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., CA
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5088643
- Journal Information:
- Environ. Health Perspect.; (United States), Journal Name: Environ. Health Perspect.; (United States) Vol. 67; ISSN EVHPA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400102 -- Chemical & Spectral Procedures
560305* -- Chemicals Metabolism & Toxicology-- Vertebrates-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AROMATICS
AZAARENES
AZINES
CHEMICAL ANALYSIS
CHROMATOGRAPHY
ELECTROPHORESIS
FOOD
FOOD PROCESSING
HEAT EXTRACTION
HETEROCYCLIC COMPOUNDS
LIQUID COLUMN CHROMATOGRAPHY
MASS SPECTRA
MEAT
MUTAGENS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PH VALUE
PROCESSING
PYRIDINES
QUINOLINES
SEPARATION PROCESSES
SPECTRA
TEMPERATURE DEPENDENCE