The international trade of shell eggs has become more important in recent years in order to feed a growing worldwide population, meet food manufacturing demands, and address supply issues during disease outbreaks or product recalls. The primary barriers for the export and import of shell eggs are: whether to wash eggs and egg storage temperature. The current study was undertaken to compare egg quality factors as influenced by egg washing and storage temperature. Three lots of nest run white shell eggs were collected on consecutive d from a commercial in-line egg production facility. The treatment and storage conditions were selected to encompass the primary egg handling and storage conditions utilized throughout the world: washed; washed, oiled; and unwashed stored at 4°C; and unwashed stored at 22°C. Eggs were assessed weekly from 0 to 15 wk. Percent egg weight loss was greatest for the unwashed 22°C eggs (15.72%) and least for washed, oiled 4°C (0.33%, P < 0.0001). Less than 24 h at 22°C had a greater impact on yolk shape measurements decline than 15 wk at 4°C (P < 0.05). After 15 wk, average Haugh unit scores for all refrigerated treatments were still Grade A, and unwashed 22°C dropped from Grade AA to almost Grade B in one week. Room temperature storage of eggs rapidly declines egg quality. Egg treatment did not impact egg quality factors when stored at 4°C. Washing and oiling eggs before refrigerated storage did suppress the rate of egg weight loss.

In the United States, all shell eggs processed under the USDA Agricultural Marketing Service voluntary grading standards must receive a shell sanitizing rinse of 100–200 ppm chlorine or its equivalent after leaving the washing process. A study was conducted to determine the concentration of peroxyacetic acid ( PAA ) which would be equivalent to 100–200 ppm chlorine ( Cl ) in reducing target organisms under the required washing conditions for shell eggs. Three isolates of Salmonella spp. (Enteritidis, Braenderup, and Typhimurium), as well as Enterobacter cloacae were used as inocula. Sanitizing treatments were negative control; deionized water; 100 and 200 ppm Cl; and 50–500 ppm PAA (7 concentrations). Considering all isolates tested, 100 and 200 ppm chlorine had 2.6 and 2.3 log cfu/mL cultural organisms remaining on shell surface; 50 and 100 ppm peracetic acid had 1.9 and 1.0 log cfu/mL cultural organisms remaining, respectively, compared with untreated control average of 3.8 log cfu/mL ( P < 0.001). Salmonella Typhimurium was least resistant to shell sanitizer treatments. Peroxyacetic acid concentrations >250 ppm did not produce significant reductions in microbial populations as PAA concentration increased. Culturing for the prevalence of viable and injured organisms, 400–500 ppm PAA resulted in fewer eggs ( P < 0.0001) being positive for Salmonella spp. E. cloacae was culturable via enrichment from 99.4% of inoculated eggs, regardless of sanitizer treatment. The results of this study indicate that 50–100 ppm PAA is equivalent to 100–200 ppm chlorine in reducing egg surface microorganisms. The use of 400–500 ppm PAA resulted in a lower incidence of viable, but not culturable, Salmonella spp. on the shell surface. E. cloacae resulted in almost 100% viable, but not culturable, organism recovery for all sanitizing treatments and should be considered as an indicator organism when studying processing facility sanitation procedures.