Colorimetric Evaluation of Mahi-Mahi and Tuna for Biogenic Amines

ABSTRACT The Food and Drug Administration and National Marine Fisheries Services grade tuna and mahi-mahi using trained sensory panels in order to determine the quality of these fish. A major concern with both species is the presence of histamine in the flesh, which can cause scombroid poisoning, a severe illness that can lead to death. Three different assays were examined in an attempt to correlate sample grade with biogenic amine content. The first method, acetic acid Dräger tubes, was only effective in identifying the highest grade (lowest quality) of mahi-mahi. The second method was a bromophenol blue (BPB) colorimetric strip that was sensitive to volatile biogenic amines. The third method was a histamine-specific enzyme-linked immunosorbant assay (ELISA) that detected analytes in the liquid phase. The results of the BPB and ELISA methods showed a correlation between sample grade and biogenic amine content for mahi-mahi. The same correlation was not observed with the tuna samples, likely due to physiological differences between the two species that affect the detection of the analytes.