Radio Frequencies may be a better way to make safer eggs.
Salmonella bacteria is a concern for the food industry, the Center for Disease Control reports an annual 1.3 million infections, 26,500 hospitalizations, and 420 deaths in the United States.
Eggs are often a reported offender but pasteurization has a time and labor intensive process, which is why researchers with the USDA's Agricultural Research Service (ARS) wanted to find another sterilization method.
ARS Research Food Technologist Dr. Daniela Bermudez says the established way of pasteurizing eggs through water is not often used, "Only three percent of the eggs are sold pasteurized because it takes a lot of time, it can damage the quality of the egg. And you need to pay an extra price for pastured eggs."
And because the ARS team noticed a lot of cases of salmonella in eggs, they searched for a faster way to pasteurize.
Bermudez says, "So when you are using water to pasteurize eggs, usually 56.7 degrees Celsius. If you start increasing the temperature, let's say you reach 60 or beyond 60, you're going to damage the quality of the egg."
The team found Radio Frequency technology, using its energy to warm temperatures to those pasteurization levels.
Without cooking the egg, of course, Bermudez says it's similar to a microwave, "The main difference is the working frequency. In the radio frequency we are using, let's say lower frequency compared to microwave technology."
Bermudez says the principle is the same as they aim at the water inside of the egg, "These water molecules start to rotate when you start the application of the electric field. It could be microwave, it could be the radio frequency. So what happens to the water molecules inside? They start to rotate, they are trying to align to the electric field that you are providing with the microwave or radio frequency. And when they start rotating they generate friction. So this friction warms up the egg."
And because the heat comes from within, it applies more evenly and efficiently, going directly to the yolk. Standard pasteurization dunks eggs in warm water for a full hour. Radio technology takes two-fifths of the time. After 10 years of research, they're now working with the fifth generation of pasteurizing technology.
Bermudez says with the billions of eggs produced every year, the saved time makes their invention more viable, it has a capacity now of 24 eggs, "You may be like, 'Well that is not going to work.' The unit we have has been designed to replicate as needed, so if you need to process a thousand eggs an hour that would be possible to do it, because it's just like adding blocks. Our design is standard and we can add as many blocks as needed and we're planning to have a semi-continuous process."
Testing Radio Frequencies at scale means working with partners, Bermudez says, "We're working with a local farm, they're processing millions of eggs every day, so our unit is expected to process many eggs at a time; 24.5 minutes is still something we can do for billions of eggs."
They are still trying to reduce the pasteurization time to under 20 minutes.
The Agriculture Research Service is always looking for collaboration, Bermudez says producers can email her or contact the ARS for more details.