title: Detection and quantification of 4(5)-methylimidazole in cooked meat.
abstract: 4(5)-Methylimidazole (4-MeI) is a nitrogen-containing heterocyclic compound found in class III and IV ammoniated caramel colors, a group of additives widely used in the food industry. A suspected carcinogen and neurotoxin and efforts are underway to limit its presence in foods. Several methods have been developed to detect and quantitate 4-MeI in different food matrices, including roasted coffee, beer, soft drinks, and soy sauce; however, no methods are available to measure 4-MeI in cooked meat and meat products containing lipids and high levels of interfering nitrogen compounds, such as amino acids and peptides. A rapid method using 0.1 M sodium acetate buffer (pH 5) as an extraction solvent followed by derivatization with isobutylchloroformate and gas chromatograph mass-spectrometry was developed to quantify 4-MeI in cooked meat products with added caramel colors containing 4-MeI. Selected ion monitoring mode was used to monitor 4-MeI ions fragments. In the 8 commercial meat products tested, 4-MeI levels ranged from 0.041 to 1.015 mg/kg, with recovery of 94.76% to 103.94%. In addition, a matrix-matched calibration performed by analyzing a spiked cooked meat sample indicated no significant difference (P > 0.05), which means the meat matrix had no effect on the developed method. This method proved useful in analyzing 4-MeI in meat products with added caramel color containing 4-MeI.
authors.affiliation: Dept. of Animal Sciences and Industry, Food Science Inst, 208 Call Hall, Kansas State Univ., Manhattan, KS, 66506, U.S.A.
authors.forename: Faris
authors.initials: F
authors.lastname: Karim
authors.forename: J Scott
authors.initials: JS
authors.lastname: Smith
mesh_terms: D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D002273:Carcinogens / Q000032:analysis; D002417:Cattle; D003296:Cooking; D005503:Food Additives / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D007093:Imidazoles / Q000032:analysis*; D016014:Linear Models; D008460:Meat / Q000032:analysis*; D008461:Meat Products / Q000032:analysis*; D015203:Reproducibility of Results; D045730:Soy Foods / Q000032:analysis; D013552:Swine; D014422:Turkeys
chemical_list: D002241:Carbohydrates; D002273:Carcinogens; D005503:Food Additives; D007093:Imidazoles; C569050:caramel coloring; C023439:4-methylimidazole
keywords: 4(5)-methylimidazole; caramel color; cooked meat