Poria cocos Solid-State Fermentation for Bioprocessing Tartary Buckwheat: Nutritional Enhancement, Antioxidant Activity, and Application in Steamed Bread

This study pioneered the application of Poria cocos solid-state fermentation (SSF) to Tartary buckwheat (TB). We aimed to enhance its nutritional value, antioxidant activity, and bioaccessibility through fungal biotransformation. Notably, SSF significantly increased protein (by 15.53%) and polysaccharides (by 158%) in TB, alongside a 4.87% improvement in DPPH radical scavenging capacity. Principal component analysis identified 5-day fermentation (FTB-5) as the optimal process, achieving the highest comprehensive score. Furthermore, SSF modified TB’s aroma profile (e.g., increasing 2(3H)-Furanone, 5-methyl by 352.02%) and optimized its amino acid composition, with essential amino acids rising by 12.90%. Critically, in vitro digestion confirmed a higher release rate of bioactive compounds in FTB-5 compared to raw TB. When applied to Chinese steamed bread, FTB-5 imparted a superior sensory score, with a soft texture and an appealing color. This study establishes Poria cocos SSF as a novel strategy for TB valorization, bridging traditional fungal biotechnology with functional food development.