An updated U.S. population dietary exposure assessment for 4-methylimidazole (4-MEI) from foods containing colour and from formation of 4-MEI through thermal treatment of foods

The current study updates the U.S. Food and Drug Administration’s dietary exposure assessment for 4-methylimidazole (4-MEI), a constituent of caramel colouring. The FDA study was published in 2018 and was based on food consumption data from U.S. National Health and Nutrition Examination Survey (NHANES) 2009-2012 cycles. This study incorporates 4-MEI levels currently found in beverages (Tier 1, based on industry reported levels), removes from the assessment foods that no longer contain caramel (Tier 2, based on food labels), and assumes 4-MEI levels in foods being reduced by half to align with the 50% lowering of the Food Chemicals Codex specification limits for 4-MEI in caramel III or IV (Tier 3). Updated food and beverage consumption data from the NHANES 2015-2018 cycles are also used. The cumulative reduction in 4-MEI levels in beverages and foods from industry reformulations results in exposures to added sources (caramel colour) and intrinsic sources (baking or roasting process) being similar. Compared to previous FDA estimates of 0.043 and 0.046 mg day−1 of 4-MEI from added caramel sources for the general population and adults, respectively, this updated assessment shows 4-MEI estimated exposures to be 0.016 and 0.017 mg day−1, when all reductions in foods and beverages are accounted for. When 4-MEI level adjustments were limited to beverages (Tier 1) and labelled food products (Tier 2), prepared meals, breads and rolls, and ice cream and frozen yogurt were the top three contributors to added 4-MEI exposures. As 4-MEI dietary exposure from added caramel continues to decrease, the contribution ranking of the food categories is expected to change.