ME103: Sourdough material analysis

Background

In this ME103 project, we investigated the mechanical properties of sourdough bread, focusing on strain, stress, creep, and elasticity. Using various hydration and protein levels, we related those inputs to crumb structure and integrity. Bread behaves as a complex viscoelastic material, elastic and time-dependent, which makes mechanical response hard to predict without testing.

Using a standard compression test, we measured strain in real time as the bread deformed under load. With image processing and load-cell integration, we tracked and calculated stress, strain, and creep characteristics. The work explores sourdough’s mechanical behavior and quantifies its response under controlled loading.

Technical architecture

We baked sourdough test specimens as Pullman loaves to keep loaf geometry consistent. The testing apparatus combined a compression stage with imaging so we could correlate load and deformation. Strain was analyzed with edge-based, random, and 10×10 grid tracking schemes to compare how displacement fields were estimated across the crumb.

Results

Our findings showed that hydration and protein content significantly impact sourdough bread’s structural integrity. Higher hydration levels lead to softer crumb structures with greater displacement, while higher protein content contributes to denser, more elastic textures. Our study highlights the interplay between these factors, showing that the combination of high hydration and protein levels could enhance bread elasticity and potentially extend shelf life without using preservatives. These results provide bakers with quantitative data to refine recipes for desired textures and longevity.