Simultaneous kinetics formation of heterocyclic amines and polycyclic aromatic hydrocarbons in phenylalanine model system

Abstract

A combination of chemical model system with kinetics study was used to investigate the simultaneous formation of heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs). Heating a mixture of phenylalanine, creatinine, and glucose at a commonly practiced household cooking time and temperature successfully differentiated the rate formation (k) of HCAs and PAHs. The good fit suggested that the simultaneous formation was an endothermic bimolecular reaction, and followed the first-order model. The rate formation (k) of HCAs and PAHs significantly increased with increasing heating time and temperature. Only 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) showed degradation rate (k) at higher heating temperatures of 210 °C and 240 °C respectively. Increasing phenylalanine concentration increased the possibility of higher HCAs and PAHs formation. The activation energy (Ea) showed that heating phenylalanine mixture resulted in higher rate of formation of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and benzo[b]fluoranthen (BbF).