Methods to increase safety of smoked salmon

A recent study from the Journal of Food Science, published by the Institute of Food Technologists, determined that smoking salmon at adequately high temperatures is a step in reducing the risk of Listeria monocytogenes in the fish.

Smoked salmon is produced by salting, smoking and trimming or slicing the fish and then vacuum-packaging the final product. Researchers from the US Department of Agriculture (USDA) examined the survival of Listeria monocytogenes during the processing of smoked salmon. This pathogen has the ability to grow at low temperatures and can cause foodborne illness upon consumption. Smoked salmon is a ready-to-eat product and, if it is not processed and handled properly, it can become contaminated with Listeria monocytogenes.

Researchers from USDA’s Agricultural Research Service (ARS) in Wyndmoor, PA, examined the survival of Listeria monocytogenes as affected by salt, smoke compound and temperature between the cold and hot smoking of salmon. Greater inactivation rates of Listeria monocytogenes occurred in samples processed at higher temperatures and in samples containing higher concentrations of salt and smoke compound. The inactivation rate increased tenfold when the temperature increased by 5 °C, indicating that smoking temperature is a main factor affecting the inactivation of the pathogen. In addition, salt and smoke compounds also contribute to the inactivation effect.

“The data and model developed in this study can be used on select concentrations of salt and smoke compound, as well as smoking temperatures of 40-55 °C, to minimise the presence of Listeria monocytogenes in smoked salmon and, therefore, increasing its safety for consumers,” says lead researcher Dr Cheng-An Hwang.