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U.S. Department of Energy
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Mutagens in cooked foods: isolation, metabolism and genetic toxicity

Conference ·
OSTI ID:6660666

Recently developed in our laboratories is an efficient extraction procedure incorporating XAD resin adsorption which yields from grilled ground beef cooked at 200 degrees C for 6 min per side an extract containing 230 Salmonella TA1538 rev. per g fresh weight of original ground beef. At higher temperatures (300 degrees C) and longer cooking times (10 min per side) up to 1500 rev per g fresh weight of meat can be recovered. These mutagenic components are specific for frameshift-sensitive Salmonella strains and have an absolute requirement for metabolic activation. Human liver microsomes and beta-naphthoflavone-induced rodent intestinal S9 were also active metabolizing fractions. Further purification of the extract by acidic and basic liquid/liquid extractions and a series of high performance liquid chromatography separations (both reverse- and normal-phase) resulted in the identification of at least 8 and possibly 10 distinct mutagenic aromatic amines. These potent mutagens are present in the original uncooked meat at 0.1 to 10 parts per billion. Two potent thermally-produced bacterial mutagens, Trp-P-2 (a pyrolysis product generated by high temperature cooking of sardines) and IQ (a minor component of pan fried hamburger but a major component of beef extract) were examined in mammalian cells. In excision repair-deficient CHO cells, Trp-P-2 exposure caused cytotoxicity, mutagenicity (thioguanine and azaadenine resistances), sister chromatid exchange, and chromosomal aberrations at concentrations more than 30-fold lower than those for IQ. In normal repair-proficient CHO cells Trp-P-2 was one-half as active and IQ was inactive. Relative to Trp-P-2, IQ is much more potent in the Salmonella bacterial system than in mammalian CHO cells. 14 references, 1 table.

Research Organization:
Lawrence Livermore National Lab., CA (USA); California Univ., Berkeley (USA)
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
6660666
Report Number(s):
UCRL-90941; CONF-8406168-1; ON: DE84013720
Country of Publication:
United States
Language:
English