lunes, 21 de septiembre de 2009

Processing under spotlight as flaws revealed in shellfish toxin testing

Industrial processing could double the level of certain marine biotoxins in shellfish a new report by the European Food Safety Authority (EFSA) has revealed, as it called for further research on the issue.

EFSA delivered its findings yesterday following a request from the European Commission to summarise the outcome of the adopted opinions on marine biotoxins - poisonous substances produced by different algae that can accumulate in shellfish - currently regulated under EU legislation. EFSA was asked to examine current EU limits with regard to human health and methods of analysis.

The safety body raised concerns over the influence of processing of shellfish on intensifying concentrations of lipophilic toxins; OA-,AZA, YTX- and PTX- group toxins that may be present.

“Processing of shellfish could lead to an approximate two-fold increase in the concentration of lipophilic marine biotoxins”, said the panel, while noting the conclusion was based on “limited information”.

The experts added: “Since the limit values for marine biotoxins in shellfish meat are meant to protect the consumer, the effect of processing (cooking, steaming, autoclaving) should be considered when testing shellfish in official control. Shellfish that contains levels of lipophilic toxins below the regulatory limits may reach, after processing levels that are higher than regulatory limits.”

EFSA also pointed out that themMouse bioassay (MBA), which is used as the official reference for lipophilic biotoxins, is not fit for purpose. The test method has “shortcomings and is not considered an appropriate tool for control purposes because of the high variability in results, the insufficient detection capability and the limited specificity”, said the panel. It added that MBA was incapable of detecting concentrations considerably below EU levels and therefore could not be used to monitor the effects of commercial processing on lipophilic biotoxins.

For each toxin the panel established the amount which can be consumed within a 24-hour period without any appreciable health risk (the acute reference dose). These were then compared with shellfish consumption and occurrence data from a number of EU countries in order to assess the EU limits. The experts identified 400g as a realistic estimate of a large portion of shellfish and used this in assessing current permitted levels of the toxins.

The panel made a raft of recommendations which included identifying knowledge and data gaps – including calling for more information on the effects of processing on levels of marine biotoxins. In March, 2009, EFSA said there was “a need for harmonisation of sample pre-treatment practices (i.e. cooking versus non-cooking) before the actual analysis of lipophilic marine biotoxins is carried out”.

More accurate and sensitive testing methods to measure concentrations of marine biotoxins in shellfish as well as establishing better characterization of their performance characteristics are also needed, said the report.

Aporte: Gabriel Zeballos R.

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