Investigation on improvement of quantitative and qualitative properties of toast bread by sourdough containing kombucha beverage and soybean milk and Lactobacillus fermentum and Lactobacillus plantarum

One of the practical and inexpensive solutions in improving the characteristics of the bakery and reducing the waste of this category of products is to use sourdough. Therefore, in this study, the possiblity to use kombucha beverage and soybean milk as a water substitute in sourdough formulations prepared from Lactobacillus fermentum and Lactobacillus plantarum separately and to evaluate the physicochemical and sensory properties of toast samples prepared from this Sourdoughs were examined. The results showed that by adding sourdough prepared from kombucha beverage and soybean milk, the moisture content and acidity of the final product increased and the pH decreased. On the other hand, Lactobacillus fermentum was more effective than Lactobacillus plantarum in reducing pH and increasing acidity. In addition, after examining the amount of lactic acid and acetic acid in the product, it was found that the amount of lactic acid in samples prepared from sourdough containing kombucha beverage and kombucha beverage was maximum while the amount of more acetic acid in samples prepared from sourdough containing kombucha beverage and Lactobacillus fermentum was higher. Samples containing kombucha beverage had the lowest amount of firmness and the highest amount of specific volume and porosity, and the type of primer used in the sourdough had no effect on the amount of these parameters. On the other hand, the study of the crust color values showed that by adding kombucha beverage and soybean milk in sourdough formulation, the amount of L* and a* values was decreased and increased respectively. Finally, sensory evaluators gave the highest score to two samples of sourdough containing kombucha beverage in the presence of both Lactobacillus plantarum and Lactobacillus fermentum. Therefore, these compounds can be used to produce sourdough with better performance properties.