Protein Content in Egg White
Egg white powder contains 7.5 grams of protein per 10 grams of powder, while whole dried egg contains 4.8 grams of protein per 10 grams. 1
Protein Composition and Quality
Egg white is recognized as the highest quality protein source available, with a biological value of 100, serving as the reference standard against which all other protein sources are compared. 1
- Egg white proteins constitute approximately 10% of egg white's total weight 2
- The protein content is remarkably pure, as egg whites are one of the few dietary sources containing pure protein without fat or carbohydrates 1
- Two egg whites provide the same protein content as 1 ounce of meat 1
Major Protein Components
The protein fraction in egg whites consists of several functionally important proteins 3, 4:
- Ovalbumin comprises 54% of total egg white protein 3
- Ovotransferrin accounts for 12% 3
- Ovomucoid represents 11% 3
- Lysozyme contributes 3.5% 3
- Ovomucin makes up 3.5% 3
Practical Equivalents for Clinical Use
For oral food challenge testing protocols, the following protein content measurements are standardized 1:
- Egg white powder: 7.5 g protein per 10 g powder
- Whole dried egg: 4.8 g protein per 10 g powder
- One whole cooked egg contains approximately 6.1 g total protein 1
Effect of Heating on Protein Quality
Heating egg whites does not diminish their protein utilization rate. 5
- The net protein utilization (NPU) remains essentially identical whether egg whites are consumed unheated (97.5%), soft-boiled (96.5%), or fully boiled (96.5%) 5
- These NPU values significantly exceed those of whey protein (90.5%) 5
- This makes egg whites a superior protein source regardless of preparation method 5
Clinical Applications
Egg white protein demonstrates multiple health benefits beyond basic nutrition 6:
- Increases in muscle mass and strength enhancement 6
- Cholesterol lowering effects 6
- Visceral fat reduction 6
- High net protein utilization rate with complete amino acid profile 6
Critical Considerations
When using egg whites for protein supplementation or food challenges, the powder form provides the most concentrated and measurable protein source at 75% protein content by weight. 1 This is particularly important in clinical settings requiring precise protein dosing, such as oral food challenge protocols or therapeutic nutrition interventions.