Mutat Res 1990 Nov;242(3):181-186

Formation of mutagens during the frying of
Hawaiian fish: correlation with creatine and
creatinine content.

Marsh NL, Iwaoka WT, Mower HF

Compounds mutagenic toward Salmonella typhimurium strain TA98
in the presence of rat-liver homogenates (S9) were formed when fish
flesh was fried at 199 degrees C. Three species of Hawaiian fish
commonly consumed in Hawaii (skipjack tuna, Katsuwonus pelamis;
yellowfin tuna, Neothunnus macropterus; and milkfish, Chanos chanos)
were cooked in an electric skillet, along with samples of sole
(Microstomus pacificus). Organic extracts of the fish were tested in the
Ames Salmonella mutagenic assay using tester strain TA98 and S9.
Basic organic extracts of fried, but not raw, samples exhibited
significant mutagenicity. The levels of mutagenicity were also higher
among the red flesh Hawaiian fish ('ahi, aku and awa) than with the
white flesh sole. Creatine and creatinine contents were highest in the
Hawaiian fish and lower in the sole. Creatine levels in the fish were
50-100 times greater than the creatinine content and varied from a
high of 645 mg/100 g wet weight of fish for yellowfin tuna to a low value
of 251 mg/100 g for sole. Mutagen levels are only approximately related
to creatine/creatinine levels suggesting that other components
contained in these fish may be as important as the guanidines in
determining the levels of mutagen in the cooked fish.