Egg yolks, which are often referred to as the yellow of eggs, comprise 30% to 33% of the total fluid weight of a whole egg. For ease of convenience, egg product manufacturers separate egg yolks from egg whites, and sell them as individual ingredients.
Yolks contain the entire fat content of the egg, along with a little less than half of the protein and a high proportion of vitamins and minerals. Egg yolks are also one of the few foods to naturally contain vitamin D, an important vitamin for bone structure.
Egg yolks have a favorable fat content. According to the USDA National Nutrient Database, the fat in one whole large egg, which again, is all contained in the egg yolk, is about two-thirds unsaturated. The unsaturated to saturated fat gram ratio is 1.67:1. Of the 2.6 grams of unsaturated fat that an egg yolk contains, 1.9 grams is monounsaturated and 0.7 grams is polyunsaturated. The result is a polyunsaturated fat to saturated fat gram ratio of 0.44:1.
Egg yolk products come in a variety of forms, with liquid being one of the most commonly used by food formulators. Liquid egg yolk products are sold refrigerated and are always pasteurized for safety and shelflife. Liquid egg yolk products can also include other ingredients such as salt or sugar for added shelflife and enhanced functionality.
All liquid egg yolk products are quick and easy to use at the commercial level, as they are readily integrated into manufacturing systems, including pumping and extrusion. They may be received in bulk tank trucks, smaller portable tanks or totes, metal or plastic containers, polyethylene-coated fiber or laminated-foil and paper cartons, or hermetically sealed polyethylene bags. These containers range in size from bags containing a few ounces to cartons up to 5 lbs and lacquer-coated tins and plastic pails up to 40 lbs.
Egg yolks are best known for their emulsification properties, particularly in mayonnaise, salad dressing and cream-style sauces. They have many other functional properties, too. For example, in bakery products, yolks impart a rich color that comes from the carotenoids present in the lipid portion of the yolk. The lecithin in the yolk also reduces the rate of moisture loss, at the same time it exerts a tenderizing effect on the crumb. Egg yolks are also used to impart richness to ice cream and frozen custard.
To locate a supplier of Refrigerated Liquid/Frozen Egg Yolk, visit http://www.aeb.org/food-manufacturers/where-to-buy-egg-products