What You Need to Know
During fermentation, Bacillus spp. proteases hydrolyze storage proteins into peptides and amino acids, lowering the pH from ~6.5 to 4.5–5.0. Lactic acid bacteria and yeasts decarboxylate amino acids to produce volatile amines such as cadaverine and putrescine, while sulfur compounds arise from cysteine degradation. The resulting flavor profile is a complex mixture of peptides, amines, and sulfur volatiles that define the characteristic pungency of iru.
The Science
Primary Reaction
Proteolytic hydrolysis of storage proteins and amino acid decarboxylation