Tyramine

A biogenic amine formed by microbial decarboxylation of the amino acid tyrosine. Tyramine accumulates in protein-rich fermented foods — notably aged cheeses, cured meats, fermented sausages, wines, and soy products — when decarboxylase-positive bacteria act during ripening or storage. In most people it is detoxified by monoamine oxidases, but in individuals taking MAO-inhibitor antidepressants, tyramine can trigger dangerous hypertensive crises, the classic ‘cheese effect‘. High tyramine levels also signal poor hygienic quality or excessive proteolysis. Controlling starter cultures, raw-material quality, and ripening conditions limits its formation, and tyramine analysis serves as a chemical marker of fermentation control.