Description
Koji fermentation converts starches and proteins into sugars and amino acids, while lipases release fatty acids that enrich flavor.
Technical
The filamentous fungus Aspergillus oryzae secretes α‑amylase, which hydrolyzes starch to maltose, and proteases that break down soy protein into free amino acids, enhancing umami. Concurrently, lipases cleave triglycerides into fatty acids, contributing to complex aroma and taste profiles. The process is highly temperature- and moisture-sensitive, with optimal ranges of 30–35 °C and 70–80 % RH for enzymatic activity; deviations can lead to contamination or enzyme denaturation.
Science
Primary Reaction
Hydrolysis of starch to maltose by α‑amylase; proteolysis of soy protein to free amino acids; lipolysis of triglycerides to fatty acids.
Sensory Profile
Aroma ()