engleski

Long-term follow-up of histamine levels in a stored fish meal sample

A shipment of fish meal highly contaminated with histamine caused an epidemic histamine poisoning among harbour workers in Rijeka, Croatia, in 1998. Samples of fish-meal were taken, histamine level determined, and samples were then stored in closed plastic bags at 4-8°C for the next 40 months. Follow-up of the histamine levels was performed by thin-layer chromatography (TLC) after 12, 28 and 40 months of storage. Initial histamine level was 5.1 g of histamine in a kilogram of fish meal (100%). After 12 months histamine level decreased to 73.5% (3.75 g/kg), remained at 71.6% after 28 months (3.65g/kg), and decreased again after 40 months of storage to 49.0% (2.5 g/kg). After 40 months of storage in a refrigerator, samples were kept at the room temperature (24°C) in the closed transparent plastic bags, exposed to natural daily light for additional 3 months. TLC histamine measurements were performed at day 1 and 7, and then after 1, 2 and 3 months of storage. Levels of histamine did not differ significantly from the starting level of 2, 5 g/kg (100%) at day1 and 7, and also after 1, 2, and 3 months of storage at 24°C (2.5, 2.3, 2.2, 2.2, 2.2 g/kg, respectively). This study confirmed the long-term persistence of histamine in contaminated fish-meal. Histamine was present at the highly toxic level (>2 g/kg) for more than 3 years if stored at 4-8°C, and for at least 3 months if kept at ambient temperature (24°C) unprotected from light. The results confirmed our previous hypothesis that fish-meal with high content of histamine is a potential long-term health hazard for poultry and other animals if used as a feedstuff and also for men manipulating it.

fish-meal; histamine; storage temperature; thin-layer chromatography

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