51A-11

S. E. ROSSI¹, L. PIVARNIK¹, C. M. Lee¹, and P. C. Ellis². (1) Food Science and Nutrition Department, University of Rhode Island, Kingston, RI 02881, (2) Food Chemistry Laboratory, Rhode Island Department of Health Laboratories, Providence, RI 02904

Histamine has been frequently associated with seafood intoxications. Histamine has a legal maximum limit of 50 ppm and must be addressed under HACCP programs. Research has shown that other biogenic amines, such as putrescine and cadaverine, enhance the toxicity of histamine. Therefore, these biogenic amines should be considered in evaluating seafood safety.

The objectives of this research were to monitor putrescine, cadaverine and histamine formation in whole skipjack (Euthynnus pelamis) and bigeye tuna steaks (Thunnus obesus) under different storage conditions and to determine the potential use of putrescine and cadaverine as indicators of decomposition.

Fresh and previously frozen samples were stored on ice at 4 °C and at room temperature at 22°C. Histamine, putrescine, cadaverine and volatile bases were monitored via fluorometric, GC, and ion specific electrode AOAC procedures, respectively. Mesophilic and psychotrophic bacteria were enumerated using plate count agar, incubated at 37 °C and 25 °C respectively, for 48 hours.

All biogenic amines were formed at all storage conditions. However, putrescine was formed at a much lower rate and concentration than cadaverine and histamine. Under both storage conditions, cadaverine appeared prior to and accumulated at a faster rate than histamine in both species. Fresh and frozen/thawed skipjack tuna had a faster accumulation of cadaverine than bigeye under all storage conditions. All samples tested had initial microbial counts of 10² to 10³ and increased over the storage trials regardless of incubation temperature.

The results show that cadaverine either alone or with histamine could be a good index of decomposition for skipjack and bigeye tuna.