What You Need to Know
During fermentation, Aspergillus oryzae secretes amylases that convert starches into sugars and proteases that hydrolyze proteins into peptides and free amino acids, notably glutamic acid, which imparts umami. Lactic acid bacteria further lower the pH to 4.5–5.5, suppressing spoilage organisms and stabilizing the product. Salt concentrations of 8–12 % NaCl control microbial growth while preserving flavor.
The Science
Primary Reaction
Hydrolysis of starches and proteins by Aspergillus oryzae enzymes, followed by lactic acid fermentation