Metodi analitici per la caratterizzazione e la valutazone della sicurezza alimentare di prodotti tradizionali della filiera lattiero-casearia ovina della Sardegna

Biogenic amines (BA) are compounds formed in fresh and fermented food. Cheese provide a good substrate for the production of BA. In this study a RP-HPLC method was developed, optimized and validated to determine eight BA (tryptamine, 2phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine and spermine) in a traditional PDO sheep cheese: Fiore Sardo. The method was validated in terms of LOD, LOQ, linearity, precision and accuracy. The method was used to analyse 36 samples of Fiore Sardo, purchased by four different Italian market chains. The chemical-physical characterization and the study of proteolysis, lipolysis and volatile profile of cheese samples was also performed. The results revealed that seven BA are almost always quantified. Only the spermine was found always less than its LOD. The average concentration of total BA in Fiore Sardo is 630mg/kg; a very wide range of variability (80÷1222mg/kg) for this parameter was observed. The most abundant BA are Tyr and Put, that represent 79% of total BA. The PCA analysis among the content of either BA, macroanalytes, volatile fraction, lipolytic and proteolytic indexes substantiates the correlation between BA and pH, but not support any positive correlation between BA and proteolytic indexes, because of proteolysis is not the most meaningful ripening way in this cheese. Lastly, the overall amount of BA in Fiore Sardo is quite high, but well within the range elsewhere reported for other cheeses from raw milk.