Impact of inhibition sensitivity on endoxylanase functionality in wheat flour breadmaking

Area of Science:

• Food Science
• Enzymology
• Baking Technology

Background:

• Endoxylanases are crucial enzymes in baking, affecting dough properties and bread quality.
• Sensitivity to endoxylanase inhibitors can influence enzyme functionality during breadmaking.

Purpose of the Study:

• To investigate the impact of endoxylanase inhibition sensitivity on breadmaking performance.
• To compare the functionality of an inhibited endoxylanase (XBS(i)) and a non-inhibited mutant (XBS(ni)) in straight-dough breadmaking.

Main Methods:

• Utilized two Bacillus subtilis endoxylanases (XBS(i) and XBS(ni)) with differing sensitivities to Triticum aestivum L. endoxylanase inhibitor (TAXI).
• Assessed bread loaf volume, arabinoxylan (AX) hydrolysis, and enzyme activity over different breadmaking stages (mixing, fermentation, baking).
• Analyzed water-unextractable arabinoxylan (WU-AX) and water-extractable arabinoxylan (AX) degradation.

Main Results:

• The non-inhibited XBS(ni) significantly improved loaf volume at lower dosages compared to XBS(i).
• XBS(ni) demonstrated greater solubilization of WU-AX and more extensive degradation of solubilized and water-extractable AX during fermentation and baking.
• While XBS(i) primarily acted during mixing due to inhibition, XBS(ni) maintained activity throughout the process.

Conclusions:

• Endoxylanase inhibition sensitivity is critical for enzyme functionality in breadmaking.
• Enzymes that remain active despite in vitro inhibition show enhanced bread-improving effects.
• Enzyme activity gradually diminishes during the breadmaking process, even for non-inhibited variants.