Cereal Chem 67:92-96   |  VIEW ARTICLE

Dynamic Rheological Properties of Bread Crumb. I. Effects of Storage Time, Temperature, and Position in the Loaf.

J. N. Persaud, J. M. Faubion, and J. G. Ponte, Jr. Copyright 1990 by the American Association of Cereal Chemists, Inc. 

The dynamic rheological properties G, G", and loss tangent of the crumb of white pan bread were characterized at ambient temperature during the first 120 hr after baking. Linear viscoelastic behavior was observed up to 0.6% (peak-to-peak ) strain. Above 0.6% strain, G" of the 3-hr-old crumb increased with increasing strains. This strain dependency shifted to higher levels after 24 hr and longer, except when storage was at 45 C. The changes in G' with age when stored at 4, 25, and 45 C showed trends similar to the firmness curves obtained using empirical static compression tests. Changes in both G' and G" with aging were temperature-dependent processes. As the storage temperature increased, the rate of increase in G' relative to G" was lowered such that, at 45 C, the tangent of the 120-hr old crumb was the same as that of crumb aged 3 hr. G' values of the middle slice bacame higher than those of the end slices as the storage temperature was reduced. Dynamic tests did not detect any significant differences in the rates or extent of change of either G' or tangent because of the plane of shearing. Two commercial bread flours had different G' values, but the difference was the same at all crumb ages.