Identification of acryloyl-histidine-related components from heat-denatured imidazole dipeptides and heated meats

This study aimed to investigate if imidazole dipeptides (IDPs) undergo heat-induced denaturation and to identify denatured IDPs in food products. Herein, IDPs were heated at 120 °C for 4 h in both model systems and various foods for denaturation and subjected to mass spectrometry and nuclear magnetic resonance analyses. Notably, denatured carnosine, anserine, and balenine were identified as acryloyl-histidine, acryloyl-Nπ-methyl-histidine, and acryloyl-Nτ-methyl-histidine, respectively. These acryloyl-histidine-related components were not detected in raw meat samples, but their levels increased significantly after heat treatment. Additionally, they were found in commercially available processed meat products and IDP-containing supplements. Further, acrylamide was not detected post-heating at 120 °C, indicating that IDPs do not serve as a precursor for acrylamide under typical cooking conditions below 150 °C. Overall, these findings link the IDP denaturation pathway to the Maillard reaction and its influence on the bioavailability of acryloyl-histidine-related components and potential health effects, considering their regular consumption in daily diets.