Analysis of Methylimidazoles in Caramel Colored Carbonated Beverages - Food and Beverage

Caramel colorings are used as additives in a broad range of food and beverage products to impart a desired color, but have no nutritional or preservative function. Recently, the potential hazard to humans of ammonia- and ammonia-sulfite-process caramel colorings was raised, because they contain the by-product 4-methylimidazole, which is a potential carcinogen.1 The methylimidazole compounds are difficult to analyze due to their polar nature and low molecular weight. Traditional reversed phase techniques are unsuccessful in retaining these small polar compounds. Therefore, most HPLC methods utilize ion-exchange resins for analysis. Another common method involves GC analysis after the analytes first undergo a derivatization step. The purpose of the work shown in this article was to develop a simple and fast analytical method to determine the levels of 2-methylimidazole and 4-methylimidazole in caramel colored carbonated beverages.