What You Need to Know
During fermentation, Aspergillus oryzae secretes amylases, proteases, and β‑glucosidases that hydrolyze starches and proteins into free amino acids—especially glutamic acid—and short peptides. The resulting organic acids lower the pH from ~6.5 to 5.5, enhancing flavor while inhibiting unwanted microbes. Precise control of temperature, moisture, and aeration is essential to maximize enzyme activity and prevent spoilage.
The Science
Primary Reaction
Enzymatic hydrolysis of plant starches and proteins by Aspergillus oryzae-derived amylases, proteases, and β‑glucosidases, producing free amino acids and peptides.