Emerging fermentation technologies: development of novel sourdoughs.

The increasing knowledge of sourdough fermentation generates new opportunities for its use in the bakery field. New fermentation technologies emerged through in depth sourdough research. Dextrans are extracellular bacterial polysaccharides produced mainly by lactic acid bacteria (LAB). These bacteria convert sucrose thanks to an inducible enzyme called dextransucrase into dextran and fructose. The structure of dextran depends on the producing micro-organism and on culture conditions. Depending on its structure, dextran has specific properties which lead to several industrial applications in different domains. The use of dextran is not widely spread in the bakery field even if its impact on bread volume and texture was shown. A new process has been developed to obtain a sourdough rich in dextran using a specific LAB strain able to produce a sufficient amount of HMW dextran assuring a significant impact on bread volume. The sourdough obtained permits to improve freshness, crumb structure, mouthfeel and softness of all kinds of baked good from wheat rich dough products to rye sourdough breads. From fundamental research on dextran technology, a new fermentation process has been developed to produce an innovative functional ingredient for bakery industry.