Development of high-fiber wheat bread using pre-saturated corn bran

Pre-hydration of fiber ingredients was used to reduce their negative effect on quality of the enriched bread. To investigate the mechanism, corn bran was pre-hydrated to different levels of water activity (a_w), ranging from 0.9875 to 0.9990, and incorporated into bread by replacing 20 % white flour in a white bread formula. The results showed pre-saturated (a_w = 0.9976) corn bran resulted in the best microstructural and textural properties of the enriched bread, including a largest specific loaf volume, lowest hardness, and highest springiness and cohesiveness of the crumb, which were closest to those of the control white bread, whereas pre-hydration levels lower or higher than saturation had more negative impacts on the final quality of bread. The underlying reason was that saturated bran was non-absorbent. Therefore, it had no interference with water that was essential for the development of a strong gluten network responsible for high quality bread.