Ask the Doctor
Dr. Glenn Froning, is a world-renown expert on everything about eggs. The author of over 200 scientific publications and articles on poultry meat and eggs, he is a Professor Emeritus in the Department of Food Science and Technology at the University of Nebraska and the Food Science and Technology Advisor to the American Egg Board. Dr. Froning also answers the Board’s EGGSolutions™ Hotline. Please call him for information about egg products properties in processing, handling, and storage.
Q: What affects the foaming properties of egg whites?
A: Egg white is sensitive to high temperatures. Thus, pasteurization temperatures must be closely controlled. Yolk contamination needs to be below 0.05% to avoid loss of foaming properties. Surface active agents are generally added to liquid and dried egg white to improve foaming properties.
Q: Which works best, shell eggs or egg products?
A: Egg products are pasteurized to eliminate Salmonella contamination and can be tailored to specific functional needs. Egg products also are labor saving. Therefore, food safety and convenience makes egg products the best choice.
Q: Are there egg products specifically formulated for a specific function?
A: Yes, for example, egg white may be processed to produce optimum foaming properties. Salted yolk is often preferred by mayonnaise firms. Knowing a user’s need, the egg industry can formulate products to that specific function.
Q: What effects do pasteurized egg products have on baking?
A: Egg white proteins are susceptible to heat damage which may adversely affect foaming properties. However, addition of whipping agents such as sodium lauryl sulfate and triethyl citrate will help restore foaming properties. Pasteurization of whole egg and yolk products does not affect baking properties.
Q: Are there any functional differences in using dried egg products versus liquid products?
A: Functional attributes are quite similar. The choice of the user largely depends on how they fit into a specific application. For example, a cake mix manufacturer would prefer a dried egg product. Also, if storage space is a concern, dried products may be the choice.
Q: Are there any functional differences in using liquid egg products versus frozen egg products?
A: Freezing does not change egg white functionality. The functional properties of plain egg yolk or whole eggs are minimally affected by freezing. Salted egg yolk, that has been frozen, generally has better emulsifying abilities. Functionality in sponge cakes and custards are not adversely affected by using frozen egg products.
Q: Does freezing or pasteurization of egg yolk or whole eggs affect emulsification properties?
A: Pasteurization of yolk or whole eggs has been shown to have minimal effect on emulsifying properties. Previous research has shown that emulsification properties of salted yolk or whole eggs are not adversely affected by freezing.