CONTAMINANT LACTIC-ACID BACTERIA OF DRY SAUSAGES PRODUCE HISTAMINE AND TYRAMINE

Exogenous biogenic amines present a food poisoning hazard in fermented foods especially with additional risk factors, e.g. amine oxidase inhibiting drugs, alcohol and gastrointestinal diseases. Forty-two lactic acid bacteria (LAB) strains were isolated from seven dry sausages during ripening (0 day, 21 day and 49 day). Their ability to produce histamine and tyramine was studied by HPLC detection from broth cultures after 2 days incubation. The tyramine and histamine concentrations in sausages increased during fermentation. 10 of 42 LAB strains produced 402-1087 ppm tyramine. Four of these 10 contaminant LABs were also histamine-positive (725-1083 ppm). Most of the amine positive strains were found in sausages at the end of ripening and with highest amine levels. On the basis of these results the contaminant LABs play an important role in tyramine and histamine formation during the ripening of dry sausages. Therefore it could be possible to decrease the levels of amines formed by limiting the initial level and growth of these contaminant bacteria.