Lactic fermentation-driven matrix remodeling of Agaricus bisporus (J.E. Lange) Imbach flour modulates lipid, sugar, and antioxidant signatures in gluten-free bread.

Lactic fermentation can restructure food matrices and modulate the molecular distribution of nutrients and bioactive compounds, thereby altering their technological and functional performance in complex food systems. In this study, Agaricus bisporus flour was used as a model mushroom matrix to investigate how fermentation-drive compositional remodeling influences the physicochemical and functional properties of gluten-free bread. Native and lactic-fermented mushroom flours were incorporated into a rice-corn-tapioca system, and their effects on dough expansion, crumb structure, nutritional composition, fatty acid profile, free sugar profiles, and antioxidant signatures assessed. Fermentation markedly altered the mushroom flour matrix, leading to reduced dough gas retention and denser crumb structures, consistent with microstructural modifications affecting viscoelastic behavior. More importantly, fermentation induced clear composition shifts, including redistribution of free sugars, modulation of fatty acid profiles, and increased α-tocopherol retention, indicating microbial metabolism-mediated molecular reorganization. These changes were directly associated with enhanced antioxidant capacity in the final breads, particularly in samples enriched with fermented flour. Multivariate analysis further confirmed that fermentation status, rather than incorporation level, was the main driver of variation across compositional and functional parameters, especially those related to lipid oxidation protection, sugar metabolism, and antioxidant potential. These findings demonstrate that lactic fermentation acts as a matrix-engineering strategy capable of redefining the structure-function role of A. bisporus flour in gluten-free bread, offering mechanistic insights into how fermented fungal ingredients can be leveraged to design nutritionally enhanced and functionally optimized cereal-free products.