An innovative agent-based technique for determination of tortuosity in porous materials – Case study: bread and bread dough

Abstract

Tortuosity is an important structural parameter of porous materials, and it is the ratio of the actual distance between two points to the shortest linear distance between them. In the current work, we illustrate the employment of Brownian motion principles for the estimation of the average tortuosity. Two types of images were used in this work. The first one was standard images with a certain pre-defined direct length and tortuosity, and they were used for the standardization and calibration of our new method of tortuosity measurement. The second one was real images of the cross-sectional view of bread samples during baking. Tortuosity and porosity of bread were tracked at different times of baking. All image types had three connected parts named start section, transmission path region, and end section. In these images, the average tortuosity from start to end section was estimated, using the principle of Brownian motion applied in a multi-agent system. The average tortuosity of bread porous structure during baking was found to be 2– ∞. In the first stage of baking, tortuosity decreased rapidly, while at the end of this process, the tortuosity of the bread structure increased slightly. Moreover, the effect of porosity and pore distribution pattern on tortuosity could be evaluated easily, and heterogeneity of the desired structure could be illustrated. Therefore, this new method is a valuable technique to measure tortuosity in bakery products and to describe porous materials.