Drying

Whole egg and egg yolk are dried by the spray-drying process. The liquid is atomised into a chamber where a flow of heated air evaporates water leaving the solids to be collected, sifted and packaged for storage and distribution. The water content after drying is in the range of 3 to 5 percent for a stable product.

Egg whites for drying must have the natural glucose (sugar) removed usually by fermentation to prevent adverse changes in storage. The fermentation may be accomplished by selected bacteria, yeast, or by enzymes. Egg white is usually spray-dried to about 6 to 8 percent water content. Egg white is also pan-dried by simply placing the fermented liquid in shallow trays where water evaporates leaving large crystals of dried egg white solids. Pan-dried egg white is ground to a fine powder for packaging.

Before drying a large part of water can be withdrawn by ultra filtration.