The purpose of the diploma work is to study the production of traditional sourdough and characteristics of bread prepared with sourdough through a literature review. Traditional sourdough is a mixture of water and flour, fermented by microorganisms introduced by raw materials and house microbiota. Heterofermentative lactic acid bacteria that produce mainly organic acids, ethanol, and CO2 dominate in traditional sourdough. Homofermentative lactic acid bacteria and yeasts are much less present in traditional sourdough. The ratio of microorganisms depends on several factors. Some of them are pH, temperature, raw materials used, presence of oxygen, house microbiota, backslopping and microbial interactions. Single parameter change can destabilise sourdough microbiota. With different combinations of factors, we can achieve the desired characteristics of traditional sourdough and the final product. Production of sourdough bread takes longer than conventional bread production, mainly because of the longer fermentation. During this time, the association of lactic acid bacteria and yeasts correspondingly increases the volume of baked goods and provides a characteristic aroma. Changes of gluten fraction, slowed starch retrogradation, exopolysaccharide formation and prolonged shelf life are important technological characteristic that improve the final product made with addition of sourdough. Characteristic sensory properties are the result of formation of aromatic compounds during traditional sourdough preparation, dough fermentation and baking. Partial degradation of starch, gluten and phytates are part of changes that improve digestibility and nutritional properties of bakery products with the addition of traditional sourdough.
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