Celiac.com 09/24/2018 - A team of researchers recently set out to investigate the degradation of gluten in rye sourdough products by means of a proline-specific peptidase.
The research team included Theresa Walter, Herbert Wieser, and Peter Koehler, with the Deutsche Forschungsanstalt für Lebensmittelchemie, Leibniz Institut in Freising, Germany.
Interestingly, they did find that Aspergillus niger prolyl endopeptidase (AN-PEP) extensively degraded gluten concentrations of up to 80,000 mg/kg in rye flour, rye sourdough, and sourdough starter under specific temperatures and pH values. Nor did the enzyme inactivate the microorganisms in the sourdough starter.
Gluten-free rye flour alone or in combination with sourdough starter was used to produce gluten-free bread, which the team then assessed for its sensory characteristics.
Whereas gluten-free sourdough bread lacked any of the favorable qualities of conventional rye bread, the replacement of sourdough by egg proteins yielded gluten-free bread comparable to the conventional rye, and with better qualities than bread made with naturally gluten-free ingredients.
This study demonstrates the feasibility of using ANPEP treatment to produce high-quality gluten-free sourdough bread from originally gluten-containing cereals, such as rye.
Rye products rendered gluten-free in this manner have the potential to increase the choice of high-quality foods for celiac patients.