Formation and stability of heterocyclic amines in a meat flavour model system. Effect of temperature, time and precursors.

A model system based on a commercial meat flavour was used to evaluate the formation of heterocyclic amines, simulating the application of this seasoning in household cooking. The effects of different treatments in both dry and aqueous conditions were studied. The lyophilized meat flavour extract was heated at temperatures ranging between 100 and 200 degrees C for times ranging from 10 min to 2 h. Similarly, an aqueous suspension of the extract was heated at 175 degrees C for 1, 2 and 3 h. Precursors of HAs, such as creatinine, glucose, and the amino acids glycine, alanine and phenylalanine were added to the meat extract and their effect was tested by heating the mixture at 200 degrees C for 30 min, when dry conditions were used, and at 175 degrees C for 2 h in wet systems. All conditions led to the formation of HAs, PhIP being the amine that was detected at the highest level of concentration in most model systems (i.e. 173 ng g(-1) at 200 degrees C, 30 min). Moreover, the addition of creatinine and amino acids to the meat extract flavour produced an important increase in IQ and MeIQx content.