Fermented plant-based foods: Insights and emerging trends

Plant-based foods (PBFs) often contain antinutritional factors that can reduce the digestibility and bioaccessibility of nutrients, along with off-flavor precursors that may affect product quality and consumer acceptance. Fermentation has been employed to enhance the nutritional, sensory, functional, as well as safety-related qualities of these foods, drawing renewed interest as part of sustainable food systems. This review examines fermentation as a substrate-engineering strategy for PBFs, with a focus on cereals, legumes, fruits, vegetables, and plant-based dairy analogs. The complementary metabolic roles of lactic acid bacteria, yeasts, and filamentous fungi are discussed in relation to acidification, proteolysis, aroma production, texture development, and formation of fermentation-derived metabolites and microbial cellular components. Key fermentation-driven changes, including phytate degradation, peptide release, phenolic biotransformation, exopolysaccharide synthesis, and modulation of volatile organic compound profiles, are integrated in major product categories. Recent advances in controlled starter culture design, mixed-cultures, omics and artificial intelligence-guided process optimization, and digital monitoring are evaluated as tools for improving reproducibility and product-specific quality properties. Several studies suggest that the outcomes of fermentation are substrate-, strain-, and process-dependent, and should be evaluated using specific biochemical and translational criteria. Critical research needs in microbial ecology control, structure-function relationships, sensory evaluation, and evidence supporting health-related claims are identified to advance next-generation fermented PBFs.