Cereal Chem 54:207 - 215. | VIEW
Bread Staling Studies. I. Effect of Protein Content on Staling Rate and Bread Crumb Pasting Properties.
S. K. Kim and B. L. D'Appolonia. Copyright 1977 by the American Association of Cereal Chemists, Inc.
The effect of flour protein content (10.6, 11.0, 13.9, and 21.6% on a 14% mb) at two storage temperatures (21 and 30 C) on bread staling was investigated. Kinetic studies at the two temperatures indicated that regardless of the protein content in the flour, the basic mechanism of bread staling involves changes analogous to crystallization of the starch fraction of the crumb. The higher storage temperature and higher flour protein sample decreased the staling rate. The primary effect of protein in reducing staling rate was dilution of the starch and not the quality of the protein. Amylograms of crumb slurries obtained from the 11.0 and 13.9% flour proteins had pasting temperatures which decreased progressively as bread aged, and showed a minor peak at a lower temperature than the peak height at 95 C. The minor peak was most prominent for the bread produced from the 11.0% flour protein. Neither the minor peak nor the changes in the pasting temperature, however, were observed with the highest protein bread (21.6% flour protein). No appreciable changes were observed for either 15-min height or setback as the bread aged. The crumb showed a unique setback pattern which was not observed with starch, flour, or dough. During the setback at a certain temperature, a sharp increase in viscosity in the bread crumb slurries was noted. This temperature did not change as the bread aged. The highest protein bread showed a different setback pattern compared to the lower protein bread.