An Assessment of the Microbiological Risks Involved with Egg Washing under Commercial Conditions

Abstract

The potential benefits of washing eggs is offset by a historical perception in the European Union that wetted eggs are prone to spoilage and water loss. This study describes the effects of spray jet washing under various processing conditions to shell surface counts of Salmonella and the presence of bacteria in egg contents. Experiments used eggs that were contaminated with Salmonella Enteritidis PT4 or Salmonella Typhimurium DT104 before cuticle hardening. Washing of contaminated eggs under optimum conditions resulted in a more than 5-log reduction of Salmonella counts from the shell surface. Salmonella was not isolated from the yolk or albumen of any egg washed by the optimal protocol, suggesting that when properly controlled, egg washing did not cause Salmonella to enter the contents. However, contamination did arise if strict control was not maintained over the wash and rinse water temperatures. Both Salmonella Enteritidis and Salmonella Typhimurium were shown to enter the egg contents when water temperatures were lowered, indicating that strict temperature control must be maintained in order to prevent the ingress of Salmonella into egg contents. Other washing machine parameters that were investigated did not significantly affect Salmonella entry into the egg contents but influenced shell surface kill levels to varying degrees.

Egg quality and age of laying hens: implications for product safety

“…However, research has also shown that wet washing can damage the cuticle layer, (which prevents the entry of bacteria across the egg shell) thereby leaving pores exposed and potentiating bacterial penetration (Sparks and Burgess 1993). Egg washing is widely used in many countries including Australia (Hutchison et al 2004). It has been demonstrated that the extent of cuticle deposition can influence the egg shell penetration of Salmonella Enteritidis at 20 C (De Reu et al 2006).…”

Effect of Egg Washing on the Cuticle Quality of Brown and White Table Eggs

“…In some countries, such as the United States, Australia, and Japan, egg washing has become a routine and established practice, is regarded as safe, and is perceived by consumers as an essential part of the hygienic production of eggs (10). Washing of class A table eggs is currently prohibited within the European Union, as Regulation (EC) No 589/2008 (4) states that ''Grade 'A' eggs shall not be washed or cleaned, before or after grading, except as provided for in article 3.''…”

Effect of rinses on microbial quality of commercially available eggs and its components before processing from Ilorin in western Nigeria

“…When compared with the rinse fresh egg components it varied from 2.3 to 1.03×10 2 cfu/ml whilst the yolk had the lowest number of 1.03×10 2 cfu/ml (Table 1). Some researchers (Musgrove et al 2005;Hutchison et al 2004) reported that rinsed eggs had a lower bacterial count compared to the unwashed eggs.…”