Description
Oncom is a Southeast Asian fermented soy product produced by inoculating cooked soybeans with a mold starter and fermenting at 30–35 °C for 24–48 h.
Technical
The mold Aspergillus secretes proteases and amylases that hydrolyze proteins and starches into peptides, amino acids, and sugars. Lactic acid bacteria further metabolize these sugars, producing lactic and acetic acids that lower the pH and generate flavor compounds such as 2‑ethyl‑4‑methyl‑5‑methylthiazole. The resulting acidic, enzyme‑rich matrix yields a characteristic nutty, earthy aroma and a firm yet slightly rubbery texture.
Science
Primary Reaction
Proteolysis and amylolysis by mold enzymes followed by lactic acid fermentation
Sensory Profile
Aroma ()
earthynuttyslightly sourmoldyfermentedmustywoodymushroom-liketoasted