Mottier Pascal, Mujahid Claudia, Tarres Adrienne, Bessaire Thomas, Stadler Richard H
Nestlé Research Center, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland.
Food Chem. 2017 Aug 1;228:381-387. doi: 10.1016/j.foodchem.2017.02.020. Epub 2017 Feb 7.
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.
某些食品中存在4-甲基咪唑（4-MEI）、2-甲基咪唑（2-MEI）和2-乙酰基-4-四羟基丁基咪唑（THI），可能是由于使用焦糖色素E150c和E150d作为食品添加剂所致。本研究表明，烷基咪唑也是食品天然成分在热加工过程中形成的副产物。通过同位素稀释液相色谱-串联质谱法分析了一系列已知不含焦糖色素的热处理食品，以确定其污染水平。在烤大麦、烤麦芽和可可粉中观察到最高的4-MEI浓度（高达466μg/kg），在某些情况下还同时存在2-MEI和/或THI，尽管其含量明显较低。在谷物类食品如早餐谷物和烤至棕色（中度烤制）的面包中也检测到少量的4-MEI（<20μg/kg）。因此，某些加工食品中4-MEI的存在并不是添加剂E150c或E150d存在的可靠指标。
