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ARS Home » Research » Publications at this Location » Publication #145911


item Jones, Deana
item Musgrove, Michael
item Northcutt, Julie

Submitted to: Poultry Science
Publication Type: Abstract Only
Publication Acceptance Date: 2/10/2003
Publication Date: 7/6/2003
Citation: Jones, D.R., Musgrove, M.T., Northcutt, J.K. 2003. External and internal microbial contamination of shell eggs during extended storage. [abstract] Poultry Science. 82(suppl.):53.

Interpretive Summary:

Technical Abstract: The current project was conducted to determine the microbial quality of commercially processed shell eggs during extended storage. Eggs were collected from a single in-line processing operation on three consecutive days. Control eggs (CE) were collected at the accumulator before entering the processing line. Washed eggs (WE) were retrieved after placement in cartons. All eggs were stored on pulp flats at 4 C for 10 wks of storage. Twelve eggs from each treatment were rinsed on the day of collection and each week of storage. After rinsing, eggs were sterilized in ethanol and contents aseptically collected for additional analysis. Total aerobes, Enterobacteriaceae, pseudomonads, and yeasts and molds were enumerated for shell rinses and pooled egg contents. During storage, no differences were found between CE and WE for Enterobacteriaceae and pseudomonads for either shell rinses or contents. No differences were found between treatments for population levels of total aerobes or yeasts and molds in the egg contents throughout the storage period. Significant differences occurred at each week of storage for external shell contamination by total aerobes between treatments. The greatest level of CE contamination occurred at 8 wks of storage (5.34 log cfu/mL). The lowest degree of contamination occurred at 0 and 1 wks of storage (4.37 and 4.35 log cfu/mL, respectively). The highest level of shell contamination with aerobic bacteria in the WE was found at 0 wks of storage (2.47 log cfu/mL) and the lowest level occurred at 7 wks (0.99 log cfu/mL). Yeast and mold contamination levels were also significantly different during each week of storage between treatments for shell rinses. Population levels ranged from 1.32 and 2.94 log cfu/mL for CE and 0.12 and 0.71 log cfu/mL for WE. Although previous plant sanitation sampling indicated high levels of bacterial contamination, commercially washed eggs were significantly less contaminated than unwashed eggs for the populations monitored.