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United States Department of Agriculture

Agricultural Research Service

Research Project: CONTROLLING EGG CONTAMINATION WITH SALMONELLA ENTERICA BY UNDERSTANDING ITS EVOLUTION AND PATHOBIOLOGY

Location: Egg Safety and Quality

Title: Implications of Negative Pressure Imaging for Microcrack Detection and Salmonella Contamination in Shell Eggs

Authors
item Jones, Deana
item Lawrence, Kurt
item Yoon, Seung-Chul
item Heitschmidt, Gerald

Submitted to: European Poultry Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 31, 2010
Publication Date: August 23, 2010
Citation: Jones, D.R., Lawrence, K.C., Yoon, S.C., Heitschmidt, G.W. 2010. Implications of Negative Pressure Imaging for Microcrack Detection and Salmonella Contamination in Shell Eggs. European Poultry Conference Proceedings.

Technical Abstract: Microcracks in eggshells are difficult for human graders to detect and pose an important food safety risk. Negative pressure imaging technology has been developed with 99.6% accuracy in detecting microcracks. A study was conducted to determine if the microcrack detection system would increase penetration of Salmonella into egg contents or lead to cross contamination. Thirty dozen Grade A large white retail eggs were used for each of three replicates. Cracked eggs were removed and 72 eggs per replicate were dip inoculated in a 105 cfu/mL solution of nalidixic acid resistant Salmonella Typhimurium, while 144 eggs were dipped in sterile buffered peptone water. All eggs were incubated overnight at 37C before imaging. Forty-five eggs of each treatment were imaged in the following order: control, inoculated, control. Imaged and non-imaged eggs from each treatment were utilized for cultural analysis of a shell rinse, shell emulsion and contents sample for each egg. S. Typhimurium levels were monitored on brilliant green sulfa agar with 200 ppm nalidixic acid. S. Typhimurium was not detected on or in any of the control eggs, including the ones imaged after the inoculated eggs. No differences in S. Typhimurium levels were found for any sample location between imaged and non-imaged inoculated eggs. Therefore, the negative pressure imaging system for microcrack detection did not result in microbial cross contamination or increase the level of microbial penetration in inoculated eggs. The imaging system can be utilized to assess eggs for cracks without negative food safety implications.

Last Modified: 10/1/2014