Quality of radio frequency pasteurized shell eggs during extended storage under normal and moderate abuse conditions

This study investigated the microbiological and physical qualities of shell eggs pasteurized with radio frequency treatment combined with hot water (RF/HW) during 5 weeks of storage at 7.2 or 10 degrees C. Shell eggs inoculated with low or high levels of Salmonella Typhimurium were subjected to RF/HW pasteurization. The results showed that regardless of storage temperature, shell eggs pasteurized by RF/HW treatment were Salmonella free during 5 weeks of storage if initial counts were 2.5 log CFU/mL. However, when the inoculation level was 6.5 log CFU/mL, 0.7 log CFU/mL of Salmonella survived the pasteurization process. This small population remained stable over 5 weeks when eggs were stored at 7.2 degrees C, but grew to 7.4 log CFU/mL when stored at 10 degrees C after 4 weeks. Physical qualities, including weight loss, yolk pH, albumen pH, Haugh unit, yolk index, and albumen turbidity were also assessed during storage. In general, pasteurized shell eggs had similar quality as untreated eggs during storage at 7.2 degrees C for 5 weeks. Therefore, this study demonstrated that shell eggs pasteurized by RF/HW process are microbiologically safe and resemble untreated eggs during 5 weeks of storage at 7.2 degrees C.