Thermomechanical behaviour of a crumb during chilling and freezing. Potential impact on crust flaking and interaction with formulation using selected enzymes

ALAIN LE BAIL; PABLO DANIEL RIBOTTA

Starch: Achievements in Understanding of Structure and Functionality

Nova Science Publishers, Inc

Lugar: New York; Año: 2006; p. 89 - 97

"Industrial" frozen bread is most of the time made out of dough that is frozen or is made from bread that is partially baked and frozen in industrial conditions. Frozen partially baked bread (PBB) is gaining market share every year because of its convenience; indeed, the end user needs only an oven to thaw and make the final baking of the product. One of the major quality problems of PBB is crust flaking. Previous studies have shown that even though a lack of humidity was responsible for the crust flaking problem, it appeared that some important mechanical deformations during partial baking and during final baking were mainly responsible of the problem. The changes in physical properties of partially-baked bread were investigated using thermoanalytical techniques (differential scanning calorimetric and dynamical-mechanical thermal analysis). The changes in the amount of non-freezable water, starch retrogradation, temperature of glass transition, shrinking degree and bread quality on part-baked bread during frozen storage were studied. The amount of amylopectin retrogradation in breadcrumb increased as consequence of part-baked bread storage. DMTA analysis permitted us to determine the pattern of breadcrumb shrinking during the chilling and freezing process. Tg of breadcrumb appeared occur at temperatures slightly lower than the ice-melting transition or to the melting of ice crystals.