Cereal Chem 72:594-597 |
Modifications of Starch During Baking: Studied Through Reactivity With Amyloglucosidase.
L. Eynard, N. Guerrieri, and P. Cerletti. Copyright 1995 by the American Association of Cereal Chemists, Inc.
Conditions that ensure starch hydrolysis by amyloglucosidase in a limited substrate system were worked out. Using these conditions, we evaluated the degree of access of the enzyme to starch molecules in different starchy materials. Raw starches of different botanical origins are hydrolyzed at different rates, but starches with limited branching hydrolyze more rapidly. A good example of this is a limit dextrin, which is more susceptible than its parent amylopectin. We also studied the effect of gelatinization on the enzymatic availability of starch. It was observed that damaged granules undergo amylolysis much more rapidly than do undamaged ones. Therefore, the extent of amylolysis in a given starch is governed by the degree of granule damage. Starch in bread is hydrolyzed more rapidly and extensively than is that in flour and dough, but no significant differences were found in conventional yeast fermentation between soft and durum wheat. On the other hand, bread obtained by acid fermentation initially undergoes slow amylolysis, although the final level reached is the same as in bread made from the same flour by conventional yeast fermentation.