhydryl (-SH), disulfide (DS), and iodate and bromate where applicable, were measured simultaneously in doughs mixed for various lengths of time in nitrogen, in air, and in oxygen. Untreated doughs showed a definite loss of -SH and a slight loss of S-S during mixing in air or oxygen. Similar doughs mixed in nitrogen showed a small increase in -SH and no significant changes in S-S. In iodate- treated doughs mixed in nitrogen, -SH losses paralleled iodate losses, giving SH/iodate molar ratios of about 6 for low iodate concentrations and 4 for iodate concentrations well in excess of -SH content of the flour. Losses of -SH and iodate (or bromate) are greater in continuously mixed doughs than in resting doughs. Bromate was found to be a slow -SH oxidizing agent for dough,.as demonstrated that during mixing bromate oxidized -SH groups of dough more slowly than air. Doughs which show a marked decrease in resistance to extension as measured with the extensigraph (high iodate treatment and prolonged mixing in air or oxygen) show as definite loss of S-S as well as the expected loss of -SH. Accordingly, it is suggested that dough breakdown under certain conditions may involve oxidative cleavage of S-S bonds.