Egg washing process and its health implication

Chicken eggs which are the most commonly eaten eggs by human, supply all essential amino acids for humans, a source of complete protein and provide several vitamins and minerals, including retinol (vitamin A), riboflavin (vitamin B₂), folic acid (vitamin B₉), vitamin B₆, vitamin B₁₂, choline, iron, calcium, phorphorus and potassium. Although not as abundant as red meats, eggs are a source of co-enzyme depending on how it was prepared

Given that water facilitate the movement of bacteria through the shell into the egg contents the way in which the water is applied (example temperature of the water, duration of washing and use of brush) and the quality of the water is critical to the success of the egg washing process. The major parameter which influence egg washing process are water temperature, quality of water and the mineral content, washing chemical, P^H of the washing water and the use of brush/jets (Hutchison et al., 2003).

Water temperature is important in washing process of eggs, when eggs are placed in a cooler bacterial suspension, a pressure gradient is set up which drains bacteria through the shell into the interior. When culture temperature was of higher temperature, a negative hydrostatic pressure was created which minimizes the movement of solvent into the egg. The temperature of washing water should be above 11⁰C higher than the egg temperature (Hutchison et al., 2003). Washing egg with colder water will heavily contaminate the egg with bacteria, especially when water contain large amount of soluble iron.

To ensure that washing does not result to contamination of the egg with organic or inorganic residues, potable water should be used at all stages of washing. Soft water with low calcium content is ideal for egg washing. Water used in washing of eggs should have an iron level of <2ppm (Hutchison et al., 2003).

Chemical used when washing eggs should be food safe and compatible with the person washing the eggs. While chlorine and quaternary ammonium compound are commonly used for sanitizing eggs, other compound such as peracetic acid has also been used in commercial egg washing. However, chemical used may be effective in reducing the bacterial load may also damage the egg cuticle or shell (Hutchison et al., 2003).