Effect of Rye Bran Particles on Structure Formation Properties of Rye Dough and Bread

Rye possesses higher nutritional value compared to wheat; and has recently gained increasing attention. However, rye is still a challenging matrix regarding structure characterization and processing. The effects of different concentrations (0.0–20.0%) and sizes (125–250 and 355–500 µm) of added rye bran particles, as well as processing methods on dough formation and bread structure were investigated. Rheological studies on dough showed decrease of loss factor by 11.0% whereas the complex shear modulus increased by 114.0%. Baking tests showed volume reduction as well as increased crumb hardness by bran addition. Xylanase addition and bran particles up to 15.0% showed similar rheological and baking performance like rye without bran and xylanase. These findings highlight the importance of arabinoxylans as main structure-forming component of rye dough and their influence on mechanical properties. Practical Applications: With increasing demand worldwide to nutritious and alternative bread tastes, rye bran represents a natural ingredient with high content in fiber. In contrast to traditional rye bread, the enhancement of rye flour with bran increases water absorption which influences shelf life positively in addition to nutritional enrichments. However, due to poor structure formation based on the molecular structure of the rye proteins and the increased amount of the polysaccharide arabinoxylan, rye dough is still a challenging matrix regarding structure characterization and processing. The addition of further ingredients such as rye bran makes the way of processing even more difficult. In this paper, the way of rye bread production enriched with bran is investigated. The paper demonstrates impressively the role of mechanical treatment of bran as well the role of enzymes to minimize the influence of bran on final dough and bread structure.