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Title: Commercial Processing and its effect on the Microbiological Safety of Shell Eggs

item Musgrove, Michael
item Jones, Deana
item Northcutt, Julie
item Cox, Nelson - Nac

Submitted to: National Egg Regulatory Officials Annual Meeting
Publication Type: Proceedings
Publication Acceptance Date: 6/17/2007
Publication Date: 6/27/2007
Citation: Musgrove, M.T., Jones, D.R., Northcutt, J.K., Harrison, M.A., Cox Jr, N.A. 2007. Commercial Processing and its effect on the Microbiological Safety of Shell Eggs. National Egg Regulatory Officials Annual Meeting.

Interpretive Summary:

Technical Abstract: Though egg shell microbiology has been studied over the years, little of it describes how modern US processing conditions impact microbial populations. When safety based regulations are implemented, this information can be used to determine critical steps critical to product safety. Shell egg surface populations (aerobic, yeasts/molds, Enterobacteriaceae, E. coli, and Salmonella spp.) were monitored at twelve points along the processing (accumulator, pre-wash rinse, washer one, washer two, sanitizer, dryer, oiler, scales, two packer head lanes). Three commercial facilities were visited three times which resulted in 990 eggs and 5,220 microbiological analyses. Though variations existed in levels recovered from plant to plant the patterns of fluctuations for each population were similar. On average, aerobes, yeasts/molds, Enterobacteriaceae, and E. coli populations were reduced by 30%, 20%, 50% and 30%, respectively. Log10 CFU/ml rinse on eggs collected from packer head lanes were decreased by 3.3, 1.3, 1.3, and 0.5, respectively, v. rinses from eggs collected at the accumulator. Salmonella were recovered from 0 – 48 % of pooled samples in the 90 repetitions. More Salmonella were recovered from pre-processed than in-process or ready to pack eggs. These data demonstrate that current commercial practices decrease microbial contamination of egg shell surfaces.