EFSA advises on heat treatment of bivalve molluscs

Experts at EFSA have evaluated possible alternatives to the current heat treatments of molluscs required by EU legislation before they are placed on the market. Such treatments, which are needed to kill possible viruses, may alter the quality of the final products. 

Bivalve molluscs, such as mussels, oysters and clams can be a source of Norovirus and Hepatitis A infections in humans. They accumulate virus particles in their tissues during filter feeding in contaminated water. 

In particular, experts of the Panel on Biological Hazards have identified time-temperature combinations equivalent to the current requirement of exposing molluscs to a heat treatment of “90°C for 90 seconds”, which would lead to the same reduction of viruses.

More importantly, scientists showed that the current heating process of 90°C for 90 seconds can lead to different levels of virus reduction, depending on the process used – and in particular on the heat-up and cool-down time (the time needed to achieve 90°C and to return to room temperature).

“EFSA experts recommend that risk managers define the appropriate level of public protection. Based on this, risk assessors can define the desired reduction of the virus and the heat treatment that would achieve that goal,” said Marta Hugas, head of EFSA’s Biological Hazards and Contaminants unit. “This will allow business operators to design a process compliant with the legislation and at the same time achieve the desired quality of the product,” she added.


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