Linoleic acid hydroperoxide concentration in relation to mutagenicity of repeatedly used deep-frying fats.

A high-performance liquid chromatography procedure was developed to measure linoleic acid hydroperoxides (LAHPO) in 19 used, deep-frying fat samples that were screened for mutagenicity. The detection limit of the method was found to be 10 nmol of LAHPO/g of fat. In eight samples, LAHPO were not detected; levels in the other samples ranged from 17 to 267 nmol/g of fat. LAHPO were not detectable in unused hydrogenated frying fat samples. Concentrations of LAHPO correlated positively with mutagenicity to Salmonella tester strains TA97 and TA100, in presence of S9 mix only; coefficients of correlation were, respectively, r=0.48 (p less than 0.05) and r=0.24 (n.s.). Without metabolic activation no significant associations or secondary autoxidation products of linoleic acid generated in presence of liver S9 mix may contribute to mutagenicity of some of the used deep-frying fat samples.