Eggs are a common food in our lives, and improper consumption can have adverse effects on our health. In daily life, we should pay attention to the following misconceptions.
Misconception 1: The darker the eggshell, the higher the nutritional value
Many people only choose red-shelled eggs, claiming they are more nutritious, but this is not the case. The color of the eggshell is mainly determined by a substance called "porphyrin," which has no nutritional value. Analysis shows that the nutritional value of an egg depends on the nutritional structure of the chicken's diet.
To evaluate the quality of the egg white, the main factor is the protein content in the albumen (the egg white). From a sensory perspective, the thicker the egg white, the higher the protein content and the better the quality of the egg white.
The color of the yolk can range from light yellow to orange-yellow. This color is related to the pigments it contains. The main pigments in the yolk include lutein, zeaxanthin, lutein, carotene, and riboflavin. The depth of the yolk color usually only indicates the amount of pigments present. Some pigments, such as lutein and carotene, can be converted into vitamin A in the body. Therefore, under normal circumstances, eggs with darker yolks are slightly more nutritious.
Misconception 2: The nutritional value of eggs is the same no matter how they are cooked
There are many ways to cook eggs, including boiling, steaming, frying, and scrambling. In terms of nutrient absorption and digestibility, boiled and steamed eggs are at 100%, soft-fried eggs are at 98%, scrambled eggs are at 97%, poached eggs are at 92.5%, hard-fried eggs are at 81.1%, and raw eggs are at 30%-50%. It is clear that boiling and steaming are the best cooking methods.
Misconception 3: Adding MSG to scrambled eggs makes them taste better
Eggs themselves contain a large amount of glutamic acid and a certain amount of sodium chloride. When heated, these two substances form a new compound—sodium glutamate, which is the main component of MSG and has a very pure umami taste. If MSG is added to scrambled eggs, the umami produced by the decomposition of MSG will destroy the natural umami of the eggs themselves. Therefore, it is not advisable to add MSG when cooking scrambled eggs.
Misconception 4: The longer you boil an egg, the better
To prevent the eggshell from bursting during cooking, wash the egg and soak it in a pot of water for one minute, then bring it to a boil over low heat. After it boils, simmer for 8 minutes. Do not boil for too long, otherwise, the ferrous ions in the yolk will react with sulfide ions to form a brown precipitate of iron sulfide, which hinders the body's absorption of iron.
If an egg is boiled for too long, the ferrous ions in the yolk combine with sulfide ions in the egg white to form insoluble iron sulfide, which is difficult to absorb. If a fried egg is overcooked, the edges will be scorched, and the high-molecular-weight proteins in the egg white will be converted into low-molecular-weight amino acids. These amino acids can often form substances harmful to human health at high temperatures.
Misconception 5: Eating eggs and soy milk together is more nutritious
Many people have the habit of eating an egg with soy milk in the morning, or boiling an egg directly in the soy milk. Soy milk is mild in nature and contains many nutrients such as plant protein, fat, carbohydrates, vitamins, and minerals, and has a great nourishing effect when consumed alone. However, it contains a special substance called trypsin inhibitor, which combines with the ovalbumin in the egg white, causing a loss of nutrients and reducing the nutritional value of both.
Misconception 6: "Functional eggs" are better than regular eggs
With the development of science and technology, various "functional eggs" rich in zinc, iodine, selenium, and calcium have appeared. In fact, not everyone is suitable for functional eggs. This is because not everyone lacks the nutrients contained in them. Therefore, consumers should be targeted when choosing functional eggs—eat what you lack, and avoid盲目 supplementation (blindly supplementing).
Misconception 7: The elderly should avoid eating eggs
Because eggs contain relatively high cholesterol, it has long been said that the elderly should avoid eating them. Scientific experiments in recent years have proven that this statement is unfounded.
The yolk contains relatively rich lecithin, a powerful emulsifier that can make cholesterol and fat particles extremely fine, allowing them to pass through the blood vessel walls and be fully utilized by cells, thereby reducing cholesterol in the blood. Moreover, the lecithin in the yolk, after digestion, releases choline, which enters the blood and is then synthesized into acetylcholine, a major neurotransmitter that can improve brain function and enhance memory.
Misconception 8: The more eggs a postpartum woman eats, the better
During childbirth, a postpartum woman experiences great physical exertion, and her digestive and absorption functions, as well as her liver's detoxification function, are weakened. Eating a large quantity can lead to an increased burden on the liver and kidneys, causing adverse effects. Consuming too much protein can also produce a large amount of ammonia, phenol, and other chemical substances in the intestines, which are highly toxic to the human body. This can easily lead to symptoms such as abdominal bloating, dizziness, limb weakness, and coma, resulting in "protein poisoning syndrome." The intake of protein should be calculated based on the body's digestive and absorption capacity. Generally, a postpartum woman eating about 3 eggs a day is sufficient.
Misconception 9: Raw eggs are more nutritious
Some people believe that eating raw eggs has the effect of moistening the lungs and throat. In fact, eating raw eggs is not only unhygienic and can easily cause bacterial infections, but they are also not more nutritious. Raw eggs contain avidin, which affects the absorption of biotin in food, and can easily lead to "biotin deficiency syndrome," with symptoms such as loss of appetite, general weakness, muscle pain, skin inflammation, and eyebrow loss. The protein structure of raw eggs is dense and contains trypsin inhibitor, so a large part of it cannot be absorbed by the human body. Only after being cooked does the protein become loose and more beneficial for human digestion and absorption.
In addition, raw eggs have a special fishy smell that can also inhibit the central nervous system, reducing the secretion of digestive fluids such as saliva, gastric juice, and intestinal juice, leading to loss of appetite and indigestion. Therefore, eggs should be cooked thoroughly before eating, and undercooked eggs should not be consumed.
Misconception 10: Boiling eggs with sugar
In many places, there is a custom of eating poached eggs in sugar water. In fact, boiling eggs with sugar causes the amino acids in the egg's protein to form a compound called fructoselysine. This substance is not easily absorbed by the human body and can have adverse effects on health.