Liquid chromatography-tandem mass spectrometry analysis of 2-amino-1-methyl-6-(4-hydroxyphenyl)imidazo[4,5-b]pyridine in cooked meats

Simultaneous quantitation of acrylamide, 5-hydroxymethylfurfural, and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine using UPLC-MS/MS

A robust and sensitive isotope dilution UPLC-MS/MS method was established for the simultaneous analysis of acrylamide (AA), 5-hydroxymethylfurfural (HMF), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP). A fairly good separation of three analytes was achieved within 4.5 min. High correlation coefficients (R² > 0.9998) of the three compounds were obtained in their respective linear ranges. This method demonstrated low limits of detection (1.57 μg/L for AA, 0.61 μg/L for HMF, and 0.02 μg/L for PhIP) and limits of quantification (5.22 μg/L for AA, 2.03 μg/L for HMF, and 0.05 μg/L for PhIP). This method also demonstrated excellent quantification accuracy (99.02%-101.12%), precision (RSD < 6%), and recovery (82.83-119.92%) in the Maillard model systems and deep-fried meatballs. This work develops a fundamental method for the rapid simultaneous determination of AA, HMF, and PhIP in thermally processed foods that are both carbohydrates-rich and protein-rich, meanwhile providing technical support for the generation mechanism of various hazards.

Heterocyclic Aromatic Amines in Meat: Formation, Isolation, Risk Assessment, and Inhibitory Effect of Plant Extracts

Heterocyclic aromatic amines (HAAs) are potent carcinogenic compounds induced by the Maillard reaction in well-done cooked meats. Free amino acids, protein, creatinine, reducing sugars and nucleosides are major precursors involved in the production of polar and non-polar HAAs. The variety and yield of HAAs are linked with various factors such as meat type, heating time and temperature, cooking method and equipment, fresh meat storage time, raw material and additives, precursor’s presence, water activity, and pH level. For the isolation and identification of HAAs, advanced chromatography and spectroscopy techniques have been employed. These potent mutagens are the etiology of several types of human cancers at the ng/g level and are 100- to 2000-fold stronger than that of aflatoxins and benzopyrene, respectively. This review summarizes previous studies on the formation and types of potent mutagenic and/or carcinogenic HAAs in cooked meats. Furthermore, occurrence, risk assessment, and factors affecting HAA formation are discussed in detail. Additionally, sample extraction procedure and quantification techniques to determine these compounds are analyzed and described. Finally, an overview is presented on the promising strategy to mitigate the risk of HAAs by natural compounds and the effect of plant extracts containing antioxidants to reduce or inhibit the formation of these carcinogenic substances in cooked meats.

The effect of using different types and rates of onion-water extract in meatball production on the formation of heterocyclic aromatic amines

BACKGROUND

The effect of using different types (yellow, white and purple) and rates (0.25%, 0.50% and 0.75%) of onion-water extract in meatball production on the various quality criteria of meatballs and the formation of heterocyclic aromatic amines (HCAs) was investigated.

RESULTS

It was determined that cooking process caused a reduction in the water content of meatballs as well as an increase in pH values. MeIQx, 7,8-DiMeIQx, 4,8-DiMeIQx, PhIP, AαC and MeAαC could not be detected in any of the analyzed meatballs, while IQx, IQ and MeIQ were determined in some of the samples.

CONCLUSION

The use of 0.25% and 0.50% white onion-water extract in meatball preparation inhibited the formation of IQx and IQ that were identified in the control group, but their quantities could not be determined. However, the use of water extract of varying types of onions in meatball preparation increased the total HCA content due to the increase of the MeIQ formation. In addition, it was determined that as the rate of onion-water extract for varying types of onions increased, the total HCA amount also increased. The total HCA amount of the meatballs varied between 0.05 and 0.1 ng g^-1 . © 2019 Society of Chemical Industry.

Influence of food condiments on the formation of carcinogenic heterocyclic amines in cooked chicken and determination by LC-MS/MS

Heterocyclic amines (HCAs) are known to be suspected human carcinogens produced by high-temperature cooking of protein-rich foods such as meat and fish. In the present study, the influence of numerous food condiments on the formation of HCAs in cooked chicken was investigated. Chicken samples were subjected to pan-frying under controlled temperature. The levels of HCAs DMIP, MeIQx, 4,8-DiMeIQx, PhIP, harman and norharman were found to be between 0.93 and 27.52 ng g(-1), whereas IQ, MeIQ, AαC, MeAαC, Trp-P-1 and Trp-P-2 were found either below the limit of quantification or not detected in the control sample. Nevertheless, for samples cooked using food condiments, the amounts of HCAs (DMIP, MeIQx, 4,8-DiMeIQx and PhIP) were between 0.14 and 19.57 ng g(-1); harman and norharman were detected at higher concentrations up to 17.77 ng g(-1) while IQ and MeIQ were at levels below the limit of quantification; and AαC, MeAαC, Trp-P-1 and Trp-P-2 were not detected in any of the samples. The outcomes revealed that the formation of HCAs (except harman and norharman) diminished after the addition of food condiments. Edible oil contributed to the highest levels of HCA formation, followed by garlic, paprika, pepper and tomato.

Simultaneous analysis of PhIP, 4'-OH-PhIP, and their precursors using UHPLC-MS/MS

A novel method allowing simultaneous analysis of PhIP, 4'-OH-PhIP, and their precursors (phenylalanine, tyrosine, creatine, creatinine, glucose) has been developed as a robust kinetic study tool by using ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A direct hydrochloric acid (HCl) extraction was applied to achieve the simultaneous extraction of all seven analytes, with the mean recoveries ranging from 60% to 120% at two concentration levels. Then, an Atlantis dC18 column selected from four different chromatographic columns was ultimately used to separate these compounds within 15 min. The limits of detection range of allseven analytes were calculated as 0.14-325.00 μg L(-1). The intra- and interday precision of the proposed method were less than 15.4 and 19.9%, respectively. The proposed method was successfully applied to depict the kinetic profiles of PhIP, 4'-OH-PhIP, and their precursors in pork model, reducing the analysis time and cost in the kinetic study.

Biomonitoring of urinary metabolites of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) following human consumption of cooked chicken

Human risk assessment of exposure to 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) through the diet may be improved by conducting biomonitoring studies comparing metabolism in humans and rodents. Eleven volunteers ingested a meal of cooked chicken containing 4 -OH-PhIP and PhIP in amounts of 0.6 and 0.8microg/kg, respectively and urine was collected for the next 16h. The large number of PhIP metabolites was by treatment of the urine samples with hydrazine hydrate and hydrolytic enzymes reduced to three substances, 4'-OH-PhIP, PhIP and 5-OH-PhIP of which the first is a biomarker for detoxification and the last a biomarker for activation. The eleven volunteers eliminated large amounts of 4'-OH-PhIP in the urine. The majority of which could be accounted for by the presence of 4'-OH-PhIP in the fried chicken, showing that PhIP only to a small extent (11%) was metabolised to 4'-OH-PhIP. A larger fraction of the PhIP exposure, 38%, was recovered as PhIP and the largest fraction (51%) was recovered as 5-OH-PhIP suggesting that PhIP in humans to a large extent is metabolised to reactive substances. In rats, less than 1% of the dose of PhIP was eliminated as 5-OH-PhIP, suggesting that human cancer risk from exposure to PhIP is considerable higher than risk estimations based on extrapolation from rodent bioassays.