Abstract
We previously reported the mutagenic activities of dailyfoodstuffs classified into 13 groups (I-XIII) by a market basket method. The mutagenic activities were generally increased by nitrite treatment under acidic conditions. In this study, methanol extracts of seven foodstuffs in group XI (meats, egg), which showed weak direct mutagenic activity and high mutagenic activity after nitrite treatment, were subjected to the Ames test using S. typhimurium TA 100 strain without metabolic activation. The mutagenic activity of group XI was mainly due to meats such as chicken, pork, beef and mutton. In particular, the mutagenic activity of mutton treated with nitrite increased to 3.9 times that of the untreated sample. It was demonstrated that the mutagens were produced during heating of the meat.
From studies on the detection of mutagens in broiled mutton by using gas chromatography, high performance liquid chromatography, and gas chromatography-mass spectrometry, three α-dicarbonyl compounds (glyoxal, methylglyoxal and diacetyl) were identified as directacting mutagens. Furthermore, four tryptophan-related compounds (5-hydroxyindole, tryptamine, L-tryptophan and 5-hydroxytryptamine) and two β-carboline derivatives ((1R, 3S)-and (1S, 3S) -1, 2, 3, 4-tetrahydro-1-furyl-9H-pyrido [3, 4-b] indole-3-carboxylic acid) were identified as premutagens which show an increase of mutagenic activity after nitrite treatment.
