Amino endogenous proteolytic enzymes

For example, intense proteolyses of muscle proteins, due to the action of endogenous proteolytic enzymes, have been reported to occur during the processing of dry-cured ham. This gives rise to the formation of free amino acids and short peptides (especially from actin through the action of cathepsin D in meat and from caseines as a result of plasmin and other proteases in cheeses) that contribute directly or indirectly to the flavour characteristics of the final product. In the case of octapeptide Lys-Gly-Asp-Glu-Glu-Ser-Leu-Ala, isolated from beef broth, this reportedly showed umami taste with a threshold value of about 500 mg/1. 

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