Effect of germinated and non-germinated soybean flour on quality of Barbari bread

Soy has long been a great source of high quality vegetable proteins rich in lysine amino acid, which the most cereals are deficient, is known. The nutritional value of soybean increases by germination, because as the result of sprouting stage, plant enzymes are activated and in consequence of enzyme activation its anti nutritional factors are diminished and digestibility of proteins and carbohydrates is increased. The aim of this study is increasing the nutritional value of bread while maintaining or even improving its quality using germinated soy flour.

In this study, effect of adding germinated and non-germinated soy flour at concentration of % 10 (based on flour weight) on dough properties and barbari bread quality was studied. After bread making; moisture content, symmetry index, dough properties such as: water absorption, dough development time, stability time, degree of softening and quality number were measured by a Farinograph.

The results of this study showed that adding germinated and non germinated soybean flour to bread formulation have not adverse effect on bread quality properties and even in some of its characteristics were improved. Moisture content analysis results showed that bread crumb including germinated soy flour had the most moisture content and it was significant different from bread including non germinated soy flour and control bread (P>0.05). According to symmetry index there was no significant difference between control bread and bread including non germinated soy flour (P>0.05), and bread sample having non-germinated soy had the most symmetry index. Moreover, based on Farinograph results, both bread samples containing soy flour were better than control sample except for stability time factor which significant difference was not seen between control bread and germinated soy bread. By addition of germinated and non germinated soy flour to bread formulation, the microstructure of bread samples improved in comparison with control bread. According to sensory evaluation, there was no significant difference among samples except for color value. The bread sample containing germinated was significantly lower than the control bread and bread including germinated soy flour based on color value.

Totally , according to quality properties such as moisture content of dough and bread and symmetry index, bread including germinated soy was superior than non-germinated soy but based on dough stability, bread color and microstructure, the bread containing non-germinated was enhanced. According to these findings, adding soy flour to the bread formulation, specially for non-germinated soy flour can be used as an inexpensive way to improve the nutritional quality of the community.