IDENTIFICATION OF THE SATURATED OXO FATTY-ACIDS IN CHEESE

The nature and composition of the saturated oxo fatty acids in Cheddar cheese have been re-evaluated following isolation by modem chromatographic procedures, including low-pressure column chromatography and HPLC (adsorption and silver ion modes). The oxo fatty acids were identified and quantified (for the first time) by gas chromatography-mass spectrometry in the form of the methyl ester derivatives and many of the structures were confirmed similarly by preparing picolinyl ester derivatives. Thirty-six saturated oxo fatty acids were identified, ranging in chain length from 9 to 22 with an oxo group on carbons 4-17 (except for 12), of which twenty-one had been identified in a previous study and fifteen were new. Fifteen fatty acids tentatively identified by others did not in fact appear to be present.