Prolamin hydrolysis in wheat sourdoughs with differing proteolytic activities

Area of Science:

• Food Science
• Biochemistry
• Cereal Chemistry

Background:

• Wheat, rye, and barley prolamins pose health risks to gluten-sensitive individuals.
• Food processing can degrade prolamins, potentially mitigating health risks.
• Sourdough fermentation is a known process involving cereal protein degradation.

Purpose of the Study:

• To compare prolamin hydrolysis in high-proteolytic germinated wheat sourdough (GWSD) versus standard wheat sourdoughs.
• To investigate the effectiveness of GWSD in degrading wheat prolamins (gliadins and glutenins).
• To assess the potential of using high-proteolytic sourdoughs for developing gluten-free products.

Main Methods:

• Wheat sourdoughs with varying proteolytic activities were prepared.
• Fermentation was conducted using germinated wheat sourdough (GWSD) and control sourdoughs.
• Prolamin levels in sourdoughs were quantified to assess hydrolysis.
• Cysteine proteinase activity in germinated wheat was identified as the source of hydrolysis.

Main Results:

• Virtually all wheat prolamins (gliadins and glutenins) were degraded in GWSD.
• Quantification confirmed extensive prolamin hydrolysis occurred during GWSD fermentation.
• Hydrolysis was attributed to the high cysteine proteinase activity of germinated wheat.

Conclusions:

• High-proteolytic sourdough fermentation, particularly GWSD, effectively degrades wheat prolamins.
• This method can be utilized in baking to produce low-prolamin cereal products.
• These products could enable gluten-sensitive individuals to diversify their whole-grain intake safely.