Mayonnaise, aioli, and other common foods rely on an ingredient that can also pose a potential food safety risk: raw eggs. But a recent study out of Australia turned to sous vide to see if the low-temperature cooking method could reduce this risk. Researchers found that cooking whole raw eggs sous vide for a brief time decontaminated the eggshell from a certain strain of salmonella—while also still retaining the unique properties that chefs rely on for light, fluffy raw-egg dishes.
The study, entitled “A Successful Technique for the Surface Decontamination of Salmonella enterica Serovar Typhimurium Externally Contaminated Whole Shell Eggs Using Common Commercial Kitchen Equipment,” was published online in November 2019 in Foodborne Pathogens and Disease. Researchers led by Thilini Piushani Keerthirathne at Adelaide’s Flinders University found that eggs contaminated on the outside shell with Salmonella enterica serovar Typhimurium—a common strain in the country, according to the study—were completely decontaminated after cooking in a water bath set to 134.6°F (57°C) for 9 minutes.
Ten local chefs and food handlers also evaluated whether eggs cooked at that time and temperature still produced acceptable results in food. These culinary volunteers were given both cooked and uncooked eggs to make mayonnaise, and then were asked to assess “overall acceptability, texture, appearance, smell, color, and stability.”
The study concluded: “There was no difference in the chef’s acceptance of the heat treated and untreated eggs, which further supports the findings that this heat-based decontamination method does not affect the physiochemical or functional properties of the eggs.”
Based on the results of this study, chefs could pre-cook whole eggs for a brief time before preparing mayonnaise and other dishes to minimize the risk of salmonella exposure. Researchers note, however, that this study did not test other strains or the cooked eggs shelf life. But for busy restaurants looking to make safer, fresh mayonnaise, a quick water bath cook might be worth a try.