Preparation of type III sourdough powders by different drying methods and their usage on white bread

The aims of this study are to produce sourdough powders from traditional sourdough and to evaluate the potential use of different type of sourdough powders in the bread making industry. Firstly, five different drying technique used for obtaining sourdough powder and chemical and microbial characteristics of obtained powders were investigated. Since spray-drying and freeze-drying are commonly used drying techniques for Type III sourdough production, their addition to bread was evaluated. Also, the effect of different levels of sourdough powders (3%, 6%, 9% and 15% w/w) on dough properties and bread quality was studied. Although the drying processes caused a decrease in microflora, the counts of microflora did not fall below the general accepted 5-7 log CFU/g level for reproduction of starters. Water absorption and dough development time were not significantly affected by sourdough powder (SP) addition (p>0,05). While dough stability and farinograph quality number significantly decreased, the degree of softening was increased with an increase in sourdough powders level. According to values of G*, the addition of SP at high levels strengthened the dough structure. However, the addition of 3% level of SP resulted in the less elastic dough. Addition of SP caused a reduction in volume and specific volume of breads with increasing level of powder. All bread sample had a higher value of hardness than control. However, using the high level of SP showed a positive effect on the value of the degree of staling. According to the result of the sensory evaluation, crust, crumb color, taste, softness and overall acceptance were not affected by the addition of SP. The results showed that sourdough powder had the effect like chemical acidifier on dough and bread structure.