egg yorks
Egg yolks are rich in choline, lutein, zeaxanthin, and selenium; they provide complete protein with all essential amino acids, and contain significant quantities of vitamin A and vitamin D, alongside beneficial phospholipids including lecithin.
About
Egg yolks are the nutrient-rich, lipid-laden central portion of a bird's egg, typically derived from chicken eggs though also sourced from duck, quail, and other poultry. The yolk comprises approximately 27% solids (primarily proteins and lipids) suspended in 73% water, encased in the vitelline membrane and surrounded by the egg white. Yolks range in color from pale yellow to deep orange depending on the hen's diet, particularly carotenoid content from feed sources, and possess a rich, slightly sweet flavor with subtle sulfurous notes.
Yolk composition is remarkably complex: it contains lecithin and other phospholipids that function as natural emulsifiers, making yolks essential in both culinary and food-industrial applications. The yolk's fat content—approximately 5.5 grams per large yolk—is primarily unsaturated, while the protein content (about 2.7 grams per yolk) provides essential amino acids including lutein and zeaxanthin.
Culinary Uses
Egg yolks function as fundamental building blocks in pastry and sauce preparation, serving as emulsifying agents in mayonnaise, hollandaise, béarnaise, and beurre blanc. They enrich custards, ice creams, and crème brûlée through their lecithin content and contribute moisture and richness to cake batters and cookie doughs. In Italian cuisine, yolks are central to carbonara and fresh pasta dough; in French cuisine, they thicken and enrich sauces, soups, and desserts. Yolks are boiled whole for salad garnish, poached in wine for œufs en meurette, and baked in piquant preparations. Their emulsifying capacity makes them invaluable for binding vinaigrettes and aioli, while their binding properties are essential in terrines, forcemeats, and pâtés.