Eggwhite

Egg white is the clear liquid (also called the albumen or the glair/glaire) contained within an egg. In chickens, it is formed from the layers of secretions of the anterior section of the hen's oviduct during the passage of the egg. It forms around either fertilized or unfertilized yolks. The primary natural purpose of egg white is to protect the yolk and provide additional nutrition for the growth of the embryo (when the egg is fertilized).

Composition

Egg white consists primarily of about 90% water into which is dissolved 10% proteins (including ovalbumins, conalbumins, ovomucoids, and lysozymes). Unlike the egg yolk, which is high in lipids (fats), egg white contains almost no fat, and the carbohydrate content is less than 1%. Egg white has many uses in food and many other applications, including the preparation of vaccines, such as those for influenza.

Nutritional Value

Egg whites are a low-calorie, fat-free food. They contain the bulk of the egg’s total protein, with minimal calories compared to the yolk. They are a popular choice for people engaging in high-intensity training regimes and those on low-cholesterol diets. Egg whites are rich in vitamins and minerals, including calcium, magnesium, potassium, and selenium, along with vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B12, and folate.

Culinary Uses

Egg whites are widely used in the culinary world. They can be used to make meringue, for leavening cakes and soufflés, and to clarify stocks and soups. Egg whites are also used in making cocktails, where they are shaken with other ingredients to create a frothy texture. Additionally, they are a key ingredient in many protein shakes and smoothies for those looking to increase their protein intake without significantly increasing calorie intake.

Health Concerns

Raw egg whites contain avidin, a protein that binds biotin (vitamin B7) and can lead to its deficiency if consumed in large quantities. Cooking egg whites denatures the avidin, making it unable to bind to biotin, and thus, cooked egg whites are considered safe to eat in terms of biotin absorption.

Allergies

Egg white is one of the most common food allergens, especially in children. People with an allergy to egg white may experience a range of symptoms from mild (such as hives) to severe (such as anaphylaxis). It is important for individuals with egg white allergy to carefully read food labels and be aware of foods that may contain hidden egg components.

Storage

Egg whites can be stored in the refrigerator for up to a week. They can also be frozen for longer storage. When freezing, it is advisable to note the number of egg whites being frozen to make it easier to use them in recipes later.

Environmental and Ethical Considerations

The production of eggs, including egg whites, has environmental and ethical considerations. These include the welfare of laying hens and the environmental impact of egg production on water use, land use, and greenhouse gas emissions. There is a growing interest in finding sustainable and ethical alternatives to conventional egg production.