Changes to Structural and Compositional Features of Water-Soluble Arabinoxylans in Sourdough Bread

This research investigates the influence of milling methods and starter cultures on the structural characteristics of water-extractable arabinoxylans (WE-AX) in stone-milled whole-grain flour and sourdough bread. Stone milling was conducted to generate six different whole wheat flour samples, from which sourdough bread was produced using wheat and rye starter cultures. The study found that both milling parameters and the type of starter culture significantly impacted the fine structural details of WE-AX, including sugar composition, arabinoxylan (AX) content, and the arabinose-to-xylose (A/X) ratio values. These differences were statistically significant (p < 0.05). Furthermore, transforming flour into sourdough bread resulted in the molecular degradation of AX, significantly reducing its molecular weight and leading to a more heterogeneous fine structure. This detailed characterization of AX’s alterations during food processing provides insights into evaluating its potential health benefits in whole-grain products.