Monatsschrift für Brauwissenschaft vol:56 issue:3-4 pages:58-63
Biogenic amines are biomolecules synthesized by eukaryotic and prokaryotic cells that can affect human health. Histamine and tyramine are the most important and can cause important troubles like headache and severe forms of allergy. Secondary biogenic amines can also be involved in the synthesis of nitrosamines in the stomach. In beer, the presence of biogenic amines is mainly due to the activity of contaminants that develop during fermentation but their synthesis was detected during malting too. The microorganisms involved are the Enterobacteria sp., possibly active at the early stage of the fermentation, and many lactic acid bacteria. Some strains of S. cerevisiae produce different biogenic amines, putrescine, spermidine and spermine mainly. Some speciality beers such as sour beers and beers produced by mixed cultures are characterized by a constitutive presence of biogenic amines due to the metabolism of the typical microflora involved. This paper demonstrates that it is possible to reduce the level of the biogenic amines significantly (up to 95 %) in speciality beers by keeping the process as traditional as possible. Mainly by assembling the freshly cooled wort with old beer containing lactic acid bacteria characterised by their lack of aminoacid decarboxylase activity.