What You Need to Know
During fermentation, Rhizopus oligosporus secretes proteases and amylases that hydrolyze soy proteins and residual starches into peptides, free amino acids, and sugars, while the pH drops from ~6.5 to 4.5–5.0, creating an environment that favors mold growth and suppresses spoilage bacteria. The resulting biochemical transformations yield a protein‑dense, shelf‑stable product with a characteristic nutty, umami flavor.
The Science
Primary Reaction
Thermophilic mold fermentation of soybeans, hydrolyzing proteins and starches into peptides, amino acids, and sugars