Cereal Chem 59:113 - 120.  |  VIEW ARTICLE
Freeze-Fracture Ultrastructure of Wheat Flour Ingredients, Dough, and Bread.

B. Fretzdorff, D. B. Bechtel, and Y. Pomeranz. Copyright 1982 by the American Association of Cereal Chemists, Inc. 

The structures of isolated flour components of mixed doughs (containing several combinations of ingredients), of fermented doughs, and of bread crumb were examined by the freeze-fracture technique. Although the shapes of the small and large starch granules were unaltered in doughs, the gluten and the water-soluble structures appeared completely different in the complex-dough system. In general, water was distributed in three forms: 1) coating around starch granules and yeast cells, 2) droplets, and 3) large areas; all three changed with protein development. Protein development was followed from a protein network in a flour-water dough to a sheetlike protein in a complete dough (containing flour, water, yeast, sugar, salt, shortening, malt, and oxidant). Both compositional and physical (dough development) effects were indicated. A transition stage between the two structures appeared after sugar was added. Fermenting a flour- water-yeast-salt dough did not affect the protein network structure, but fermenting a complete dough altered the sheetlike protein to a fine network. In bread, regular dense-structured sheets were observed. In most doughs, protein-starch interaction was clearly visible; thin "pearl chains" or thin protein strands connected starch and protein. Those interactions intensified after fermentation. In bread crumb, protein and starch were tightly connected.