Studies on Developing Starter Cultures with Gluten Degrading Ability

Wheat is at the forefront of staple foods for humans. However, consumption of wheat-based products may lead to discomfort in sensitive individuals. The component responsible for this sensitivity, emerging from wheat consumption, is gluten. There is no effective treatment for individuals with gluten sensitivity. Individuals with gluten sensitivity, especially those with Celiac Disease (CD), must maintain a gluten-free diet for their lifetime. Moreover, gluten-free products, often made with starches or flours of non-cereal plants, are not preferred by consumers because of their flavor and aroma. Therefore, this study aims to develop a "new sourdough starter" that can be used in the production of bread that has the flavor of traditional wheat bread, yet contains a lower gluten ratio. With this new sourdough, bread production may not be suitable for individuals with CD but can be more easily tolerated by those with gluten sensitivity will be possible. For this purpose, Lactic Acid Bacteria (LAB) and yeasts were isolated from sourdough samples collected from local producers. These isolates were inoculated into GUA medium, which contains gluten as the sole nitrogen source, and after observing colony development in this medium, their glutendegrading abilities were determined using C.B.B. R-250 protein stain. Then, fermentative properties of LAB and yeast isolates capable of degrading gluten were identified. In addition, the antagonistic effects of these isolates/strains on each other were investigated using a coexistence test. 11 LAB, 11 yeast, and 6 stock LAB strains that can degrade gluten were selected, and none showed antagonistic effects against each other in the test. As a result, from among these 28 isolates, the top 2 LAB strains and 1 yeast isolate were selected in terms of their fermentative properties, and a new "sourdough starter" was prepared. The dough was then prepared using sourdough and, wheat flour. Initially, end of fermentation, various tests, such as fresh and dry gluten determination, pH, aw, % dry matter, TTA, leavening power, were conducted and compared with the control groups. To sum up, it has been determined that the new sourdough composition reduced the initial gluten content by 86.64% at the end of fermentation. This new sourdough composition has the potential to be used as a starter culture in the production of bread with classic wheat bread flavor and low gluten content.