Novel approach to investigate the mechanical properties of crumb matrix during storage - Re-engineering of gas-free crumb pellets

Abstract

Since commonly used texture profile analysis (TPA) depend on gas volume fraction, a detailed development of mechanistic relationships between firming-relevant additives and structural crumb matrix alterations often fail. Thus, a method to prepare gas-free crumb pellets was developed to exclude porosity effects. Therefore, reference white bread crumb was freeze-dried, crushed and rehydrated with either distilled water or maltose solution to the native moisture content. Freeze-dried crumb matrix, rehydrated after baking with maltose solution (0.5 g maltose/100 g flour), did not retard firming in comparison to reference pellets (crumb matrix rehydrated with water). Thus, maltose showed no functionality on pellet firming during storage. However, crumb pellets exhibited a reduced firmness, when maltose was added during dough preparation resulting in an altered crumb formation. Additionally, results demonstrated, that differences between leavening methods (chemical vs. biological) on firming kinetics were not significant, which was confirmed by comparable Avrami firming rates k.

Keywords: Anti-firming; Bread; Firming; Freshness; Maltose; Retrogradation; Staling; Texture analysis.