Can fermentation methods and granulometry modulate bread starch digestibility without hindering its technological quality?

• Fermentation methods affect the quality of durum wheat bread. • Spontaneous sourdough negatively affected the overall quality of bread. • The use of fine semolina compromised bread quality reducing specific volume. • The combination of sourdough and fine semolina reduces starch digestibility. Reducing starch digestibility in bread while maintaining its quality has been a trending topic in recent decades. This study explores the effects of different fermentation methods—Direct Method (DM), Poolish (PO), and Sourdough (SD)—combined with semolina of varying granulometry (Fine Semolina (FS), ∼150 µm; Coarse Semolina (CS), ∼550 µm) on bread properties. A full factorial design was employed to assess the influence of these variables on dough properties (pH and total titratable acidity (TTA)), bread quality (porosity, texture profile analysis, and volume), and in vitro digestibility (using Englyst’s method). Results indicate that SD-fermented doughs exhibited higher TTA and lower pH, leading to bread with reduced porosity and volume compared to PO and DM, and a reduced starch digestibility due to a dense crumb structure. CS produced slightly more porous bread with lower resistant starch than FS. To conclude, the fermentation method was the major factor influencing bread quality and digestibility.