Cereal Chem. 70:707-711   |  VIEW ARTICLE

Effects of Twin-Screw Extrusion on the Physical Properties of Dietary Fiber and Other Components of Whole Wheat and Wheat Bran and on the Baking Quality of the Wheat Bran.

W.-M. Wang, C. F. Klopfenstein, and J. G. Ponte, Jr. Copyright 1993 by the American Association of Cereal Chemists, Inc. 

The effects of twin-screw extrusion processing at three different screw speeds on the physical properties of whole wheat and wheat bran were evaluated. Also a baking study was conducted to show how different extrusion-processing conditions affected the functionality of wheat bran in whole wheat bread. Small decreases in total and insoluble dietary fiber were noted in extruded versus raw wheat and wheat bran, along with increases in soluble dietary fiber. The largest increase in soluble dietary fiber occurred in wheat bran extruded at the highest screw speed. Protein solubility decreased in the extruded products. Although total fat was somewhat lower in both whole wheat and bran after extrusion, the percentage of ether-extractable fat increased in wheat bran and decreased in whole wheat. Enzyme-digestible starch and water absorption were higher for extruded samples than they were for raw samples. Although viscosities of whole wheat and wheat bran slurries at 95 C were much lower for the extruded samples than they were for the raw samples, slurries of extruded whole wheat at 37 C were more viscous than those of the raw sample. The baking study showed that extruded wheat bran is an acceptable product for use in preparation of "whole wheat" bread.