Effect of Dough Yield, Flour Type and Fermentation Time on Sourdough Near‐Infrared Spectral Data With ANOVA–Simultaneous Component Analysis

Near‐infrared (NIR) spectroscopy combined with ANOVA–simultaneous component analysis (ASCA) provides a powerful approach for investigating sourdough fermentation. Two complementary longitudinal experiments (repeated four times) were conducted to evaluate the influence of key design factors on sourdough development over a 28‐day refreshment period. Experiment 1 examined the effects of dough yield (DY, firm DY 150 and liquid DY 200) and fermentation time, whereas Experiment 2 evaluated the effects of flour type (coarse stone‐milled, two sifted stone‐milled or roller‐milled) and fermentation time in firm and liquid sourdoughs. Prior to each refreshment (every fourth day), pH and total titratable acidity (TTA) were measured, and NIR spectra acquired. In Experiment 1 (64 samples), DY significantly ( p ≤ 0.05) influenced pH but not TTA ( p > 0.05). DY, fermentation time and their interaction significantly ( p ≤ 0.05) influenced the spectral profiles. Liquid sourdoughs are associated with moisture, organic acids and starch‐related spectral bands, whereas firm sourdoughs showed stronger amino acid and aromatic alcohol features. In Experiment 2 (256 samples), flour type and fermentation time significantly ( p ≤ 0.05) affected pH, TTA and the spectral profiles, with refined flours producing more compositionally stable sourdoughs over time. In firm sourdough, all three factors were significant ( p ≤ 0.05); in liquid sourdough, only flour type was significant, indicating greater temporal stability. Across both experiments, fermentation time contributed to progressive biochemical changes reflected in shifts from moisture‐dominated to metabolite‐associated spectral regions. These findings demonstrate the capability of ASCA to resolve complex multivariate effects in sourdough fermentation and highlight the importance of hydration and flour refinement in determining sourdough stability and biochemical evolution.