The use of novel yeast strains in mixed starters containing lactic acid bacteria (LAB) could contribute to the creation of innovative breads with unique aromatic characteristics. Two yeast strains isolated from natural sourdoughs and one LAB strain were used as inocula to prepare Type III wheat flour sourdoughs and were maintained through back-slopping. The fermentation dynamics and microbial diversity of these sourdoughs were studied. The volatile organic compounds (VOCs) in the sourdoughs and the breads made with them were identified using GC-MS analysis.
Saccharomyces cerevisiae was predominant in the inoculated sourdoughs, whereas the yeast Wickerhamomyces anomalus dominated in the spontaneous sourdough. Levilactobacillus brevis and Lactiplantibacillus plantarum were consistently found across all sourdoughs, with abundance ranging from 12% to 55%. A significant positive correlation was found between the presence of S. cerevisiae, L. brevis, and L. plantarum and the production of certain ethyl esters and alcohols, which accounted for 60% of the total VOCs. The Weissella cibaria strain BAL3C5B2 included in the inoculum was not the dominant LAB during successive refreshments (20% of the LAB population). Overall, the results highlight the strong fermentation performance of the newly developed mixed starter, along with its distinctive VOCs, underscoring the innovative potential of Type III sourdoughs.