Characterization of the Extracellular Fructanase FruA in and Its Contribution to Fructan Hydrolysis in Breadmaking.

Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) trigger symptoms of irritable bowel syndrome (IBS). Fructan degradation during bread making reduces FODMAPs in bread while maintaining the content of dietary fiber. This study explored the presence of the fructanases FruA in lactobacilli and characterized its use in bread making. FruA was exclusively present in vertebrate-adapted lactobacilli. In DSM29598, FruA was located in cell wall fractions and includes a SLAP domain. FruA hydrolyzed levan or inulin; expression of was not subject to catabolite repression. Fructans in bread were reduced by less than 50% in a straight dough process; conventional sourdough fermentation reduced fructans in bread by 65-70%. Sourdough fermentation with reduced fructans in bread by more than 90%. In conclusion, reduction of FODMAP by sourdough fermentation may improve tolerance in many IBS patients. Fermentation with FruA-expressing DSM29598 produces a low FODMAP bread.