eggs separate yolks
Egg yolks are rich in choline, lutein, and zeaxanthin, essential for cognitive and eye health; they provide high-quality protein and beneficial lipids including phospholipids and cholesterol needed for cellular function.
About
Egg yolk is the nutrient-rich yellow center of a chicken egg (Gallus gallus domesticus), composed of lipids, proteins, and micronutrients suspended in an emulsion. Yolks represent approximately 32% of a whole egg's weight and are distinctly separated from the albumen (egg white) by the vitelline membrane. The yolk's color ranges from pale yellow to deep golden-orange, depending on the hen's diet and breed, with deeper hues indicating higher levels of carotenoid pigments such as lutein and zeaxanthin.
Chemically, the yolk is an oil-in-water emulsion stabilized by lecithin and other phospholipids, making it a powerful natural emulsifier. This unique composition grants egg yolks their critical role in culinary science—they possess the ability to bind fats and liquids together in applications from mayonnaise to béarnaise sauce. The yolk also contributes richness, color, and structure to countless preparations.
Culinary Uses
Egg yolks are fundamental to classical European cooking and appear extensively in pastry, sauce work, and custard preparations. They serve as emulsifiers in hollandaise, béarnaise, and mayonnaise; bind and enrich egg-based custards, crémes anglaises, and ice cream bases; provide structure and moisture in cakes, pastries, and pasta doughs; and create richness in carbonara and other cream-based sauces. In Asian cuisines, yolks are preserved through salting (to create pidan and salted duck eggs) or fermented preparations. Yolks are also used to create luxurious pasta doughs, terrines, and are brushed onto pastries as an egg wash for browning and shine.