The heat of two liang bird's nest is equivalent to two liang rice cakes
The bird's nest contains 50% protein, 30% carbohydrate, 5% iron, 3% other minerals and 1.4% cellulose. The protein of bird's nest is mainly mucin (in other words, saliva) secreted by epithelial cells, which contains only one essential amino acid (lysine) and three conditionally essential amino acids (which some people lack).
However, human body needs 8 kinds of essential amino acids and 13 kinds of conditional essential amino acids. Therefore, the protein nutritional value of bird's nest is extremely low, which has been confirmed by animal experiments. Feeding rats with bird's nest with another single ingredient food will result in protein malnutrition. In other words, the nutritional value of bird's nest protein lies in quantity, not in quality. However, the amount of food people eat occasionally is negligible in terms of quantity. Therefore, the nutritional value of bird's nest in protein is far less than that of high protein food such as meat and soybean.
Carbohydrate has no nutritional significance for people who are not lack of nutrition. Erliang bird's nest can provide 345 calories, equivalent to two liang rice cakes or bread, but the price is tens of thousands of times higher.
When it comes to iron and mineral content, bird's nest is really the best. However, the minerals in bird's nest, especially blood swallow, come from the penetration of natural minerals or impurities brought in by swallows' nest building. These minerals are inorganic substances, which are absorbed little or never by human body, so their nutritional value can be ignored.
The last nutritious ingredient is cellulose. The content of this component is normal. One apple is worth 4 liang of the fiber contained in the bird's nest.
In a word, the composition and function of bird's nest are single. Unlike other foods we eat, most of them are whole cell foods, which are rich in various raw materials needed for organic life. In terms of nutritional value, bird's nest is only a kind of low-grade food with limited nutrition.
Eight functions of zixuwu
Common reference books list the eight main functions of bird's Nest: 1. Nourishing yin and lung; 2. Tonifying deficiency and nourishing stomach; 3. Tonifying deficiency and soothing tuberculosis; 4. Reinforcing spleen and Qi; 5. Nourishing skin and skin care; 6. Benefiting intelligence and brain; 7. Preventing and curing tumors.
One of the functional principles of bird's nest is that it is believed that there is EGF (epidermal growth factor) in bird's nest. Some people advocate that EGF is the key component of bird's nest beauty. There are three reasons why this statement can not be established. First, EGF itself is a protein macromolecule (only small molecules such as iron can be directly attracted). If it enters the digestive tract, it will be completely digested like other foods without any effect. Second, the content of EGF in bird's nest is very small, which is not as much as that in milk; Third, if EGF can stimulate growth, that is one of the causes of cancer, but dare not eat.
Many studies have shown that bird's nest extract can combine with pathogens such as influenza virus, so as to protect cells from the virus. This kind of research is not enough to provide evidence that bird's nest has a corresponding effect as food, because the mechanism of action in vitro is completely different from that of human digestion, and the mechanism of human resistance to virus is completely different in vivo.
Other propaganda functions, such as anti-aging, anti fatigue, anti radiation, lowering cholesterol and so on, are basically nonsense. There is no experimental evidence, and the mechanism lacks logical self consistency. It is said that bird's nest is naturally far away from pollution, good environment, clean air, no radiation, so it can have these functions. Because of this, we can say that the natural bird's nest lacks the resistance to these factors if we apply the natural selection factors.
We should know that any food is not allowed to enter our body freely, and any ingredient must have a certain content to achieve certain effect. Generally speaking, the bird's nest can not provide most of the essential amino acids, and does not have any substance that can play the eight major roles.
It should be noted that if bird's nest is used as a panacea and recommended regardless of crowd and occasion, especially if it is assumed that the consumption of bird's nest can replenish the brain of newborn infants and children, there will be risks. These people eating bird's nest may cause allergic reaction, even life-threatening in serious cases. In 2000, Pediatrics published 39 cases reported, with an average age of 6 and a half years. No reports were reported in mainland China, not that Chinese mainland did not occur, but that doctors were not well known or lack of case reports.