Sourdough bread
“Sourdough” is one of the oldest forms of cereal fermentation utilized primarily for baking purposes. It is the result of the fermentation of flour from cereals and pseudocereals or legumes, among others, by the action of the microorganisms present in the preparation. Some sourdoughs can also incorporate added microorganisms.
Sourdough is the oldest form of leavened bread used as early as 2000 BC by the ancient Egyptians.
Sourdough breads are produced when a sourdough starter is combined with flour and water to make dough. This sourdough starter contains lactobacilli bacteria that feed on the flour, producing gases that get trapped in the flour-water mixture and cause the bread to rise.
Most lactic acid bacteria (LAB) isolated from sourdough belong to the genus Lactobacillus, but species of Pediococcus, Leuconostoc and Enterococcus are occasionally found or used.
LAB produce a number of metabolites such as organic (lactic and acetic acid), exopolysaccharides (EPS), anti-microbial substances (i.e., bacteriocins) and a variety of species specific enzymes (i.e., α-amylase, pectinase, phytase, etc.) that have been shown to impart beneficial effects on the texture, nutritive values, and staling of bread.in sourdough processes.
Sourdough provides multiple benefits to the quality of the products:
*Extending of the life of the bakery products due to the lowering of pH, which induces the inhibition of microbial development, and to the decomposition of starch during lactic acid fermentation, resulting in staling delay.
*Products with greater aroma and sweetness, due to the hydrolysis processes and the compounds generated in the Maillard reaction during the baking process.
Sourdough bread