Dieters and weightlifters who seek to gain muscle mass turn to the egg white as a lean protein source that can be used in an assortment of dishes. In fact, eggs often are dubbed a "perfect protein" and are regarded as the standard for comparing protein quality, according to Linda Page's "Cooking for Healthy Healing."
Caloric Content
A raw egg white provides 14.4 calories that come from protein. That's most of the egg white's 15.8 overall calories, according to Nutrition Data. The egg white's other calories come from fat, 0.5 calories, and carbohydrates, 0.9 calories. In general, protein has about four calories per gram.
Protein Grams
One large egg white provides about 4 g protein, while at the same time being low in saturated fat as well as cholesterol, advises Nutrition Data. An egg white provides a person about 7 percent of his recommended daily protein. This value is based on a 2,000 calorie diet, and is meant to apply to people ages four years old and older.
Amino Acids
An egg white's amino acid score is 145. An amino acid score that is above 100 means a food provides a high-quality or complete protein. Protein quality is dependent on a food containing all nine of the essential amino acids required by humans in the correct proportions, as per the U.S. Institute of Medicine's Food and Nutrition Board. If one amino acid is not present in a food it is classified as an incomplete protein, according to Nutrition Data.
Digestibility
The digestibility for egg protein is rated at 97 percent, according to the Egg Nutrition Center. That means a person's body absorbs 97 of an egg's protein as amino acids. These amino acids are available for new protein synthesis in the body and to replace lost protein.
Protein Types
An egg white's proteins have some unique biochemical characteristics, according to George F. Stewart's "Advances In Food Research." The protein called ovalbumin makes up about 54 percent of an egg white's proteins. This protein is easily denatured, or made unfit for eating without destroying its usefulness for alternate applications, and often is used by chemists. An egg white also has conalbumin, an iron-binding protein, as well as ovomucoid, lysozyme, ovomucin, flavoprotein, and avidin, which binds the B vitamin biotin. About 8 percent of the protein content in an egg white is unidentified.
Potential
The U.S. Department of Agriculture is researching various ways to pasteurize raw egg whites for use by food service providers, food manufacturers and for people to purchase in grocery stores. Thermal treatment to pasteurize eggs damages the eggs' functional properties. Ultraviolet light pasteurizing, used and approved by the Federal Drug Administration in juice pasteurization, might reduce the amount of thermal treatment needed to rid egg whites of E. coli and other bacteria that pasteurization seeks to neutralize.
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