Total Heterocyclic Aromatic Amines Content Research Articles

Determination of 10 heterocyclic aromatic amines in beef jerky by high performance liquid chromatography

An analytical method was developed for the simultaneous determination of 10 heterocyclic aromatic amines (HAAs) in beef jerky by solid phase extraction-high performance liquid chromatography (SPE-HPLC). The HAAs were eluted from an Extrelut NT 20 SPE column with 60 mL dichlormethane (containing 5% toluene), and then the extract was purified with a propylsulfonic acid silica (PRS) column and a C18 SPE column, and finally, the HAAs were stored in a methanol-ammonia solution. The separation was achieved by using a TSK-gel ODS-80 column and a gradient elution with the mobile phases of acetonitrile and 0.05 mol/L acetic acid-ammonium acetate buffer (pH 3.5). The identification and quantitative analysis of the HAAs fraction were carried out using an HPLC system with ultraviolet-fluorescence detectors. The results showed that the correlation coefficients of the 10 HAAs were all above 0.999 and the limits of detection were in the range from 0.02 to 2.46 ng/g. The recoveries of the 10 HAAs spiked in beef samples were 61.69% - 101.81% with the relative standard deviations (RSDs) between 0.28% and 7.81%. 1-Methyl-9H-pyrido[4,3-b] indole (Harman) and 9H-pyrido [4,3-b]indole (Norharman) were detected in all beef jerky, and the total HAAs content of beef jerky were between 16.65 and 60.38 ng/g. This method is with wide linear range and high sensitivity, and is enough for the analysis of the HAAs in actual meat samples.

Evaluation of Escherichia coli DJ4309 expressing human P450 1A2 in mutagenicity testing of complex food mixtures

Heterocyclic aromatic amines (HAAs) are potent bacterial mutagens and potential human carcinogens formed in heat processed proteins. The Ames test (strain TA98) is a useful mutagenicity test system to screen food products for these compounds. HAAs require activation to their genotoxic forms, and in the Ames test, a rat liver S-9 preparation is normally used. In order to better understand the mechanisms of mutagen activation with respect to human metabolism, new bacterial strains containing human cytochrome P450s and other metabolic enzymes have recently been developed. We have investigated the capacity of one of these strains, DJ4309 [Josephy et al., Chem. Res. Toxicol. 11 (1998) 70–74] as a screening tool for mutagens in food products. DJ4309 expresses the human P450 1A2, human NADPH cytochrome reductase and the bacterial acetyl CoA:arylamine N-acetyltransferase. This strain is as sensitive as the Ames system to the mutagenic effects of the heterocyclic aromatic amines 2-amino-3-methylimidazo[4,5- f]quinoline, 2-amino-3,4-dimethylimidazo[4,5- f]quinoline and 2-amino-3,8-dimethylimidazo[4,5- f]quinoxaline, but less sensitive to 2-amino-1-methyl-6-phenylimidazo[4,5- b]pyridine. However, the mutagenicity of the arylamine 2-aminofluorene is considerably higher in DJ4309 than in the Ames test system. Meat extracts with a total HAA content ranging from less than 2 ng/g to 20 ng/g are efficiently detected by the Ames TA98 strain with rat liver S-9 activation. DJ4309 is less sensitive, with fewer revertants induced over the same dose range. Unknown compounds present in the meat extracts appear to inhibit the activity of the P450 1A2 enzyme in the DJ4309 strain. We have therefore demonstrated that although DJ4309 is a useful tool for mechanistic studies in chemical carcinogenesis, the screening of complex food matrices for HAAs by this bacterial strain must be conducted with caution.

3322. Bacterial mutagens from smoked foods: Nagao, M., Honda, M., Seino, Y., Yahagi, T. & Sugimura, T. (1977). Mutagenicities of smoke condensates and the charred surface of fish and meat. Cancer Lett.2, 221

The large yellow croaker (Pseudosciaena crocea) is one of the most commercially important marine fish in China and is a fixture at Chinese tables. Herein, we determined the formation of heterocyclic aromatic amines (HAAs) in roasted yellow croaker and evaluated the inhibitory effect of natural fruits extracts (blueberry extract, acerola cherry extract and grape seed extract) on the formation of HAAs in roast yellow croaker. All the three fruit extracts treatments minimize the amount of HAAs and the addition of blueberries extracts is the most effective approach on reducing the total HAAs content, which caused a signification reduction of 94.85% and 71.15% of the Norhaman and PhIP content, respectively, led IQ, 8-MeIQX, 4,8-DiMeIQX below the detected limitation, compared to the control group. Furthermore, antioxidant index of fruits extracts, precursors (free amino acids, creatine, creatinine and glucose) of HAAs, lipid and protein oxidation, flavor changes are evaluated to determine the mechanism and physical/chemical changes of fruit extracts on the formation of HAAs. This research develops a new method to minimize the amount of HAAs, which is helpful to food manufacturers for the production of healthier yellow croaker products and may be applicable to various meat systems.