Egg albumin is the protein-rich, gel-like substance that makes up the white of an egg. It contains about 10.9 grams of protein per 100 grams, virtually no fat, and only trace amounts of sugar. Often called “egg white protein,” it’s one of the most widely used protein sources in cooking, food manufacturing, and sports nutrition.
What’s Actually in Egg Albumin
Egg albumin isn’t a single protein. Over 220 distinct proteins have been identified in egg white, though a handful dominate. Ovalbumin is the most abundant, making up about 54% of the total protein. Ovotransferrin accounts for 12 to 13%, ovomucoid about 11%, and ovoglobulins roughly 8%. Smaller but functionally important proteins include ovomucin (3.5%), lysozyme (3.4%), and avidin (0.05%).
Each of these proteins behaves differently when heated, whipped, or dissolved, which is why egg whites are so versatile in the kitchen. Lysozyme, for instance, has natural antibacterial properties. Ovomucin helps stabilize foams. Ovalbumin is the primary driver behind the firm texture you get when you cook an egg white.
Egg Albumin vs. Blood Albumin
The word “albumin” shows up in two very different contexts, and they’re not the same thing. Ovalbumin, the main protein in egg whites, has a molecular weight of about 45 kilodaltons. Human serum albumin, the protein your liver produces and that circulates in your blood, weighs about 67 kilodaltons. They’re structurally and functionally distinct. Having an egg allergy does not mean you’ll react to albumin-based medical products derived from human blood, and vice versa.
Nutritional Profile
Egg albumin is essentially pure protein with almost nothing else. Per 100 grams of egg white, you get about 10.9 grams of protein, 0.34 grams of glucose, and no meaningful fat. That makes it one of the leanest whole-food protein sources available. A single large egg white (about 33 grams) delivers roughly 3.6 grams of protein for only about 17 calories.
The amino acid profile is what sets egg albumin apart from many plant proteins. Per 100 grams of egg white, you get approximately 820 to 845 milligrams of leucine, the amino acid most directly linked to triggering muscle repair. It also delivers strong amounts of lysine (around 740 mg), valine (565 to 613 mg), isoleucine (503 to 567 mg), and all other essential amino acids. Total essential amino acid content runs between 4,100 and 4,490 milligrams per 100 grams, depending on the source of the eggs.
Your body absorbs cooked egg protein at roughly 3 grams per hour. That’s relatively slow compared to something like whey protein, which means a 20-gram serving of egg protein takes about 7 hours to fully absorb. This slow, steady delivery can be useful for sustained amino acid availability, particularly overnight or between meals.
How It Builds Muscle
Egg whites are a staple in high-protein diets for good reason: they provide all nine essential amino acids in proportions the body can use efficiently. Research has compared whole eggs to egg whites for muscle building, and the results are nuanced. Whole eggs appear to stimulate slightly more muscle protein synthesis in the hours after eating, likely because of nutrients in the yolk like fats and vitamins. But when people eat egg whites as part of a consistently high-protein diet while strength training, the difference in actual muscle gain compared to whole eggs appears negligible, at least in young men.
For anyone managing calorie intake while trying to hit a high protein target, egg whites offer an advantage: you can eat a large volume of protein without the added fat and calories that come with yolks.
Why Egg Whites Work So Well in Cooking
Egg albumin has two functional properties that make it nearly irreplaceable in food: it foams and it gels.
When you whip egg whites, the proteins unfold and form a thin, elastic film around air bubbles. This creates the stable foam structure behind meringues, soufflés, and angel food cake. The proteins in egg white, particularly ovomucin and ovalbumin, adsorb rapidly at the boundary between air and liquid, creating a cohesive network that holds its shape. Foam stability depends on temperature, pH, freshness, and how long you whip.
Gelling happens in two stages. Heat first causes the proteins to unfold (denature), then the unfolded proteins link together into a three-dimensional network. This is what turns liquid egg white into a solid when you fry or boil it. The firmness of the gel increases with protein concentration, which is why a thick layer of egg white sets up more solidly than a thin one. Salt affects this process too: a small amount (up to about 0.1 molar) can slightly improve gel strength, but too much weakens it.
These properties also make egg albumin valuable in processed foods, where it serves as a binder, emulsifier, or texturizer in everything from baked goods to processed meats.
Egg Albumin Powder
Most commercial egg albumin powder is made by spray-drying liquid egg whites. The process is effective but harsh: the high heat and air exposure damage the protein’s foaming ability. To compensate, manufacturers typically heat the dried powder at 75 to 80°C for 10 to 15 days after drying. This extended low-heat treatment restores both gelling and foaming properties that were lost during spray-drying.
Egg white powder dissolves in water and can be used as a protein supplement, a baking ingredient, or a base for meringue. It’s shelf-stable and pasteurized, which eliminates the salmonella risk associated with raw liquid egg whites.
Allergenic Proteins in Egg White
Egg white is one of the most common food allergens, particularly in children. Four proteins are primarily responsible: ovalbumin, ovotransferrin (also called conalbumin), ovomucoid, and lysozyme. Of these, ovomucoid is often considered the most clinically significant because it resists heat. While some people with egg allergies can tolerate thoroughly cooked egg (where heat-sensitive proteins like ovalbumin have broken down), those who react to ovomucoid typically cannot.
Egg albumin can also appear as a hidden ingredient in processed foods, vaccines, and certain wines or beers that use egg white as a clarifying agent. If you have a confirmed egg allergy, checking labels for terms like “albumen,” “egg white solids,” or “lysozyme” is important.