Impact of using the developed starter culture on the quality of sourdough, dough and wheat bread

There is no technological necessity of sourdough usage when preparing wheat bread as it can be prepared without sourdough but only with yeast using. However, sourdough helps to solve such problems as fast microbial spoilage, unexpressed taste and smell, crumbling crumb. The use of sourdough prepared with directional cultivation of microorganisms allows to produce high-quality competitive bread. Developing a starter culture with an optimized microbial composition was the purpose of this study, allowing the quality and the microbiological stability of wheat bread improving. A new starter microbial composition for the sourdough was developed. Lactic acid bacteria strains L. plantarum Е90, L. brevis Е120 and yeast S. cerevisiae Y139 were selected for the new composition. It was proven that the rice products using to microorganism immobilization allows saving the largest number of living cells after drying and during storage. The rate of acid accumulation in sourdough was established. The sourdough dynamic viscosity decrease at the end of fermentation by 2.2 times was established, which means that the fermentation process leads to the sourdough liquefactio. The optimal dosage was established (5–10% flour in sourdough). This dosage provided good physico-chemical and organoleptic quality indicators of bread. It was proved that the sourdough usage allows getting good-quality bread even when the flour with unsatisfactory amylolytic activity (high drop number) is used. Slowing down the microbial spoilage in sourdough bread was proven. In general, the developed sourdough wheat bread biotechnology improves bread quality and its resistance to the ropy-bread disease.