Presenza di amine biogene in formaggi

The aims of the research were to evaluate the presence of biogenic vasoactive amines (β-phenylethilamine, putrescine, cadaverine, histamine and tyramine) in cheeses, to isolate potential amine-producer microorganisms and to verify the capability of the isolated strains to produce these compounds in vitro (in different conditions).Tyramine was always present in the 30 cheese samples (at medium and long ripening) analysed by HPLC; putrescine in 96%; histamine, cadaverine and β-phenylethilamine in 90% of the samples. Hystamine was found with a maximum value of 142 mg/kg and tyramine of 141 mg/kg. Enterococcus faecalis and Klebsiella pneumoniae var. oxytoca (greater in vitro producers of tyramine and histamine respectively) in presence of their amino acid precursors hystidine and tyrosine, have preferentially produced tyramine. Even if such levels of amines are usual for these products and don't reach toxic values, the problem of their occurrence must not be underestimated because such compounds can be also found in other foods and their total intake could in some cases be beyond safety limits.