MIXING PROPERTIES AS A MEASURE OF REVERSIBLE REDUCTION AND OXIDATION OF DOUGHS

The effects of reductants and oxidants on the functionality of gluten proteins during dough mixing were studied for seven mixing parameters using a prototype 2-g mixograph. Structural changes in the dough prote ins were monitored by size-exclusion high-performance liquid chromatog raphy and by multistacking sodium dodecyl sulfate polyacrylamide gel e lectrophoresis. Using dithiothreitol as the reducing agent, experiment al conditions were established that resulted in partial reduction of t he glutenin polymers and radical changes in mixing parameters. Studies of the effects of iodate, bromate, permanganate, and hydrogen peroxid e on reduced doughs showed that careful selection of oxidant concentra tion and oxidation conditions allowed an essentially complete recovery of the original dough mixing properties. Size-exclusion high-performa nce liquid chromatography and electrophoresis studies showed that samp les reoxidized under optimum conditions had protein size distributions almost identical to those of control samples. This test system provid es a basis for directly evaluating hypotheses on the functional roles of specific glutenin subunits by incorporating them into reduced dough s by oxidation.