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

Area of Science:

• Food Science
• Biochemistry
• Materials Science

Background:

• Arabinoxylan (AX) significantly influences wheat dough and bread characteristics.
• The behavior of water-unextractable AX (WU-AX) during breadmaking remains incompletely understood.
• WU-AX plays a crucial role in determining the rheological properties of dough.

Purpose of the Study:

• To investigate the transformation of WU-AX during breadmaking.
• To understand the role of alkali treatment in solubilizing WU-AX.
• To elucidate the relationship between WU-AX changes and bread quality.

Main Methods:

• Wheat flour was treated with varying concentrations of sodium hydroxide (NaOH) to produce alkali-solubilized AX (AS-AX).
• The ratio of AS-AX to total AX was determined at different NaOH concentrations.
• Changes in AS-AX ratio and ferulic acid release were analyzed during breadmaking stages (flour to proof).

Main Results:

• Higher NaOH concentrations (up to 2.0 M) increased the AS-AX ratio, exceeding 80%.
• Ferulic acid release increased with NaOH concentration, plateauing at 0.5 M.
• During proofing, the AS-AX ratio decreased from 46.0% to 30.5%, indicating WU-AX conversion to WE-AX via ferulic acid bond cleavage.
• Low molecular weight AS-AX solubilized more readily and converted preferentially to WE-AX.

Conclusions:

• Alkali treatment effectively solubilizes WU-AX, with higher NaOH concentrations yielding greater solubilization.
• The conversion of WU-AX to WE-AX during breadmaking is mediated by the cleavage of ferulic acid-dependent bonds.
• Understanding these dynamic WU-AX transformations offers potential for optimizing dough properties and enhancing bread quality.