Formation of Biogenic Amines in Idiazábal Ewe's-Milk Cheese: Effect of Ripening, Pasteurization, and Starter.

The importance of biogenic amines stems from their toxicity and their potential as a cause of food poisoning. After fish, cheese has been the foodstuff most often responsible for cases of food poisoning caused by ingestion of biogenic amines. Changes in biogenic amine (histamine, tyramine, putrescine, cadaverine, tryptamine, isopentylamine, spermidine, and phenylethylamine) content during the ripening of a cheese made from raw ewe's milk were studied, together with the effects of pasteurization and a commonly used commercial starter and indigenous starter cultures. Biogenic amines were determined by high-pressure liquid chromatography following extraction from the cheese and derivatization with dansyl chloride. Levels of histamine, potentially the most toxic amine, in the semihard Idiazábal cheese were very low. Tyramine, putrescine, and cadaverine were the main amines present in this type of cheese. Levels of those amines increased during ripening. Pasteurization of the milk brought about a reduction in the biogenic amine content of the ripened cheese, irrespective of the starter culture employed. The indigenous starter cultures considered in this study produced higher levels of histamine and cadaverine and lower levels of tyramine and putrescine than the commercial starter culture tested.