Q. How can egg products help breading adhere to frozen appetizers?
A. The proteins in egg products, specifically the whites, assist with adhesion or binding of the breading to the foods. Research suggests that batters with protein levels of 10% to 15% tend to be the most effective as binding agents.
Q. What affects the foaming properties of egg whites?
A. Egg whites are 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 whites to improve foaming properties.
Q. Are there egg products specifically formulated for a specific function?
A. Yes. For example, egg whites may be processed to produce optimum foaming or gelling properties, and salted yolks are often preferred by mayonnaise or salad dressing manufacturers. Knowing a user's need, the egg industry can formulate products to that specific function.
Q. Are there any functional differences in using dried egg products versus liquid products?
A. The functional attributes are quite similar. The choice largely depends on how they fit into a specific application. For example, a cake mix manufacturer would prefer a dried egg product. Dried products are also an option if storage space is a concern. Liquid egg products readily mix with other wet ingredients and can be incorporated into manufacturing systems, including pumping and extrusion.
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 frozen sugared or salted egg yolks or whole eggs are minimally affected as compared to refrigerated plain yolks or whole eggs. Functionality in sponge cakes and custards are not adversely affected by using frozen egg products. However, salted egg yolks generally have better emulsifying properties if frozen.
Q. Why are egg yolks used in noodles?
A. Besides adding a rich yellow color, egg yolks are a natural protein binder for all types of noodles. This is particularly useful in par-cooked pasta sold refrigerated under modified packaging conditions, or in prepared foods refrigerated or frozen.
Q. Can eggs help get a crispy coconut batter to stick to a frozen appetizer product?
A. Egg whites have excellent adhesive properties. To simplify the coating process, blend dried egg white with the remaining dry ingredients before creating the batter. The dried egg white can be 20% to 30% of the dry ingredient blend. Normally, high-protein sources such as dried egg white produce better adhesion than starches, gums or alginates.
Q. Why is salt or sugar added to frozen egg yolks?
A. Commonly, 10% salt or 10% sugar is added to egg yolks before they are frozen in order to prevent an increase in viscosity and inhibit gelation. The addition of salt or sugar reduces gelation by preventing the aggregation of the lipoproteins during freezing. Gelled egg yolks are quite difficult to blend with other ingredients.
Q. Why is glucose removed from egg whites prior to dehydration?
A. Glucose is removed to prevent glucose-protein (Maillard) and glucose-cephalin reactions, which may produce egg products with off-flavors during storage. The interaction of reducing sugars (glucose) with amino acids needs to be prevented both during spray drying and during the hot-room pasteurization method used for spray-dried egg whites.
Q. We often develop prototype products using shell eggs before we develop large-scale formulations using egg products. What is the conversion between shell eggs, dry eggs, and refrigerated liquid egg products?
A. The simple table below should help.
Q. What makes high-whip egg whites superior foaming agents than regular egg whites?
A. Processors first must produce an egg white which is low in yolk-fat content (less than 0.05%). If the egg white is liquid or frozen, tri-ethyl citrate is commonly added at 0.03% to improve foaming properties by reducing surface tension and helps counteract any yolk contamination. Some processors add a combination of 0.03% sodium lauryl sulfate and 0.03% tri-ethyl sulfate.
Dried egg white is handled differently. First glucose is removed from the liquid egg white prior to spray-drying to prevent the Maillard reaction (browning) during the hot-room pasteurization method after drying to 6 - 8% moisture. Sodium lauryl sulfate, which also lowers surface tension, has been found to be a more effective foaming agent when used in dried egg white at a level of less than 0.1% (solids basis). The hot-room pasteurization of spray-dried egg white (e.g. 60º- 70ºC/140-158ºF for 7-10 days) has also been shown by some researchers to improve foaming properties of dried egg white. Hot room pasteurization likely opens up hydrophobic regions by partial unfolding of the protein structure. This helps stabilize the film around the air bubbles.
Q. What is an enzyme modified egg yolk product, and what advantages does it have over regular egg yolk products?
A. Egg yolk has components (e.g. low density lipoproteins) which provide excellent emulsification properties to mayonnaise and salad dressings. Phosphatidylcholine (lecithin) is a part of the lipoprotein complex. Enzymatic treatment of phosphatidylcholine with phospholipase converts phosphatidylcholine to lyso-phosphatidyl-choline. Modified egg yolk has high water solubility, enhanced emulsifying properties and is more heat-stable. Both liquid and dried yolk can be modified. The improved solubility and heat stability offer advantages to food formulations.