Eggs are rich in nutrition, abundant in supply, convenient to cook and economical. It is not only an ideal non-staple food for every household, but also a high-quality tonic for pregnant women, wet nurses, the elderly and infirm, and children.
According to the analysis, every 100 g egg (with shell) contains protein 14.7 g, fat 1.6 g, carbohydrate1.6g, cholesterol 0.68 g, calcium 55 mg and phosphorus 2/kloc. In addition, eggs are also rich in nutrients such as lecithin, choline and vitamin D.
Although eggs are nutritious, they must be cooked and not eaten raw. Raw eggs are not only harmful to human body, but also have the following adverse effects:
1. Eating raw eggs is easy to get biotin deficiency.
This is because raw egg white contains a kind of protein called avidin, which is harmful to human body. This protein can bind closely with biotin in the intestine, becoming a stable and inactive complex, thus hindering the absorption of biotin. Biotin is a water-soluble vitamin and a coenzyme of carboxylase in human body, which participates in the fixation and carboxylation of carbon dioxide. If you eat a lot of raw egg white, you may suffer from biotin deficiency, which is characterized by general fatigue, allergies, dandruff dermatitis, and exfoliation of squamous epithelial cells in the lips. If heated, avidin in egg white will be destroyed, which will no longer hinder the absorption of biotin.
2. Eat raw eggs, of which protein is not easy to digest and absorb.
Because the protein structure of raw eggs is dense, it is not easy to be hydrolyzed by proteolytic enzymes in gastrointestinal tract. Raw eggs contain an antitrypsin, which can inhibit the hydrolysis of food protein by trypsin. In addition, raw egg is a kind of semi-liquid viscous substance, and its residence time in gastrointestinal tract is very short. Due to incomplete digestion and absorption, most of protein and other nutrients in raw eggs are wasted. After the eggs are heated, some non-valence chemical bonds, such as hydrogen bond, salt bond and hydrophobic bond, break, which makes the protein with dense structure loose and irregular. That is, protein denaturation is beneficial to its catalytic hydrolysis by proteolytic enzymes. At the same time, due to the thermal denaturation of antitrypsin, trypsin will no longer be inhibited. The latter can decompose the protein of various molecules into small peptides, even amino acids, which can be absorbed and utilized.
Eating raw eggs will increase the burden on the liver.
A large amount of undigested protein is destroyed by E.coli in the lower part of the large intestine, producing more toxic substances, such as amine, phenol, ammonia, indole and hydrogen sulfide. Although some of these toxic substances are excreted with feces, a considerable part of them are absorbed by the intestine, enter the liver through the portal vein and are detoxified. If the liver function of people who eat raw eggs is damaged, poisoning will occur due to the increased burden on the liver, and symptoms such as headache, dizziness, and even lower or higher blood pressure will occur. When eggs are cooked and eaten, usually about 95% of protein may be digested and absorbed. In this way, the toxic substances produced by the large intestine are greatly reduced, and the burden on the liver is relatively reduced.
Eating raw eggs is easy to get intestinal inflammation.
The shell of an egg looks almost airtight to the naked eye, and nothing is allowed to pass through it. However, under the microscope, the shell is covered with small holes, and its aperture ratio pathogenic bacteria are dozens or even hundreds of times larger. Therefore, after the eggs are laid, it is inevitable that some pathogens (such as Salmonella) will invade. If you eat raw eggs contaminated by pathogens, you may get acute gastroenteritis, which is characterized by chills and fever, nausea and vomiting, abdominal pain and diarrhea. After the eggs are heated, the germs have been killed, so there will be no gastrointestinal symptoms.
Eating raw eggs can lead to loss of appetite and indigestion, because raw eggs have a special fishy smell, which can inhibit the central nervous system and reduce the secretion of digestive juice.
Although eating raw eggs has so many adverse effects, there are still many people eating raw eggs now. According to the author's investigation of 220 first-year students in our technical secondary school, it is found that 36% students eat raw eggs. This ratio cannot but attract people's attention. The main reason is that these young students don't know nutrition and health knowledge. Some students mistakenly think that eating raw eggs is more nutritious than eating cooked eggs. In view of this situation, the author suggests that as teachers, especially primary and secondary school teachers, it is necessary to publicize the truth that eggs should not be eaten raw to young students in the classroom or through blackboard newspapers and popular science lectures. When students understand these truths, they can not only stop eating raw eggs themselves, but also widely publicize and spread nutrition and hygiene knowledge to their families and others, which is undoubtedly a very beneficial thing.
