Novel technology to reduce pathogens in intact eggs

As we all know raw eggs and egg products can carry salmonella and cause foodborne illness and outbreaks, in some circumstances. Now researchers at the U.S. Department of Agriculture (USDA) have found a way to combat this risk through radio frequency (RF) technology.

A simple solution to minimise the risk of foodborne pathogens in eggs would be to pasteurise all raw eggs before they are consumed; however, less than 3% of commercial eggs are pasteurised in the US. Conventional thermal pasteurisation of intact eggs is usually a long process that involves submerging eggs in hot water for more than 57 minutes to inactivate salmonella cells. Researchers at the Agricultural Research Service’s (USDA-ARS) Eastern Regional Research Center in Wyndmoor, Pa., have now used a novel thermal technology that pasteurises eggs and inactivates salmonella cells with a short processing time.

During the study, the water molecules inside the egg rotate and align with the RF instrument’s electric field. This molecular friction causes the liquid inside the egg to heat up quickly and subsequently reduce salmonella by 99.999% within 24 minutes. The RF-processed eggs were transferred to the refrigerator and kept at 7°C for seven days to simulate the commercial cold chain temperature.

“After treatment with the system, no intact salmonella or sub-lethal salmonella cell remnants were recovered, and no cell recovery was found in the RF-treated eggs when stored at retail refrigerated temperature,” said USDA-ARS Research Food Technologist Daniela Bermudez-Aguirre. “The egg quality, such as the colour and other parameters, were also preserved through the processing.”

The technology is claimed to have shown several advantages when used in food, all without a negative effect on food quality. It is being described as a promising advancement for small farmers or egg processors, which could help to ensure food-safe eggs while minimising salmonella. As the technology is designed to preserve the quality of the eggs, they could then be suitable for special markets such as nursing homes, hospitals or schools.

ARS researchers will continue to develop this technology’s capabilities and expect it to be commercially available in the near future.

Image credit: iStock.com/Poravute