A COMPARISON BETWEEN CONVENTIONAL AND FLUORESCENCE DETECTION METHODS OF COOKING-INDUCED DAMAGE TO TUNA FISH LIPIDS

The damage to tuna fish lipids induced by cooking was investigated in the Thunnus obesus and Th. thynnus varieties, using conventional and f luorescence detection methods, and the results were compared. As a con sequence of thermal processing, the peaks at longer wavelengths increa sed, which correlated with other conventional indices of lipid damage (i.e. carbonyl compound formation, browning and increases in the free fatty acid content). A special significance was given to the fluoresce nce ratio between the maxima of the excitation emission data at 393/46 0 nm and 327/415 nm; increases in this ratio as a result of cooking we re less dependent on the samples than were other conventional methods of measuring lipid damage.