MIXING AND EXTENSIONAL-PROPERTIES OF WHEAT-FLOUR DOUGHS WITH ADDED CORN FLOUR, FIBERS, AND GLUTEN

Fibers prepared by peroxide delignification of wheat straw and of oat hulls replaced 5, 10, or 15% of wheat flour solids in doughs to determine the effect on farinograph mixing parameters and on rested dough properties as measured on the extensigraph. Corn flour was evaluated as a nonfibrous replacement for comparison. The water content of doughs (at a 500 Brabender unit farinograph consistency) was greater with treated fiber than with crude fiber, corn flour, or the control. Replacing as little as 5% of the wheat flour solids resulted in a significant change in mixing characteristics and extensigraph parameters. Mixing times depended on the fiber type and amount of replacement. Stability was less with the replacement fibers than with the control flour and also depended on fiber type. Extensigram areas and extensibilities decreased linearly and significantly (P < 0.05) as more fiber was incorporated, but resistance to extension increased. The magnitude of these changes depended on the amount of replacement and type of replacing material. Corn flour replacement had the least effect on farinogram and extensigram parameters. Adding a commercial wheat gluten to raise the flour gluten-solids ratio equal to the control did not completely restore mixing or rested physical dough properties to those of the control.