Mutagen formation in a model beef supernatant fraction. IV. Properties of the system
To identify the precursors and elucidate the reaction conditions that yield heterocyclic amine mutagens in cooked meat products and fish, the authors have used a supernatant 2 (S/sub 2/) fraction prepared from H/sub 2/O-homogenized lean round steak. Compounds (MW < 500) in S/sub 2/ are the sources of the microsomal-dependent, Salmonella TA 1538 mutagenic activity in open boiled (aqueous), 200/sup 0/C pressure-heated (aqueous), or 200 to 300/sup 0/C oven-baked (freeze-dried) homogenates. Combined incorporation-HPLC experiments show that they are also the precursors for frameshift mutagen formation in the outer surfaces of 200/sup 0/C griddle-fried ground beef. Maximal stimulations of boiled S/sub 2/ mutagenic activity are given by 10 mM Trp, 2.5 mM creatine phosphate (CP), and synergistically by 10 mM Trp + 2.5 mM CP + 1.0 mM FeSO/sub 4/ (a mixture abbreviated as S/sub 2/). Boiling S/sub 2/ for 30 hr at the acidic optimum pH of 4.0 ..-->.. 600 TA 1538 revertants (no additions) and 1400 revertants (+CP), while S/sub 2/ ..-->.. 24,000 revertants/10/sup 8/ bacteria/g of dry beef. By the criteria of HPLC, paper electrophoresis, and resistance of the active HPLC fractions to acid-nitrite inactivation, boiled S/sub 2/ contains 2-amino-3-methylimidazo(4,5-f)quinoline (IQ), 3-amino-1-methyl-5H-pyrido(4,3-b)indole (Trp-P-2) and a minor amount of 2-amino-3,4-dimethylimidazo(4,5-f)quinoline (MeIQ). Once the soluble S/sub 2/ precursors have been concentrated to a freeze-dried powder, aqueous conditions are not essential to obtain heterocyclic amine mutagens at this ordinary cooking temperature. Water behaves as an important reactant that influences the relative proportions of HPLC polar, nitrite-resistant, IQ-type as opposed to HPLC nonpolar, nitrite-sensitive, non-IQ-type mutagens. Dry heating S/sub 2/ favors the former.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5088643
- Journal Information:
- Environ. Health Perspect.; (United States), Vol. 67
- Country of Publication:
- United States
- Language:
- English
Similar Records
Mutagenic activities of heterocyclic amines in Chinese hamster lung cells in culture
Mutagens in cooked foods - metabolism and genetic toxicity
Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
MEAT
CHEMICAL ANALYSIS
FOOD PROCESSING
MUTAGENS
HEAT EXTRACTION
QUINOLINES
MASS SPECTRA
ELECTROPHORESIS
LIQUID COLUMN CHROMATOGRAPHY
PH VALUE
TEMPERATURE DEPENDENCE
AROMATICS
AZAARENES
AZINES
CHROMATOGRAPHY
FOOD
HETEROCYCLIC COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PROCESSING
PYRIDINES
SEPARATION PROCESSES
SPECTRA
560305* - Chemicals Metabolism & Toxicology- Vertebrates- (-1987)
400102 - Chemical & Spectral Procedures