What You Need to Know
During fermentation, Aspergillus oryzae secretes proteases that hydrolyze soybean proteins into peptides and free amino acids, especially glutamic acid, creating umami flavor. Concurrently, saccharification releases sugars that participate in Maillard reactions during drying, generating brown pigments and complex flavor compounds such as melanoidins.
The Science
Primary Reaction
Proteolysis and Maillard reaction