Thermal processing of live bivalve molluscs for controlling viruses: On the need for a risk-based design

ABSTRACT

Norovirus (NoV) and Hepatitis A virus (HAV) are the most important viral hazards associated with human illness following consumption of contaminated bivalve molluscs. The effectiveness of the current EU criteria for heat processing of bivalve molluscs (i.e. raising the temperature of the internal mollusc flesh to at least 90°C for a minimum of 90 seconds) was evaluated using predictive microbiology. A HAV thermal inactivation model was developed based on literature data in mollusc matrices during isothermal heat treatment. Application of the developed model demonstrated that the 90°C–90 s requirement may lead to significantly different virus inactivation depending on the commercial process design. This shows the need for the establishment of a Performance Criterion for bivalve molluscs heat processing which will assure a common specified level of consumer protection. A risk-based approach is described that allows for an effective processing design providing a more transparent and objective relation between the thermal processing targets and public health. Model simulations demonstrate that the F-value is a more appropriate Process Criterion than a single time-temperature combination since it enables the food business operators to design a process that is compliant with the safety requirements while at the same time achieving a desired product quality.

KEYWORDS:

• Bivalve molluscs
• hepatitis A virus
• norovirus
• heat treatment

Acknowledgments

The authors thank the members of the Biological Hazards Panel that adopted the EFSA Opinion on ‘Evaluation of heat treatments, different from those currently established in the EU legislation, that could be applied to live bivalve molluscs from B and C production areas, that have not been submitted to purification or relaying, in order to eliminate pathogenic microorganisms’ [EFSA Journal 2015;13(12):4332]. This paper is largely based on the mentioned Opinion prepared under the auspices of EFSA.

Conflict of interest

The authors declare no conflict of interest. The authors Winy Messens and José Cortiñas Abrahantes are employed by the European Food Safety Authority (EFSA). The present article is published under the sole responsibility of the authors and may not be considered as an EFSA scientific output. The positions and opinions presented in this article are those of the authors alone and do not necessarily represent the views or scientific works of EFSA.