Considering sourdough from a biochemical, organoleptic, and nutritional perspective

Sourdough is made from water and cereals fermented by yeasts and lactobacilli which has a long history in bread making. A feature of the fermentation process is the variability of the microorganisms involved which gives enhanced nutritional and structural properties to the final product. Based on the production technology, there are four types of sourdoughs, type I (traditional sourdough), type II (starter culture-initiated sourdough), type III (dried sourdough), and type IV (mixed dried). Sourdough is a complex ecosystem using yeast and lactic acid bacteria that have a positive impact on the technological and nutritional properties of the final baked product. Lactic acid bacteria increase proteolysis and hydrolyze flour biopolymers (gluten and starch), thereby improving the texture and increasing the shelf-life of bakery products. As with all bread, yeast improves the loaf volume and aroma of the products by producing CO2 and ethanol. In addition, sourdough microorganisms synthesize bioactive compounds and some vitamins as well as increasing mineral bioavailability that can offer nutritional advantages compared to other bread products. This paper reviews published descriptions of the types of sourdoughs, the range of cereals, and the diverse microorganisms, and probiotic species found in products prepared in a wide range of countries.