Abstract
Microbial fermentation plays a crucial role in enhancing the functional and sensory qualities of soybean-based products. This review summarizes the biotransformation of proteins, phenolics, lipids, and other substrates during fermentation and the associated improvements in antioxidant, antihypertensive, antimicrobial, and antidiabetic activities. The potential mechanisms of action are discussed with reference to representative fermentation-derived metabolites. In addition, the effects of fermentation on flavor modulation are reviewed, including the reduction of bitterness and enhancement of umami perception, highlighting the contribution of amino acids and small peptides to overall sensory improvement. Future research should focus on elucidating the mechanistic links between fermentation-derived compounds and functional properties through strain improvement and multi-omics approaches, thereby providing a scientific foundation for the development of value-added fermented soybean products.