New bread formulation with improved rheological properties and longer shelf-life by the combined use of transglutaminase and sourdough

The combined use of the protein reticulating enzyme transglutaminase (TGase) and a selected microbial consortium of Lactobacillus sanfranciscensis and Candida milleri for improving the rheological properties, aroma, and shelf-life of a bakery product was evaluated. A microbial TGase, showing the highest activity over a wide temperature range on different protein substrates, was selected among different types. Results showed that this TGase was able to produce isodipeptide bonds, especially in the gluten fraction, leading to the formation of protein aggregates, which improved the structure of a sourdough bakery product. The microbial TGase in combination with sourdough exhibited a positive synergistic effect allowing the production of flavor-enriched bread, with rheological properties similar to those of standard bread.