Process-induced formation of imidazoles in selected foods.
The presence of 4-methylimidazole (4-MEI), 2-methylimidazole (2-MEI) and 2-acetyl-4-tetrahydroxybutylimidazole (THI) in some foods may result from the usage of caramel colorants E150c and E150d as food additives. This study demonstrates that alkylimidazoles are also byproducts formed from natural constituents in foods during thermal processes. A range of heat-processed foods that are known not to contain caramel colorants were analyzed by isotope dilution LC-MS/MS to determine the contamination levels. Highest 4-MEI concentrations (up to 466µg/kg) were observed in roasted barley, roasted malt and cocoa powders, with the concomitant presence of 2-MEI and/or THI in some cases, albeit at significantly lower levels. Low amounts of 4-MEI (<20µg/kg) were also detected in cereal-based foods such as breakfast cereals and bread toasted to a brown color (medium toasted). The occurrence of 4-MEI in certain processed foods is therefore not a reliable indicator of the presence of the additives E150c or E150d.
Nestlé Research Center, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland. Electronic address: pascal.mottier@rdls.nestle.com.
Pascal
P
Mottier
Nestlé Research Center, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland. Electronic address: claudia.mujahid@rdls.nestle.com.
Claudia
C
Mujahid
Nestlé Research Center, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland. Electronic address: adrienne.tarres@rdls.nestle.com.
Adrienne
A
Tarres
Nestlé Research Center, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland. Electronic address: thomas.bessaire@rdls.nestle.com.
Thomas
T
Bessaire
Nestlé Research Center, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland. Electronic address: richard.stadler@rdls.nestle.com.
Richard H
RH
Stadler
D002853:Chromatography, Liquid / Q000379:methods*; D005503:Food Additives / Q000737:chemistry*; D005511:Food Handling / Q000379:methods*; D007093:Imidazoles / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*
D005503:Food Additives; D007093:Imidazoles
2-acetyl-4-tetrahydroxybutylimidazole (PubChem CID: 108037); 2-acetyl-4-tetrahydroxybutylimidazole (THI); 2-methylimidazole (2-MEI); 2-methylimidazole (PubChem CID: 12749); 4-methylimidazole (4-MEI); 4-methylimidazole (PubChem CID: 13195); Food; LC-MS/MS; Thermal treatment