What You Need to Know
During fermentation, Aspergillus oryzae secretes proteases and amylases that hydrolyze soy proteins into free amino acids, especially glutamic acid, and starches into simple sugars. The resulting amino acids, peptides, and sugars undergo further fermentation and Maillard reactions, generating a complex umami flavor profile and characteristic aroma.
The Science
Primary Reaction
Enzymatic hydrolysis of soy proteins and starches by Aspergillus oryzae, followed by fermentation of sugars and Maillard reactions during aging