During the last decade an increased incidence of infections and outbreaks attributed to foodborne viruses, in particular noroviruses (NoV), has been observed world wide. The awareness of the presence of viruses in food emphasised the need to acquire knowledge regarding the effect of preservation methods upon viruses. Most foodborne viruses cannot be cultured in the laboratory, which hinders studies of their stability in food. Cultivable surrogate viruses, genetically related to the human infecting strains, are taken as a substitute to define inactivation rates. In this review, state-of-the-art information regarding the efficacy of preservation methods to reduce the level of viruses in food has been compiled. Firstly, the effect of preservation methods establishing microbial growth inhibition (chilling, freezing, acidification, reduced water activity and modified atmosphere packaging) upon foodborne viruses is described. Secondly, the use of preservation methods establishing microbial inactivation such as heat treatment, high hydrostatic pressure processing and irradiation to eliminate viruses is discussed. Finally, the efficacy of decontamination methods on fresh produce and purification procedures applied on live bivalve shellfish to reduce the viral load are examined. These studies indicate that viruses persist well on chilled, acidified, frozen foods and foods packed under modified atmosphere or in dried conditions. Intervention strategies inducing microbial inactivation are required to achieve a 3 log reduction of the level of viruses. Decontamination of fresh produce reduces viruses with a maximum of 1 to 2 log, while purification of live bivalves is not adequate to prevent viral outbreaks. It was noted that the effect of a particular food preservation method is dependent upon the virus tested and the type of food.
Baert L, Debevere J, Uyttendaele M.
Int J Food Microbiol 2009;131 (2-3): 83-94