Fermented Legumes as a Clean-Label Strategy for Shelf-Life Extension of Flatbread Under Modified Atmosphere Packaging: A Pilot-Scale Validation

This study investigated fermentation-mediated antifungal activity across different legume matrices and their potential for extending the shelf life of legume-based bakery products. Chickpea, lentil, pea, and grass pea flours were fermented using selected lactic acid bacteria and yeasts. Water/salt-soluble fractions from fermented doughs were screened against bakery spoilage fungi, revealing marked substrate- and starter-dependent antifungal activity. The most promising formulations were incorporated into focaccia-type flatbreads and evaluated for 60 days under CO2/N2 modified atmosphere packaging at pilot scale. Compared with their non-fermented counterparts, grass pea fermented with Levilactobacillus brevis AM7 maintained mold populations below the detection limit (<2 Log CFU g−1) throughout storage, with visible mold detected in 5% of packages at day 60. Pea fermented with Lactiplantibacillus plantarum 1A7 maintained mold populations below the detection limit up to day 45, with approximately 3% of packages showing visible mold at day 60. These two formulations showed the strongest antifungal performance among the fermented legume formulations, approaching the protection provided by the calcium propionate-containing wheat control, which showed the highest level of fungal protection. Fermentation partially mitigated the increase in hardness throughout storage, particularly in grass pea-based flatbreads. Overall, the findings highlight the importance of substrate–starter combinations in determining the antifungal performance of fermented legume ingredients and demonstrate their potential, when combined with modified atmosphere packaging, to improve the microbiological stability and shelf-life performance of selected legume-based flatbreads.