Additional of defatted soybean flour was caused enriching bread by essential amino acids, vitamin and minerals. By using sourdough in bread production, properties of dough's texture, flavor and smell will be improved, in comparison with bread made by yeast. In this research, defatted soybean flour in 3, 5 and 10 percent were mixed with wheat flour then rheological properties of dough were evaluated by Farinograph and Extensograph. After this, with adding of 25 percent of Lactobacillus Plantarum sourdough on dough, some of rheological properties were evaluated again. Farinograph results showed that increasing rate of enrichment with soybean flour, was caused increasing rate of water absorption, development time, dough stability, resistance and valorimetry number. Furthermore, Extensograph results showed that the dough with different percent of soybean flour and sourdough had less energy than in comparison with dough that having soybean along. On the other hand, the rate of ash and protein in bread that enriched by soybean flour and also mixture of soybean flour and sourdough were more than in comparison with control bread. However, the rate of ash and protein in bread with sourdough were less than without it. Finally the results of sensory evaluation showed that toast bread which contains 5% soybean flour and sourdough, has the most acceptability regarding to the other samples.
