Submitted to: Poultry Science
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2004
Publication Date: June 1, 2004
Citation: Musgrove, M.T., Jones, D.R., Northcutt, J.K., Harrison, M.A., Cox Jr, N.A. 2004. Impact of commercial processing on the microbiological safety and quality of shell eggs [abstract]. Poultry Science. 82:157. Technical Abstract: Egg shell microbiology has been studied extensively over the years though little of it describes how modern US processing conditions impact bacterial populations. As food safety regulations (sanitation/HACCP) are being drafted for the industry, such information can be important in determining processing steps that are most critical to product safety. Five different shell egg surface populations (aerobic, yeasts/molds, Enterobacteriaceae, E. coli, and Salmonella spp.) were monitored at 12 points along the processing line (accumulator, pre-wash rinse, washer one, washer two, sanitizing rinse, dryer, oiler, scales, re-wash belt entrance, re-wash belt exit, and two packer lanes). Three commercial in-line facilities were visited three times allowing for the sampling of 990 eggs that were subsequently analyzed by 5,220 microbiological samples. Though variations existed in levels recovered from plant to plant the patterns of fluctuations were similar for each population at the three plants. Aerobes, yeasts/molds, Enterobacteriaceae, and E. coli populations were reduced by 30%, 40%, 75% and 50%, respectively, by the end of processing. Log10 counts / ml rinse on eggs collected from packer lanes were decreased by 3.2, 0.8, 1.4, and 0.5, respectively, when compared to rinses from eggs collected at the accumulator. Salmonella were recovered from 0 to 48% of pooled samples in the nine replications. More Salmonella were recovered from pre-processed (accumulator, pre-wash, re-wash belts) than in-process (washers, sanitizing rinse, dryer, oiler) or ready to pack eggs (scales, packing lanes). These data demonstrate that current commercial practices decrease microbial contamination of egg shell surfaces.