Biogenic amines formation influenced by tissue enzymes and pH value in themixture prepared for raw sausages

The purpose of this paper was to clarify the influence of tissue enzymes an d pH value in the mixture prepared for the production of raw sausages on th e formation of biogenic amines (histamine and tyramine). A meat mixture very similar in composition to the typical fermented sausage (40% of beef, 40% of pork and 20% of pork fat tissue) was prepared and div ided in to three parts. The pH value of these portions was adjusted to 5,5; 6,0 and 7.0 through the addition of acetic acid, water and sodium hydrocar bonate solution, respectively. The samples were then radiodecontaminated (5 kGy) to exclude the possible influence of native microflora and stored at 18-22(0) C. The histamine and tyramine contents were determined immidiately and on the 0th, 5th, 10th and 15th days of storage. The obtained results showed that the initial contents of biogenic amines in the fresh meat mixtures were low.- 1,05- 1,16 mu g of histamine and 1,82-2 ,04 mu g of tyramine per gram of mixture. The final contents of these two b iogenic amines, created after storing under conditions similar to the norma l processing conditions in the production of this type of fermented sausage s (two weeks at 18-220 C) also were low and unimportant for the hygienic sa fety of sausages (1,64-1,88 mu g of histamine and 2,26-2.94 mu g of tyramin e per gram of the mixture). From the results presented the general conclusion could be drawn that enzym atic activity of the meat itself does not contribute very much to the total biogenic amines formed in the fermented sausages. However, comparison of t he relative biogenic amine contents in the three groups of samples revealed that pH value of the meat exerts great influence on the intensity of amino acids decarboxylation and on the activity of enzymes which catalyse the fo rmation of biogenic amines.