title: Effects of glycerol and moisture gradient on thermomechanical properties of white bread.
abstract: The thermomechanical properties of breadcrumb were investigated using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The main transition (T(1), near 0 degrees C) shifted to lower temperature with added glycerol due to freezing point depression. The low-temperature transition (T(3), approximately -50 degrees C), found only in high-glycerol (8.8%) bread, suggested that of excess or phase-separated glycerol. The high-temperature transition (T(2), 60-85 degrees C) appeared only in aged breadcrumbs; its temperature range was correlated well with the amylopectin melting transition (DSC) but its tan delta amplitude did not correlate well with the amylopectin melting enthalpy (r(2) = 0.72). On the other hand, the change of E' ' (viscous behavior) suggested that T(2) might be related to the change in the amorphous region. Domain-to-domain (amorphous) and crumb-to-crust moisture migrations are two critical phenomenological changes associated with aging and could lead to significant local dehydration of some amorphous regions contributing to mechanical firming during storage.
authors.affiliation: Department of Food Science, University of Massachusetts, Amherst, Massachusetts 01003, USA.
authors.forename: M Y
authors.initials: MY
authors.lastname: Baik
authors.forename: P
authors.initials: P
authors.lastname: Chinachoti
mesh_terms: D001939:Bread / Q000032:analysis*; D002152:Calorimetry, Differential Scanning; D002623:Chemistry Techniques, Analytical; D005511:Food Handling; D005615:Freezing; D005990:Glycerol / Q000494:pharmacology*; D012212:Rheology; D013696:Temperature; D013816:Thermodynamics; D013997:Time Factors; D014867:Water / Q000494:pharmacology*
chemical_list: D014867:Water; D005990:Glycerol