SYNTHESIS, CHARACTERIZATION AND USE OF 2-TETRADECYLCYCLOBUTANONE TOGETHER WITH OTHER CYCLOBUTANONES AS MARKERS FOR IRRADIATED LIQUID WHOLE EGG

The synthesis and characterisation of 2-tetradecylcyclobutanone (TCB) is described. Both 2-dodecylcyclobutanone and TCB were shown to be present in liquid whole egg irradiated at doses of 2.5 and 10.0 kGy. These compounds were absent from the unirradiated pasteurised samples. Using gas chromatography and infrared spectroscopy, there was also evidence for the presence in irradiated egg of 2-tetradecenyl- and 2-tetradecadienylcyclobutanone which are formed from oleic and linoleic acids, respectively. Authentic standards for these unsaturated cyclobutanones were not available commercially but the presence of 2-tetradecenylcyclobutanone was substantiated by hydrogenating the egg extracts so converting this unsaturated cyclobutanone to TCB. Saturated and unsaturated cyclobutanones appear to be specific products of irradiation and are potential markers for detection of irradiated liquid egg and probably other fat-containing foods.