Histamines released after death by cells in many species of fish – including tuna, sardines, mackerel and anchovies – can cause illness when ingested. Efsa notes there were 231 recorded cases of such poisoning in EU during 2014, though suggests the true figure is likely to be much higher.
Ernesto Liebana, head of biological hazards and contaminants at Efsa, says: ‘Cooking, freezing and canning will not destroy this toxin, histamine, after it has formed. The best prevention is to stop it from forming by maintaining the cold chain and keeping fish refrigerated.’
To address this hazard Liebana’s team conducted studies on prepacked fish, the impact of refrigeration on histamine formation, and how packaging can affect this process. Its findings were published on 1 July in the Efsa Journal. In it the authors note that storage time and the content of carbon dioxide in sealed packaging are the main factors that influence histamine formation.
Working with samples stored at 3°C, Efsa estimates that the EU threshold of 100 parts per million of histamine will be reached after six days if no carbon dioxide is added to the pack headspace. Consequently the shelf life limit should be set at this level.
If 20% of the gas in the headspace is carbon dioxide this projection rises to seven days, and eight days if 40% is used.
The investigation also considered two other common hazardous bacteria – listeria monocytogenes and yersinia enterocolitica. It gives similar shelf life estimates for keeping within the EU prescribed limits for these as well.
With specific reference to EU Regulation 2073/2005 on microbiological criteria for foodstuffs, Efsa concludes with the recommendation that: ‘if a temperature limit is deemed necessary, then future legislation should include a clear temperature value instead of statements such as a “temperature approaching that of melting ice”.’
This article comes from Food Contact World, which provides exclusive news and analysis on developments in digital print trends, markets, and technologies.