How many eggs do you eat a week? According to statistics from the Ministry of Agriculture, Food, and Rural Affairs in 2016, consumption of eggs in Korea is 1.35 billion and consumption of eggs per person is 268 annually. In addition, the consumption is steadily increasing every year. In 2000, an average person consumed 184 eggs a year, but now that number is 268. Korea ranks in the top 10 in the world for egg consumption, which shows Koreans' strong preference for eggs. An organization that promotes egg consumption said that only one percent of Koreans do not eat eggs each week. What qualities do eggs have and how do you choose fresh ones? Find out various things about eggs that you do not know.
1. Let's Learn about Eggs!
a. The Structure of an Egg
On the surface of an egg, a hard shell which is called an eggshell protects the egg. Inside it, there are two layers of skin. The shell contains several thousand pores that permit the egg to breathe. Through these pores, carbon dioxide and water evaporate and microorganisms can pass through the egg, which can damage the contents of the egg. There is an air house between the two layers of inner shell. The air house is small when the chicken lays an egg. However, it grows bigger when water and carbon dioxide evaporate. There are also egg whites in the inner shell. There is a watery egg white between the outer skin, the yolk, and a stiff egg white in the middle of it. To hold the yolk in a central position, there is a connection of tissues from the membrane that surrounds the yolk from the top and bottom of the second membrane that is technically known as the chalaza. If you crack an egg then you may see a whitish string in the egg white and this is the chalaza. An egg consists of approximately 2/3 egg white and 1/3 egg yolk.
b. The Origin of Eggs
The chicken was a wild bird that lived in South Asia. Bird eggs have been valuable foodstuffs since prehistoric times, in both hunting societies and more recent cultures where birds were domesticated. The chicken was domesticated for its eggs. The spread of domesticated chickens around the world has been the question under debate for 30 years in academic circles. The strong theories now are Darwin's theory and the Northern route hypothesis claimed by British and Chinese paleontologists. According to Darwin's theory, chickens became domesticated firstly in India and Phoenicians spread them to Europe on the way through West Asia and the Middle East. According to the Northern Route hypothesis, chickens were domesticated in China, which spread across Korea to Japan as it conducted trade with Korea. Another theory says that chickens spread to Europe along the Silk Road. We do not know exactly about this, but we can see that humans have been eating eggs for a long time.
c. The Types of Eggs
We can classify eggs according to their weight, breeding conditions, and color of egg shells. Differentiated by weight, eggs which weigh less than 43g are classified as small eggs, 44~51g being medium eggs, 51~60g as large eggs, 60~67g as extra-large eggs, and eggs heavier than 68g are called jumbo eggs. Depending on the farming environment, it can be divided into two categories: a fertile chicken egg and an unfertilized egg. In reality, both kinds of egg are equally nutritious. The chickens that produce unfertilized eggs live in a small hen house and undergo artificial fertilization, while the chickens that produce fertile chicken eggs are bred for natural mating. We cannot distinguish whether it is a fertile egg or not with the naked eye. The price of a fertile chicken egg is higher as a chicken is raised in an environment that is less stressful than the others. Depending on the colors of eggs, it can be classified as white, blue, or brown. Also, the three kinds of eggs are equally nutritious. Egg color is determined by the genetics of the hens. Brown eggs are usually available on the market because these hens lay eggs often, which makes sales more profitable compared to other kinds of chickens.
d. How to Choose Fresh Eggs
If you go to buy an egg, you can find various kinds and prices of eggs depending on the food a chicken eats. It is better to look for fresh eggs because there is no big difference in nutritional content, although it is true that a chicken which is well-fed produces better eggs. It is good to have a thick shell when choosing an egg. This is because the glossy shell means an egg is old. Also, the shell should be translucent when exposed to sunlight and rough when touched. It does not make any noise when you shake it. It is fresh if it is heavy for its size. When you break an egg to cook at home, the yolk should rise round. If the yolk spreads, it means the egg is old. There is also a way to check whether it is fresh or not by soaking it in salt water. If it floats, it also means that the egg is old. Because, as mentioned before in the structure of the egg, the air house of the egg grows bigger with age. The weight of the egg is reduced by 3 grams because of this, so it is lighter than the fresh egg and floats.
e. How to Store Eggs
You should not think eggs will stay fresh if you just keep them in the refrigerator. Eggs are more fragile than you think, and even a slight shock can cause the yolk to come loose, reducing freshness. Therefore, for safe storage, keep it deep inside rather than the refrigerators’ door, with the sharp part of the egg pointing downward and the round part facing upwards. In some cases, you wash an egg to keep it clean, but when you wash an egg, the protective membrane of the egg shell falls off, and pollutants are absorbed, which affects the freshness of the eggs. Furthermore, eggs have so many components to the shell that absorb odors and flavors of other food well. It is not recommended to store them with foods that have strong smells.
f. The Nutrients Which an Egg Has
Eggs are one of the perfect foods that can provide all the nutrients what we need. The formation of amino acids in proteins is said to be the best in nutrition. Egg whites mainly contain protein and yolk which are both a source of fat and protein at the same time. The number of people who refuse to eat eggs because of the cholesterol in the yolk causing adult diseases has been increasing in recent years. However, because the yolk contains a lot of vitamins A, B2, D, E and iron, eating one a day is better for one’s health except for those who suffer from hyperlipidemia. There are also cases of people eating eggs raw. It has a cause-absorbing quality, which is good for soaking up alcohol after drinking. However, it is generally healthier to first cook before eating them than eating them raw, as the protein avidin in the raw egg destroys the soluble vitamin “biotin.” Cooking is more nutritious because it does not destroy nutrients by changing the characteristics of avidin.
g. The Traits of an Egg
The traits of eggs include thermal coagulation, emulsification, and foamability. First, thermal coagulation is the property by which an egg is coagulated when heated. Using this trait, you can make egg dishes such as fried eggs, steamed eggs, and omelet. It is interesting that the coagulation, temperature of the egg white and yolk are different. Hot spring eggs also use this principle. If you soak the egg in water at 70 ℃ for 20 minutes, the egg white is coagulated about halfway and the yolk is fully coagulated. The second characteristic, emulsification, is the property of mixing well with oil. For example, the mayonnaise sauce which is made using eggs is made by adding a little bit of oil to the yolk to get it more emulsified. The last characteristic, foamability, is the phenomenon of bubbles forming when the egg whites are strongly beaten. We use this to make dough and soften the food.
Do you like eggs? A research team led by Professor Uhm Ae-sun of Hanyang University's Department of Food Engineering conducted a survey on university students` preference for eggs. Eggs ranked fourth among university students’ favorites, while 76 percent of students said the reason for eating eggs is because they are delicious. Most people probably do not know which eggs are fresh, how to keep them fresh and which nutrients they contain. People eat eggs because they are delicious not knowing these kinds of things. Let’s learn more about eggs and use eggs. If you learn more about eggs, including how to cook them, you can enjoy them better.< 저작권자 © 중앙헤럴드 무단전재 및 재배포금지 >