Structural and quantitative changes in alkali-solubilized arabinoxylan throughout the breadmaking process

Arabinoxylan (AX) substantially impacts wheat dough and bread quality; however, the behavior of water-unextractable AX (WU-AX) during breadmaking is not fully understood. This study investigates WU-AX changes during breadmaking by treating it with various sodium hydroxide (NaOH) concentrations to produce alkali-solubilized AX (AS-AX). Higher NaOH concentrations (up to 2.0 M) increase the AS-AX ratio, reaching over 80 %. The release of ferulic acid also increases with NaOH concentration but plateaus at 0.5 M NaOH. Analysis with 50 mM NaOH revealed the AS-AX ratio decreased from 46.0 % in wheat flour to 30.5 % at the proof stage, indicating WU-AX conversion to water-extractable AX (WE-AX) through the cleavage of ferulic acid-mediated bonds. High and low molecular weight AS-AX exhibit different solubilization patterns; low molecular weight AX with weaker bonds solubilizes more readily and converts preferentially to WE-AX. Understanding these dynamic changes can enhance dough properties and bread quality through targeted WU-AX.