What You Need to Know
During fermentation, Aspergillus oryzae secretes proteases and amylases that hydrolyze soy proteins into peptides and free amino acids and starches into sugars. Lactic acid bacteria convert sugars into lactic acid, lowering the pH to 4.5–5.0 and inhibiting spoilage microbes while enhancing umami flavor. Salt concentration and temperature control the growth of halotolerant molds and bacteria, shaping the final taste and texture.
The Science
Primary Reaction
Proteolytic hydrolysis of soy proteins by Aspergillus oryzae and lactic acid bacteria, coupled with amylolysis of starches, producing peptides, amino acids, and lactic acid