Simultaneous occurrence of saxitoxins and biogenic amines in mackerel fish

Seafood toxins resulted from a wide variety of naturally occurring or man-made toxic compound may cause a serious hazard to consumers. Biogenic amines that cause histamine poisoning and (STX) that cause paralytic shellfish poisoning (PSP) are among these seafood toxins that may occur in mackerel fish and their presence may be affected by seasonal and locality variation. The presence of STX and biogenic amines together will increase the hazard to consumers. That is why the present study was conducted to explore the simultaneous occurrence of these toxins in mackerel fish in Egyptian markets. Also, to study the effect of catching areas and seasonal variation on the level of these toxins. Mouse bioassay method was used for STX determination, where the toxicity detected in mackerel fish in this study ranged from 21.4 to 45 mu g STX/100 g. The quantitative Thin-layer chromatography (TLC) technique was applied for biogenic amines determination indicating that catching source had the main significant impact on the level of biogenic amines in mackerel fish samples under study. However, catching areas combined with seasonal variation affect the incidence level of STX in mackerel fish. Significant increase in the level of histamine (71), putrescine (64), cadaverine (42%), spermidine (65%), spermine (88%) and tyramine (48) was detected in the samples due to the thawing process.