Effects of Rhizopus oligosporus-Mediated Solid-State Fermentation on the Protein Profile and -Glucosidase Inhibitory Activity of Selenium-Biofortified Soybean Tempeh

Solid-state fermentation (SSF) enhances the nutritional profile of legumes. This study evaluated Rhizopus oligosporus-mediated SSF for selenium (Se) biofortification in soybean tempeh (a traditional Southeast Asian food), assessing the effects of selenate and selenite (0–60 mg kg−1) on R. oligosporus growth, substrate consumption, mycelium morphology, and Se speciation in tempeh. Selenium supplementation at 18–24 mg kg−1 reduced soybean protein content by 9.4~13.8% relative to the protein...