Effect Of The Addition Of Dietary Fiber On Dough Performance And Bread Quality

Dietary fibre is the food ingredient that is not enzymatically degraded within the human alimentary digestive tract, which is proved a good correlation in preventing and assistant therapy colonic cancer, fat, diabetes and other chronic diseases. The present work investigates the effect of some potential use of various commercial fibres (soy fibre, sweet potato fibre, apple fibre and oat fibre) on the rheological properties of wheat flour dough and the final quality of breads. The following results were achieved.1. The result of rheological properties by using the Brabender Farinograph and Extenograph showed that, water absorption and stability time increased as the amount of dietary fibre increased, and the addition of dietary fibre enhanced the degree of dough. Apple fibre was the most prominence thereinto, while except the soy fibre, the development time and degree of softening decreased as the amount of dietary fibre increased. From the studies of extensographic, the result showed that energy and extensibility decreased as the mount of dietary fibre increased except the oat fibre, While the degree of resistance increased.2. From the studies of the properties of dough during the fermentation, the influence of fibre additions on the fermentation characteristics showed that dough with dietary fibre could make more gas during the middle of fermentation (60-120min), but this trend could not keep to the terminal. Dietary fibre addition interfere with the cross link of dough, at the same time, weaken the holding-gas capability of dough, which make the dough volume became small, especially when the amount was more than 7%. But the speed of dough increase was not influenced.3. The result of texture properties of dough and bread by using the TA-XT2i texturometer showed that, although the addition of dietary fibre increased the hardness of dough before the ferment, with the ferment progress, this effect became not evident. During this process, the Adhesiveness of dough decreased as the mount of dietary fibre. Low levels of dietary fibre caused slightly decreases in total sensory scores, and slightly effects in hardness, springiness, chewiness and resilience of breads.4. In breadmaking, dietary fibre breads had similar or slightly smaller specific volumes than the control breads, when the addition at level of 4%. The differences among the crust color of control and dietary fibre breads were significant when the addition were higher than 4% and increasing levels of fibre caused serious decreases in both sensory and texture. Regarding the effect on bread store properties, the fibre be added at level of 4% can enhance the shelf life.