Sourdough-Based Starter Cultures for Fermentation in Agri-food Industry

Sourdough-based starter cultures can be characterized by the simultaneous presence of lactic acid bacteria (LAB) and yeasts in dough and can be obtained either by spontaneous fermentation or by selecting the species. Lactobacilli species are the most common LAB species in sourdough starters and Kazachstania, Torulopsis, Pichia, Candida, Yarrowia, and Saccharomyces are the most frequent yeast genera in this microbiota. The production of exopolysaccharides and the decrease of gluten proteins, both promoted by sourdough microbiota, can contribute to a positive effect on bread texture. These microorganisms also produce bioactive compounds and organic acids, which can improve the nutritional aspects and shelf-life of products, respectively. The microorganisms from the sourdough starter can be applied in several other agri-food industries such as feed and pet food, dairy, meat, alcoholic and non-alcoholic beverages, nutraceuticals, and in other industrial sectors such as cosmetics and pharmaceuticals. For example, there are successful studies with sourdough starter cultures as biocontrol agents for agriculture and also to reduce wheat allergens. Besides, it has been reported that beer quality can be improved by the presence of this microbiota during fermentation and several food products can have a reduced glycemic index with the use of these cultures. It is also indicated as a potential biopreservative and probiotic. In addition, drying processes can be a good strategy to stabilize the sourdough starter and expand its use.