Evaluation of biogenic amines in some Portuguese quality wines by HPLC fluorescence detection of OPA derivatives

Biogenic amines are present in wines in relatively low quantities, when compared with other food products. The difficulty in accurately analyzing biogenic amines in wines is due to matrix interference and to the generally low quantities of the amines present. In this work data on 30 Portuguese wines, including fortified wines: Porto, Madeira, and Moscatel de Setúbal; red D.O.C. wine Dão and white D.O.C. wine Vinho Verde are presented. OPA-fluorescent derivatives of 10 amines - histamine, tyramine, β-phenylethylamine, tryptamine, putrescine, cadaverine, ethylamine, methylamine, isoamylamine, and ethanolamine - were separated by reverse phase HPLC. Advantages of the method were: low detection limit (90 μg/L average), an acceptable reproducibility (relative standard deviation was 10.4% average - minimum 3.0% for ethanolamine and maximum 21.1% for cadaverine), absence of previous laborious and less accurate extraction procedure and possibility of automation. Time of analysis (60 minutes) was sacrificed in order to obtain a better resolution between amines. Results show that amines suspected to have toxicological effects (histamine, tyramine and β-phenylethylamine) do not represent any concern, as their amounts do not generally exceed 5 mg/L. The contents of amines associated with deficient sanitary conditions (putrescine and cadaverine) are very low varying between 0.2 and 0.6 mg/L. Tryptamine was not detected and care must be taken when quantifying ethanolamine and ethylamine, as other wine compounds may co-elute with them.