It’s a maze: The pore structure of bread crumbs

Bread has a foam-like structure, but to date there is little information about the morphology of void structure in breads in three dimensions. In this paper, permeability testing and analysis of computer aided micro-tomography data were used to investigate the structure of breads as a function of connectivity of voids in a range of breads. The findings were related to bread properties obtained via material testing. Results indicated that a single, massively interconnected, open cell was responsible for approximately 99% of bread’s total porosity. Closed pores are also present with the number and average volume of closed pores significantly affecting strengths of bread crumbs. Bread behaved similarly to foams described by Gibson and Ashby (1988). The role of open and closed pores in affecting bread toughness and texture requires further investigation via structural–mechanical models.

► We examined a range of bread microstructures using SkyScan microCT system.
► Computational method developed to separate and quantify open and closed pore sizes.
► 99%+ of porosity in breads and cakes due to one large, interconnected open pore.
► Mechanical properties of bakery products related to both porosity and distribution of closed pores.