In addition to the washing of eggs, a difference between whole shell egg marketing standards in the USA and the EU countries is the USA’s use of cool chain distribution for eggs. From the time and grading at the packing station to the purchase of eggs by final consumer at retail level, eggs must kept at a controlled low temperature not exceeding 8ºC.
The primary function of egg washing is to remove visible contamination from the egg shell as efficiently as possible so resulting in a reduction of downgraded eggs and the enhanced visual appearance of final product. The washing operation should preferably be an industrial scale process and be carried out by using washing water of higher temperature than the eggs. If not eggs may suck contaminants inside the shell, which may induce egg spoilage. Damaged eggs should preferably be kept away from the washing process in order to avoid heavy pollution of the wash water.
In addition to the washing of eggs, shell egg marketing standards in the USA prescribe a cool chain distribution for eggs. EU countries are not allowed neither washing or cooling of Grade A shell eggs (See EFSA report).
Most important risks during egg washing are:
• Cross contamination during washing between eggs of the same batch. The machines, brushes and water can be contaminated and contaminate all eggs.
• Washing and drying eggs may damage the egg. Some eggs break or the egg cuticle is damaged. When an egg is still wet while packed this can cause increased mould growth.
• the egg washing machine should be located so the steam or vapor produced should not reach areas of other egg packing and grading activities.
• Water quality, temperature, pH is important, to prevent contamination by water and decreasing egg quality.
• Mostly washed eggs are oiled afterwards. This increases shelf life of eggs during chilled storage. When the cuticle is damaged oil protects eggs against micro organisms to enter.
• The machines should be well maintained and thoroughly cleaned, while remaining dirt poses a risk for the next eggs being washed.