Investigations on the origin of two radiation-induced compounds in irradiated meat.

After irradiation with 0.5 Mrad or higher doses, a radiation-induced ninhydrin-positive compounds was found in the muscle tissue of warm-blooded animals. In carp muscle another compound called X was formed. The origin of these two compounds was investigated. Irradiation of various amino acids and related compounds showed that substance Y is formed from the dipeptides carnosine and anserine, which are present in muscle tissue of warm-blooded animals unusually high concentrations. In carp muscle containing relatively high levels of histidine, but only low concentrations of anserine as the only dipeptide, histidine furnished compound X. This compound was found to be relatively stable in acid medium. After acid hydrolysis of irradiated carnosine solutions and of extracts of irradiation muscle tissue from warm-blooded animals, compound Y was no longer observed, but another compound appeared that was similar to X with regard to colour and migration properties during high-voltage electrophoresis and column chromatography.