Description
Koji fermentation uses Aspergillus oryzae to convert starches and proteins in non‑soy substrates into sugars and amino acids.
Technical
The process relies on controlled growth of A. oryzae at 30 °C ± 2 °C and 85‑95 % RH, with a substrate moisture of 40‑55 %. Peak α‑amylase (150‑200 U g⁻¹) and neutral protease (30‑45 U g⁻¹) activities occur when the pH drops to 5.5‑6.0 after 12‑18 h. Deviations in temperature or humidity favor spoilage organisms or mycotoxin precursors, while proper pre‑gelatinization and cooling preserve enzyme activity.
Science
Primary Reaction
Hydrolysis of starches and proteins by α‑amylase and proteases producing glucose, amino acids, and dipeptides
Sensory Profile
Aroma ()
earthynuttyumamisweetmild
Origin & History
Civilization
Japanese
Era