Edited By: Dr. Asha Jyoti Bharati
An egg is made up of 3 components namely eggshell (9–12 %), egg white (60 %), and yolk (30–33 %). Egg white or albumen,is clear viscous liquid within the egg which protects yolk from the microorganisms and supply of nutrients to the embryo during the late stages of maturity (1).
Egg white contains more than 100 types of soluble major proteins like ovalbumin (54 %), ovotransferrin (12 %), ovomucoid (11 %), lysozyme (3.5 %), and ovomucin (3.5 %) and minor proteins like avidin (0.05 %), cystatin (0.05 %), ovo macroglobulin (0.5 %), ovo flavoprotein (0.8 %), ovoglycoprotein (1.0 %), and ovoinhibitor (1.5 %) (2).
Nutritional value of egg white
Egg white possess high nutritional and therapeutic value with significant antioxidant, anticancer, metal binding, antimicrobial, enzymatic and nonenzymatic properties (3). Egg white is low fat, cholesterol free and made up of water (88%) and protein (11%), carbohydrates, ash, trace amounts of lipids (1%) and other components as follows (4).
|Total lipid ( Fat)s||0.17 g|
|Dietary Fiber||0 g|
|Vitamin B-6||0.005 mg|
|Vitamin B-12||0.09 µg|
|Vitamin A||0 IU|
|Vitamin C||0 mg|
|Vitamin K||0 µg|
Health benefits of egg white
1. Egg white is rich in nutrients
Ovomucin found in egg white is highly glycosylated protein and 33% of ovomucin is made up of carbohydrates. Thus ovomucin alone can fulfill the demand of protein and carbohydrates in the body. Furthermore, ovalbumin (egg white protein) contain an adequate amount of amino acid composition and thus can be used as a drug carrier (5).
2. Ovalbumin in egg white recovers iron deficiency
Egg white contains ovalbumin which is very effective in the recovery of iron deficiency anemia (IDA) than egg yolk protein which delayed recovery of IDA. Thus ovalbumin in egg white influence iron absorption and maturation of red blood cells without affecting iron transport and hematogenesis in recovery from IDA (6).
3. Eating egg white boost muscle strength
A research study suggested that egg white is an excellent source of leucine (amino acid) which encourages the production of maximal skeletal muscle protein, increase muscle strength resistance as well as body mass growth in people (7).
4. Lowers the blood pressure
Thermolysin and pepsin hydrolysate present in egg white significantly reduced blood pressure in hypertensive patients. Therefore, egg white-derived bioactive peptides may be useful in the management of hypertension and associated complications (8).
5. Eating egg white helps in controlling the cholesterol level
Ovalbumin and ovotransferrin found in egg white decreased concentration of cholesterol in the serum, liver and intestinal mucosa. Thus egg white consumption is very beneficial for lowering triacylglycerides and low-density lipoprotein cholesterol levels, increasing high-density lipoprotein (HDL) cholesterol, and thereby lowers the risk of arteriosclerotic diseases (9).
6. Prevents obesity
Daily intake of egg white is safe for people who want to lose their weight. As egg white decreased feed intake, reduce appetite and fat accumulation in the liver, muscle and adipose tissues (10).
7. Boost immunity
Egg white act as an immune activator which regulates B and T lymphocyte activation, enhance the host defense mechanism against infectious diseases. Therefore, egg white is essential for the maintenance of the immune response and good choice to be included in a diet (11).
8. Egg white is rich in antioxidants
Proteins in egg white help in neutralizing free radicals and bind metal ions and protecting organs from damage. Thus, can act as powerful free radical scavengers which suppress reactive oxygen species and prevent the progress of various oxidative stress-related diseases (12).
9. Antimicrobial properties
Egg white is a rich source of antimicrobial proteins like lysozyme, ovotransferrin, ovomucin, and ovomucoid which act as a drug carrier, antimicrobial and immunomodulating agents. Therefore, egg white is very efficient to prevent bacterial growth and can be used in the pharmaceutical, nutraceutical, and food industries (13).
10. Anticancer property
Egg white is an excellent source of ovotransferrin, ovalbumin, ovomucin, and lysozyme which act as an antioxidant and tumor suppression agent. Thus egg white supplementation can inhibit the growth of tumors, and thus can be used as an anticancer agent (14).
Side effects of Egg white
1. Raw egg white prevents biotin (Vitamin B) absorption
Presence of anti-nutrient known as avidin in egg white is bound to the B vitamin biotin tightly and preventing its absorption. Further resulted in many problems such as dermatitis, hair loss, and neuromuscular dysfunction, However, this problem can be solved after cooking do not cause further detrimental effects (15).
2. Risk of contamination
Although egg white possesses tremendous nutritional values, it also contains a high risk of contamination on the outer shell surface and internally by Salmonella Enteritidis which is also known as food‐borne salmonellosis pandemic. Therefore, proper precautions like proper cooking until solidification before consumption is needed (16).
3. High allergy risk in children
Egg white contains important allergens such as ovomucoid, ovalbumin, ovotransferrin/conalbumin, and lysozyme. Egg white allergy generally found in children and continues re-exposure of egg white persistence of egg allergy beyond childhood resulted in several complications (17). However, the research study suggested that most people who are egg allergic were able to tolerate heated egg whites (18).
What is pasteurized egg white?
Well as we already know that whole egg is very prone to foodborne illness by Salmonella, loss of bioactive compound in normal temperature and can be contaminated by another way. Therefore, it should be mandatory to pasteurized egg to prevent contamination (19).
A research study suggested that after pasteurization of egg white the Salmonella illness would be reduced from 2636 to 270. Moreover, because of heat treatment, the pasteurized egg is less allergenic than fresh eggs, cheaper, easier to handle and store under the refrigerator to prevent bioactive compound (20).