Protein structure of raw eggs is dense, and digestive enzymes in gastrointestinal tract are difficult to contact and be digested and absorbed. However, the cooked egg protein structure becomes soft and is easily digested and absorbed by the human body.
About 10% of fresh eggs carry pathogenic bacteria, mold or parasitic eggs. Some parents wash their children's eggs with boiling water and add sugar. Because the germs and parasitic eggs in eggs can not be completely killed, it is easy to cause diarrhea and parasitic diseases. If there is salmonella in eggs, it will also cause food poisoning. Recently, it has been found that there may be 0- 157 enterohemorrhagic Escherichia coli on eggshells. Even if the amount of bacteria is small, laying eggs is enough to cause food poisoning. Some folks use raw eggs to treat constipation in children, which can not only cure constipation, but also infect people and animals with Toxoplasma gondii. The disease is acute, and almost all organs in the whole body are invaded by Toxoplasma gondii, causing lesions and even death in severe cases.
So eggs must be cooked and eaten, and it is best to eat steamed eggs. It is not advisable to wash eggs with boiling water, let alone eat raw eggs.
There are many ways to eat eggs. In terms of nutrient absorption and digestibility, boiled eggs are 100%, scrambled eggs are 97%, tender fried eggs are 98%, old fried eggs are 8 1. 1%, boiled eggs with boiled water and milk are 92.5%, and raw eggs are 30% ~ 50%. From this point of view, boiled eggs are the best way to eat, but pay attention to chewing slowly, otherwise it will affect absorption and digestion.
How to eat eggs with the highest nutrition?
The nutritional components of eggs are comprehensive and balanced, and almost all the nutrients needed by the human body are available. Whether it is egg white or egg yolk, their protein physiological value is extremely high, and they are easy to digest and absorb, and the utilization rate can reach over 95%, so they are full-price natural foods.
How many eggs should I eat a day? First, let's see how much nutrition we can get from an egg.
A medium-sized egg, with an average weight of about 50g, can provide protein 6g, fat 5g, calories 72kcal, calcium 23mg, phosphorus 89mg, iron1.2mg, vitamin A6 12 IU, thiamine 0.07mg, riboflavin 0.13mg, and so on. Considering both nutrition and economy, eating eggs is more economical.
In recent years, many people are afraid of cholesterol because they know that the blood cholesterol of people with atherosclerosis and coronary heart disease has increased. They are afraid that eating egg yolk will cause arteriosclerosis, so they dare not eat eggs. This kind of worry is unnecessary. Under normal circumstances, cholesterol is harmless and an indispensable substance for human body. In the body, cholesterol is not only one of the basic substances to form cells, but also can synthesize several important hormones and convert them into vitamin D3 in the body.
On the other hand, cholesterol in human plasma is not all from food, but from exogenous and endogenous sources. Exogenous comes from food, and all meat, eggs and animal fats contain cholesterol. It is estimated that you should eat about 500 mg a day. If you eat less animal food, you will not reach this figure. Endogenous is synthesized by the body itself, and about 1.0 ~ 1.5g is synthesized every day, which is far more than what is eaten from food, so most of the cholesterol in the body is made by the body itself. Under normal circumstances, the body has the ability of automatic adjustment, that is, if you eat more cholesterol, the amount of synthesis in the body will be less; The less you eat, the more you synthesize in your body. In addition, egg yolk is rich in lecithin, which is a strong emulsifier. It can make cholesterol and fat particles in blood smaller and remain suspended, thus preventing cholesterol and fat from depositing on the blood vessel wall and applying them to body tissues through the blood vessel wall without increasing plasma cholesterol. Dr Margaret Flynn of Missouri State University organized a special research group on "Eggs and Cholesterol" and conducted an experiment on 1 16 men aged 32-62 for half a year. They first asked the subjects not to eat any egg food for three months in a row, and measured the serum cholesterol content, then each person added two eggs a day, and then measured the cholesterol three months later. There is no obvious difference between the two results, which shows that the cholesterol content of the subjects is not affected by egg cholesterol. Scientists believe that if an elderly person with normal blood cholesterol concentration eats two eggs a day, his blood cholesterol will increase by at most 2 mg%. This trace will not cause atherosclerosis, and other nutrients in eggs will bring more benefits to people, so there is no need to be afraid to eat eggs. Of course, eating too many eggs is not good. First, waste high-quality protein. Second, protein decomposition products will increase the burden on the liver and kidneys, which is also bad for health. And a person with normal metabolism, eating some eggs properly, such as 1~2 eggs a day, or eating several times a week, is good for the health.
