USDA scientists develop technology for pathogen reduction in intact eggs
Researchers at the U.S. Department of Agriculture’s Agricultural Research Service (USDA’s ARS) have developed a thermal pasteurization method based on Radio Frequency (RF) technology that effectively reduces the presence of Salmonella in intact eggs. A simple solution to foodborne pathogens in eggs would be to pasteurize all raw eggs before consumption; however, less than 3 percent of commercial eggs are pasteurized in the United States. Conventional thermal pasteurization of intact eggs is usually a lengthy process involving 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., utilized a novel thermal technology to pasteurize eggs and inactivate Salmonella cells with a shorter processing time. During the study, water molecules inside the egg rotated and aligned with the RF instrument’s electric field. This molecular friction caused the liquid inside the egg to heat up quickly and subsequently reduce Salmonella by 99.999 percent 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. The egg quality, including color and other parameters, was also preserved through the processing. ARS researchers will continue to develop this technology’s capabilities and expect it to be commercially available in the near future.