PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine) is a heterocyclic aromatic amine belonging to a class of mutagens found in food. This project studied the effects of commercially available flavours of spices on the formation of PhIP, one of the most common heterocyclic aromatic amines in heated meat and fish products. The model reactions were carried out in diethylene glycol. Highest amounts of PhIP were obtained at 200 degrees C, a heating time of 60 min and an equivalent molar ratio of phenylalanine and creatinine. With this model system, the influence of Monascus red and flavours extracted from thyme, marjoram and rosemary on the formation of PhIP was tested. The flavours were added to the model system in different amounts. The oxidative properties were determined with the rancimat method. It was shown that all tested products, independent of their pro- or antioxidative properties, increased PhIP in the model system.