Cereal Chem 66:128-132   |  VIEW ARTICLE

Water Activity and Moisture Content of Dough and Bread.

Z. Czuchajowska, Y. Pomeranz, and H. C. Jeffers. Copyright 1989 by the American Association of Cereal Chemists, Inc. 

Water activity (aw) and moisture contents were determined in mixed dough, fermented dough, bread crumb, and crust of loaves baked with various amounts of water (optimum, +3%, or -3%) and/or for various times (21, 24, or 27 min). In addition, effects of changes in formulation, including replacement of original wheat flour by ball-milled wheat flour, on aw and water content were determined. A decrease in added water considerably lowered loaf volume; an increase in baking time slightly decreased loaf volume. Proofed samples, generally, were higher than mixed doughs in water contents and aw. Doughs mixed with optimum water were lower in aw than doughs mixed with excess water. There were large differences in water contents of crumb in bread baked with various baking absorption levels but not in samples baked for various times with optimum baking absorption. There was little change in aw between the 1- and 24-hr-old bread crumb. Moisture and aw were higher in proofed dough than in 1-hr-old bread crumb. As time of baking increased, moisture and aw in the crust of 1-hr-old bread decreased. In the crumb, aw and moisture content were the lowest in bread baked by the full formula with the original flour. Exclusion of sugar or salt increased most moisture contents and water activity. The moisture and aw, generally, were lowest in the crust of bread baked by the full formula with the original flour and highest in bread baked with flour in which the starch was damaged.