How to eat eggs without increasing blood lipid
For a long time, many people equate eggs with cholesterol, because egg yolk contains cholesterol, and think that eating eggs can improve blood lipid, so patients with arteriosclerosis, coronary heart disease and hypertension should not eat it. Some people even want to remove the yolk when eating eggs. Have eggs really become the "bad guys" on our table?
In recent years, medical experts all over the world have done this experiment: the elderly aged 60-80 (including those with arteriosclerosis, coronary heart disease and hypertension) eat two eggs a day, and after three months, serum cholesterol and blood lipids have not increased. Experts point out that eating eggs in moderation will not increase cholesterol. Laboratory analysis shows that cholesterol in eggs can combine with protein to form a lipoprotein, which can be divided into ultra-low density lipoprotein, low density lipoprotein and high density lipoprotein according to the particle size. The former two can be deposited on the blood vessel wall, and the latter has the function of clearing cholesterol from the blood vessel wall. Therefore, the cholesterol in eggs can offset each other. Egg yolk is also rich in lecithin, which is a powerful emulsifier. It can make cholesterol and fat particles very fine, emulsified into fine particles suspended in blood, but not deposited on the blood vessel wall, and can be used by cells through the blood vessel wall smoothly, thus reducing cholesterol in blood. In fact, the occurrence of various vascular diseases is mainly caused by human dysfunction. The increase of cholesterol content in blood is not only due to eating 1 egg every day, but also due to the imbalance of cholesterol metabolism in the body, that is, the amount of cholesterol synthesized is more than the amount of cholesterol decomposed. Cholesterol in the human body is not only ingested through diet, but also synthesized in the body. Even if the food does not contain cholesterol at all, the liver will synthesize it by itself.
Lecithin and yolk protein contained in egg yolk are of great benefit to human nervous system and growth and development; The protein contained in it is of high quality, while ovalbumin and ovalbumin are the top grade in the protein family, and ovalbumin is a necessity for the growth and development of infants.
In addition, iron and calcium in eggs are also necessary for hematopoiesis and bone growth. The benefits of eggs to human body
Lecithin, triglyceride, cholesterol and yolk protein in brain-strengthening and intelligence-improving egg yolk have good effects on nervous system and physical development, and can delay the mental decline of the elderly and improve their memory. Lecithin is regarded by medical experts as the bane of Alzheimer's disease.
Protecting protein in liver eggs can repair liver tissue damage. Lecithin in egg yolk can promote the regeneration of liver cells, increase the amount of human plasma protein, and enhance human metabolism and immune function.
Prevention and treatment of atherosclerosis American nutritionists and medical staff used eggs to prevent and treat atherosclerosis according to the emulsification of lecithin in egg yolk, and achieved unexpected results.
Prevention of cancer eggs contain more vitamin B2, which can decompose and oxidize carcinogens in the human body. Trace elements in eggs, such as selenium and zinc, also have anti-cancer effects. Japanese scholars have found that eggs also contain anti-cancer substances, namely phytochrome and phytochrome. An egg contains about 10 microgram of phytoflavin, which can inhibit the proliferation of EB virus that causes laryngeal cancer and lymphoma.
Anti-aging eggs contain almost all nutrients needed by human body, so they are called "ideal nutrition banks". Nutritionists call it the "complete protein model", and insisting on eating eggs in moderation is one of the experiences of many longevity people. The correct way to eat eggs
There are many ways to eat eggs. In terms of nutrient absorption and digestibility, boiled eggs are 100%, scrambled eggs are 97%, tender fried eggs are 98%, old fried eggs are 8 1. 1%, boiled eggs with boiled water and milk are 92.5%, and raw eggs are 30% ~ 50%. It can be seen that boiled eggs are the best way to eat, but we should pay attention to chewing slowly, otherwise it will affect absorption and digestion. But for children and the elderly, steamed egg soup and egg drop soup are the most suitable, because these two methods can make protein loose and easy to digest and absorb. The content of vitamin C in eggs is not high, so it is best to eat eggs with proper amount of vegetables. How many eggs does www.qzsun.com eat every day?
From the point of view of nutrition, in order to ensure a balanced diet, meet the needs of the body, and not be overnourished, it is generally appropriate for the elderly to eat 1 ~ 2 eggs a day. Young and middle-aged people, who are engaged in mental or light manual labor, can eat 2 eggs a day; Those who are engaged in heavy physical labor and take more nutrients can eat 2 ~ 3 eggs a day; Children have a long body and a fast metabolism, and eat 2 ~ 3 eggs every day. Pregnant women, lying-in women, nursing mothers, infirm people and patients recovering from major surgery need to increase excellent protein, and they can eat 3-4 eggs a day, not more.