Comparison of the formation of biogenic amines in irradiated and smoked fish

Levels of eight biogenic amines (putrescine, cadaverine, spermidine, spermine, histamine, tyramine, tryptamine and phenylethylamine) were determined in vacuum-packed fillets of grass carp ( Ctenopharyngodon idella ) and bighead carp ( Hypophthalmichthys molitrix ). Fish flesh was treated by high-energy electron beam irradiation at low doses of 0.25 and 0.50 kGy or by smoking. The control and treated packs were stored at 3.5 °C for up to 70 days (irradiated) and for 181 days (smoked). Tyramine content was the most sensitive indicator of the improper status of samples, levels exceeding 10 mg/kg indicated the loss of meat freshness, in spite of persisting good sensory indices. Irradiation prolonged the shelf-life of samples 4–5 times, smoking was more effective. The formation of tyramine, putrescine and cadaverine fitted well the Gompertz model.