Determination of 4(5)-Methylimidazole in Sugar–Amino Acid Aqueous Model Systems by UPLC-Q-ToF-MS

Abstract

4(5)-Methylimidazole (4(5)-MEI) can be formed during the caramelization procedure and the Maillard reaction and has been classified as possibly carcinogenic to humans. Data concerning the formation of 4(5)-MEI by the reaction between amino acids and sugars are still scarce. In this study, an ultrahigh performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-ToF-MS) method was developed for the determination of 4(5)-MEI in aqueous model systems containing sugars (fructose and glucose) and amino acids (proline, phenylalanine, tyrosine, and lysine), after thermal processing at 100 °C. The results showed that the 4(5)-MEI was formed in all model systems, with the highest concentrations to be determined in fructose–proline (3.5 μg mL−1) and fructose–tyrosine (3.0 μg mL−1) aqueous model systems.

Keywords

• 4(5)-methylimidazole
• Maillard reaction
• liquid chromatography
• mass spectrometry