What You Need to Know
The salt and acidity of miso draw out surface moisture and lower pH, activating proteolytic enzymes such as subtilisin from Aspergillus oryzae that hydrolyze muscle proteins into peptides and amino acids. During smoking, phenolic compounds from wood smoke react with these amino acids and sugars, initiating Maillard reactions that produce brown pigments, pyrazines, furans, and complex aromas.
The Science
Primary Reaction
Proteolytic hydrolysis of fish muscle proteins by miso enzymes and Maillard reaction between miso-derived amino acids/sugars and wood smoke phenolics