What You Need to Know
Proteolytic enzymes from halophilic bacteria hydrolyze fish proteins into free amino acids, especially glutamate, which imparts the characteristic umami taste. The fermentation also produces organic acids that lower the pH from ~6.5 to 5.0‑5.5, and the high salt concentration (15‑25 % NaCl) selects for desirable microbes while inhibiting spoilage organisms.
The Science
Primary Reaction
Proteolysis of fish proteins into free amino acids and peptides, followed by further breakdown into volatile flavor compounds