Dietary fiber content, texture, and in vitro starch digestibility of different white bread crusts

Abstract

Different types of white bread are sold and widely consumed worldwide. The objective of this study was to evaluate the starch digestibility in the crust of different white breads. Three popular commercial white breads were analyzed for dietary fiber (DF), thermal properties, texture, starch hydrolysis and resistant starch (RS) contents, in freshly baked and stored samples. The DF content in fresh crusts “as eaten” (6.8–7.2%) represents about 25% of the recommended daily consumption. The hardness and elasticity, RS and DF contents increased upon storage, associated with incomplete starch gelatinization and retrogradation, corroborated by the thermal analysis. The hydrolysis rate suggested that the structural arrangement of the starch components in the crust, possibly due to the low water content resulting from evaporation during baking and upon storage, restricts the susceptibility to digestive enzymes action. Consumption of bread crust may be suggested as a means to increase the DF intake.