Impact of fish dry-curing on the behaviour of Listeria monocytogenes during the production of ready to eat fishery products

Fish dry-curing technologies performed within dedicated cabinets are gaining popularity in restaurants and food companies. These technologies are based on a constant control and adjustment of temperature, relative humidity and ventilation parameters and are used to transform raw fillets or whole fish into ready to eat products. To date no scientific data are available regarding the impact of these technologies on the survival of foodborne pathogens such as Listeria monocytogenes. Thus, we performed challenge tests to evaluate the behaviour of L. monocytogenes throughout the curing process conducted within a patented cabinet on salmon, yellowfin tuna and swordfish. A significant decrease of L. monocytogenes count was recorded during salting for salmon, yellowfin tuna and swordfish (0.72, 0.51 and 0.84 Log10 CFU/g; p<0.05 and <0.001) and during drying and aging for tuna and swordfish (0.77 and 0.49 Log10 CFU/g; p<0.01 and <0.05). However, an increase of the pathogen was expected applying two predictive microbiology models using the parameters of the challenge tests. Further studies are therefore necessary to include into predictive models relevant parameters which may affect the behavior of L. monocytogenes, such as ventilation, relative humidity and effect of competitive microflora.