- About one out of every 20,000 chicken eggs produced in the United States has a high risk of being contaminated with Salmonella bacteria, and some of the harmful kinds, notably S. enteritidis, are often found in raw or undercooked eggs.
- Until now the only way to be safe was to either cook or pasteurize the eggs in a hot-water-immersion process, but now there may another alternative.
- Studies led by Agricultural Research Service chemical engineer Dave Geveke have resulted in a better, faster way to pasteurize raw shell eggs without harming their taste, texture, color, or other key characteristics by heating them with energy from radio waves followed by a short hot-water bath.
The technique was tested on 4000 eggs, with each raw egg positioned between two electrodes that produce radio waves as the egg is slowly rotated. Water is also sprayed on the egg to cool it and offset some of the heat created by the waves. Unlike conventional cooking, which heats from the outside in, radiofrequency (RF) heating warms the egg from the inside out, giving more heat to the dense, heat-tolerant yolk than the heat-sensitive white. The warmth of the bath also effectively completes the pasteurization process without without overprocessing it. The whole process takes around 20 minutes, which is 1/3 the time of the hot-water-immersion technique.
This new technique may prove a boon to chefs who want to make mousses, frostings, and other recipes that call for raw eggs without introducing the risk of salmonella.