Cereal Chem 45:269 - 279. | VIEW
Gelatinization of Starch During Bread-Baking.
T. Yasunaga, W. Bushuk, and G. N. Irvine. Copyright 1968 by the American Association of Cereal Chemists, Inc.
The amylograph was used to study the pasting characteristics of starch in baked bread. A slurry was prepared by dispersing the crumb in distilled water with a Waring Blendor. Crumb amylograms were characterized by a positive initial viscosity and one or, under some conditions, two viscosity peaks. The appearance of a peak in the amylogram was taken as evidence that the starch was only partly gelatinized during baking. The degree of gelatinization depends mainly on moisture but also on temperature during baking. Within a loaf, the starch in outer layers of crumb was gelatinized to a greater degree than the starch in the center. Peak viscosity (PV) of crumb decreased continuously during post-baking storage of bread and was also decreased by additions of malt to the bread formula. The extent of starch damage in flour was important in relation to the condition of starch in the baked loaf. Shortening showed little effect in fresh crumb but delayed the decrease in PV with storage. Glyceryl monostearate produced an increase in gelatinization temperature, increased PV, and slowed down the drop in PV with storage. On the basis of changes in hydration capacity of crumb, the effects investigated can be divided into two categories: those that decrease PV by increasing the extent of gelatinization (e.g., baking absorption) and thereby increase hydration capacity, and those that decrease PV by degrading the starch (e.g., malt) and thereby decrease the hydration capacity.